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BINOCULAR VISION & STRABOLOGY QUARTERLY, Simms-Romano’s: Print Version ISSN 2160-5351 (formerly 1088-6281)LIMITED PRINT version for libraries, since the 2007 addition of identical electronic Internet ONLINE version, ISSN 2160-5904,

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Binocular V ision & Strabology Quarterly S im m s-Rom ano’s© EDITORIAL BOARD FOURTH Quarter of 2013, Volum e 28 (No 4) Page196

Robert W. ArnoldKyle ArnoldiE.S. Avetisov, RussiaJohn D. BakerP. Vital Berard, FranceFrank Billson, AustraliaMichael C. BrodskyJorge A. Caldeira, BrazilAlberto O. Ciancia, ArgentinaKenneth J. CiuffredaDavid K. CoatsJeffrey CooperJan-T.H.N. de Faber, NetherlandsJay M. EnochRobert W. EnzenauerCaleb GonzalezMichael H. Gräf, GermanyDavid GuytonEugene M. HelvestonRichard W. HertleCreig S. HoytRobert S. JampelEdward Khawam, Lebanon

Lionel Kowal, AustraliaStephen P. Kraft, CanadaMalcolm L. MazowHenry S. MetzJoel MillerJames L. Mims IIIScott E. OlitskyGian Paolo Paliaga, ItalyEvelyn A. PaysseJ.V. Plenty, United KingdomZane F. PollardJulio Prieto-Diaz, ArgentinaMichael X. RepkaJames D. ReynoldsDavid L. Romero-Apis, MexicoAlan B. ScottKurt SimonsAnnette Spielmann, FranceDavid R. Stager, Sr.Martin J. Steinbach, CanadaDavid S.I. Taylor, EnglandGuillermo Velez, ColombiaM. Edward Wilson, Jr.Kenneth W. Wright

EMERITUSLeonard Apt†Shinobu Awaya, JapanHenderson Almeida, BrazilBruno Bagolini†, ItalyAlbert W. BiglanEileen BirchWilliam N. Clarke, CanadaJohn S. Crawford†, CanadaRobert A. Crone, NetherlandsEugene R. Folk†David A. HilesDavid HubelBela JuleszHerbert Kaufmann, GermanyPhilip Knapp†Burton J. KushnerJoseph Lang†, SwitzerlandJohn P. Lee†, EnglandPinhas Nemet, IsraelEdward L. RaabRobert D. ReineckeWilliam E. ScottR. Lawrence Tychsen

mailto:[email protected],

mailto:[email protected].

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http://www.binocularvision.net

“... the belief that one’s view of reality is the only reality is the most dangerous of all delusions ...”-Watzlawick, 1976

ISSN 2160-5351 (Print)EDITOR ISSN 2160-5904 (Online) FOURTH Quarter of 2013

Paul E. Romano, M.D., M.S.O TABLE OF CONTENTS Volume 28, Number 4

MEDLINE Abbr. Binocul Vis Strabolog Q Simms Romano NLM ID: 101556982

198 DAVID H. HUBEL, M.D. 1926-2013

203 Correspondence: Strabismus: Delayed into Adulthood Diagnoses and UnreportedDamage to Qualities of Life Tom Koch, Ph.D., Myra C. Butler, M.D.

206 Tutorial: Strabismus: An Introduction for Medical StudentsTom Koch, M.D., Myra C. Butler, M.D.

209 Editorial: Strabismatic; Tenotomy and Replacement (TAR); More Words and Terms;Confucius; Hashtags

*** ORIGINAL “EVIDENCE-BASED” SCIENTIFIC ARTICLES***

211 Effect of Four Horizontal Rectus Muscle Tenotomy and Replacement (TAR) Alone and inCombination with Recessions for Strabismus, on Visual Function and EyeMovements in Patients with Infantile Nystagmus Syndrome (INS) WithoutAbnormal Head Posture (AHP)Mohammad Reza Akbari, M.D., Marjan Akbari-Kamrani, M.D., MPH, Arman Mohseni, Ph.D., Alireza Keshtkar Jafari, M.D., Masoud Aghsaei Fard, M.D.,Ahmad Ameri, M.D.

222 Flip Chart Visual Acuity Screening for Amblyopia Risk Factors Compared to thePlusoptiX A09 Photoscreener, Tests Performed by a Lay ScreenerDavid I. Silbert, M.D., Noelle S. Matta, CO, CRC, COT, Abby Brubaker

229 Is the Sphere Value Measured by an Autorefractor Reliable in Children UnderCycloplegia? Comparison with Streak RetinoscopyRita Dinis Da Gama, M.D., Tânia Yang Nom, CO, Daniela Cândido Da Costa, CO,Joana Chambel Dos Santos, CO, Rute Sousa Da Costa, CO, Catarina Relha, CO

*** CASE REPORT with Management, Outcome and Literature Review ***

238 Corneal Topography Analysis in Establishing the Pathophysiologic Mechanism of CyclicBrown’s Syndrome Strabismus. A Case ReportDeniz Somer, M.D., Koray Budak, M.D.

244 Abstracts of the Current Literature ; Erratum (page 247)248 Hyde Park Editorial: 3D Printing Everything: Products, Weapons, Also: Gravity; Flex

Screens for Smart Phones, Keys; Lots of Data, An Ode in Praise of Knobs

Binocular Vision & Strabology Medically Historical Obituary FOURTH Quarter of 2013Quarterly Simms Romano’s© David H. Hubel, MD, 1926-2013 Volume 28 (No.4)A Medical Scientific ePeriodical DK Coats, MD and PE Romano, MD, MSO PAGES 198-202

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Obituary

Medically Historical Obituary DAVID H. HUBEL, 1926-2013

Nobel Prize Winner in Medicine 1981

We have been most happy andproud that Dr. Hubel agreed toparticipate on the editorial board of thisjournal for a number of years His workand that of his Nobel co-winner, TorstenWiesel, M.D. (whom we also invited tojoin our Board but who demurred to ourinvitation).

But the work that this pair did thatwon the Nobel for them is indeed thefoundation of so much that we nowknow and understand about binocularvision especially and strabismus.

In preparation for this report wereviewed the issue of this publicationfrom 2007 when George Beauchampengineered their joint appearance at ourannual AAPOS meeting in Seattle thatyear, to receive the Marshall ParksAward. That was really something as anevent, having them there “up close andpersonal” (TV commentary oninterviews) live and in person. If you stillhave that issue in hand take a look at thepictures of them on page 115 of that issue(courtesy of James L. Mims III, MD).

The following fascinating historicalstory of their accomplishments has beencompiled from the current obituaries writtenby two journalists: Steve Chawkins (LATimes), Alyssa A. Botelho, (WashingtonPost) which works have also been condensed.

When neurobiologist David H. Hubelaccepted his Nobel Prize in 1981, it had only

been a couple of decades since he and TorstenWiesel had danced in front of an anesthetizedcat.

David H. Hubel, a Nobel Prize-winningneuroscientist, whose astonishing map of thevisual cortex pulled back the curtain on one ofthe brain’s most mysterious functions, thepower of sight, died Sept. 22 at Lincoln,Massachusetts. He was 87.

Born Feb.27,1926, in Windsor, Ontario,Canada, to American parents, David HunterHubel grew up in Montreal, the son of an


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American chemical engineer,

He used his chemistry set to fire toycannons, built radios and sent off hydrogenballoons into the Canadian countryside withattached notes, one of which he recalled,“brought an answer, after many months, froma farmer’s daughter 100 miles away.”

At McGill University in Montreal, hegraduated with honors in mathematics andphysics in 1947. Though accepted to graduateschool for physics, he applied to McGill’smedical school on a whim. He recalled yearslater in his memoir that “to my horror I wasaccepted there, too.”

He enrolled, having taken only onebiology class, a summer course oninvertebrate zoology and botany, andgraduated in 1951. During his medicalinternship, Dr. Hubel met his future wife,Ruth Izzard, at the university choral society,where they sang together. They married in

1953. He was drafted by the U.S. Army,serving at the Walter Reed Army Institute ofResearch.

After serving the army, in 1955, hestarted working for renowned researcherSteven Kuffler at Johns Hopkins University.

Dr. Hubel originally joined JohnsHopkins to continue his research withVernon Mountcastle, one of the leadingneurophysiologists of the era.

He discovered upon arrival, however,

that Mountcastle’s lab was undergoing a six-month-long renovation. Stephen Kuffler, aneurophysiologist who studied vision, invitedDr. Hubel to team up with Wiesel, a youngscientist who had just arrived from Sweden,to pass the time.

On his first day, he was nervous, hetold the dignitaries at his Nobel lecture.

"Steve, (Kuffler) at his desk, rotatedaround on his chair and said 'Hi, David! Takeoff your coat. Hang up your hat. Do up yourfly.' His laboratory was informal! But it tookme a month, given my Canadian upbringing,

to force myself to call him Steve."

Once, Dr. Hubel recalled, Mountcastle


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stopped by to check on their progress andasked how many visual cells the men hadstudied. Mountcastle himself had justpublished a paper compiling observations ofsome 600 neurons.

“To us, that was an astronomical

number, literally,” Dr. Hubel wrote in thememoir. He answered that they were currentlystudying three cells No. 3,006, 3,007 and3,008 in their series of experiments.

“In order to catapult ourselves into a

league that came close to Vernon’s we hadbegun our series of cells with No. 3000,” hewrote. “But we did not tell Vernon.”

Drs. Hubel and Wiesel moved with the

Kuffler team to Harvard Medical School in1959, where they formed the core ofHarvard’s neurobiology department, the firstof its kind in the country. There, Dr. Hubelcontinued research and lecturing for the nextfour decades. His favorite course was hisfreshman seminar, which he taught for morethan a decade, even after he retired.

Each year, he would accept a dozenHarvard freshmen into his lab, leading themthrough dissections of sheep brains,practicing surgical sutures on pieces of scrapleather and teaching them how to weld andbuild their own simple electronic gadgets.

Outside of academia, Dr. Hubelpursued a range of hobbies. He learnedJapanese and French and studied astronomy.He was also a pianist and flutist. His interestin photography led to a friendship with EdwinH. Land, a co-founder of Polaroid.

In the 1950's, Dr. Hubel together withSwedish neurophysiologist Torsten N.Wiesel, discovered how nerve cells (neurons) analyze the light rays that hit our retinas, bit

by bit, to assemble in the visual cortex of theoccipital lobe of the brain, the detailed,moving and almost infinitely diverse finalimages that we perceive as our external world (i.e. “binocular vision”).

Hubel and Wiesel were measuringelectrical activity in particular cells of thecerebral cortex, the brain area that was knownto be the seat of vision. But nothing theyshowed their cats — a dot on a screen, abright light — seemed to move the dial. Infrustration, they did a little dance. Theyjokingly displayed magazine photos of sexywomen to the cats — but to no avail.

Over their 25-year collaboration andwith a few strokes of serendipity, theyeventually broke through — to spectaculareffect. With the aid of tiny tungsten electrodesdesigned by Hubel, they discovered theprofoundly elegant neural systems that enableus to see, mapping the complex process downto individual cells. Their insights changed thestandard treatment of newborns with eyedisorders such as cataracts and strabismus.

Over that 25 years of work together, themen revealed that the cortex is arranged invertical columns of cells, each moduledevoted to process a different constituent ofthe seen world: form, contour, color,movement and three-dimensionality.

For their collaboration, begun at JohnsHopkins University and carried out for thenext two decades at Harvard Medical School,Drs. Hubel and Wiesel won the 1981 NobelPrize in Physiology or Medicine. They sharedthe prize with Roger W. Sperry, thenaffiliated with the California Institute ofTechnology.

When the men began studying thevisual system, little was known about the


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functional organization of the cerebral cortex,and scientists had only recently begunrecording electrical impulses from thathighest and most complex area of the brain.The Nobel Prize committee cited the twomen’s research as having “disclosed one ofthe most well guarded secrets of the brain: theway by which its cells decode the messagewhich the brain receives from the eyes.”

In their first experiments together in1958, Dr. Hubel and Wiesel, an inquisitiveand often mischievous pair, crammed aprojector inside their 15-by-15-foot laboratoryat Johns Hopkins and sat their research cats,adorned in electrical headgear, before ascreen.

They displayed spots of all sizes beforethe animals — dark spots on brightbackgrounds and bright spots on dark —trying to find a stimulus that could coax asingle neuron, wired to a surgically implantedelectrode, to fire.

For the first several days, they got no

responses. Desperate, they even danced infront of the cats waving their arms. No luck.

In the scientists’ 2004 co-memoir,“Brain and Visual Perception: The Story of a25-Year Collaboration,” they described that“our small room must have seemed like acircus, complete with a tent and exoticanimals.”

"I knew we were losing traction in anexperiment when Torsten began to talk to mein Swedish," he said. "Usually this wasaround 3 a.m."

It was a “SHADOW” created whenDrs. Hubel and Wiesel were rearranging theirequipment — a faint line that swept across theprojector screen in one specific orientation”

— that finally made a cat neuron fire that theycould detect.

It was a serendipitous first step in acareer-long journey of understanding thevisual system.

(There is another description of this first stepwhich is a bit more colorful and interesting:)

Sometimes the cells they were studyingfailed to react even when the animals' eyeswere hit with blasts of light. Other times, thepair got lucky and the audio monitors hookedup to the electrode on a particular cell wouldstart clicking like crazy.

"When we succeed and suddenly canmake a cell fire like a machine gun, it can bethrilling — and on a good day the thrills maycome every few hours," Hubel wrote in"Brain and Visual Perception," a 2004memoir he co-wrote with Wiesel. "When itcomes to sheer fun, our field is hard to beat.We try to keep that a secret."

One day, they found a cell reactingwildly when a cat viewed a straight line —the edge of a slide that was accidentallyjammed in their projector. Testing that cell fornine hours, they were astonished to realize itreacted only to straight lines at exactly thesame angle.

This suggested, as their experimentsover the years proved, that the cellsresponsible for vision are exquisitelyspecialized, with some responding tovertically oriented lines, some to horizontal,others to corners, still others to colors.Through what Hubel called a "scarcelyimaginable" array of neural connections, eachcell contributes to building an image, which,in an instant, is transmitted to other areas ofthe brain.

Dr. Hubel recalled that, upon this


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discovery, they then studied this firstresponding cat neuron for nine hours straight.Their seminal 1959 publication of thesefindings, they wrote, “of course gives no hintof our struggle. As usual in science reports wepresented the bare results, with little of thesense of excitement or fun.” (Or sheer work!)

Other lines of Hubel and Wiesel’s

work led to the landmark discovery that visualcells begin developing immediately after birthand degenerate quickly if they aren’t used.That finding led to a change in the establishedprotocol of delaying congenital cataractoperations to correct visual impairments inchildren. Now they are operated at an age ofonly a few months instead of years.

When neuroscientist Eric Kandel, aNobel laureate in 2000, was told by a fellowscientist that the findings had "limitedbiological generality," he had a tart reply:

"You are right — it does not apply to thekidney or the spleen," Kandel said. "It ismuch more restricted. It only helps to explainthe workings of the mind."

Hubel also had passions outside the lab.The sheer number of his hobbies was "both astrength and a curse," he wrote in his memoir.

"Today I keep up interests in piano,flute, ham radio, weaving (rugs and blankets),amateur astronomy, photography, languages(French novels mainly, some German,Japanese) and tennis. I make up for the timethese interests consume by reading as little aspossible in my field of neurophysiology.Reading most papers today is like eatingsawdust .…" Colleagues kept him up to date,he added.

Earlier in this, his last year, Hubel tookup the oboe.

His wife, Ruth, whom he met whenthey were choir members at McGill, died inJanuary. He is survived by sons Carl, Eric andPaul, and four grandchildren.

David K. Coats, M.D., Houston, TexasPaul E. Romano, M.D., M.S.O.

Binocular Vision & Strabology Letter to the Editor: Strabismus: Delayed into Adulthood Diagnosis and FOURTH Quarter of 2013Quarterly Simms Romano’s© Unreported Damage to Qualities of Life AND Tutorial: Strabismus: An Introduction Volume 28 (No.4)A Medical Scientific ePeriodica T. Koch, PhD and M.C. Butler, MDl PAGES 203-208

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Letter to the Editor

Strabismus: Delayed into Adulthood Diagnoses andUnreported Damage to Qualities of Life

TOM KOCH, Ph.D. and MYRA C. BUTLER, M.D.

From the University of British Columbia, Department of Medical Geography (Dr. Koch) andthe Department of Medicine (Dr. Butler), Vancouver, British Columbia

The authors wish to express their thanks to the patient, “Mary Margaret” who kindly gave permissionfor our presentation of her case.

Correspondence: [email protected]

INTRODUCTION: METHODOLOGY

Narrative-based medicine employingpatient stories and reports has developed inrecent decades as a way to broaden physicianunderstanding of patient lives (1). As ateaching modality narrative personalizes theclinical studies of medical students (2). Whenproduced by patients, narratives are typicallyperceived as therapeutic attempts by patientsto “reclaim their own voices from the healthcare system” (3). Clinically, physiciannarratives reflect the strengths andweaknesses of the traditional, one-off casereport identifying a specific diagnostic ortreatment problem.

Here we attempt to combine thevarying views of narratives in a brief, “storiedcase report” of a case of severe undiagnosedstrabismus and of post-surgical complicationsthat were similarly untreated. Within thisframe the case report describes the complexinterpersonal realities of clinical interactionsthat may begin in social settings (4). Thenarrative, therefore, is a clinician’s and

teacher’s. That the principal author is also astrabismatic was an integral element in hisrelations to the patient as well as his laterpresentation of this as a teaching case.Clinically, the narrative seeks to demonstratethe serious consequences of misdiagnosis andtrivializing a patient’s experiences withstrabismus. It identifies a previouslyunreported problem in treatment deservingattention by family physicians andophthalmologists.

The narrative was reviewed by thepatient prior to submission and is offered withher approval. It was presented to medicalstudents in 2010 and again in 2011 as both adiagnostic caution and an example of thecomplexities inherent in the care of patientswith presumably mundane, well-understoodconditions. The report is joined by a briefreview of the underlying etiology,strabismus, as well as the “take-home”lessons students concluded in their review ofthe materials.

THE CASE



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At the party Mary Margaret was thecenter of attention as she told friends aboutthe life-changing operation that corrected hercongenital strabismus. Diagnosed at the ageof thirty-eight years, and given correctivesurgery the following year, life, she told ustwo months after surgery, would be differentnow. Life had been hard and now it would bebeautiful.

As a child she had been diagnosed witha congenital scoliosis that presumablyexplained her perpetual head tilt up and to theleft. And, physicians told her nurse mother, itexplained as well the chronic back and neckpain her child experienced. There was reallynothing to be done. And so Mary Margaretwent through school as an odd child, the headtilt making her seem “weird” and standoffishto schoolmates, the pain affecting herconcentration. Sports, when she tried them,were difficult.

At the party she blamed her lack of asustaining career and her still single status onher condition. She was vivid in herdescription of the agony of trying to sit in anoffice chair for hours. And, too she waspoignant in a recitation of the ways in whichchronic pain impeded her relationships andher general quality of life. Things were goingto be better now, she proclaimed, and allproblems would be resolved. After all, thespinal curvature had all but disappeared withthe corrective surgery.

As she talked I watched MaryMargaret. Both eyes were well centered butthere was still a reflexive head tilt, like anervous tick that won’t go away. She carriedone shoulder higher than the other, a remnantof the posture that had developed over yearsas she turned her head, twisting her body soshe could focus on others. More ominously,there was a pronounced asymmetry to her

neck and shoulders, trapezium andsternocleidomastoid muscles were visiblyoverdeveloped on one side. She describedhow she had for years used weight lifting as ameans of diminishing pain and“strengthening” her spine.

And, of course, she was stillstrabismatic and that presents challenges of itsown.

“Jeez’, Mary,” a friend asked, “Whydidn’t they figure this out earlier?” Shereplied that they’d called it scoliosis andnobody had thought any more about it until achiropractor she was dating had her put on aneye patch and, Voila! Her head tilt almostdisappeared. While she made light of themisdiagnosis there was in her narrative astrong undercurrent of anger at what shecalled the “lost life” of her pre-surgical years.I’ve heard this kind of anger time and again asan ethicist and gerontologist working inchronic care.

I gave Mary Margaret my card andsaid, “I hope life will be grand but if you havea problem and need to talk, you can call. I’malso a strabismatic undiagnosed untiladulthood. It’s not always a simpletransition.”

THE FOLLOWUP

Two problems were immediately clearwhen she called two months later. First, shewas again in chronic severe pain. The musclesof her neck, shoulders and back were reactingbadly to new postures that came following thesurgery. After accommodating to a lifetime ofthe old, the false scoliosis and withoutphysiotherapy her body was fighting thepostures her corrected eyes dictated. Second,she was angry but couldn’t admit it. In ourfirst meeting she said she had made peacewith her history, but when I asked for her to


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list those people she might be angry with, thelist presented at our second session wasbiographic: the ophthalmologist who neverdiagnosed the strabismus, the doctor whomisdiagnosed the scoliosis, the nurse motherwho didn’t “protect” her; the school kids whoteased her as “weird”, the teachers who didn’tstop them; the seemingly endless successionof bosses who didn’t understand the pain sheendured; and the boyfriends who came andwent because, she assumed, her problemsmade her damaged goods.

My work is normally short-term, amatter of helping people find the correctprofessionals to deal with their challenges.Working with Mary Margaret, however, wasa long-term project requiring several years ofmeetings. Only another “like her” couldunderstand, she said. She distrusted doctorsand traditional medicine because they hadfailed her and continued to do so as herproblems worsened. Because I was astrabismatic I just might understand, she said.

Unfortunately, her medical teambelieved her problem was purely psychiatric.Her ophthalmologist told her the surgery hadbeen a success and if she had post-operativepain she should talk to her family doctor who,nearing retirement, knew little about paincontrol or rehabilitation. She refused thepsychiatric consult he suggested—“I’m notcrazy, she said”—and a therapy group shethought she might attend was over-enrolled.

Through a colleague in sports medicineI arranged an appointment for her with aphysiatrist who, after a brief examination,said he had only heard of one or two caseslike hers and neither had turned out well.There was little to be done but suggest astronger course of pain medication. MaryMargaret was devastated.

She frequently talked of euthanasia andsuicide, arguing that when life was pain anddisappointment there was no reason to live.Twice I was on the verge of accompanyingher to Emergency and asking she be admittedbecause of suicidal statements. I promised herthings would get better if she would only giveme a chance. I found for her a younger familydoctor with a knowledge of pain control butMary Margaret was suspicious of drugs andneeded more time for counselling than thedoctor’s brief office visits could provide. Still,it was a start. Finally, colleagues in palliativecare recommended a physiotherapist whocould treat her underlying musculo-skeletalproblems. He promised no quick fixes butslow improvement over time.

Three and a half years after our firstmeeting I heard Mary Margaret laugh a laughthat was, for the first time, fulsome and notbitter. She was still unmarried but hopefulabout both her personal and professionallives.

CONCLUSION

While extreme, the case of MaryMargaret is not unique. Over the years thefirst author has met a number of strabismaticswhose condition went undiagnosed until lateadolescence or adulthood. None evidenced inchildhood either the marked exotropia oresotropia that often makes the conditionobvious on simple examination. Few receivedgeneral support and most were told theirc o n d i t i o n — w h e n e x o t r o p i amanifested—was, at worst, merely cosmetic.All reported varying life difficulties. One onlydiscovered his condition when, after takingpilot training, he failed the visualexamination. Some had trouble with transientdiplopia and others with reading skills. Mostreported they were always assumed to be“naturally clumsy” and of course were


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“terrible at sports” requiring binocular vision.

Patients diagnosed with strabismus inmiddle age, when questioned, typically reportan increase in visual problems, especially inrelation to automobile driving and in reading.In most of these cases brought to our attentionthe typical medical response has been to shrugand say, “well, you’re aging.” In at least somecases, modalities to improve vision areavailable, for example through the use ofprisms to corrective lenses. In other cases,simply understanding the source of theirdifficulties offered some comfort and relief(“So it’s not just that I’m past it at 50?” askedone patient).

I told Mary Margaret’s story to agathering of medical students including thisarticle’s coauthor, then a fourth year medicalstudent interested in ophthalmology. Togetherwe formulated a set of recommendations thatwhile designed for medical students wouldserve equally well for both ophthalmologistsand general practitioners.

And, too, we began to develop aresearch plan that would investigate thefailure to treat strabismus as it seems to affectpatients whose condition are either notdiagnosed or treated as an at worst cosmeticinconvenience. This program involves thecreation of a set of adult strabismatics whocan be questioned about the care they havereceived and the possible effect of theircondition on their personal and professionallives.

REFERENCES

1. Greenhalgh T, Hurwitz, B. Eds. Narrative-Based Medicine: Diaglogue and Discoursein Clinical Practice. BMJ Books, London,

1998.

2. Charon R, Hermann N. A sense of story, orwhy teach reflective writing? Acad Med2012; 87(1):5-7.

3. Shapiro J. Narrative medicine and narrativewriting. Fam Med 2012; 44(5):309-311.

4. Bayoumi AM, Kopplin PA. The storiedcase report. Can Med Assoc J 2004;171(6):470-56

Tutorial: Strabismus: An Introduction for Medical Students

Strabismus is a general term to denotea category of disorders involving amisalignment of a person's eyes. Theseinclude the more common infantile tropias(turns that are evident at all times); phorias(turns that are unmasked by “stress”); as wellas less common syndromes and palsies (1).There is a hereditary component to manystrabismus conditions that is often autosomaldominant with varying degrees of severity(2).

Congenital or infantile esotropia (a“crossed-eye” or a “lazy-eye”) is one of themost common forms of strabismus and tendsto present within the first two years of lifewith a large angle turn in of one or both eyes.It is often found early in life by a parentnoticing a turn, often worse at night or whenthe child is tired. Larger-angle turns arereadily diagnosed by checking for a de-centred corneal light reflex (3). Failure to


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diagnose may result in amblyopia, a deficit inthe development of vision that results inpermanent poor vision in one or both eyes.

Standard treatment seeks to avoidamblyopia and to straighten eyes with a viewto restoring normal cosmesis and allowing forsingle binocular vision (2). Conservativemanagement includes a full cycloplegicrefraction for glasses and patching as neededto improve visual acuity (1). Surgery isreserved for large angle cases that are unlikelyto improve with glasses alone. New evidence(4) suggests that early surgery (4 months to 2years) may improve future stereopsis andvisual outcomes.

The strabismus described in this case(reported above) is less common. Theabnormal head tilt Mary Margaret assumed asa child was an unconscious attempt todecrease the diplopia and improve binocularsingle vision (5). If she had presented with thecomplaint of a head tilt or even double vision,a full investigation of ocular, inner-ear,musculoskeletal, and systemic disordersprobably would have been initiated (6). It wasassumed, however, that her head tilt wascaused by the scoliosis, not the other wayaround. The signs that pointed to anotheretiology, such as difficulty playing sports andpoor depth perception were simplyoverlooked.

Current literature on the psychosocialeffects of strabismus is largely focused uponchildren with this condition (7). Amongadolescents and adults its effect has beenassumed to be largely cosmetic; however, asmall body of literature is starting to emergeregarding the psychosocial effects of adultstrabismus, such as decreased self-esteem andpoorer job prospects (8-11). “MaryMargaret’s” case report is unique in itsdetailing of the severe consequences that may

result when patients are not correctlydiagnosed in their early years or when post-operative care following corrective surgeryfor strabismus does not take into account thewhole person.

Together we formulated a set ofrecommendations that while designed by andfor medical students serve equally well forboth ophthalmologists and family physicians.

• Strabismus is an important diagnosis tocatch, preferably in early childhood).

• The benefits of strabismus treatments gowell beyond the cosmetic. Improved functionleads to positive psychosocial outcomes forboth children and adults (7-11).

• Failure to diagnose, and explain thediagnosis to patients and their families, mayresult in serious life quality deficiencieswhose effect extends far beyond the effects ofstrabismus on visual acuity.

Following on presentation anddiscussion of these points the authors beganto collect the case histories of otherstabismatic patients undiagnosed untiladulthood or if diagnosed given littletreatment.

REFERENCES

1. Olitsky SE, Nelson LB. CommonOphthalmologic Concerns In Infants AndChildren, Pediatric Clinics of NorthAmerica 1998; 45(4): 993-1012.2. American Academy of Ophthalmology.Basic and Clinical Science Course, Section.Pediatric Ophthalmology and Strabismus.3. American Association for PediatricOphthalmology and Strabismus. Info forPatients: Vision Screening-Corneal LightReflex Testing.www.aapos.org/terms/conditions/107


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4. Simonsz HJ, Kolling GH. Best age forsurgery for infantile esotropia. Eu JPaediatric Neurol 2011; 15:205-208.5. Kushner BJ. The influence of head tilt onocular torsion in patients with superioroblique muscle palsy. J AAPOS 209; 13:132-135.6. Rubin SE, Wagner RS. Ocular torticollis.Surv Ophthalmol 1986; 30:366-376.7. Birch EE, Wang J. Stereoacuity outcomes

following treatment of infantile andaccommodative esotropia. Optom Vis Sci2009; 86(6):647-652/8. Durnian JM, Noonan CP, Marsh IB. Thepsychosocial effects of adult strabismus: Areview. Br J Ophthalmol 2011; 95:450-453.doi:10.1136/bjo.2010.188425.9. Davidson S, Quinn GE. The impact ofpediatric vision disorders in adulthood.Pediatrics 2011; 127:334-339.10. Carlton J. Kaltenhaler E. Health-relatedquality of life measures (HRQoL) in patientswith amblyopia and strabismus: A systematicreview. Br J Ophthalmol 2011; 95:325-330.11. Edelman PM. Functional benefits of adultstrabismus surgery. Am Orthoptic J 2010;60:43-47.

Binocular Vision & Strabology Strabismatic; Tenotomy and Replacement (TAR). More Words and Terms; FOURTH Quarter of 2013Quarterly, Simms-Romano’s© Confucius; Hashtage Volume 28 (No 4)

A Medical Scientific Eye e-Periodical Paul E. Romano, MD, MS Ophthalmology Pages 209-210

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EDITORIAL: Strabismatic; Tenotomy and Replacement (TAR);More Words and Terms; Confucius; Hashtags (#)

Words word words, we sure do seem to getinvolved with them in these editorial columnslately. And the proper word is of courseETYMOLOGY, the science of words in allregards, origins, history, use, etc, etc. Adictionary is an etymology book. Ours evenhas a whole section on etymology.

And our first word for today is as in the titleabove, “strabismatic”. Which means a personor organism otherwise affected by or havingstrabismus.

Until Dr. Koch (Koch T, Butler MC.Strabismus: Delayed into AdulthoodDiagnoses and Unreported Damage toQualities of Life. BV&SQ 2013; 28(4):203)sent us his interesting letter and his tutorialcontribution, we had never run across theword in the 50 years we have been learningabout strabismus. It is not in an ordinarydictionary, or medical dictionary or even inmany of our books and sources on strabismusor strabology.

But “google” it and it is out there. Andthe meaning is obvious from context.

Strabismatic: Someone who suffers fromhaving strabismus.

From Art Rosenbaum’s obituary in googlefrom www. Timeshigher education.co.uk 3years ago: “He corrected the vision of more than 10,000strabismatic - or “cross-eyed” children.”

It is also a term often used to describestrabismus associated with amblyopia,“strabismatic amblyopia” especially as part of

the symptoms of abnormalities of the SCN8Agene on chromosome 121q13 which is associated primarily with ataxia and othermovement disorders, in man and severalanimals. And even strabismatics.

The term is also in google in one of thestandard optometric textbooks aboutbinocular vision abnormalities.

Regarding the lead article, (Akbari MR et al:Effect of Four Horizontal Rectus MuscleTenotomy AND REPLACEMENT, Aloneand in Combination with Recessions forStrabismus, on Visual Function and EyeMovements in Patients with InfantileNystagmus Syndrome Without AbnormalHead Posture. BV&SQ 2013; 28(4):211) We just had to edit the title by adding amodifying term to the word “Tenotomy”which is all this procedure is titled in thecurrent literature but that, is simply notadequate or enough to us. But we left itunedited in the text of the paper per se foryour appreciation.

Plain “Tenotomy”? This is the first step in 95% of our eye musclesurgeries but it is no longer even part of thename of the procedure. We just use thesecond part “recession” or “resection” most ofthe time. A fully proper and complete namewould be “tenotomy and recession” forexample. We have tried unsuccessfully toadvance the more complete name form forinferior oblique transpositions.

And is an otherwise unspecified tentotomy a“free” tenotomy, or something less or

Binocular Vision & Strabology Strabismatic; Tenotomy and Replacement (TAR). More Words and Terms; FOURTH Quarter of 2013Quarterly, Simms-Romano’s© Confucius; Hashtage Volume 28 (No 4)

A Medical Scientific Eye e-Periodical Paul E. Romano, MD, MS Ophthalmology Pages 209-210

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different, like “partial”?

Historically, John Taylor and Dieffenbach didthe first strabismus surgery: tenotomies. It isthe very original eye muscle surgery but thesewere initially all “free” teonotomies, notrecessions or any manipulation like that.There are also “z” tenotomy and otherconfigurations.

But the term not otherwise modified can meanany of these but is currently being used aloneto describe the newest tenotomy fornystagmus, in which the tendon is simplyreplaced to the insertion from which it hasjust been severed and detached.

Confucius, who we have quoted in thesepages before said in response to the questionwhat was the single most important thing foran administrator to do, is to make sure thev o c a b u l a r y i s c o r r e c t b e c a u s emisunderstandings of words is so commoncause of further misunderstandings andconflict.

Which is precisely the status of this one.

We need an adjective or modifier to describesubtypes; or adverbs,....

The best terms we could imagine were:“tenotomy and replacement” or maybe“tenotomy and repair”.

But we elected the first, as the best anatomicaldescription of the surgery. And we likeespecially the acronym that goes with it“TAR”

HASHMARKS: From The Wall StreetJournal October 28, 2013: Notable &Quotable from the Times Literary Supplement

September 30.“Twitter users may not know it but they

are likely to be addicts of the octothorpe, asymbol with a Latin provenance. Now morecommonly known as the hashtag, theoctothorpe first served as an abbreviation of‘libra pondo’ (‘a pound by weight’) inmedieval England. The ‘lb’ was written witha tilde just above the mid-height of the lettersto signify a contraction, and was thencorrupted into ‘#’ by rushing scribes. ‘Pound’later became ‘number’ before evolving into avariety of different signifiers, including acopy-editor’s space, a chess player’scheckmate and a Tweeter’s keyword. How itcame to be known as the octothorpe is quiteanother matter.

“This story comes from ShadyCharacters by Keith Houston, a paean totypographical curiosities old and new.Houston’s ‘magnificent case’ includes theasterisk, with its origins in the starlikecuneiform symbol denoting heaven; thehumble hyphen - not to be confused with abewildering variety of dashes; and a modernupstart, the interrobang: a conflation of thequestion mark and the exclamation mark, asin ‘how cool is that?!’ Houston’s book isfilled with passion, whether its author isdecrying the neglect of the noble pilcrow orthe sad fate of the percontation point, areverse question mark invented by the sixteencentury printer Henry Denham to indicate arhetorical question.”Happy Holidays! PER

Bin ocular Vision & Strabology & Effect of Four Horizontal Rectus Muscle Tenotomy and FOURTH Quarter of 2013

Quarterly Simms Rom ano’s© Replacement (TAR) Alone and in Combination with Recessions for Volume 28 (No.4)

A Medical Scientific ePeriodical Strabismus on Visual Function and Eye Movements in Patients with PAGES 211-221

Infantile Nystagmus Syndrome (INS) Without Abnormal Head Posture (AHP)

MR Akbari, MD, M Akbari-Kamrani, MD, MPH, A Mohseni, PhD, AK Jafari, MD, MA Fard, MD, A Ameri, MD

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Original Scientific Article

Effect of Four Horizontal Rectus Muscle Tenotomy andReplacement (TAR) Alone and in Combination withRecessions for Strabismus, on Visual Function and EyeMovements in Patients with Infantile Nystagmus Syndrome(INS) Without Abnormal Head Posture (AHP).

MOHAMMAD REZA AKBARI, M.D.1,MARJAN AKBARI-KAMRANI, M.D., MPH1,ARMAN MOHSENI, Ph.D.2, ALIREZA KESHTKAR JAFARI, M.D.1,MASOUD AGHSAEI FARD, M.D.1, AHMAD AMERI, M.D.1

from 1 Strabismus Department, Eye Research Centre, Farabi Hospital, Tehran University ofMedical Sciences (TUMS), 2 Faculty of Mechanical and Energy Engineering, Power and WaterUniversity of Technology (PWUT), Tehran, Iran

ABSTRACT: Purpose: To evaluate and compare the effect of four horizontal rectus muscleTenotomy And Replacement (TAR) alone and in combination with recessions for strabismus,on visual function and eye movement records in patients with INS without AHP, and to comparethese results.

Methods: This was a prospective interventional case series of 14 patients with INS withno AHP or eccentric null point. Patients underwent 4 horizontal eye muscle tenotomy andreplacement (TAR) alone or 2 muscle TAR in combination with conventional bilateral horizontalmuscle recession according to the presence and type of strabismus. Outcome measures includedbest corrected visual acuity and nystagmus intensity from eye movement recordings pre and postoperatively. Data were compared between patients with strabismus and those without.

Results: Overall nystagmus amplitude and velocity was decreased 28.7% and 21.9%respectively for 4 muscle TAR and 2 muscle TAR with paired strabismus recessions. Visualoutcome of combined procedure in patients with INS and strabismus was less comparing with4-muscle tenotomy. All binocular deviations were surgically corrected and there was noundercorrection or complication. Visual acuity showed improvement in patients who had moreimpaired pre-operation vision. Most patients were satisfied with cosmetic outcomes.

Conclusions: Tenotomy alone and combined with recession improves both visual functionand eye movement records in INS. The procedures show better results in more visually impairedpatients. We should consider patients’ pre-op VA and their visual potential as prognostic factorsfor their visual gain. Although visual outcomes are not advanced in all patients, nystagmusdampening effect and cosmetic outcome of these procedures can make them reconstructiveoptions for patients with INS who will not achieve better vision.Received for consideration May 8, 2013; accepted for publication June 17, 2013.Sources of support and acknowledgments: Research and Thesis Committee at Eye ResearchCentre, Farabi Hospital, Tehran University of Medical Sciences (TUMS), IranCorrespondence: Ahmad Ameri, MD; Email: [email protected]






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INTRODUCTION

There are various surgical options(recessions, resections, or their combinationsuch as Anderson-Kestenbaum) for patientswith Infantile Nystagmus Syndrome (INS),which has proven efficacy on associatedabnormal head posture (AHP), eccentric nullpoint or strabismus. For patients with INSwho have no AHP, eccentric null point orstrabismus. There is no definitive treatmentyet.

Retroequatorial 4-horizontal rectusmuscles recessions were proposed as an optionfor these patients by Bietti in 1956; however,these large recessions have technicaldifficulties. Previous investigators noticedthat beside mechanical effect of extraocularmuscle (EOM) displacements – Kestenbaumsurgery for associated AHP or strabismus-nystagmus waveforms are also improved afterthese surgical manipulations. Based on theseobservations, in 1990s Dell’Osso and Hertleintroduced “teno tomy” (i .e . s implydisinserting and reattaching EOMs at theiroriginal insertions) [named formally as“tenotomy and replacement”, acronymed“TAR”, which names have been inserted inthe title and abstract of this text but notfurther -ed] as a hypothetical treatment forcongenital nystagmus (1,2). It is advantageousover large rectus recessions because it istechnically easier and has less adverse effects,such as diplopia in extreme lateral gaze.

Although the etiology of INS isunknown, it seems an interruption between thedeveloping sensory and motor systemsinterferes with ocular motor calibration (neural“cross talk”) and results in involuntaryoscillations (3,4). It is hypothesized thattenotomy probably changes proprioceptiveinputs which control resting tension of theEOMs (5, 6). So, it can reduce the slow-phasegain of nystagmus. Some recent studiesreported supportive information for this theory

by introducing palisade endings withproprioceptive role at the tendino-scleralinterface (“enthesis”) of EOMs (7,8).

Recently, some interventional case-series have reported 4-muscle tenotomyefficacy in VA and nystagmus waveformsimprovement (9,10,11). Also, there are somereports on advanced efficacy of combiningpreviously known surgical treatments (i.e.recession or resection for AHP, shifting nullpoint, or strabismus) with tenotomy (12,13).

We performed this study to evaluateeffect of combined recession with tenotomyand 4-muscle tenotomy on visual function andeye movement records, as primary outcome, inpatients with INS without AHP, and tocompare their results. We considered patients’satisfaction with their cosmetic appearance asa secondary outcome. In patients with INS andstrabismus, ocular alignment outcome,undercorrection or need for second surgery isalso assessed.

METHODS

This study was approved by researchand thesis committee at Farabi Eye Hospital,Tehran University of Medical Sciences(TUMS), Iran. We performed this prospectiveinterventional case-series from 2011 Januarytill 2012 December.

Recruitment of patients: We recruitedpatients older than 18 years old with clinicaldiagnosis of INS and binocular best correctedvisual acuity (BCVA) of 20/400 to 20/30 atdistance for this study. They should be able tosign informed consent and undergo a completeophthalmic evaluation and standard eyemovement recording. Exclusion criteria were:1) history of EOM surgery, 2) being on othernystagmus treatment modality such asmedication, prisms, biofeedback, acupuncture,injection of botulinum toxin, etc, 3) otherocular disorders which needed specificmanagement such as cataract, glaucoma, etc,






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4) significant AHP (>10/) or eccentric nullpoint which required surgical correction, 5)large angle strabismus (>45 prism diopter(PD)which needed surgical manipulation on morethan 2 muscle), 6) vertical deviation more than5 PD or dissociated vertical deviation (DVD)which needed surgical correction, 7) follow upless than 3 months.

Ophthalmic evaluation and eye movementrecordings: Two investigators evaluated allpatients separately, in at least 2 different visitswithin 2 months before surgery. Ophthalmicevaluation consisted of a complete slit-lampexamination of anterior and posteriorsegments, measuring intraocular pressure(IOP) –by Goldman tonometry, both binocularand monocular BCVA –by using a Snellenchart at distance (6 meters) and near(33centimeters), cycloplegic refraction –byusing a combination of retinoscopy andsubjective techniques after full medicalcycloplegia, fusion at distance (6 meters) andnear (33 cm)–by using worth4dot, stereovision –by using Stereo FLY and RANDOTStereo Tests at 33cm, and ocular alignment at6 meters and 33 cm.

A masked investigator performed eyem o v e m e n t r e c o r d i n g s u s i n g av ideonystagmography mach ine (G NOtometrics A/S, MADSEN, AURICAL, ICS,Chartr 200, version 6.8.2). We asked patientsto look at a stationary target in the straighthead position at 120cm from the patient and at20/ gaze positions with both eyes open.Duration of each trial, considering the patientcooperation, was as long as possible but lessthan one minute to minimize patient’sinattention which causes nystagmus intensityreduction.

Surgical procedure, and post-op care andassessment: For patients with horizontaldeviation more than10PD, we performed acombined recession with tenotomy surgery(Group 1), i.e. bilateral medial rectus (BMR)

recession and bilateral rectus(BLR) tenotomyin patients with esoteropia, and BLR recessionand BMR tenotomy in patients with exotropia.For patients with horizontal deviation less than10PD, we performed four-muscle tenotomy(Group 2), i.e. BMR and BLR tenotomy.

One surgeon (MRA) performed alloperations. All patients received topicalsteroid and antibiotic 4 times daily for 7 to 10days. Two investigators, masked to patients’pre-operation information, visited all patientsat 1 day, 1 week, 1 months, 3 months, andevery 3 months post operatively. Theyperformed a complete ophthalmic exam asmentioned for pre-operation evaluation. Also,any complaints of patients or side effects suchas muscle movement limitation weredocumented. The same investigator obtainedpost-operation records of eye movementswhich were performed at least 3 months afterthe procedure. We also assessed satisfaction ofall patients with the procedure cosmetic resultby two simple questions: whether “they wouldtake the surgery if they were at beginning ofthis study” or “they would recommend it totheir affected relative or close friends”.

Signal analysis: One investigator chose bestfoveation segments in each trial for pre- andpost operation records. Segments with 3 to 4seconds length were appropriate to containenough data (8 to 16 beats) and to avoid blinksand inattention periods. At each gaze,depending on the data availability, 2 or 3calculations were possible to make. Amplitudeis defined as peak to peak excursion of theoscillation. Amplitudes of all beats in eachsegment were averaged. Frequency ismeasured as number of nystagmus cycles persecond. We also measured slow phase velocity(SPV) which is the velocity (degree/second) ofeye movement during its slow phase.






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RESULTS

A total of 14 patients with pre-operationBCVA of 20+/200 to 20/30 completed thisstudy. Table 1, next page shows their pre-operation information. Their age ranged 18 to44 years (mean: 26.8 +/- 7.5y). Four patientshad associated ocular albinism and 1 hadoculocutaneous albinism. Six had a transientor variable AHP which could not be surgicallycorrected. Only one had distance fusion; but 4patients had fusion at near and demonstratedgross amount of streopsis (700-2000 secondsof arc) preoperatively.

Among all, 6 patients had horizontalstrabismus with ocular deviation of 14 to 45prism diopter (PD) which required surgicalcorrection (group 1). Eight other patientsunderwent 4-muscle tenotomy. The follow upperiod was between 3 to 15.5 months (median7.3 months).

Table 2, overleaf next page,summarizes BCVA and eye movementrecords’ changes in pre and post operationperiods in all 14 patients. Among all, 5patients showed >= 0.1 LogMAR VAimprovement with statistical significance (P=0.03). Pre-op amplitude was in the range of 4to 24.8 degree (mean 12.1deg, median 10.6deg). It had an average reduction of 28.7%post operatively (P=0.001). Nine of 14patients showed marked decrease (>25%), 2had moderate (10-20%) and one 5.1%decrease in amplitude. Two patients had asmall increase in their amplitude (0.8% and1.1%). In contrast to amplitude, nystagmusfrequency was in a smaller range (2.2 to 5. Hz)pre operatively and we found no clinicalsignificant change in it (P=0.88). Peak SPVwas in the range of 7 to 162.3 degree/secondpre operatively and had a 21.9% averagedecrease (P=0.001). Nystagmus waveforms ofpatient 4 with INS and strabismus, and patient14 with INS alone are illustrated as examplesin Figures 1 and 2 respectively.

We performed subgroup analysis forsurgical procedures. In Group 1 we couldn’tfind a meaningful change in BCVA. In Group2, BCVA change had a borderline significance(P=0.07). In Group 2, patients who showedVA improvement had pre-op VA less than orequal to 20/50; where as in group 1, onlypatients with pre-op VA of =< 20/100 showedimprovement, and others with better pre-opVA showed no change. Subgroup analysis ofeye movement records are shown in Table 3.In Group 1 amplitude and SPV showedreduction of 24.7% (P=0.06) and 24.9 %(P=0.06) respectively. In group 2 amplitudeand SPV a l so show ed n oticeab leimprovements (P= 0.002 and 0.004respectively). Comparing effect of these twosurgical procedures on eye movement records,showed no difference between two groups.

We also compared eye movementrecords between different gazes. Table 4summarizes these findings. Pre-op’ amplitudehad no significant difference at primaryposition, right and left gazes (P=0.88) whichconfirms our patients had no null point. Itsreduction had a considerable significance ateach gaze (P= 0.07, 0.03 and 0.03respectively), and there was no differencebetween amplitude improvements at primaryposition and lateral gaze (P=0.61). Pre-op SPVwas somewhat better at primary positioncompared with lateral gazes (P=0.07). Itsimprovement was marked at right and leftgazes (P= 0.02 and 0.01 respectively) but itschange at primary position was smaller anddidn’t show significance (P=0.27).

In Group 1, all patients had correctedstrabismic deviation in the accepted range.There was no undercorrection, and no need tosecond corrective operation. We had nocomplication or reported discomfort duringtheir follow up period (5.5 to 12.5 months).

We found no remarkable change in theamount or duration of AHP in our patients. No






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Figures 1&2 below (Akbari et al)- Pre and post-op eye movement records of Figure 1, toppatient4 in group1 and Figure 2 bottom, patient 14 in group2, both showing marked reductionof nystagmus amplitude and velocity after the procedure. Top level of each set shows pre-op andbottom level shows post-op records. Nystagmus waveforms at left gaze, primary position andright gaze are shown in left, center and right column respectively.






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patient lost his fusion or stereopsis, and alsothere was no fusion gain or stereopsisimprovement. Six of 6 patients withstrabismus and 7 of 8 patients withoutstrabismus, were subjectively satisfied withcosmetic results of the procedure. Theydeclared they would recommend the surgeryand would take it themselves if they were atbeginning of study. Only one patient inGroup2 (patient 1) stated he had no change inhis vision and eye movement appearance afterthe surgery.

DISCUSSION

Many recent studies have shownbeneficial effect of 4-muscle tenotomy aloneon visual performance and waveformcharacteristics (9, 10). We also demonstratedthat tenotomy alone in 8 patients couldimprove primary position VA and eyemovement indices. We found better visualoutcome in patients with worse BCVA(=<20/50) before surgery which has beenobserved in other studies too (9,13).

In this study, overall visionimprovement by both procedures (5 of 14patients, with >=0.1 LogMAR) wasundersized compared with previous reports(9,13) on effect of different EOMs surgeries(5 of 10 >=1 Snellen line, and 73% >=0.1LogMAR respectively). This can be explainedby difference of studies inclusion criteria forpre operative VA. We recruited patients withVA of equal to or less than 20/30, whereasthose studies included patients with VA of lessthan 20/50. Here in this study, if we consideronly patients with pre-op VA of =<20/50,visual gain of >=0.1 LogMAR would be62.5% (5 of 8 patients). These evidencessuggest that for having a favorable effect onvisual functions we should consider anoptimum pre-op VA, however, we didn’t findthis association between pre-op VA andimprovement of nystagmus intensity. Wefound nystagmus dampening effect of the

procedure was more at lateral gazes where thewaveform characteristics were worse. Thisresults in broadened visual field with higherquality vision. The same effect has beenreported by Wang et al previously (11,12).

An early study of combining recessionwith tenotomy by Wang et al in 2007 (12),reported favorable outcome on nystagmuswaveform and VA in one patient with INS andhorizontal deviation. In 2010, Hertle et al (13)in their large study of 100 patients with INSproposed combining tenotomy with otherEOM surgeries as a therapeutic approach inINS patients who have other indication forsurgery. They reported effectiveness ofcombined strabismus surgery and tenotomy in15 patients with INS and ocular deviation.

Recently, superior results of Andersonprocedure combined with tenotomy onpatients with INS and AHP are also described(13,14). In our study of 6 patients with INSand ocular deviation of =< 45PD, we foundthat tenotomy in combination with recessioncan result in ocular alignment and there’s noundercorrection. In addition, we showed theprocedure had good results in improvingnystagmus intensity and visual function.Reduced beneficial effect of the combinedprocedure on visual function in this group(favorable results in patients with pre-op VA=<20/100) compared with tenotomy alone canbe explained by probable underlyingamblyopia in patients with strabismus.“Amblyopia” can be a limiting factor inpatients’ maximum visual potential, thuseliminating expected therapeutic effect of theprocedure. This confounding effect has beensimilarly reported in previous studies (9,11).

Here in our study, 13 of 14 patientswere greatly satisfied with the operationcosmetic result. Although visual gain wassmall in our study patients (5 of 14 patients),we found noticeable reduction in nystagmusamplitude (11 of 14 patients, with moderate






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to high dampening) which is the maincontributor to patients’ cosmetic appearance.It seems that nystagmus dampening effects ofthese procedures are independent of theirvisual outcome which makes them areconstructive option for patients with INSand no expected visual gain.

Limitation of this study is its smallsample size. We also did not have a controlgroup of patients with INS and strabismuswho undergo only recession to compare withGroup 1 and assess nystagmus dampeningeffect of addition of tenotomy.

CONCLUSIONS

Tenotomy alone and in combinationwith recession in patients with INS withoutAHP, has an overall therapeutic effect onprimary position VA and broadens area withhigher quality vision. Based on ourobservation, it seems that expected visual gainfrom combined procedure in patients with INSand strabismus is much less compared with 4-muscle tenotomy in patients with INS and nostrabismus. We highlight prognostic role ofpre-op BCVA and maximum visual potentialof patients on the procedure expectedtherapeutic effect to improve visual function.However, in those patients who seem to haveno visual gain, we should not overlook markeddampening effect of these procedures on eyemovement indices, which results in desirablereconstructive effects.

Further studies are needed to identifyother predictive factors, and to evaluatecosmetic and psychologic outcome of theseprocedures.

REFERENCES

1. Dell’Osso LF: Extraocular muscletenotomy, dissection and sutu re: ahyp othe tical therapy f or co nge nita lnystagmus. J Pediatr Ophthalm olStrabismus 1998; 35(4)-232-233.

2. Dell’Osso LF, Hertle RW, Williams RW, etal: A new surgery for congenital nystagmus:effects of tenotomy on an achiasmatic canineand the role of extraocular proprioception. JAAPOS.1999; 3:166-182.3. Hertle RW, Maldanado VK, Maybodi M, etal: Clinical and ocular motor analysis of theinfantile nystagmus syndrome in the first 6months of life. Br J Ophthalmol. 2002;86(6): 670-675.4. Jacobs JB, Dell’Osso LF: Congenitalnystagmus: Hypotheses for its genesis andcomplex waveforms within a behavioralocular motor system model. J Vision. 2004; 4:604-625.5. Hertle RW: Does eye muscle surgeryimprove vision in patients with infantilenystagmus syndrome? Ophthalmology.2009; 116(10):1837-1838.6. Hertle RW, Felius J, Yang D, et al: Eyemuscle surgery for infantile nystagmussyndrome in the first two years of life. ClinOphthalmol. 2009; 3: 615-624.7. Hertle RW, Chan CC, Galita DA, et al:Neuroanatomy of the extraocular muscletendon enthesis in Macaque, normal humanand patients with congenital nystagmus. JAAPOS. 2002; 6: 319-27.8. Jaggi GP, Laeng HR, Muntener M, et al:The anatomy of the muscle insertion(scleromuscular junction) of the lateral andmedial rectus muscle in humans. InvestOphthalmol Vis Sci. 2005; 46: 2258-63.9. Hertle RW, Dell’Osso LF, FitzGibbon EJ,et al: Horizontal rectus tenotomy in patientswith congenital nystagmus: results in 10adults. Ophthalmology. 2003; 110(11):2097-2105.10. Hertle RW, Dell’Osso LF, FitzGibbon EJ,et al: Horizontal rectus muscle tenotomy inchildren with infantile nystagmus syndrome:a pilot study. J AAPOS. 2004;8(6):539-54811. Wang Z, Dell’Osso LF, Jacobs JB, et al:effects of tenotomy on patients with infantilenystagmus syndrome: foveation improvement






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over a broadend visual field. J AAPOS. 2006;10(6):552-560.12. Wang ZI, Dell’Osso LF, Tomask RL, et al:Combining recessions (nystagmus andstrabismus) with tenotomy improved visualfunction and decreased oscillopsia anddiplopia in acquired downbeat nystagmus andin horizontal infantile nystagmus syndrome. JAAPOS 2007; 11:135-141).

13. Hertle RW, Yang D, Tai Z, et al: Asystematic approach to eye muscle surgery forinfantile nystagmus syndrome: results in 100patients. Binocul Vis Strabismus Q. 2010;25(2):72-93.14. Bishop JE: A novel new [yet again]procedure for correction of compensatory headposture in infantile nystagmus: augmentedAnderson plus Dell’Osso-Hertle. Binocul VisStrabismus Q . 2011; 26(1):37-42.

Binocular Vision & Strabology Flip Chart Visual Acuity Screening for Amblyopia Risk Factors Compared to the FOURTH Quarter of 2013

Quarterly Simm s Rom ano’s© PlusoptkX AO9 PhotoscreenerTest Performed by a Lay Screener Volume 28 (No.4)

A Medical Scientif ic ePeriodical D. I. Silbert, MD, N. S. Matta, CO, CRC, COT, A. Brubaker PAGES 222-228

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Flip Chart Visual Acuity Screening for Amblyopia RiskFactors Compared to the PlusoptiX A09 Photoscreener,Tests Performed by a Lay Screener

DAVID I. SILBERT, M.D., NOELLE S. MATTA, CO, CRC, COTand ABBY BRUBAKER

from Family Eye Group, Vision Science Department, Lancaster, Pennsylvania

ABSTRACT: Importance: The gold standard of vision screening is considered acuity testing,this article will compare the gold standard against new technology to provide more choices forpediatric vision screening programs.

Objective: To determine the reliability of recognition visual acuity screening performedby a lay screener compared to the plusoptiX A09 photoscreener for the detection of amblyopiarisk factors.

Design: One lay screener received basic training in how to test monocular visual acuityusing the 10-foot Patti Pics single crowded chart and the plusoptiX A09 photoscreener. Allchildren underwent a complete pediatric ophthalmology examination and cycloplegic refractionafter screening and this examination was the standard against which the screening method wascompared. Each patient received a “pass” or “refer” grade after either screening. For the PattiPics screening, children were referred if they failed to reach threshold visual acuity of 20/40 ineither eye; the plusoptiX determines if the child is a pass or refer based on pre-set referralcriteria.

Setting: Pediatric ophthalmology clinic.Participants: Screening was performed on children ages 3 to 10 years.Results: Seventy-one children were screened. Flip chart-screening was found to have asensitivity of 83%, specificity of 44%, false positive rate of 56% and false negative rateof 17%. Those same metrics for the plusoptiX A09 were 94%, 89%, 11% and 6%,respectively.Conclusion: The plusoptiX photoscreener was more sensitive and specific in making

appropriate referrals for further care than flip chart-screening in this cohort of children age 3-10.The plusoptiX A09 photoscreener operated by a lay screener is a reliable method to screen foramblyopia risk factors. These finding have important implications for community based visionscreening, and screening in the medical home.

Received for consideration March 8, 2013; accepted for publication April 22, 2013

Correspondence: Noella Matta Email: [email protected]





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INTRODUCTION

Pediatric vision screening hastraditionally been a subjective test of visualacuity requiring a child to read an eye chart;referrals are based on the child’s ability torespond correctly. This method of screeningrequires pat ient unders tanding andcooperation. There is also subjectivity on thepart of the screener in interpreting responses.

To improve reliability of responses,single optotypes with crowding bars havebeen employed and have been validated asprov id ing repe atable visu al acu itymeasurements (1). Flip charts displayingsimilar optotypes are felt to be useful in youngchildren, as there are fewer images presentedand less distraction.

Objective vision screening devices havealso recently become more widely available.These devices, which include photoscreeners,autorefractors and visual evoked potentialsystems, require less attention and cooperationfrom the child. The systems are typicallyautomated, and only require the child to lookbriefly at a fixation target. Photoscreeningdevices include the iScreen (2), MTI (3)(which is no longer commercially available),visiscreen (4) and plusopitX (5,6).Autorefractive devices include the Retinomax(7) and SureSight (8). All of these devices, aswell as visual evoked response systems (9)have been validated as objective vision-screeners.

We compared a subjective eye chartscreening using the Patti Pics flip chart to anobjective vision screening using the plusoptiXA09 photoscreener. The Patti Pics acuitysystem utilizes shaped optotypes (apple, circlesquare etc) and has been shown to beequivalent to acuity as tested with Lea

Symbols (10) In both screenings a layscreener administered the test.

The plusoptiX is an infrared videoautorefractor and photoscreener. Softwareanalyzes the data instantly based on user-defined referral criteria. The plusoptiX A09device was chosen primarily for thiscomparative study due to its simple interface,quick learning curve and automation. Thedevice can be programmed to indicate whethera test subject should be referred for furtherevaluation.

METHODS

Prior to starting this research wereceived Institutional Review Board approvalthrough the Lancaster General Hospital. Wefollowed appropriate Health InsurancePortability and Accountability Act of 1996guidelines.

One volunteer lay screener (AB)screened visual acuity on verbal childrenpresenting for a pediatric ophthalmologyexamination and had a plusoptiX performedas is typical in our pediatric ophthalmologypractice. All children were patients in ourpediatric ophthalmology practice. Allchildren received a comprehensive pediatricophthalmologic examination by a singleexaminer (DS). In addition, all children eitherreceived a cycloplegic refraction that day orhad received one within the prior 6 months.The children did not wear spectacle correctionfor the screenings.

The screener received basic training inthe use of the 10-foot Patti Pics flip chart withcrowding bars as well as the plusoptiXphotoscreener. When using the flip chart, thelay screener recorded monocular visual




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acuities of each eye. A stick-on occlusive eyepatch was used to ensure monocular testing asper American Association for PediatricOphthalmology and Strabismus (AAPOS)recommendations (11). Children were testedten feet from the chart, either on a comfortablechair or on a parent’s lap. Parents wereinstructed not to provide hints or answersduring the testing. Testing started with a largeoptotype and the children were encouraged toread progressively smaller until theyconsistently missed a set of optotypes. Thesmallest acuity line where 3 of 4 optotypeswere correctly identified was recorded as thevisual acuity.A matchingc a r d w a sprovided tothe children sothat they couldchoose to pointto their choiceor to respondverbally.

For screeningw i t h t h eplusoptiX, thec h i l d w a sprompted to look at the photoscreener by aseries of sounds and a smiley face on theinstrument’s surface. The lay screener viewedthe child’s eyes on a monitor to confirm thatthe child was looking at the target. The layuser was guided by the image on the device tofocus it appropriately at a distance of 1 meter;once this occurred, the photoscreener took asuccession of readings in three differentmeridians 120 degrees apart over the course ofa few seconds. If a “not able” reading wasreported by the photoscreener, the lay screenerrepeated the test and a second result was

recorded. If this second reading was also a“not able” this was recorded in the chart andthe patient was considered a “refer”. Bothscreening methods were performed on everychild tested.

Based upon their flip chart acuity-screening test, children were considered torequire a referral for further evaluation if theirvision was 20/40 or worse in either eye. TheplusoptiX A09 photoscreener referredchildren for further evaluation based on theMatta/Silbert referral criteria (see Table 1below).

These criteria identify amblyopia risk factorssuch as blepharoptosis, heterophorias andlarge refractive errors. The comprehensivepediatric ophthalmic exam identified allamblyopic risk factors by employing thecurrent AAPOS referral criteria (12):

• Anisometropia (spherical or cylindrical) >1.5 D;

• Any manifest strabismus;

• Hyperopia > 3.5 D in any meridian;

• Myopia magnitude > 3.0 D in any meridian;

Table 1: PlusoptiX A09 Photoscreener: Matta/Silbert Referral Criteria




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• Any media opacity > 1 mm in size;

• Astigmatism > 1.5 D at 90 degrees or 180degrees; > 1.0 D in oblique axis (more than 10degrees from 90 degrees or 180 degrees);

• Blepharoptosis #1 mm margin reflexdistance.

RESULTS

Seventy-one children, ranging in agefrom 3 to 10 years were screened (see Graph1, below). Fifty-three children were found to

have amblyopia risk factors based upon thecomprehensive pediatric eye examination(75%). Two children had visually significantcongenital blepharoptosis, 14 children hadsignificant refractive error alone, 6 childrenhad strabismus alone and 31 children had bothsignificant refractive error and strabismus.Thir ty-one children had sig nif icantastigmatism, 27 children had hyperopia, 4children had myopia and 10 hadanisometropia.

Graph (Figure) 1: Patient-Subject Data: Age Distribution of the 71children-patients who were screened for amblyopia risk factors. Of the71, 53 were found to have amblyopia risk factors as listed above on theprior page.




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When comparing the referral pattern ofthe flip chart screening to the results of thisstandard, the flip chart method was found tohave a

• sensitivity of 83%,

• specificity of 44%,

• false positive rate of 56%,

• false negative rate of 17%,

• positive predictive value of 81% and

• negative predictive value of 47%

(seeTable 2 below).

There were 5 children for whom the layscreener was unable to obtain visual acuityreadings from (ages 3, 3, 4, 6 and 9). For thatreason, all of these 5 children were consideredto require a referral. Of these, 3 were falsepositives. There were 9 false negative

readings in children ages 4-10. Of the childrenreferred by the acuity screening, 3 childrenhad strabismus, 4 children had significantrefractive error and 2 children had bothsignificant refractive error and strabismus.

The plusoptiX also scores a “refer”when a “not able” reading is obtained on themachine. This can happen if the entire pupilcannot be found (such as with blepharoptosisor a coloboma), if there is a misalignment ofthe eyes preventing the device from getting areading in one eye or if the child is notlooking at the device. Of the 9 children whoreceived a “not able” reading, 6 had confirmedstrabismus, 2 were highly myopic and 1 hadcongenital blepharoptosis.

Comparing the referral pattern of theplusoptiX to the comprehensive eye examdemonstrated that the plusoptiX photoscreenerprovided a

• sensitivity of 94%,

• specificity of 89%,

Table 2: RESULTS: Comparison of Flip Chart and PlusoptiXscreening for Amblyopia Risk Factors.




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• false positive rate of 11%,

• false negative rate of 6%,

• positive predictive value of 96% and

• negative predictive value of 84%.

This was similar to our previouslyreported experimental results where thisphotoscreener was operated by trainedtechnicians or an orthoptist (3).

CONCLUSION

Recognition acuity by a lay screenerwith a flip chart performed poorly, whilephotoscreening by a lay screener performedsimilarly to the results obtained by trainedophthalmic personnel.

Our study was on an enrichedpopulation with a high prevalence of disease.If the results are extrapolated to a typical




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screening population with a lower prevalenceof disease, the poor specificity of the flip chartwould become an even greater issue.Assuming a prevalence of disease of 10%, theplusoptiX would refer 18 children out of 100,with 9 of the children meeting AAPOSreferral criteria for amblyopia risk factors.The flip chart would refer 53 patients forfurther examination, with only 8 meetingAAPOS referral criteria for amblyopia riskfactors (see Table 3, prior page ).

We recognize that subjective eye chartacuity screening is a very low cost method toassess patients. However, there is cost tosociety for under- and undiagnosed eyedisease as well as real costs to patients andinsurers for unnecessary referrals in childrenwithout disease. Photoscreening from age 3-10 years of age was found to outperform flipchart recognition acuity screening by a layscreener in the same cohort of children. In thisstudy, the plusoptiX A09 photoscreener wasfound to be both more sensitive and specific,missing fewer children with pathology andhaving a lower false negative rate. This studysecondarily demonstrates that the plusoptiX issatisfactorily effective even when used by alay screener with minimal training. Thisincreases the opportunity to provide validvision screenings to underserved patientpopulations.

REFERENCES

1. Drover JR, et al. Normative pediatric visualacuity using single surround HOTV optotypeson the Electronic Visual Acuity Testerfollowing the Amblyopia Treatment Studyprotocol. J AAPOS 2008;12:145-9.2. Kennedy RA, Thomas DE. Evaluation ofthe iScreen digital screening system foramblyogenic risk factors. Can J Ophthalmol.2000;35:258-62

3. Matta NS, et al Comparison between theplusioptiX and MTI photoscreeners. ArchOphthalmol 2009;127:1591-54. Morgan KS, Johnson WD. Clinicalevaluation of a commercial photorefractor.Arch Ophthalmol 1987;1528-315. Matta NS, Singman EL, Silbert DI.Performance of the plusoptiX S04photoscreener for the detection of amblyopiarisk factors in children aged 3 to 5. J AAPOS2010;14:147-96. Matta NS, et al. Screening for amblyogenicrisk factors using the PlusoptiX S04photoscreener on the indigent population ofHonduras. Ophthalmology 2010;117:1848-507. Borchert M, et al. Testability of theRetinomax autorefractor and IOLMaster inpreschool children: the Multi-ethnic PediatricEye Disease Study. Ophthalmology2008;115:1422-58. Kember AR, et al. Comparison ofmonocular autorefraction to comprehensiveeye examinations in preschool-aged andyounger children. Arch Pediatr AdolescMed. 2005;159:435-99. Simon JW, et al. A new visual evokedpotential system for vision screening ininfants and young children. J AAPOS2004;8:549-5410. Mercer ME etal. Comparison of Patti Picsand Lea Symbols optotypes in children andadults. Optom Vis Sci 2013; 90:236-24111. American Academy of Pediatrics.Pediatric Eye Evaluations: Screening andComprehensive Ophthalmic EvaluationsPreferred Practice Pattern. September 2007. 12. Donahue SP, Arnold RW, Ruben JB, forthe AAPOS Vision Screening Committee.Preschool vision screening: What should webe detecting and how should we report it?Uniform guidelines for reporting results ofpreschool vision screening studies. J AAPOS2003;7:314-6.

Binocular Vision & Strabology Is the Sphere Value Measured by an A utorefractor Reliable in Children Under Cycloplegia? FOUR TH Q uater of 2013

Quarterly Simm s Rom ano’s© Comparison with Streak Retinoscopy Volume 28 (No.4)

A M edical Scientific ePeriodical RD da Gama, MD, TY Nom, CO, DC da Costa, CO, JC dos Santos, CO PAGES 229-237

RS da Costa, CO, C Relha, CO

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Is the Sphere Value Measured by an Autorefractor

Reliable in Children Under Cycloplegia?

Comparison with Streak Retinoscopy.

RITA DINIS DA GAMA, M.D., TÂNIA YANG NOM, CO,

DANIELA CÂNDIDO DA COSTA, CO,

JOANA CHAMBEL DOS SANTOS, CO,

RUTE SOUSA DA COSTA, CO, and CATARINA RELHA, CO

from Hospital da Luz, Lisbon, Portugal

ABSTRACT: Purpose: To compare and repeatedly measure cycloplegic refraction in a cross-

section of children using retinoscopy and automated refraction.

Methods: A total of 560 children (corresponding to 1120 eyes) ranging in age from 3 to

10 years (mean 4,3 ± 1,7 years) participated in the study. Each child underwent a comprehensive

eye examination, which included table mounted autorefractor evaluation (Kowa KW-2000®) and

streak retinoscopy, both after cycloplegia with 1% cyclopentolate hydrochloride. Data were

analyzed using Fourier decomposition of the power profile.

Results: More positive values of M component and sphere value were given by

cycloplegic autorefraction (AKW) compared with cycloplegic streak retinoscopy (RR) (p <

0.0001). More negative values for the J45 vector and more positive for J0 were given AKW

although this difference was not statistically significant.

Conclusions: Our study shows that the table mounted autorefkeratometer Kowa KW-

2000 can be applied to young children with cycloplegia as instrument for cycloplegic refraction,

and a discount of +0.67 should be applied on the sphere value. Similar care should be taken on

the evaluation of the sphere and spherical equivalent values should be applied in other devices.

Received for consideration May 7, 2013; accepted for publication June 16, 2013

The authors have no commercial associations that might be perceived as a conflict of interest in

connection with this manuscript.

Correspondence: Rita Gama, M.D.: e-mail: [email protected]





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INTRODUCTION:

The traditional gold standard for thedetermination of refractive error in pre-schoolchildren is cycloplegic retinoscopy (1-7). Inwell trained hands, it is considered a verya cc urate and effe ct ive m eth od . (4 )Nonetheless, retinoscopy can be quite userdependent; subject to inter-observer variabilityand is less accurate in the presence of highametropia. (2,3,4,6)

Recently, there has been an emphasison the development of automated devices thatare free from operator bias and can be used forrefract ion on chi ldren: hand helda u t o r e f r a c to r s a n d t a b l e - m o u n t e dvideoretinoscopy are instruments that allowquicker evaluations of children’s refraction(2,8-11). However, using autorefractors inchildren has its own problems, such as,difficulty in maintaining the appropriateposition of the child, ensuring alignment andhaving them fixating on a target for asufficient length of time (6,8,9) .

Do table-mounted autorefractors have arole on children’s refraction? (12).

The purpose of this study was to obtaina comparison between the table-mountedautorefkeratometer Kowa KW-2000® andstreak retinoscopy in children undercycloplegia using mean spherical equivalent(M) and astigmatism measurements (J0 , J45).

MATERIALS, SUBJECTS AND METHODS:

Design: The study was a method comparisonand repeatedly measured refraction in a cross-section of children using cycloplegicretinoscopy and automated refraction.

Subjects: The study population consisted ofchildren between 3 and 10 years old who were

admitted to our ophthalmology clinic for aneye observation between January 2010 andJuly 2012.

Procedure: Slit-lamp, direct and indirectophthalmoscope examinations were performedin all participants. Eyes with media opacity orrecognized cyclopentolate adverse reactionwere excluded from the study. Informedconsent was obtained from all children’sparents. This study conformed to the tenets ofthe Declaration of Helsinki.

Cycloplegia was achieved with twodrops of 1% cyclopentolate hydrochlorideadministered 15 min apart and autorefractivemeasurements were performed at least 45 minafter the instillation of the first drop (1,13,14).

All autorefractor measurements wereperformed by a certified orthoptist using thethe Kowa KW-2000, a table mountedautorefkeratometer. Children were asked toremain still fixating on the internal fixationtarget. At least three separate measurements ofboth eyes were performed at eachexamination, and average values werecalculated from those readings. The sameautorefractor was used for all subjectsthroughout the study.

Finally, retinoscopy was performedusing a streak retinoscope (Welch Allyn,Skaneateles Falls, NY). Hand-held trial lenseswere used to neutralize the refractive erroralong the two principal meridians of each eye.While each instrument was used by differentexaminers, the retinoscopic refraction in allchildren was done by a senior ophthalmologist(RG) who was masked to the othermeasurements.

Statistical analysis: Most investigatorsr ecogn i ze tha t t ra d i t iona l c l inic a l





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representations of refraction, including sphere,cylinder and axis, are not suitable forquantitative analysis (15-18). For this reason,sphero-cylindrical refractive results wereconverted into vector representations byFourier analysis as recommended by Thibos inwhich the familiar formula S (sphere) + C(cylinder) x " (axis) is converted into a vectorwith 3 variables (15-18).

• M or spherical equivalent= S+ (C/2)

• J0 or Jackson cross-cylinder at 0º= (–C/2)*cos (2 ")

• J45 or Jackson cross-cylinder at 45º= (–C/2)*sin (2 ").

The agreemen t betw een th eautorefractor findings, and retinoscopy resultswas then evaluated using the methods ofBland and Altman. (20,21). Plots ofdifferences against means have beenrecommended as the best method to comparemeasurements obtained with differentinstruments or techniques, when the actual

measurement is unknown. (4,17,18,20,21)

In this study, data was analyzed usingthe statistical package SPSS v.18 (SPSS Inc.,Chicago, IL, USA). The bias was assessedstatistically as the mean of the differencescompared with zero. The hypothesis of zerobias was examined by the nonparametric testof Wilcoxon. The 99% limits of agreement(mean of the difference ±3 S.D. of thedifference) were also calculated. This type ofanalysis simplifies the assessment of the levelof agreement between techniques, spot outliersand detection of eventual trends.

RESULTS

Among the 560 recruited infants(corresponding to 1120 eyes), 270 (48,2%)were girls and 290 (51.8%) were boys. Theaverage child age at presentation was 4.3 ± 1.7years.

Table 1, below summarizes the mean,standard deviation and range of M, J0 and J45

components of the orthogonal functions





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obtained with the autorefractor KW-2000(AKW) and retinoscopic refraction (RR).These values show that the autorefractorAKW reads more positive or less negative forM and J45, conversely, more negative or lesspositive for J0.

Using AKW, the mean recorded spherevalue was +1.89 diopters (range -13.50 to+10.25) and the mean sphere value recordedwith RR was +1.22 diopters (range -13.50 to+8.50). The mean difference was +0.67 withstatistical significance (p <0.001).

Table 2, below displays the meandifference, the level of statistical significanceas well as the limits of agreement betweenAKW and RR. The difference found for the Mcomponent (+0 .68) was sta tisticallysignificant, and similar to the sphere value,meaning that it should be inputted to thesphere value. We divided the results in twogroups: aged 3-6 and 7-10 years old and wedidn't find any difference on the M component(p <0.001).

The Bland–Altman plots of thedifferences between AKW and RRmeasurements are represented on Figure 1,next page. This analysis shows the detectionof any trend in difference variability as afunction of the mean value to be measured.

DISCUSSION:

So far, several studies have usedautorefractors on children, but none has usedthe table mounted autorefkeratometer KowaKW-2000 (AKW) so far. The current studyshowed that AKW was highly correlated withthe streak retinoscopy, but the sphere valueand spherical equivalent were significantlymore positive compared to that obtained byusing the retinoscopy (Tables 1 and 2). Wealso observed that AKW under-estimated J0

and overestimated J45 but with no statisticalsignificance (Tables 1 and 2).





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Since there was no significantdifference between the age groups (3-6 versus 7-10 years old), we canconclude that it is instrument and notan age related error.

Figure 1 (Gama et al): RIGHT-Scatter dot plot for the difference vsmean of autorefractor KW-2000(ARK) and retinoscopic refraction(RR) for M, J0 e J45 components (M, JO and J45 right, respectively).

For M the mean difference is +0,68(statistically significant), meanwhileis -0,23 for J0 and+0,30 for J45 (notstatistically significant)..

Full line- the mean difference for M,J0 e J45 components

Dashed lines- limits of 99%agreement for the mean difference ofM, J0 e J45 components





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Previous studies have found similarresults, which are shown on Table 3.Interestingly the difference on the spherevalue was not considered relevant by most ofthese authors, but we find it clinically

significant. While some authors used differentparameters, like the spherical equivalent toevaluate the astigmatism, we preferred a morereliable method like the Fourier analysis.Nevertheless, the difference found on the





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cylinders power was not significant in most ofthe studies as it occurred in the present study.

Oral et al., Prabakaran et al., Paff et al.,Steele et al. and Iuorno et al. found nodifference on the sphere value or sphericalequivalent (3,5,10,22,23). In contrast, therewas an overestimation on the sphere value orspherical equivalent by the autorefractor thatwas also assessed by Cordonnier et al., Gole etal., Harvey et al., Salvesen and Køhler andRotsos et al that was not mentioned on thediscussion of these studies (1,2,6,11,24). Thisoverestimation can be as high as +0.70 D anddoesn’t seem to be instrument related since itappears either with table mounted refractors(Nidek AR-1000®, Topcon RMA-3000®) orwith Retinomax® (Cordonnier et al. andHarvey et al.).

Can this overestimation of the sphere(more positive value by the autorefractor) beexplained by a different procedure onobtaining cycloplegia? The method we usedwas similar to the ones described on Table 3,therefore the difference found on the spheremeasurement doesn’t seem to be related withit. Even if it was, how could we explain this“more positive” value, of the sphere,measured before the retinoscopy was made?

Could these findings be attributed to avariance induced by a larger pupil? Miller et aldescribe the paths of illumination andobservation of the automated refractor aspassing separately through different portionsof the patient’s pupil to avoid cornealreflection noise. A variation of patient’s eye’soptics across different parts of the pupil like aspherical aberration, a crystalline lens tilt orabrupt changes in corneal power could beresponsible for an inaccurate measurement bythe autorefractor (25). Buehren et al found a

correlation between the changes of cornealsurface and pupil size. The total of aberrationsof the eye increased significantly for pupilsizes of 5-6mm and was not significant forpupil sizes of 2.5 and 3mm (26). These resultssuggest that the pupil diameter can influencethe refraction value. In our study we didn’tanalyse the pupil diameter, so we can’tevaluate its contribution on the determinationof the sphere value. Even though Buehren et aldidn’t include children, future research shouldaddress corneal topography or aberrometry onthe evaluation of children’s refraction.

The present study addresses the validityof the table mounted autorefkeratometer KowaKW-2000 on the evaluation of children’srefraction after cycloplegia. It shouldn’treplace retinoscopy, still the gold standard, butlike others table mounted autorefractors, hasshown its value on the evaluation of children’srefraction between 3 and 10 years of age. Newdevices that work without cycloplegia havebeen developed but their role is still unsettled.

An overestimation of the sphere valueof +0.68 D on cycloplegic refraction was theerror found with this instrument. Since adifference of the evaluation of the spherevalue has been detected on several devices,our advice is to assess it on the autorefractorone is using when performing cycloplegicrefraction on children.

CONCLUSIONS

In conclusion our study shows that thetable mounted autorefkeratometer Kowa KW-2000 can be applied to children as aninstrument for cycloplegic refraction.

Before prescribing glasses, however,one should be cautious about sphere valuegiven by the autorefractors either table





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mounted or hand held.

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1. Salvesen S, Køhler M: Automatedrefraction. A comparative study of automatedrefraction with the Nidek AR-1000autorefractor and retino scop y. ActaOphthalmol 1991;69(3):342-6.2. Harvey AM, Miller JM, Wagner LK, et al:R e p r o d u c i b i l i t y a n d a c c u r a c y o fmeasurements with a hand held autorefractorin children. Br J Ophthalmol 1997;81:941-948.3. Prabakaran S, Dirani M, Chia A, et al:Cycloplegic refraction in preschool children:comparisons between the hand-heldautorefractor, table-mounted autorefractor andretinoscopy. Ophthalmic Physiol Opt.2009;29(4):422-6. 4. Zandnik K , Mutti DO, Adams AJ: Therepeatability of measurements of ocularcomponents. Invest Ophthalmol Vis Sci1992;33:2325-33.5. Steele G, Ireland D, Block S: Cycloplegicautorefraction results in pre-schoolchildren using the Nikon Retinomax Plus andthe Welch Allyn SureSight. Optom Vis Sci.2003;80(8):573-7.6. Gole GA, Schluter PJ, Hall J, et al:Comparison of the Retinomaxautorefractorwith hand-held retinoscopy in 1-year-oldi n f a n t s . C l i n E x p O p h t h a l m o l .2003;31(4):341-7.7. Isenberg SJ, Del Signore M, Madani-BeckerG: Use of the HARK autorefractor in children.Am J Ophthalmol. 2001;131(4):438-41.8. Kulp MT; Vision in Preschoolers StudyGroup. Findings from the Vision inPreschoolers (VIP) Study. Optom Vis Sci.2009 Jun;86(6):619-23. 9. Schmidt P, Maguire M, Dobson V, et al:

Vision in Preschoolers Study Group.Comparison of preschool vision screeningtests as administered by licensed eye careprofessionals in the Vision In PreschoolersStudy. Ophthalmology. 2004;111(4):637-50.10. Oral Y, Gunaydin N, Ozgur O, et al: AComparison of DifferentAutorefractors WithRetinoscopy in Children . J PediatrOphthalmol Strabismus 2012; 49(6):370-7.11. Cordonnier M, Dramaix M, Kallay O, etal: How accurate is the hand-held refractorRetinomax(R) in measuring cycloplegicrefraction: a further evaluation. Strabismus.1998;6(3):133-142. 12. Rosenfield M, Chiu NN: Repeatability ofsubjective and objective refraction. OptomVis Sci. 1995;72:577-9.13. Egashira SM, Kish LL, Twelker JD, et al:Comparison of cyclopentolate versustropicamide cycloplegia in children. OptomVis Sci. 1993;70(12):1019-26.14. Gadioux-Maden F, Lelez ML, Sellami L,et al: Influence de l’instillation de 2 ou 3 goutsde cyclopentolate 0,5% sur la refraction del’énfant caucasien non strabique. J FrOphthalmol 2008;31(1):51-515. Bullimore MA, Fusaro RE, Adams CW:The repeatability of automated and clinicianrefraction. Optom Vis Sci 1998;75:617-22.16. Thibos LN, Wheeker W, Horner D: Powervectors: an application of Fourier analysis tothe description and statistical analysis ofrefractive error. Optom Vis Sci 1997;74:367-75.17. Jorge J, Queirós A, Almeida JM, ParafitaM: Retinoscopy/autorefraction: which is thebest starting point for a noncyclopleegicrefraction? Optom Vis Sci 2005;82:64-8.18. Jorge J, Queiros A, González-Méijome J,et al: The influence of cycloplegia in objectiverefraction. Ophthalmic Physiol Opt.





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2005;25(4):340-5.19. Zandnik K, Mutti DO, Bullimore MA:Use of statistics for comparing twomeasurement methods. Optom Vis Sci1994;71:539-41.20. Bland JM, Altman DG: Comparingmethods of measurement: why plottingdifference against standard method ismisleading. Lancet. 1995;346:1085-7.21. Bland JM, Altman DG: Statistical methodsfor assessing agreement between two methodso f c l i n i c a l m e a s u r e m e n t . L a n c e t1986;327:307-10.22. Paff T, Oudesluys-Murphy AM,Wolterbeek R, et al: Screening for refractiveerrors in children: The plusoptiX S08 and theRetinomax K-plus2 performed by a layscreener compared to cycloplegic retinoscopy.J AAPOS. 2010; 14(6):478-83.

23. Iuorno JD, Grant WD, Noël LP. Clinicalc o m p a r i so n o f t h e W elch A l ly nSureSighthandheld autorefractor versuscycloplegic autorefraction and retinoscopicrefraction. J AAPOS. 2004;8(2):123-7. 24. Rotsos T, Grigoriou D, Kokkolaki A, et al:A comparison of manifest refractions,cycloplegic refractions and retinoscopy on theRMA-3000 autorefractometer in children aged3 to 15 years. Clin Ophthalmol. 2009; 3:429–431. 25. Miller M, Thall EH, Atebara NH:Ophthalmic instrumentation in ophthalmologyIn Ophthalmology. Yanoff M, Duker JS.Mosby-Elsevier; Philadelphia: 2009: 77-95.26. Buehren T, Collins MJ, Carney L: Cornealaberrations and reading. Optom Vis Sci2003;80(2):159-166.

Binocular Vision & Strabology Co rneal To pography Analysis in Establishing the P atho physiologic FOURTH Quarter of 2013

Quarterly Simm s Rom ano’s© Me chanism of Cyclic Brown’s Syndrom e Strabism us. A C ase Report Volume 28 (No.4)

A Medical Scientif ic ePeriodical D. Somer, MD and K. Budak, MD PAGES 238-243

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Case Report

Corneal Topography Analysis in Establishing thePathophysiologic Mechanism of Cyclic Brown’sSyndrome Strabismus. A Case Report

DENIZ SOMER, M.D. and KORAY BUDAK, M.D.

from Ankara Education and Research Hospital, Department of Ophthalmology, Ankara, Turkey

ABSTRACT: Purpose: To evaluate the responsible pathophysiological mechanism in a 15year old patient with acquired Brown’s Syndrome presenting with cyclic characteristics.

Methods: In addition to a full orthoptic assessment, magnetic resonance imaging (MRI)of the orbit, corneal topography and computerized videokeratography data analysis during thediplopic period, during resolution and following betamethasone injection into the trochlearregion were accomplished.

Results: The MRI scan demonstrated enlargement of the tendon-trochlea complex that wassimilar during the diplopic episode and resolution. The tendon-trochlea complex revealedhyperintensity on T1 weighted sagittal images. At the time of resolution topographicexamination revealed steepening of the 55 degree meridian. The patient received an injection ofdepot betamethasone into the trochlear region. Compared to the period of spontaneousresolution, a steeper 55 degree meridian was demonstrated on corneal topography followingsteroid injection. The patient was symptom free for more than a year after steroid injection.

Conclusion: The topographical findings and the relief of symptoms after steroid injectionsuggests a vascular etiology for the condition of Brown’s Syndrome in this particular case.

Received for consideration September 8, 2013; accepted for publication October 10, 2013

Competing interests: This study has been carried out with no financial and material support ofany organization.

Approval of the study was obtained from the institutional review board and informed consentwas gained from patient’s family conforming to all local laws and principles of the Declarationof Helsinki.

Correspondence: Deniz Somer, M.D., email: [email protected]





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INTRODUCTION

Of the various subcategories, theacquired and intermittent forms of Brown’sSyndrome have apparently been ofinflammatory origin, with the area of trochleabeing the focus of that inflammation (1,2). Inthis form of Brown’s Syndrome, the tendon isintermittently prevented from passing throughtrochlea. The clinical picture can alternatebetween Brown’s Syndrome and superioroblique muscle palsy depending on thedirection in which the tendon movementthrough the trochlea is impeded (3).Conditions associated with this processinclude sinusitis, trauma to the orbit,rheumatoid arthritis and periocular surgery.

The objec t of the presentcommunication is to evaluate the responsiblepathophysiologic mechanism in a patient withacquired Brown’s Syndrome presenting withcyclic characteristics.

CASE REPORT

A 15 year old boy experiencing verticaldiplopia that occurred upon waking in themorning, was referred to our clinic. Verticaldiplopia was more evident on upgaze. Aspontaneous resolution occurred within 4-5hours or the diplopia could then be overcomeby attempted forced elevation in adductionwhile digitally pressing over the righttrochlea. The, same but a shorter lasting,symptomatic picture appeared following a nap(Figures 1a and 1b, see next page, ).

Limitation of elevation was first elicitedat the age of 3.5 and the symptoms and signsof the cyclic phase have since remained staticand regular. The past medical history wasnegative except for a prolonged episode ofipsilateral maxillary sinusitis.

In addition to a full orthoptic

assessment, magnetic resonance imaging(MRI) of the orbit and corneal topographywere performed using the EyeSys CornealAnalysis System™ [Version 3.2 (ECAS™)](EyeSys Technologies, Inc., Houston, TX),during the diplopic period and duringresolution in the afternoon. Computerizedvideokeratography data analysis includedaxial difference and refractive power maps.Vision at the time was OD 20/200 and OS20/20. Cycloplegic refraction revealed –5.50Cyl x 75 OD and + .25S + .50Cyl x 90 OS. Asimilar enlargement of the tendon-trochleacomplex was demonstrated by the MRI scanduring the diplopic episode and resolution.The tendon-trochlea complex revealedhyperintensity on T1 weighted sagittal images(Figure 2, below).

Figure 2 (Somer & Budak): MRI scan: Theincrease in signal intensity in the superioroblique tendon-trochlea complex isdemonstrated on T1 weighted sagittal images.




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Figure 1a (Top image) (Somer & Budak): Motility examination during diplopic period.

1b (Bottom Image). Motility examination during period of spontaneous resolution.




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Afternoon topographic examinationrevealed steepening of the 55° meridian(Figure 3a, below). The boy received aninjection of depot betamethasone into thetrochlear region. The steepening of the 55°meridian on corneal topography persisted aftersteroid injection (Figure 3b, next page).Compared to the period of spontaneousresolution, a steeper 55° meridian wasdemonstrated.

Hard contact lens trial smoothened thecorneal surface and the patient achieved 20/50vision. The patient was symptom free formore than a year after steroid injection.

DISCUSSION OF RESULTS:

The function of trochlea is to redirectthe superior oblique tendon so that it pulls in

Figure 3a below (Somer & Budak): Central steepening on the 50-55° axis in the differencemap during spontaneous resolution of restriction. Figure 3b, next page The difference mapafter steroid injection: cornea became steeper on the 55° axis corresponding to a greaterresolution of restriction.




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anterior direction along a line approximately55 degree nasal to the sagittal plane.Steepening of the 55 degree meridian oncorneal topography suggested release of aformer trochlear compression onto thecorresponding site. A n inte rmitte ntcompression of trochlea onto cornea suggestsa vascular aetiology for the condition ofBrown’s Syndrome in this case. Local edemacreated by possible vascular dilatation of thevessels in the highly vascular sheath of theintratrochlear portion of the tendon mighthave lead to restricted passage of the tendonthrough trochlea on an intermittent basis andthus have produced Brown’s Syndrome.Accompanying fluid accumulation anddistension of the bursa-like space described byHelveston and co-workers (4), could add tothe trochlear compression that accounted for

the trochlear compression demonstrated oncorneal topography.

The therapeutic response to localsteroid injection and topographic analysis onemonth after steroid injection support the viewthat an inflammatory process is responsible,with the area of the trochlea being the focus ofthat inflammation. Compared to the period ofspontaneous resolution, a steeper 55° meridiancorresponding to a greater resolution ofrestriction was demonstrated on cornealtopography following steroid injection.Establishment of full ocular motility persistedfor more than a year.

The increase in signal intensitydemonstrated on T1 weighted sagittal imagesmay also verify the existence of inflammation,edema in the corresponding area or fluid




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accumulation in the bursa-like space.However, there was a similar enlargement ofthe tendon-trochlea complex during thediplopic episode and resolution and theincrease in signal intensity could not beconfirmed on the T2 weighted images. MRIscanning does not seem to providecomplementary info rma tion o n th epathological process encountered in this case.

It is difficult to explain the regularfashion of the disorder. Restriction to the freepassage might arise as a consequence of fluidaccumulation and/or stretching of the superioroblique tendon with Bell’s phenomenonduring sleep. Free passage might be re-established as the edema fluid is absorbedwhile the patient is in upright position andafter the muscle tendon exceeds thenarrowing within the trochlea with a forcedadduction or a massage over the region. Longtime stretching of the cornea producedirregular astigmatism and resulted inamblyopia in the long term.

An acquired Brown’s Syndromepresenting with cyclic characteristics was firstreported by Can and co-workers (5). Manifestin the morning as the patient wakes up,resolving spontaneously within hours andreappearing following a nap, the pattern of thedeviation most resembles our own. A non-contributory past medical history except for along standing ipsilateral maxillary sinusitissupports the view that an inflammatoryprocess was again responsible.

CONCLUSION

In this case, the concept of anintermittent trochlear compression caused byvascular etiology remains a viable theorybased on the evidence assembled. The highlyvascular sheath of the intratrochlear portion ofthe superior oblique tendon may create the

anatomic basis for vascular dilatation, edemaor fluid accumulation in the bursa-like spacebetween the vascular sheath and the trochlearsaddle. The previously introduced concepts ofstenosing tenosnovitis (1,2) or remnants ofembryological trabeculae (6) as the etiologyof Brown’s Syndrome seem quite improbableto explain the intermittent troch learcompression observed in this case.

REFERENCES

1. Wright KW, Silverstein D, Marrone AC,Smith RE. Acquired inflammatory superioroblique tendon sheath syndrome; aclinicopathologic study. Arch Ophthalmol1982; 100:1752-1754.2. Sandford-Smith JH. Superior obliquetendon sheath syndrome. Br J Ophthalmol1975; 59: 385- 386.3 . Wilson EM, Eutis SH Jr, Parks MM.Brown’s syndrome. Surv Ophthalmol 1989;34:153-172.4. Helveston EM, Merriam WW, Ellis FD,Shellhamer RH, Gosling CG. The trochlea: Astudy of the anatomy and physiology.Ophthalmology 1982; 89:124-133.5. Can I, Yarangümeli A, Kural G. Brown’ssyndrome with cyclic characteristic: Casereport and review of physiopathologicmechanism. J Pediatr OphthalmolStrabismus 1995; 32:243-247.6. Sevel D. Brown’s syndrome- A possibleetiology explained embryologically. J PediatrOphthalmol Strabismus 1981; 18:26-31.

Binocular V ision & Strabology ABSTRACTS FOURTH Quarter of 2013

Quarterly, S imm s-Rom ano’s© Volum e 28 (No 4)

A Medical Scientific e-Periodical Pages 244-247

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Vision / Visual Acuity / Amblyopia

Assessment of OLED Displays for VisionResearch. Cooper EA, Jiang H, Vildavski V,Farrell JE, Norcia AM. J Vision 2013; 18:12Article 16. [Authors Abstract Condensed]

... With cathode-ray tubes (CRTs) becomingvirtually unavailable on the commercial market, it isuseful to determine the characteristics of newlyavailable displays based on organic light emittingdiode (OLED) panels ... the Sony Trimaster EM-BVM-F250 and PVM-2541. The results show that theOLED displays have large contrast ratios, wide colorgamuts, and precise, well-behaved temporalresponses. Correct adjustment of the settings on bothmodels produced luminance nonlinearities that werewell predicted by a power function (“gammacorrection”). Both displays have adjustable pixelindependence and can be set to have little to no spatialpixel interactions. OLED displays appear to be asuitable, or even preferable, option for many visionresearch applications.

Fast Development of Global Motion Processing inHuman Infants. Blumenthal EJ, Bosworth RG,Dobkins KR. J Vis 2013; 13: 13 [Authors Abstractcondensed]

Results revealed remarkably stable globalmotion sensitivity between 3 and 7 months of age, aswell as between infancy and adulthood. These resultssuggest that the mechanisms underlying global motionprocessing develop to an adult-like state very quickly.

Compliance with Occlusion Therapy forChildhood Amblyopia. Wallace MP, Stewart CE,Moseley MJ, Stephens DA, Fielder A. InvestOphthalmol Vis Sci 2013; July 23. Authors AbstractCondensed]

Methods: ...to dose for 6 hrs/day (MOTAS) orrandomized to 6 or 12 hrs/day (ROTAS). Dose wasmonitored continuously using an Occlusion DoseMonitor (OCM). Results: ... Mean compliance was44%, mean proportion of day with no patch worn was42%. ... lower (39%) on weekends. ...dosing at all(52% vs. 60%, p=0.028) ... lower ... with prolongedtreatment duration (p<0.001). ... Conclusions: ... thatcompliance with patching treatment averages less than50%. ...

Impaired Mechanisms of Suppression inAmblyopia. Yang E, Silver M, Levi D. J VisionJuly 24 2013; 13. [Authors Conclusions]

The magnitude of surround suppression and toa weaker extent, interocular suppression waspredictive of the severity of amblyopia, as indexed byinterocular differences in acuity. Our results areconsistent with physiological evidence that amblyopiais associated with heightened GABAergic inhibitionand that surround and interocular suppression, but notoverlay suppression, are most likely mediated byintracortical inhibition.

Perceptual Learning in Children with VisualImpairment Improves Near Visual Acuity.Huurneman B, Boonstra FN, Cox RFA, van RensG, Cillessen AHN. Invest Ophthalmol Vis Sci2013; 54: 6208-6216 [from IOVS mailer September23, 2013]

Perceptual learning induces not only specificlearning effects on a training task, but learning effectstransfer to improvements in single and crowded nearvisual acuity in children with visual impairment.

Visual Acuity Deficits in Children with Nystagmueand Down Syndrome. Felius J, Beauchamp CL,Stager Sr. DR. Am J Ophthalmol. Available onlineSeptember 28, 2013 [Authors Conclusions]

There was a small mean difference betweenthe measured visual acuity deficit and the predictionof the nystagmus model. While other factors alsocontribute to visual acuity loss in Down syndrome,nystagmus alone could account for most of the visualacuity deficit in these children.

Compliance with Occlusion Therapy forChildhood Amblyopia. Wallace MP, Stewart CE,Moseley MJ, Stephens DA, Fielder AR for theMonitored Occlusion Treatment Amblyopia Study(MOTAS) and Randomized Occlusion TreatmentAmblyopia Study (ROTAS) Cooperatives. InvestOphthalmol Vis Sci 2013; 54:6158-6166. [fromIVOS Mailer September 30, 2013]

Compliance with occlusion treatment foramblyopia reduces as time in followup increases.However, this is not caused by a decrease in the dailydose rate, but an increase in the percentage of days




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that an individual receives no dose at all (no patchdays).

Ocular Aberrations in Amblyopic Children. SaudiJ Ophthalmol - Online July 16, 2013. Aldebasi HI[Author Conclusion]

Lower order aberrations remain the majorfactor that affect retinal image quality and henceamblyopia development especially in ametropic eyes.This can be corrected optically. Studying HOA profilein amblyopic eyes failed to explain why refractoryamblyopia does not respond to orthoptic treatments.This outcome indicates that theories of centralproblems in image processing and binocularinteraction are likely the main cause of refractiveamblyopia.

Risk Factors for Amblyopia in the Vision inPreschoolers Study. Pascual M, Huang J, MaguireMG et al for the Vision in Preschoolers (VIP)Study Group. Ophthalmology. Available onlineOctober 18, 2013. [Authors Conclusions]

Strabismus and significant refractive errorswere risk factors for unilateral amblyopia. Bilateralastigmatism and bilateral hyperopia were risk factorsfor bilateral amblyopia. Despite differences inselection of the study population, these resultsvalidated the findings from the Multi-Ethnic PediatricEye Disease Study and Baltimore Pediatric EyeDisease Study.

The Effects of Blur and Eccentric Viewing onAdult Acuity for Pediatric Tests: Implications forAmblyopia Detection. Formankiewiza MA, WaughSJ. Invest Ophthalmol Vis Sci 2013; 54:6934-6943.[from IOVS mailer October 28, 2013]

Dioptric blur and eccentric viewing wereimposed on the normal visual system to mimicanisometropic and strabismic amblyopia. The resultssuggest that crowded charts might be of limited use inthe detection of anisometropic amblyopia but shouldbe valuable in the detection of strabismic amblyopia.

The Regional Extent of Suppression: StrabismicsVersus Nonstrabismics. Babu, RJ, Clavagnier SR,Bobier W, Thompson B, Hess RF. InvestOphthalmol Vis Sci 2013; 54:6585-6593. [fromIOVS-Mailer October 14, 2013]

A novel method for measuring the degree andextent of suppression scotomata. Suppression instrabismic and anisometropic amblyopia are similar,both are diffuse, selective for central vision, anddirectly related to the degree of amblyopia.

Binocular Vision / 3D / Stereopsis

Clinical Evaluation of Stereopsis. Westheimer G.Vision Res 2013; 90:38-42. [Authors Abstract]

Principles of the design and administration ofclinical stereopsis tests are outlined. Once thepresence of the distinct sense of the third dimensionby binocular vision alone and without help frommonocular cues has been established in a patient, theexamination can proceed to the measurement ofstereoscopic acuity. Best results are obtained withhigh-contrast, sharp, well articulated and uncrowdedelements from easily recognized target sets, displayedwith no time constraints. Polarization is the preferredmethod of right/left eye separation; time-sharing at aminimum of 60 Hz on computer displays withcounterphase occluding goggles is a feasibleprocedure. Random-dot stereograms are problematicbecause not all observers can disentagle the coherentglobal disparity on a first view. (Division ofNeurobiology, University of California, Berkeley CA94720-3200)

Three Dimensional Viewing

Cross-Cultural Effects on the Assumed LightSource Direction: Evidence from English andHebrew Readers. Andrews B, Aisenberg D,d’Avossa G, Sapir A. Trans Vis Sci Technol 2013.[Authors Abstract condensed]

When judging the 3D shape of a shadedimage, observers generally assume that the lightsource is placed above and to the left. This leftwardbias has been attributed to experiential factors shapedby the observers’ handedness or hemisphericdominance. ... we assessed the contribution of culturalfactors affecting the way visual scenes are customarilyinspected, in determining the assumed light sourcedirection., Left- and right-handed first languageEnglish and Hebrew participants, who read and writefrom left to right and from right to left, respectively,judged the relative depth of the central hexagonsurrounded by six shaded hexagons. We found a left




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bias in first language English participants, but asignificantly smaller one in Hebrew participants.

The Effect of Age upon the Perception of 3-DShape from Motion. Norman JF, Cheeseman JR,Pyles J, Baxter M, Thomason KE, Calloway AB.Vision Res 2013; Online 21 October, 2013.[Highlights from Science Direct.]

• We evaluated the effects of aging upon the ability toperceive 3-D shape from motion.

• Older adults were less able to judge shape whentemporal correspondence was reduced.

• Middle-aged adults’ performance was as high as thatof younger adults.

• Participants’ shape discrimination abilities areapparently related to GABA concentration in V1.

Strabismus Pathophysiology

Why Do Only Some Hyperopes BecomeStrabismic? Babinsky E, Candy TW. InvestOphthalmol Vis Sci 2013; 54:4941-4955. [AuthorsAbstract]

Children with hyperopia greater than +3.5diopters (D) are at increased risk for developingrefractive esotropia. However, only approximately20% of these hyperopes develop strabismus. Thisreview provides a systematic theoretical analysis ofthe accommodation and vergence oculomotor systemswith a view to understanding factors that could eitherprotect a hyperopic individual or precipitate astrabismus. The goal is to consider factors that maypredict refractive esotropia in an individual andtherefore help identify the subset of hyperopes whoare at the highest risk for this strabismus, warrantingthe most consideration in a preventive effort. (ErinBabinsky. [email protected])

Changes in the Amygdala Produced by ViewingStrabismic Eyes. Berberat J, Jaggi GP, Wang FM,Remonda L, Killer HE. Ophthalmology 2013;120:2125-2129 [Authors Abstract condensed]

Purpose: The aim of this study was to look forthe response to strabismus images in the limbicnetwork (amygdala, hippocampus, parahippocampus)of healthy volunteers and to compare it with their

reaction to viewing normal eyes. Methods:Functional magnetic resonance imaging data andblood oxygen level-dependent signal changes wereanalyzed using the BrainVoyager QX softwarepackage (Brain Innovation, Maastricht, TheNetherlands) Results: Strabismus images led tosignificant activation of the amygdala, hippocampus,parahippocampal, and fusiform gyri in 30 of 31subjects compared with normal eye images, indicating[in contrast] a negative emotional response. Figure 2Legend: Functional magnetic resonance imaging scansshowing a strabismus patient versus a normalindividual. Statistically significant activation (P<0.05)by pooled data (n=31) demonstrating strong emotionalreaction in the left amygdala and fusiform gyri whencomparing strabismus images with those from normaleyes. FDR=false discovery rate. Conclusions: ThesefMRI results confirm that strabismus influencesorganically not only the patient with nonparallel eyesbut also observers. Treatment of strabismus thereforechanges [even] the interpersonal dynamic for patientswith strabismus on a demonstrable organic basis.

Strabismus Chemo-Surgery

Bupivacaine Injection Remodels ExtraocularMuscles and Corrects Comitant Strabismus. MillerJM, Scott AB, Danh KK, Strasser D, Sane M.Ophthalmology 2013; 120:2733-2740. [AuthorsAbstract condensed]

Methods: Nineteen patients with esotropiareceived bupivacaine injections in the lateral rectusmuscle, and 12 patients with exotropia receivedbupivacaine injections in the medial rectus. Sixteen ofthese, with large strabismus angles, also receivedbotulinum type A toxin injections in the antagonistmuscle at the same treatment session. A secondtreatment was given to 13 patients who has residualstrabismus after the first treatment. Results: At anaverage of 15.3 months after the final treatment,original misalignment was reduced by 10.5 prismdiopters with residual deviations of 10 prism dioptersor less in 53% of patients. A single treatment withbupivacaine alone reduce misalignment at 11.3months by 4.7 prism diopters with residual deviationsof 10 prism diopters or less in 50% of patients.Alignment corrections were remarkably stable overfollowups for as long as 3 years. Six months after




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bupivacaine injection, muscle volume had increasedby 6.6%, and maximum cross-sectional area hadincreased by 8.5%, gradually relaxing towardpretreatment values thereafter. Computer modelingwith Orbit 1.8 (Eidactics, San Francisco CA)suggested that changes in agonist and antagonistmuscle lengths were responsible for the enduringchanges in eye alignment. Conclusions:Bupivacaine injection alone or together withbotulinum toxin injection in the antagonist muscleimproves binocular eye alignment in comitanthorizontal strabismus by inducing changes inrectus muscle structure and length.

Strabismus Surgery

3 Horizontal Muscle Surgery Shown Effective inLarge Angle Infantile Esotropia. OphthalmologyAugust 2013. [from AAO Academy Express]

This retrospective review included 194consecutive patients who underwent 3 horizontalmuscle surgery by the same surgeon for primarycorrection of large angle infantile esotropia. At amean followup of 4.5 years, 62.4% were successfullyaligned at the last followup visit or prior toreoperation, and 79.4% were successfully aligned at 8weeks postop. An exotropic drift occurred more oftenthan an esotropic drift over time, especially in patientswith smaller preoperative esodeviations. The authorssuggest reserving 3 muscle surgery to largerpresenting angles of esodevation to decrease the rateof late overcorrection.

Fibrin Glue Reduces Operating Time,Inflammation in Strabismus Surgery.Ophthalmology, September 2013. [from AAOsAcademy Express]

Investigators searched the PubMed andCochrane Library databases, comparing fibrin glue tostandard sutures for the closure of limbal conjunctivalincisions after strabismus surgery. They found lesspostoperative inflammation and shorter operatingtimes with glue, but it also resulted in a greaterpercentage of wounds that required followup repairwith sutures. Data included 68 incisions closed withfibrin glue and 74 with sutures. In three studies thatevaluated wound apposition, 2 of 50 eyes (4 percent)initially closed with fibrin glue required followupsurgical repair. In two studies that evaluated surgical

time, fibrin glue required one to five fewer minutes inone study and 55 percent less time (3.9 vs.8.4minutes) in the other.

Surgical Results of a Muscle TranspositionProcedure for Abducens Palsy without Tenotomyand Muscle Splitting. Muraki S, Nishida Y, OhjiM. 2013; 156:819-824 - check Science Direct forjournal title. [Authors Conclusions]

This procedure, which achieved the samecorrective results as other popular procedures, issimple to perform because it requires only a suturefrom the muscle to sclera. Tenotomy or splitting ofthe transposed muscles is unnecessary.

Abstracts edited by P.E. Romano, MD, MSO. Abstracts are

selected on the basis of interest to our readers. To avoid

duplication you will find none are from The American

Orthoptic Journal, The British Orthoptic Journal, The

Journal of the American Association for Pediatric

Ophthalmology and Strabismus, The Journal of Pediatric

Ophthalmology and Strabismus, or Strabismus, as most of our

readers already subscribe to and/or read them. Publication herein

does not constitute endorsement, recommendation or a validation

of author’s conclusions.

ERRATUM

Two authors were inadvertently omitted in anarticle in the last issue. The citation shouldread:

Functional Amblyopia andDeficient Binocular Vision asInitial Clinical Features inDuane’s Syndrome

Binocul Vis Strabolog Q SimmsRomano 2013; 28(3):176-180

Sekeroglu HT, Turan KE, Sevim DG, Sanac AS, Arslan U, Sener EM.

The journal regrets this error. (The citation inMedLine is correct)

Binocular V ision & Hyde Park Editorial ’B’LOG FOURTH Quarter of 2013

Strabology Quarterly S-r’s © Volum e 28 (No. 4) A Medical Scientific EYE e-Periodical Pages 248-256

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HYDE PARK EDITORIAL: The Editor's Soapbox, Sandbox & B'LOG(Prehistoric) Since 1985

3D Printing Everything: Products, weapons, also:Gravity; Flex screens for smart phones, keys, Lots ofData, An Ode in Praise of Knobs.

. Stereoscopic 3 Dimensional

depth perception binocular

vision remains the Acme,

Epitome and GOAL of all of

both (monocular) vision and

Binocular Vision. I t ’ s t h e

Very Foundation of Ego-

Centric Localization, Your

Very Own Cornerstone of

SPACE and your unique world for you, and for us, ALIVE in 3D.

EXTRACTED FROM OUR LOCAL NEWSPAPER -ed: Bio-printing.From the Summit Daily News November 6, 2013 by David Woodland. 3D Printing. TheAdvent of Bio-Printing. “Three-dimensional (3D) printing is an emerging technology that willalmost certainly revolutionize many aspects of our lives. These new, highly sophisticatedprinters essentially ‘print’ multiple layers of a compound such as metal or plastic, to construct3D objects. New machines are being developed that can print with increasing precision andefficiency, and new materials are being added to the list of ‘inks’ that the machines can print.The technology offers considerable benefits to manufacturers who can ‘print’ components usingminimal amounts of material, thereby eliminating the waste associated with conventionalmanufacturing practices. In fact, the European Space Agency has embraced the technology asa way to print ultra-light metal components for its aircraft and space vehicles. And as the costof 3D printers declines (some machines now cost only a few hundred dollars), they will becomea boon for hobbyists wishing to design and construct novel objects. On a darker note, nefarioususes are also possible, such as the recent construction of a working gun from printedcomponents. ...

“... in the biomedical field. At the basic research level, scientists have been able toconstruct 3D structures from protein that contain a series of ‘rooms’ in which individual bacteriacan be held. This allows researchers to study communication between bacteria under highlycontrolled conditions and is advancing our understanding of how bacterial resistance toantibiotics is transferred between individual bacteria. ...

“... One company is printing small strips of liver tissue that can be used to test new drugs



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for efficacy and toxicity. Other advancesinclude the printing of fitted componentsfor hearing aids, hip implant cups anddental crowns and for printed patient-specific surgical guides to assist duringsurgery. 3D printing has also been usedto create surgical splints. For example, aprinted splint was used to save the life ofa baby born with a condition calledtracheobronchomalacia, which results inthe lack of support for the trachea. Thesplint was custom-printed for the baby’sthroat and used to guide the developmentof the baby’s trachea.

“Perhaps one of the most excitingpromises of 3D printing is the creation ofbrand new organs for transplant patients.This new technology will allow designerorgans to be created using theindividual’s own cells, therebypotentially eliminating the need to find adonor match. The basic idea is to printlayers of live cells along with a biomatrixthat supports the structure. The printercan be programmed to print a variety ofcells in each layer, potentiallyconstructing a fully functioning organ. ...including the ability to print a 3Dvasculature directly into the organ duringconstruction. The current challenge is toprevent ‘printed’ blood vessels fromcollapsing after printing. One potentialsolution is to print a supporting materialin the blood vessels that can be meltedaway under the right conditions. Such anapproach is currently under developmentby doctors at Harvard University. Itshould also be noted that the body has theability to spontaneously grow new bloodvessels into transplanted organ, perhapsreducing the need to print them all that



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3D Printer Products

extensively in the first place.

“While we are still many years away from truly printing vital internal organs ready fortransplantation, there have already been some amazing successes in printing bone- and cartilage-based structures. For example, just this year, researchers in Belgium printed a new jawbone fora woman. And cartilage-based structures, such as ears, have also been successfully printed. Forthose of you who are fans of the show Star Trek, you may remember the ‘replicator’ that wasused to produce all sorts of foods including cooked meals. At the time, the concept seemedridiculously futuristic. But maybe that future is already upon us. Time to print a Scotch on theRocks.” (L. “Woody” Woodland, PhD, is the Chief Scientific Officer of Silverthorne-basedKeystone Symposia on Molecular and Cellular Biology, a non-profit dedicated to accelerating



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life science discovery byconvening internationallyrenowned researchconferences in SummitCounty and worldwide.Woody can be reached [email protected].)

Below: 3D movies

p.50-55 Novermber 2013Popular Mechanics.com

From Popular Mechanics “Cinematech” November 13, 2013, by Steve Daly. OrbitalMechanics. How Gravity Simulates Free Floating in Space. “The new space thriller ‘Gravity’opens with an unbroken 12 minute shot of two astronauts installing a data-gathering device onthe Hubble Space Telescope. ... float in zero gravity while bantering, chasing a stray bolt, andmarveling at the sight of Earth far below. Then things quickly go very, very wrong. A



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catastrophic accident triggered by a debris field cripples the shuttle and sends the astronautspinwheeling into space, forcing them to improvise their own rescue mission. At the core of thistaut, 90 minute survival story are the physical facts of life in low Earth orbit. Thanks to acombination of mechanical ingenuity and breakthrough visual effects, weightlessness especiallyis conveyed with a sense of realism unmatched by any other space mission movie. And noprevious film has depended so heavily on computer-generated animation that looks as if it’s liveaction. In each of Gravity’s nerve jangling space walk sequences, only the heads inside thehelmets are real. The spacesuits and all background elements p including the Hubble, the shuttle,and the International Space Station - are rendered entirely in photo-realistic CG. ...

“... more than 500 people involved in both physical and CG trickery. .... The entire filmwas essentially reverse-engineered. ... The solution was a pioneering system called IRIS. A SanFrancisco company, Bot & Dolly, created it by ingeniously redeploying robotic arms originallydesigned for precision assembly line tasks such as automotive welding and painting. Instead ofairbrushes or blow torches, a quartet of IRIS rigs wielded cameras, lights, props, and even theactors in appropriate synchronization. ...

“... wire-rig harnesses that spun them upside down to simulate weightlessness. ... aplatform that moved along the studio ceiling and configured Bullock into various positions likea marionette’s. On-set puppeteers - their actual job title - supplemented preprogrammed moveswith joysticks to smooth out jerkiness. ... The results of all this wizardry is a movie filled withzero-gravity shots that set a formidable new standard. ... Cuaron hopes moviegoers with havea new appreciation of life after watching these spacewalkers defy death in so many ways.”



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Information Technology: Whiteboards:

From The Wall Street Journal October 31, 2013 “high Definition” by Farhad Manjoo. HighTech’s Secret Weapon: The White Board. “... app Evernote ... When the company moved lastyear into the Redwood City, Calif., building, it painted almost every surface with IdeaPaint, asubstance that makes walls amenable to dry-erase markers. Now most of the building is a canvasfor brainstorming, produce design, strategy war-gaming and, of course, doodles. ...

“... you might guess that the old-fashioned, hopelessly analog dry-erase marker would beout of place among such future folk. Yet Evernote, like pretty much every tech company I’veever visited, is in thrall to the whiteboard. Indeed, as technologically backward as they mayseem, whiteboards are to Silicon Valley what legal pads are to lawyers. ...

“... The whiteboard has three chief virtues: It’s fast. It’s easy to use. And it’s big. ...Unlike a computer or phone, the whiteboard is always on, fully charged, and it doesn’t requirethat people download, install and launch software to begin using it. ... This is in marked contrastto digital tools. ...

“...Steve Jobs - who certainly had a keen interest in the smallest of product details - wasan artist with the whiteboard. ... Sure, there are disadvantages to the whiteboard. ... It’s also noteasy to back up or search. ... Well, not until recently. At Evernote, the team usually snaps photosof every whiteboard session, shuffling them all off to the company’s app for long-term backup.Evernote also recognizes whiteboard text, allowing the documents to be searched. So there yougo: with a digital tweak, the analog whiteboard is unbeatable. ([email protected])




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Data: New problem. We have always had lots of data but until now, it

was not feasible to collect and save it. Now we can and do, and this is

the result:

next page: A memorial? To knobs. They are going too...



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ulusal akademİk aĞ ve bİlgİ merkezİ · binocular vision & strabology quarterly,...

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