www.eyeworld.org

The News Magazine of the American Society of Cataract and Refractive Surgery

“ Our goal as surgeons is clear, we should use technology that targets zero higher order aberrations, such as spherical aberration, in order toprovide patients with the best visualquality.”

Ret. Capt. Steven C. Schallhorn, M.D.

Customizing cataract andcorneal refractive surgery

CONTRIBUTORS

Y. Ralph Chu, M.D.Roger F. Steinert, M.D.Steven Dewey, M.D.Donald R. Nixon, M.D.Jack T. Holladay, M.D.Stephen Coleman, M.D.John Marshall, Ph.D. Steven C. Schallhorn, M.D. Colman R. Kraff, M.D.William J. Lahners, M.D.Rosa M. Braga-Mele, M.D.Eric D. Donnenfeld, M.D.Thomas W. Samuelson, M.D.William Trattler, M.D.Frank A. Bucci Jr., M.D.

Supported by a grant from AMO, Inc.

S U P P L E M E N T T O E Y E W O R L D — N O V E M B E R 2 0 0 7

November 2007

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PremiumRefractive IOLs Pages 10–15

Merging Femtosecond & Wavefront-Guided Laser TechnologiesPages 6–9

Next GenerationPhacoemulsificationPages 2–5

2 AAO New Orleans • Show Supplement — Customizing cataract and corneal refractive surgery

Signature’s fluidics combines the advantages of bothVenturi and peristaltic pumps in a single cassette

Get the best of both pumps

by Y. Ralph Chu, M.D.

Until recently, surgeons havelargely been forced tochoose between peristalticand Venturi pumps—andlive within the limitations

of the technology. The forte of Venturi, with its

fast, efficient vacuum, is cortexremoval and vitrectomy. However,Venturi’s always-on vacuum makesit easier to grab the capsule andcause a posterior capsule rupture.

Peristaltic pumps are ideal fornuclear fragmentation and epinu-clear cleanup, and they offer theadvantage of being able to sepa-rately control vacuum, flow rate,and rise time. Most anterior seg-ment surgeons have gravitatedtoward the safety and control ofthe peristaltic pumps.

The exciting thing about thenew WhiteStar Signature system(Advanced Medical Optics, AMO,Santa Ana, Calif.) is that it not onlyhas both pumps, but they are oper-ated with a single cassette. Thismakes switching back and forth,even on the fly and during a case,easy and immediate. It is even pos-sible to use both pumps at thesame time, making this a true com-bination system.

Pump choice can be pro-grammed by mode or sub-mode inadvance. Signature’s Venturi pumphas a maximum vacuum of 600 mmHg. The peristaltic pump has a maxi-mum flow rate of 60 cc/min, withmaximum vacuum of 650 mm Hg.

Even without the Venturi’s help,this peristaltic pump offers dramati-cally improved efficiency. It has theability to sense intraocular pressurechanges and react to a potentialsurge by reversing the pump andstepping down the vacuum within26 milliseconds (Figure 1). Theextreme stability of the anteriorchamber fluidic environment meansthat surgery proceeds very efficientlyeven in more complex cases.

Making the switchThere are many scenarios in whichthe ability to switch back and forthfrom peristaltic to Venturi during asingle cataract extraction makessense. In a typical procedure, Iwould perform the nuclear frag-mentation and removal with theperistaltic system, switch to Venturifor irrigation and aspiration, andremain with the Venturi pump forviscoelastic removal at the end ofthe case.

“ The extremestability of theanterior chamberfluidic environ-ment means thatsurgery proceedsvery efficientlyeven in morecomplex cases”

Y. Ralph Chu, M.D. I ntraoperative floppy iris syndrome (IFIS) creates a challenging environ-ment for cataract surgery. With this condition, there is significant poten-tial for iris sphincter damage, posterior capsular rupture, and other

complications. Patients may have a cosmetic deformity, increased post-opinflammation, and/or a poorer refractive result.

By following these steps, however, surgeons can successfully manageeven complicated IFIS cases: • History and physical: Patients who have ever taken Flomax (tamsulosin

hydrochloride, Boehringer Ingelheim GmbH, Germany) or similar agentsfor enlarged prostate should be considered at risk for IFIS.

• Pre-op medical therapy: We prescribe atropine b.i.d. for three daysbefore surgery to improve and maintain pupillary dilation. Just beforesurgery we give an intracameral injection of diluted, preservative-freeepinephrine (Shugarcaine, as described by Joel Shugar).

• Viscoelastic devices: A thick, cohesive viscoadaptive like Healon 5(sodium hyaluronate 2.3%, AMO) is almost essential because of its abili-ty to physically hold the iris open.

• Instrumentation: In severe cases, where the iris is very floppy and thepupil is very small, it may be necessary to mechanically hold the irisopen.

• Phaco incision: Make a clear corneal, limbal-based incision that is nottoo far posterior. The tunnel should be longer than usual to make it moredifficult for the iris to flop out through the wound.

• Phaco settings: A low-flow, low-vacuum setting will keep the viscoelas-tic in place and reduce turbulence inside the eye, which keeps the irismore stable. We use something we call the “Flomax setting” on theWhiteStar Signature system (AMO) Figure 1.

• Post-op: I have a low threshold for putting a suture in the eye to keepthe pressure stable and prevent the iris from flopping into the wound. Incase of iris damage, more anti-inflammatory medication may berequired; otherwise, the post-op course is normal.

Solutions for complicated IFIS cases

Preferred WhiteStar Signature Settings

Flow Rate VacuumNormal Phaco 36 cc/min 150-200 mm HgFlomax Setting 24 cc/min 100 mm Hg

Figure 1: The persistaltic pump has the abili-ty to sense intraocular pressure changes andreact to a potential surge by reversing thepump and stepping down the vacuum within26 milliseconds

As we gain further experiencewith Signature, we’ll be able toexplore other combinations of thetwo pump styles. Using bothpumps simultaneously, for exam-ple, would be a great option forepinuclear removal or for a casewith “sticky” cortex. If I can turnthat Venturi level down, I increasethe safety, but by adding it to theperistaltic pump action, I canincrease efficiency.

To my mind, the new dual-pump system makes WhiteStarSignature ideal for the refractivecataract surgeon. With the Venturipump we can achieve better, fastercortical cleanup without giving upthe peristaltic control. We can alsoreduce the risk of PCO and IOPspikes and, by reducing phaco ener-gy, restore vision more quickly aftersurgery.

Y. Ralph Chu, M.D., is the founder and med-ical director of Chu Vision Institute in Edina,Minn., and adjunct assistant professor of oph-thalmology at the University of Minnesota.Contact him at (952) 835-0965 or yrchu@chu-vision.com.

New transversal phaco technology blends lateral movementswith advanced longitudinal ultrasound for greater efficiency,safety and surgeon comfort

Making a lateral move

by Roger F. Steinert, M.D.

Micropulse technologyand other modulationsof phaco power havegreatly advanced thescience of ultrasound

delivery. Now, armed with a moresophisticated understanding of theseparate effects and interaction ofthe mechanical breakup of thenucleus (jackhammer effect) andcavitation, manufacturers havebegun to introduce new-generationphaco devices. Unique modes, suchas torsional and transversal ultra-sound, add to the capabilities oflongitudinal ultrasound.

In torsional phaco, the bent-tipneedle moves in a side-to-side oscil-lating movement, similar to a pen-dulum.

Transversal ultrasound is a newconcept that is being introducedin New Orleans during the annualmeeting of the American Academyof Ophthalmology (AAO). TheELLIPS Transversal Ultrasoundtechnology (Advanced MedicalOptics, AMO, Santa Ana, Calif.)allows the phaco tip to move inan elliptical fashion, blending theforward-and-back motion of longi-tudinal ultrasound with the side-to-side or transversal motion(Figure 1).

The primary advantages ofincorporating a lateral movementof the ultrasound tip are enhancedcutting power and followability.The lateral movements increasecutting efficiency by emulsifyinglens material in more than one

direction of movement.In addition, we see much better

followability of nuclear fragmentswith these approaches. In longitu-dinal phaco, the forward-and-backpunching or jackhammering is veryeffective at breaking up material,but it also repulses the nuclearmaterial with each punch, resultingin more trauma and a slower proce-dure as the surgeon tries to followthe repulsed fragments. Certainly,recent advancements in powermodulation and fluidics have gonea long way toward reducing theseconsequences, but adding a non-longitudinal motion should reduceenergy, thereby lessening trauma tothe eye.

A significant advantage oftransversal ultrasound is that itincorporates both longitudinal andtransversal modes simultaneously.The surgeon doesn’t have to switchback and forth between the twomodes as he or she might with tor-sional ultrasound.

This means that the WhiteStarmicropulse technology (AMO) canbe utilized throughout the proce-dure. Micropulsing provides fasterphaco with minimum power.Moreover, the WhiteStar Signaturesystem allows customizable pulse-shaping, with a pre-programmedmillisecond energy punch at thebeginning of each micropulse toaccelerate cavitation (Figure 2).

Another advantage of transver-sal ultrasound is that it can be per-formed with either a straight- or

bent-tip phaco needle, so that sur-geons who want the capabilities ofnew-generation phaco don’t neces-sarily have to make any techniquechanges. Torsional ultrasoundworks only with a Kelman-stylebent tip, which changes the sur-geon’s angle of approach and alsomakes it a little more challengingto maintain adequate suction.

Surgeon and patient benefitThe harder the nucleus, the moredramatic the improvements we willsee in efficiency and cutting abilityduring phacoemulsification.

I would anticipate advantagesfor the patient regardless of nucleardensity. Any time nucleus removalcan be accomplished with less tur-bulence and trauma to the eye, theresult is a clearer cornea with lessendothelial cell loss, for improvedoutcomes over both the short andlong term. Additionally, those rarebut significant complicationscaused by excessive trauma shoulddecrease.

WhiteStar Signature with ELLIPSTransversal Ultrasound gives cataractsurgeons a new set of tools that max-imize our ability to emulsify all typesof lens materials with minimal stresson the corneal endothelium andother ocular structures.

Roger F. Steinert, M.D., is a professor of oph-thalmology and biomedical engineering; direc-tor of cornea, refractive and cataract surgery;and vice chair of clinical ophthalmology at theUniversity of California-Irvine. Contact him at(949) 824-0327 or roger@drsteinert.com.

“ Another advan-tage of transversalultrasound is thatit can be performedwith either astraight- or bent-tip phaco needle,so that surgeonswho want the capabilities ofnew-generationphaco don’t neces-sarily have to makeany techniquechanges”

Roger F. Steinert, M.D.

Figure 1: Phaco tip with the ELLIPS Transversal Ultrasound tech-nology moves in an elliptical fashion, blending the forward-and-back motion of longitudinal ultrasound with the side-to-side ortransversal motion

Figure 2: Pulse-shaping can be customized with the Signature sys-tem, with a pre-programmed millisecond energy punch to acceleratecavitation at the beginning of each micropulse

Next Generation Phacoemulsification — Show Supplement • AAO New Orleans 3

4 AAO New Orleans • Show Supplement — Customizing cataract and corneal refractive surgery

To achieve the optimal refractive result, surgeonsmust use the best technology and techniques

Refractive lens exchangedemands precision

by Steven Dewey, M.D.

Intraoperatively, there is very lit-tle distinction between a refrac-tive lens exchange (RLE) and a“standard” cataract procedure.To consistently achieve the goal

of RLE, the real difference isn’t howthe procedure is performed, but theprecision with which it is executed.

Within this new paradigm ofrefractive lens exchange that is rap-idly becoming our 21st centurystandard for cataract surgery, thereare two important goals. The first isto avoid significant problems, suchas a ruptured capsule, torn iris,leaking incision, or other complica-tion that may not leave the patientin the best refractive conditionpost-op.

The second is to inflict theabsolute least amount of traumapossible during a routine case. Thatmeans using the minimum phacopower and minimum BSS and maxi-mizing the stability of the chamberthroughout the case. What was once“good enough” for restoring visionwith cataract surgery is not necessar-ily good enough to achieve the pre-cision required of RLE.

Phaco technologyThe WhiteStar Signature (AdvancedMedical Optics, AMO, Santa Ana,Calif.) is the ideal platform for thisnew paradigm in cataract surgery.Its micropulse power modulationreduces phaco power deliverytremendously—by as much as 30%compared to standard WhiteStar. Inaddition, WhiteStar Signature’s flu-idics software is the first softwaredesigned to proactively prevent asurge, rather than just react to thebreak in occlusion.

It anticipates the break in occlu-sion, reversing the pump to reducevacuum levels before the break canoccur—accomplishing this fasterthan any human could (Figure 1). Iview it as a major safety advance,somewhat analogous to anti-lockbreaks. No matter how good adriver—or surgeon—one is, theremay be circumstances when theextra safety features come in handy.

The phaco needle can providean additional measure of safety ifone uses a rounded tip like the oneI have designed. With this tip, evenif the needle does touch the cap-sule or other tissues, they won’tnecessarily rupture or tear.

Technique is obviously just ascritical, if not more so. For exam-ple, a well-sized capsulorhexis is ofparamount importance. Other keycomponents of the procedureinclude making a tight incision,performing LRIs, if needed, to min-

imize post-op astigmatism, andappropriate use of viscoelastics. Ialso believe that a chopping tech-nique is most efficient. I haveachieved a two-thirds reduction inphaco power just by switchingfrom divide-and-conquer to hori-zontal chopping (Figure 2).

Striving for perfectionFor the refractive cataract surgeon,the importance of routinely review-ing cases cannot be underestimat-ed. The surgical media center inWhiteStar Signature greatly facili-tates such review by superimposinga real-time graph of vacuum, flow,and other settings on the digitalvideo so the user can see exactlywhat is happening throughout thecase. In a fast-paced surgical envi-ronment, this is the only way toevaluate and make educated adjust-ments to techniques and settings.

Although we strive for perfec-tion, it is impossible to achieve theideal refractive result 100% of thetime. If I can give that patient a per-fect anatomical result, there are a lotmore options for achieving thedesired refractive result.

State-of-the art phaco technolo-gy and proven surgical techniquesoffer the best chance to reduce bothcomplications and routine trauma. Ifwe can achieve these two surgicalgoals, our RLE patients will be in anexcellent position to achieve theirrefractive goals, with the rapid recov-ery to routine activities that ourpatients have come to expect.

Steven Dewey, M.D., is in private practice atColorado Springs Health Partners in ColoradoSprings, Colo. Contact him at (719) 475-7700or sdewey@cshp.net.

“ WhiteStarSignature’s fluidics softwareis the first soft-ware designed to proactively prevent a surge,rather than justreact to the breakin occlusion”

Steven Dewey, M.D.

Figure 1: The new Signature technology anticipates the break in occlusion, quickly reversingthe pump to reduce vacuum levels before the break can occur

Figure 2: By switching from a divide-and-conquer to a horizontal chop technique, surgeons canachieve a further reduction in phaco power use

Next Generation Phacoemulsification — Show Supplement • AAO New Orleans 5

In eyes with pseudoexfoliation, zonular dehiscence, IFIS, or previoustrauma, look to the latest phaco and OVD technology to save the case

Enhance your “working space”with new phaco technology

by Donald R. Nixon, M.D.

Challenging conditions suchas intraoperative floppy irissyndrome (IFIS), prior trau-ma, pseudoexfoliation syn-drome, and other situa-

tions in which zonules are weak-ened demand a different approachto cataract surgery.

My approach in such cases isthreefold: I use viscoadaptive anddispersive viscoelastic devices toeffectively stabilize the anteriorchamber; I lower the irrigation bagsignificantly to reduce stress on theiris-lens complex; and I rely onhighly controlled fluidics to furtherstabilize the working environment.

In an IFIS case, for example, Ilike to have the viscoadaptive prop-erties of Healon 5 (AdvancedMedical Optics, AMO, Santa Ana,Calif.). It has sufficient dispersivecapabilities that I can use tomechanically dilate the pupil in apatient with Grade 3 or 4 IFIS, sothat I can safely perform the capsu-lorhexis. In addition, it will hold theperipheral iris away from the posteri-or surface of the cornea—and moreimportantly, away from my incision,to prevent iris chafing.

In many complex cases, Healon5 works very well on its own. But ifit is not dispersive enough I use avariant of the soft-shell techniqueadvocated by Steve Arshinoff,M.D., University of Toronto,Canada, with a combination ofHealon 5 centrally and Vitrax II(AMO) in the periphery.

Fluidics controlUnder normal conditions, with awidely dilated pupil and a healthyeye, surgeons typically keep theirrigation bottle high above thepatient’s head, because this mini-mizes chamber shallowing associat-ed with post-occlusion surge andmaximizes anterior chamber space.

However, during surgery thiscan also be associated with signifi-cant fluctuations in intraocularpressure. The resulting dynamicforces from the anterior-posteriormovement of the iris-lensdiaphragm may be easily toleratedin healthy eyes, but in compro-mised eyes they place significantstress on the zonules, may damagethe iris or capsule, and may evenput stress on the retinal vascula-ture. Pressure rises in eyes withzonular deficiency may lead to vit-reous loss into the anterior cham-ber. Finally, further damage to thezonules intraoperatively may leadto long-term instability of theimplanted IOL and possible latedislocation.

Lowering the bottle to half thenormal height or lower allows me tohave a more controlled environmentand a safer surgical approach inthese difficult cases without compro-mising the efficiency of phaco. Mystandard bottle height is 65 cm, but Ilower it to 20 to 30 cm in the settingof chamber instability.

A lower bottle height canincrease chamber instability by

“ The WhiteStarSignature systemhas commandingdominance in termsof its fluidics, particularly incases with IFIS or zonular complications”

Donald R. Nixon, M.D.

magnifying chamber collapse or“surge” when a break in occlusionoccurs. This provides the greatesttest of a phaco machine’s fluidicssystem. It requires technology thatcan monitor and rapidly adjust forchanges in flow and vacuum, mini-mizing surge without the need forflow restrictors in the tube orphaco needle.

The WhiteStar Signature system(AMO) with CASE fluidics, designedto keep the chamber stable andminimize surge under many differ-ent fluidic conditions, were alreadypart of the AMO Sovereign system.The WhiteStar Signature is now fivetimes more responsive, further con-trolling the micro-environment orworking space for increased safetyand confidence. Adjustments to theCASE fluidics settings can be madeon the fly, for those times whenzonular dehiscence is noted part-way through the procedure.

In my experience, theWhiteStar Signature system hascommanding dominance in termsof its fluidics, particularly in caseswith IFIS or zonular complications.The system is so responsive andflexible that surge is minimized ineven the most demanding cases(Figure 1).

Donald Nixon, M.D., is senior ophthalmologistat Royal Victoria Hospital, Barrie, Ontario,Canada. Contact him at 705-735-4567 ortrimedeyedoc@rogers.com.

Figure 1: Challenging cataract cases that would benefit from the CASE technology in Fusion Fluidics: Morganian cataract (left); pseudoexfolia-tion (center); and traumatic cataract (right)

Pre-select CASE Profile and apply it to the Complete Cataract Procedure

CONTROL

6 AAO New Orleans • Show Supplement — Customizing cataract and corneal refractive surgery

With wavefront-guided LASIK, the goalis to reduce all higher order aberrations

LASIK with wavefront-guided andfemtosecond technology superior

by Jack T. Holladay, M.D.

“ Wavefront-guid-ed ablations pro-vide the bestresults for the vastmajority ofpatients with thelowest rate ofretreatment overconventional LASIKand wavefrontoptimized LASIK”

Jack T. Holladay, M.D.

Preliminary results from anew study show that wave-front-guided ablations pro-vide the best results for thevast majority of patients

with the lowest rate of retreatmentover conventional LASIK and wave-front optimized LASIK.

Reducing aberrationsConventional LASIK induces higherorder aberrations, including spheri-cal aberration and coma, which arethe most prominent. With opti-mized LASIK, the goal is not tochange the spherical aberration tar-get. The treatment basis is sphereand cylinder. Optimized simplymeans “not intended to inducespherical aberration,” and thereforedoes not address the patient’sspherical aberration or any otherhigher order aberrations. However,very few patients have zero spheri-cal aberrations; those that do, arein their early 20s or younger.Numerous studies have shown thatby the time most patients reachtheir 40s, they have positive spheri-cal aberrations. With wavefront-guided LASIK, the goal is to reduceall higher order aberrations. Thespherical aberration target is zero.

Study and resultsThe purpose of our study is to com-pare wavefront-optimized andwavefront-guided procedures todetermine which is more effective.The retrospective chart reviewstudy of 200 IntraLASIK proceduresincluded 100+ IntraLase (AMO)Wavelight (optimized) eyes and100+ IntraLase VISX CustomVue(wavefront-guided) eyes. Pre-op andpost-op wavefront scans were doneon all eyes at a 6-mm pupil sizePrimary spherical aberrations, pri-mary trefoil, and high order aberra-tions were measured. Thirty-nineCustomVue and 35 Wavelightswere reviewed to this date (Figures1 and 2).

These preliminary study resultsshow that wavefront-guided abla-tion with femtosecond technologyis optimal for the majority ofpatients who do not have zerospherical aberrations.

Overall, the wavefront-guidedtreatment induced significantly lesshigher order aberrations than theoptimized procedure. There was sig-nificantly more variation with theoptimized eyes. For best spectaclecorrected low contrast letter acuity(BSCVA) at 5%, more wavefront-

Figure 1: Post-op wavefront-guided outcomes for spherical aberration correction are more predictable than optimized outcomes

Figure 2: Post-op optimized ablations result in significant induction of HOA compared to wavefront-guided ablations

guided ablation patients achieved20/20 than the optimized patients.When we looked at the contrastthreshold using a 20/100 letter sizefor both groups, more wavefront-guided patients could read thelower contrast letters compared tothe optimized group. This demon-strated that wavefront-guided abla-tion patients had better contrastletter acuity and lower contrastthreshold.

For the study, the pre-op meanhigher order aberration is 0.36microns over a 6-mm pupil forboth groups. With wavefront-guid-ed, about 33% of patients were bet-ter, 33% were the same, and 33%were worse post-op. With wave-

front–optimized, about 15% werebetter, 25% were the same, and60% were worse. This shows thatnot trying to induce spherical aber-rations doesn’t help 60% of thepatients. The wavefront-guidedablations provide the best resultsfor the majority of patients becausethey do not have zero sphericalaberrations.

We are now evaluating the dataon more than 100 eyes and we lookforward to presenting the addition-al results from this study as theybecome available.

Jack T. Holladay, M.D., is clinical professor ofophthalmology at Baylor College of MedicineHouston, Texas. Contact him at 713-668-7337,holladay@docholladay.com .

Post-op Primary SA

Merging Femtosecond & Wavefront-Guided Laser Technologies — Show Supplement • AAO New Orleans 7

Create a custom flap to match a custom treatment

Thin-flap LASIK benefits outweighsurface ablation and LASIK

by Stephen Coleman, M.D.

Thin-flap LASIK, a procedurethat uses a customized flapwith respect to such param-eters as thickness, diameter,and side-cut architecture, is

a compelling concept in laser visioncorrection.

Also referred to as sub-Bowman’s keratomileusis (SBK),thin-flap LASIK appears to have sev-eral advantages over traditionalLASIK, including improved short-term vision results, decreased treat-ment times and enhancement rates,improved flap centration, and pre-served or perhaps increased cornealstrength.

The evolution in flap creationhas allowed surgeons to customizeLASIK similar to the way excimertechnology has evolved from stan-dard treatments to customized,wavefront-guided treatments. I usethe iLASIK Suite (Advanced MedicalOptics, AMO, Santa Ana, Calif.),which consists of the IntraLase fem-tosecond laser and the AdvancedCustomVue excimer profile usingthe VISX Star laser (AMO). Thismethod has been shown to maxi-mize residual corneal thickness,thereby decreasing the risk of post-LASIK ectasia as it is commonlyunderstood today.

Thin-flap benefitsSimilar to traditional LASIK, visualrecovery is significantly faster thanwith surface ablation. In addition,retinal image quality was higher inall post-op visits for thin-flap LASIKeyes when compared to PRK eyes.

Thin-flap LASIK procedures alsotypically involve a small diameterflap which can significantly reducetreatment times. In my experienceusing the 60 kHz IntraLase FS laserwith an 8.2-mm flap diameter formyopia, this first step of LASIKtakes 16 seconds.

Structural integrityWith thin-flap LASIK, Bowman’smembrane is preserved and theexcimer treatment is also concentrat-ed in the anterior cornea where thelamellae are most densely packed.Both of these factors are positivesteps toward avoiding post-LASIKectasia and have the added benefit ofeliminating the potential of post-ophaze formation associated with PRK.

Recent research has shown thatthinner flaps do in fact preservecorneal integrity to a greater extentthan thicker flaps.

Additionally, direct confocalmicroscopy comparisons haveshown that femtosecond flaps havemore predictable actual dimensions

“ Thin-flap LASIKhas several poten-tial advantagesover traditionalLASIK, includingimproved short-term vision results,decreased treat-ment times,improved flap centration, andpreserved or perhaps increasedcorneal strength”

Stephen Coleman, M.D.

Figure 1: More patients preferred their post-op vision with thin-flap LASIK (SBK with IntraLase)than with PRK

Biomechanics of wound healingby John Marshall, Ph.D.

T hin-flap LASIK offers advantages over surface ablation and con-ventional LASIK, according to our recent research. While surfaceprocedures, such as PRK, are mechanically stable, they result in

some pain and haze. Conventional LASIK is mechanically unstable, buthas no pain and limited haze. So thin-flap LASIK appears to be the bestof both worlds: no haze, no pain, and stability.

Our research has concentrated on the biomechanics of wound heal-ing comparing shallow and regular depth flaps. Overall, we have foundthat the biomechanical disturbances induced by the femtosecond(IntraLase, Advanced Medical Optics, AMO, Santa Ana, Calif.) flap of an80 to 90 micron depth is comparable to the biomechanics of changesinduced by surface procedures. We have also found that regular LASIKflaps with depths from 140 to 160 microns have significant disturbance inthe biomechanical integrity of the cornea whether the flap is cut withIntraLase or mechanical microkeratome.

For many years I have been concerned about the use of LASIK flapsbecause when a LASIK flap is made, about 200 million collagen fibers inthe cornea are cut. In contrast, with a surface procedure only about fivemillion collagen fibers are cut. Therefore, I have long been an advocate ofsurface ablation.

With the ability to cut superficial flaps using the femtosecond laser, Inow believe that you can cut very thin flaps and have a similar effect to asurface procedure in terms of strength. Because they represent lessresistance than thicker flaps, thin flaps become more stable more rapidly.The more stable the flap, the faster the recovery, and therefore there is anapparent increase in rate of acquisition of adhesion and wound healing.

John Marshall, Ph.D., is a professor, department of ophthalmology, The RayneInstitute, St. Thomas’ Hospital, London. Contact him at +44 20 7188 4296 or atmarshall-eye@kcl.ac.uk.

than microkeratome created flaps. Therefore, thin-flap LASIK with

CustomVue has become my proce-dure of choice over PRK and tradi-tional LASIK due to the improvedshort-term vision results, reducedtreatment times and more accurateflap centration, and preservedcorneal strength.

Stephen Coleman, M.D., is the director ofColemanVision in Albuquerque, N.M. He has afinancial interest with AMO/VISX and can bereached at 505-821-8880 or at stephen@cole-manvision.com.

8 AAO New Orleans • Show Supplement — Customizing cataract and corneal refractive surgery

Clinical outcomes improve with state-of-the-art“best of the best” wavefront-guided LASIK

NASA astronauts and Navy aviatorsnow receive state-of-the-art LVC

by Steven C. Schallhorn, M.D.

The National Aeronauticsand Space Agency (NASA)recently approved LASIK foruse on astronauts and astro-naut candidates. The NASA

decision was made followingreview of extensive military clinicaldata using all-laser LASIK with thefemtosecond laser, which showedthe combination of technologiesprovides outstanding safety andvision.

It wasn’t until LASIK developedinto an all-laser procedure thatNASA approved it for use on pilotsas well as mission and payload spe-cialists who face extreme and phys-ically demanding conditions inspace. Smith L. Johnston, M.D., aNASA physician who overseesastronauts’ medical standards, toldThe Wall Street Journal that this newapproval will open the door tomany people who in the pastwould have been ruled out.

The exacting visual standardsof the space program have longbeen the number one disqualifierfor astronauts, said Dr. Johnston.Under this new change, NASA can-didates whose uncorrected visionwould otherwise disqualify themcan now have surgery. NASA’srevised refractive surgery protocolfollows similar moves by the AirForce and Navy regarding their eye-sight standards for pilots.

Navy aviatorsWhile the PRK program for Navyaviators was successful, slow visualrecovery resulted in a minimumaviator “down time” of threemonths. A significant complicationof PRK was late corneal haze,which in some cases temporarilygrounded aviators from flying.

With the recent advancementsin laser vision correction, a new erain vision correction has been ush-ered in. For outstanding safety andeffectiveness, aviators can nowreceive the “best of the best” LASIKor all-laser LASIK, which is nowoffered at all Navy centers. Itincludes the creation of the LASIKflap with a femtosecond laser andcorrection of their refractive errorwith a wavefront-guided (WFG)ablation. Aviators can enjoy a fastervisual recovery and quicker returnto flight duty.

Improved LASIK resultsIn a recent study, WFG LASIK per-formed with a femtosecond laserhad improved clinical results,specifically faster visual recoveryand better contrast sensitivitywhen compared to WFG LASIK

with a mechanical or bladed ker-atome (Figure 1). We testedpatients in low light and photopiccontrast sensitivity testing at oneweek, one month, and threemonths post-op. The uncorrectedvisual acuity was significantly bet-ter through three months. Thevision of the mechanical keratomegroup was improving, but even bythree months there were betterresults and faster visual recoverywith the femtosecond laser.

To ensure the improved UCVAof the femtosecond laser wasn’tdue to residual refractive error, apaired analysis was performed con-sisting of patients who had verygood refractive outcomes with aspherical equivalent between –0.25D and +0.5 D. Even with this pair-ing, the femtosecond had signifi-cantly better visual performance atall post-op time intervals.

There was a significant differ-ence in contrast sensitivity early onfavoring the femtosecond flapgroup, which diminished but wasstill significant at three months.

The results also favored thefemtosecond WFG laser group con-cerning safety, with the bladedmicrokeratome group experiencinga greater percentage of a loss of oneor more lines of vision. The resultssuggest that femtosecond WFGLASIK may cause fewer night visionproblems, which is especially criti-cal for aviators (Figure 2).

This new procedure overcomesmany of the previous issues withLASIK and has set new standardsfor laser vision correction. Mostimportant, it is now being per-formed in aviators.

Ret. Captain Steve C. Schallhorn, M.D., is theformer director of refractive surgery at theNaval Medical Center, San Diego. Contact himat scschallhorn@yahoo.com

“ Aviators cannow receive the‘best of the best’LASIK or all-laserLASIK, which isnow offered at allNavy centers”

Steven C. Schallhorn, M.D.

Figure 1: In a recent study, wavefront-guided LASIK performed with a femtosecond laser pro-vided improved overall clinical results, including visual acuity at one month post-op, whencompared to wavefront-guided LASIK with a mechanical or bladed keratome

Figure 2: Combining femtosecond and wavefront-guided results in both improved object detection and identification in night driving situations compared to conventional ablations

Merging Femtosecond & Wavefront-Guided Laser Technologies — Show Supplement • AAO New Orleans 9

Long-term results of the U.S. clinical trial showgood visual acuity and high patient satisfaction

Positive results for correctingpresbyopia with monovision

by Colman R. Kraff, M.D.

Post-op results for the U.S.clinical trial of theAdvanced CustomVueMonovision (AdvancedMedical Optics, AMO,

Santa Ana, Calif.) procedure for thecorrection of presbyopia in patientswith low to moderate myopia, withor without astigmatism, show posi-tive outcomes in the uncorrecteddistance and near visual acuity inall subjects at 6 and 12 months.

Twelve months after theAdvanced CustomVue Monovisionprocedure, 86% of patientsachieved 20/20 for both uncorrect-ed distance visual acuity (UCDVA)and uncorrected near visual acuity(UCNVA) (Figure 1). Patients indi-cated that they were very satisfiedwith monovision LASIK, with 98%of subjects indicating that if giventhe opportunity, they would electto have the Advanced CustomVueMonovision treatment again. Noeye lost more than two lines ofBSCVA. Furthermore, at 12 months,91% of subjects had a reduction inneed for spectacles.

The studyIn this clinical trial, 296 eyes of160 presbyopic patients with lowto moderate myopia, with or with-out astigmatism, were treated. Thedominant eye was targeted foremmetropia and the non-dominanteye was under-corrected. The studytargeted up to –2.0 D myopia toprovide near vision. Mean patientage was 50 ± 5 years (40 to 65years). The pre-op refractive error(MRSE) was –3.82 ± 1.25 D in dom-inant eyes and – 4.15 ± 1.05 D innon-dominant eyes.

Men and women of any racewho were older than 40 years oldpre-op with BSCVA of > 20/20 inboth eyes and < –6.0 D MRSE withastigmatism < –3.0 D were includedin the study. In the non-dominanteye, pre-op myopia had to be atleast as great as targeted post-opmyopia. Planned laser treatmentwas < 0.75 D MRSE and might nothave been a required treatment.Pre-op refractive stability had to bewithin ± 0.50 D and the WaveScanpupil measurement had to be > 5.0mm in dim light.

Exclusion criteria includedintolerance to monovision correc-tion, concurrent use of medicationswhich impair healing (such as topi-cal/systemic steroids, antimetabo-lites, isotretinoin, or amiodaroneHCl), or systemic disease (such asdiabetes, collagen vascular disease,autoimmune disease, endocrine dis-orders, immunodeficiency, lupus, or

rheumatoid arthritis). Patients withocular disease prior to surgery, activeophthalmic disease, dry eye, atopicdisease, IOP > 21 mm Hg, abnormaltopography, corneal irregularity, orparticipating in any other clinicaltrial were also excluded.

A physician nomogram wasused with a 6-mm minimum opti-cal zone and an 8-mm ablationzone. Either the IntraLase (AMO),Hansatome (Bausch & Lomb,Rochester, N.Y.), or Amadeus ker-atome (AMO) was used to createthe LASIK flap.

ResultsTwelve months post-op, 93% ofpatients achieved 20/20 or betterUCDVA, while 69% reached 20/16or better. Ninety-two percent ofsubjects achieved 20/20 or betterUCNVA, and 44% achieved 20/16or better. At 12 months, 99% ofdominant eyes and 98% of non-dominant eyes were within ± 1.0 Dof intended correction. Also there

were no significant changes inhigher order aberrations. Patientsreported satisfaction with their dis-tance vision at night, their sus-tained near vision, and depth per-ception (Figure 2). In addition, theyreported a low incidence of glareand halo.

This procedure proved to bevery safe and effective. Only eighteyes of seven subjects (2%) hadwavefront-guided retreatment.Seven dominant eyes were retreatedto improve distance vision and onenon-dominant eye was retreated toimprove near vision.

Based on the results from theU.S. clinical trial, the AdvancedCustomVue Monovision procedurefor the correction of presbyopia inpatients with low to moderatemyopia, with or without astigma-tism, is an excellent procedure.

Colman R. Kraff, M.D., is director of refractivesurgery at the Kraff Eye Institute in Chicago.He may be reached at (312) 444-1111 or atc.kraff@ix.netcom.com.

“ Patients indi-cated that theywere very satisfiedwith monovisionLASIK, with 98% ofsubjects indicatingthat if given theopportunity, theywould elect tohave the AdvancedCustomVueMonovision treat-ment again”

Colman R. Kraff, M.D.

Figure 1: At 12 months post-op, 86% of patients simultaneously achieved 20/20 for uncorrected distance visual acuity and uncorrected near visual acuity

Figure 2: At 12 months, 99% of patients were either very satisfied or satisfied with their depthperception post-op versus 90% pre-op

Binocular UCVA:Simultaneous Distance and Near

Depth Perception(Pre-Op BSCVA to 12M Post-Op UCVA)

10 AAO New Orleans • Show Supplement — Customizing cataract and corneal refractive surgery

Combining premium lenses can sometimesoffer patients the best overall vision

Staged implantationwith multifocal IOLs

by William J. Lahners, M.D.

“ With thestaged implan-tation approach,my favoritealgorithm is tobegin with theReZoom lens inthe dominanteye and thenbuild fromthere”

William J. Lahners, M.D.

Sometimes the way to offerpatients the best range ofvision is by using morethan one type of multifocallens. While the majority of

patients are very happy with bilat-eral implantation of premium IOLssuch the ReZoom lens (AdvancedMedical Optics, AMO, Santa Ana,Calif.), there may be a fewinstances where patients report dif-ficulties. In those cases I try anoth-er lens in the second eye, but I findthis isn’t something that can bestbe determined at the outset.Instead I can sometimes serve mypatients better by using a tech-nique dubbed “staged implanta-tion.” With this approach I utilizethe information obtained from thefirst eye to make an informed deci-sion about the lens selection in thesecond eye.

With the staged implantationapproach, my favorite algorithm isto begin with the ReZoom lens inthe dominant eye and then buildfrom there. I use the ReZoom 80 to90% of the time and generally dobilateral implantation of the lens. Ihave a lot of confidence in the quali-ty of the distance and intermediateoptics of the lens, and in many caseshave found that even the nearvision can be exceptional.

Reassessing the patientWith staged implantation, after Ihave done the first eye, I thenreassess the patient. It is, however,important not to do this too soon.Making this assessment on day onecan be a mistake—the eye is stillslightly dilated, which can affectreading vision with the lenses.

After the patient has had thelens for a week, I then perform thereassessment to determine whetherto put the same lens in the secondeye or to choose another one.

If I find that the patient is dis-satisfied with his near vision, Idon’t necessarily opt for anotherlens. I begin by asking him lifestylequestions. I try to get an idea ofwhether or not the lens that Iselected for the first eye is still theappropriate choice. Some educa-tion, reassurance, or modificationmay be all that is needed. With thezonal refractive ReZoom lens, Iwould ask the patient, “What arethe conditions in which you arehaving difficulty reading?” Simplyturning the light down a little orincreasing the working distance a

Figure 1: Using a staged implantation diagram can help to determine the optimal second lensto meet the patient’s needs

Staged implantation: how it works

Figure 2: Uncorrected & corrected distance vision with bilateral ReZoom implants is excellent

bit may be all that is needed for thepatient to be completely satisfied.In such a case I would choose thesame lens for the second eye. In themajority of cases I find thatpatients are more than satisfiedwith bilateral implantation of theReZoom lens, which is the IOL thatI favor. (Figure 2)

However, if patients report thatthey’re having some difficultiesmanaging day to day, then I’llchoose a different lens based ontheir feedback and their measure-ments.

Overall I have seen tremendoussatisfaction with the staged implan-tation approach. From the start Ihave been getting excellent feed-back using premium lenses such asthe ReZoom. Now with mixing,these patients are extremely satis-fied. In our last poll, patient satis-faction was at 96%. Going forwardis going to be tough to beat.

William J. Lahners, M.D., is the medicaldirector at Center for Sight in Sarasota, Fla.,and an assistant clinical professor of ophthal-mology at the University of South Florida. Hecan be reached at ( 941) 925-2020.

Premium Refractive IOLs — Show Supplement • AAO New Orleans 11

Outstanding multifocal acuity requiresattention to detail

Attaining excellent outcomes withsecond generation multifocal IOLs

by Rosa M. Braga-Mele, M.D.

Patients undergoing cataractsurgery with multifocalIOLs such as the ReZoomlens (Advanced MedicalOptics, AMO, Santa Ana,

Calif.) have an eye toward attain-ing more than just excellent dis-tance acuity. They’re hoping forgood near and intermediate visionas well. Such patients can some-times be demanding. The goodnews is that for many of thesepatients it is quite possible toachieve excellent results in the nearand intermediate ranges as well asfor the usual distance vision.

In my practice we have doneover 100 bilateral implantationswith the ReZoom lens with someoutstanding outcomes. Nearlyalways, I find that following bilat-eral implantation, distance vision is20/25 or better uncorrected.Intermediate vision with the lensesis very good, and about three quar-ters of patients also do not needany correction for near. In caseswhere a small near correction isneeded, it is usually only in the 1to 2 D range.

Managing patient expectationsOne of the major keys to achievingexcellent outcomes with multifocalIOLs such as the ReZoom lies inproper patient selection at the out-set. In my experience, the best suit-ed patients are those who are moti-vated and who understand the giveand take of multifocal lenses. Inorder to attain optimum vision,with reduction of glare and halos,there is often a period of neuroad-aptation needed. So patients mustunderstand and accept going in tosurgery that they will not be seeing

perfectly right after the procedure. Patient personality is also an

essential component here. I tend tofind that the laid-back patient ismuch better suited for these multi-focal lenses than the “type A,”highly critical client. Ocular healthis also important in attaining suc-cess. The patient should have mini-mal or no ocular diseases. I suggeststeering away from patients withpseudoexfoliation, previous eyetrauma, and those with severe ocu-lar diseases.

To obtain optimal outcomes,one of the keys lays in setting real-istic patient expectations. AsStephen Lane, M.D., clinical pro-fessor, University of Minnesota, St.Paul, recommends, I believe in“under selling and over delivering.”With this in mind, I tell patientsexactly what they can expect fromthe procedure. I let them know inadvance that it will take some timefor them to adapt to their nearvision. I tell patients to expect glareand halos, but also let them knowthat these will get better with time.In addition, I tell them that theymay still need to wear glasses aftersurgery.

I find that this is a win/winapproach. If the patient doesn’texperience glare or halos or doesn’tneed to wear spectacles, he walksaway feeling very good about theprocedure. In the cases where someof these issues do occur, the patientis prepared and expects to seeimprovement with time.

Maximizing techniqueIn performing the procedure itself, Ifind that it is very important to dothe most atraumatic procedure pos-

sible. I begin by making a good,shelved clear corneal temporal inci-sion to try to induce as little astig-matism as possible. I find that adispersive agent such as Vitrax II(AMO) is preferable to a cohesivehere. To help with IOL centration,it is important to make a 4.5 to 5mm capsulorhexis that is perfectlycentered on the visual axis.

The phacoemulsification proce-dure itself should be minimallyinvasive using more mechanicalforce and vacuum to remove thelens than power, with less fluidgoing into the eye to maximize effi-ciency. This should be followed bya meticulous cortical clean-up tominimize posterior chamber opaci-fication which can exacerbate glareand halos.

To minimize the risk of cystoidmacular edema post-op, it is essen-tial to put the patient on a goodnon-steroidal anti-inflammatoryagent. Also, a fourth generation flu-oroquinolone should be used tohelp lower the risk of endoph-thalmitis.

Ultimately, I find that with theextra care taken, nearly all of mypatients walk away with pristinedistance vision, reasonable interme-diate, and very good near vision,with just a small percentage need-ing a slight prescription for fineprint or reading in dim light. Withsuch outcomes, most patients walkaway happy to have selected multi-focal lenses.

Rosa M. Braga-Mele, M.D., is an associateprofessor, University of Toronto, and director,cataract unit and surgical teaching, MountSinai Hospital, Toronto. She can be contactedat 416-462-0393 or atrbragamele@rogers.com.

“ To obtain optimal outcomes,one of the keyslays in settingrealistic patientexpectations”

Rosa M. Braga-Mele, M.D.

Overall Spectacle Independence Improvement with Halos

Figure 2: Between 6-week and 6-month follow-ups, 67% ofpatients in a Canadian multicenter study reported having improve-ment with halos

Figure 1: In a Canadian multicenter study, 91% of patients at 6-months post-op said they never or seldom wore vision correctionglasses

12 AAO New Orleans • Show Supplement — Customizing cataract and corneal refractive surgery

Simple additions to cataract procedurescan offer striking improvements

Providing the refractive cataract patientwith the best quality-of-vision

by Eric D. Donnenfeld, M.D.

With the advent of pre-mium IOLs such as themultifocal ReZoomlens (AdvancedMedical Optics, AMO,

Santa Ana, Calif.) and the Tecnisaspheric (AMO), there has trulybeen a revolution in patient expec-tations and in delivery of quality-of-vision following cataract surgery.Patients today not only expect butalso demand premier vision. Inmany cases they also value the abil-ity to see clearly at all distances. Inaddition to excellent Snellen acu-ity, they want superb quality-of-vision with reduced glare and halosand increased ability to functionwithout glasses.

When it comes to providingthese patients with such excellentvision following cataract surgery,we find that astigmatism correctionis the single most important factor.The reason for this is that approxi-mately 30% of patients have pre-existing cylinder that is greaterthan 1.0 D. Significant cylinder isenough to reduce the quality-of-vision. In addition, many surgeonswill induce cylinder during the pro-cedure with their incisions, whichwill further distort acuity.

Using LRIsTo tackle the majority of astigmaticcases, I usually use limbal relaxingincisions (LRIs) during cataract sur-gery. The advantage of these is thatthey’re easy to perform, they canbe made extremely rapidly, theycan be adjusted and titrated at alater date, and they are extremelycost effective. I am very aggressivewith LRIs and use these on approx-imately one-third of my cataractpatients.

I find that these are prettyaccurate. They correct approxi-mately 70% of refractive error.They are particularly helpful incases where the amount of astigma-tism is low. The fact is that evencylinder as low as 0.5 D can some-times be visually disturbing tocataract patients—particularlythose who are expecting pristinevision without glasses. For correct-ing these small amounts of cylin-der, LRIs are absolutely idealbecause even a small astigmaticcorrection can make a big differ-ence. I find that almost always ifyou can get the patient down to0.25 D of cylinder or less, it dra-matically improves the quality-of-vision. In addition, it is quick andeasy. The patient walks away seeingmuch more clearly immediatelyfollowing the procedure.

Plugging into the LRI CalculatorAnother easy way to enhance qual-ity-of-vision for patients is by usingthe new LRI Calculator (AMO).Those interested in reducing astig-matism during or followingcataract surgery can use this calcu-lator, free of charge, atLRIcalculator.com (Figure 2). Thefact is we need to concern our-selves not only with inherent astig-matism, but also astigmatisminduced by surgical incisions.

Typically post-surgical astigma-tism is a vector analysis of the pre-existing astigmatism and the inci-sion-induced cylinder. As a result,the LRI made by the surgeon is notusually at the site where the pre-existing astigmatism resides. TheLRI Calculator has a nomogramthat enables surgeons to determinewhere to place the LRI for mosteffect and precisely how long thisshould be. It also provides a visualanalysis, via a printout, of preciselywhere the LRI should be made.

In cases where the astigmatismis too high to effectively be han-

dled by LRIs alone, or where thereis residual myopia or hyperopia, Irely on excimer laser photoablationto fine tune my results. I use thisapproach with approximately 7%of my patients. Post-cataract LASIKcan help many of these patients toachieve the best possible outcomes.For those who are older, for whomsurgeons don’t feel comfortableusing LASIK, I think that PRK is avery viable alternative and onewhich is in the purview of virtuallyevery cataract practitioner.

Overall, I think that this is anexciting time in ophthalmology forpatients and surgeons alike. Ibelieve that those who take theextra step and begin performing“refractive” cataract surgery withits enhanced visual outcomes willreap the benefits of greater patientsatisfaction and increased surgicalvolume.

Eric Donnenfeld, M.D., is a founding partnerof Ophthalmic Consultants of Long Island andNational Medical Director of TLC. He can becontacted at eddoph@aol.com.

“ When it comesto providing thesepatients with suchexcellent visionfollowing cataractsurgery, we findthat astigmatismcorrection is thesingle most important factor”

Eric D. Donnenfeld, M.D.

Figure 1: Approximately 30% of patients have pre-existing cylinder greater than 1.0 D thatneeds to be addressed for optimal results

Figure 2: The LRI Calculator has a nomogram that enables surgeons to determine where toplace the LRI for most effect and precisely how long this should be. It also provides a visualanalysis, via a printout, of precisely where the LRI should be made

Premium Refractive IOLs — Show Supplement • AAO New Orleans 13

Patients with glaucoma andconcurrent cataract haveinherent challenges whenundergoing phacoemulsifi-cation compared to those

with otherwise healthy eyes.Contrast sensitivity (CS) is adverse-ly affected with aging, especiallywith cataract. In the glaucomatouspatient, this becomes even morerelevant, as a patient can still haveexcellent visual acuity but a pro-nounced reduction in CS.Researchers have postulated thebasis for this is probably neuronalas retinal ganglion cell loss may notaffect VA, but may affect CS.Therefore, for glaucoma patients,it’s generally a double hit to theircontrast discrimination, with boththe developing cataract and theirglaucoma contributing to theirdeficit. The cataract removal willhelp improve CS, but the underly-ing deficiency on the basis of theglaucoma remains. As surgeons, wemust ask how we can help thesepatients. Most of the time, CS is anoptical phenomenon and a mainbasis for the science behind aspher-ic IOLs.

Traditional IOLs have positiveasphericity, and give a pseudopha-kic eye a larger amount of positivespherical aberration. Aspheric IOLs,on the other hand, are availablewith differing amounts of negativeasphericity, ranging from zeroasphericity to –0.27 microns. Thenegative asphericity of the lens off-sets the positive corneal sphericity,delivering the sharpest possibleimage focus.

To optimize contrast sensitivity for glaucoma patients,aspheric IOLs make the most sense

Choosing the right lens forvisually compromised patients

by Thomas W. Samuelson, M.D.

“ The negativeasphericity of thelens offsets thepositive cornealsphericity, deliv-ering the sharpestpossible imagefocus”

Thomas W. Samuelson, M.D.

Clinical pearlsIOL Selection• Choosing an aspheric IOL, that completely neutralizes the spherical aberration of the cornea for the sharpest

possible image focus. There is scant literature concerning the influence of multifocal IOLs in glaucoma patients,so it seems prudent to proceed cautiously. Many glaucoma patients are already uncomfortable with theirmesopic vision; multifocal lenses may further compromise them.

IOL Centration• When implanting aspheric lenses, be vigilant about centration. A generalization is that the more negative spher-

ical aberration in an IOL, the more careful the implantation with regards to centration needs to be. Some glau-coma patients are prone to decentration (they may have lax zonules due to exfoliation, for example). A goodrule of thumb for the Tecnis (which has the most negative asphericity): ensure centration within 0.4 mm of thevisual axis and tilt of less than 7 degrees from the visual axis.

Meeting Patient Expectations• Monovision achieved with bilateral aspheric IOLs remains a viable option in glaucomatous patients who desire

spectacle independence for most activities but are accepting of spectacle use when best corrected vision isneeded.

If you have a patient with com-promised CS, it is our responsibilityto do whatever we can to restore it.Aspheric IOLs can enhance CS,which may offset some of the lossincurred with glaucoma and helpgive the patient better quality ofvision.

Lens material choicesBiocompatibility of the lens materi-al is especially important for glau-comatous patients undergoingcataract surgery. Typically, patientswith glaucoma are more prone toperioperative inflammation second-ary to medication toxicity, pupilmanipulation, shallow anteriorchambers, and IOP fluctuations tovarying extremes.

The current generation of sili-cone and hydrophobic acrylic lens-es, are as biocompatible as any lens

material currently available in theUS. For my glaucoma patients, Idon’t hesitate to use the silicone oracrylic versions of the TECNIS IOL.It does, however, make sense toselect an aspheric lens material thatis clear and maximizes the amountof visible light entering the system.Evidence suggests visible blue lightimportant to visual function in lowlight conditions. While unprovenand theoretical, it could be deleteri-ous to block low wavelength lightin patients with substantial opticdisc damage. Rather, in suchpatients it may be beneficial tomaximize the levels of visible lightavailable for visual processing.

Thomas W. Samuelson, M.D., is a clinicalassociate professor, University of Minnesota,and attending surgeon, Minnesota EyeConsultants, Minneapolis. Contact him at 612-813-3628 or at twsamuelson@mneye.com.

Figure 1: Aspheric IOLs are available with differing amounts of negative asphericity rangingfrom zero to –0.27 microns

14 AAO New Orleans • Show Supplement — Customizing cataract and corneal refractive surgery

Identifying the best acrylic IOL materials andassessing the visual significance of glistenings

Glistenings visually relevant

by William Trattler, M.D.

ing from the nose. The preferredslit is 2 mm (it will appear about2.5 mm spread across the lens).Focusing on the bulk material atthe center of the lens rather thanthe apex optimizes the contrastavailable for analysis. Waite andcolleagues used this system to eval-uate 53 IOLs of 32 patientsimplanted with the SA60 or SN60(Alcon). The number of glisteningsranged from 3 to 892/4 mm2, whilethe density of the glisteningranged from 21 to 740 µm2. Aseverity index, which was calculat-ed by number per 4 mm2 multi-plied by the size in square microm-eters, ranged from 327 to 46,361.

Clinical relevance to lens material choiceGlistenings have been most report-ed with the AcrySof lens, but theyhave also been reported in otheracrylic materials. Tognetto com-pared seven IOLs of differing mate-rials and found the majority didnot have glistenings above Grade

Acrylic foldable IOLs havegrown in popularity dueto stable clinical resultsand a low incidence ofposterior capsular opacifi-

cation. One concern of these lensesis the potential to form glistenings.As documented extensively in peer-reviewed literature, glisteningscommonly occur in certainhydrophobic acrylic IOL materials,and clinical significance has beenreported to range from none to asignificant loss in visual acuity andcontrast sensitivity. Glistenings arefluid accumulation in themicrovoids of the optic, which arelikely caused by temperaturechanges rather than materialchanges. (Figure 1)

The AcrySof lens material(Alcon, Fort Worth, Texas) is partic-ularly susceptible to glistenings.Incidence rates have been pub-lished ranging between 11% to60%. Waite and colleagues noteglistenings might impact high spa-tial resolution contrast sensitivity.

Determining the frequencyGlistenings related to the AcrySofhave been well described in the lit-erature and can occur as early asone week post-op. In an analysis ofstudies by Trivedi, some degree ofglistenings have been reported inAcrySof lenses by six months. Thelength of implantation time as itcorrelates to severity, however, hasbeen disputed, although Mitookareported a prevalence of glisteningformation of nearly 60% betweenfour and 22 months post-op.

Safran found that over time78% of the MA series lenses devel-op glistenings, although no set def-inition of severity was used(Personal communication, Feb. 13,2007).

Measuring severity levelsWe initiated an investigation todetermine the frequency and sever-ity of glistenings as they occur in aclinical setting. We found the bestresults involved a magnification of20 to 30X, with an angle of 30 to55 degrees (can be adjusted formaximum vacuole visibility).Consistently lighting the eye fromthe temporal side reduces shadow-

1; the AcrySof was the only acryliclens to have some Grade 2 glisten-ings.3 Glistenings have also beenobserved in PMMA lenses, but havenot been shown to cause anyadverse clinical effect. Miyata andYaguchi explained that glisteningsin PMMA were less likely to bevisually significant, as this materialfeatures less temperature-dependentwater absorption, and thus wouldbe less likely to form glistenings.

SummaryWith the ability to analyze andgrade glistening in various types ofIOL materials, the next step isdetermining the degree to whichglistenings impact visual perform-ance. The relevance of glisteningsand visual functioning may beeven more significant in visuallydemanding situations, such aswith multifocal IOLs, which haveoptics that may reduce contrastsensitivity.

William Trattler, M.D., is a cornea specialist,Center for Excellence in Eye Care, Miami, Fla.He can be contacted at 305-598-2020 or atwtrattler@earthlink.net

“ Glisteningscommonly occur incertain hydropho-bic acrylic IOLmaterials, andclinical signifi-cance has beenreported to rangefrom none to a significant loss invisual acuity andcontrastsensitivity”

William Trattler, M.D.

Figure 1: Glistenings are fluid accumulation in the microvoids of the lens optic

Lens Glistenings

Premium Refractive IOLs — Show Supplement • AAO New Orleans 15

Many of my patientswho have received oneof the 300 ReSTORmultifocal lenses(Alcon, Fort Worth,

Texas) that I have implanted expe-rience mild to moderate “waxy” or“hazy vision.” Unfortunately,almost 5% of my ReSTOR patientsreported a severe form of waxyvision that I call “Vaseline visiondysphotopsia” (VVD). These casesrequire explantation and IOLexchange to relieve their symp-toms.

Our recent study demonstratedthat severe VVD is a debilitatingvisual syndrome which occurred in4.33%, or 13 out of 300 ReSTOReyes, and 0 of 400 ReZoom(Advanced Medical Optics, SantaAna, Calif.) eyes over a period of 24months. Fifty-two percent of allcases were refractive lensectomies,while 48% were cataract surgeries.The overall incidence of explanta-tion for the ReSTOR was 3%(9/300) and 0 for the ReZoom(Figure 1).

Symptoms and treatmentThe retrospective study looked atthe incidence, profile, and rate ofexplantation of patients experienc-ing VVD. Patients frequently hadvisual complaints within days afterimplantation. They described theirsymptoms of VVD as “vaselinevision,” “waxy vision,” “shadowyvision,” “3-D vision,” “filmyvision,” “hazy vision,” “hologramvision,” and “dirty lens vision”(Figure 2).

Despite excellent near and dis-tance acuities and nine months ofneuroadaptation, explantation wasrequired to relieve symptoms inmost cases of VVD. All cases under-going explantation achieved rapidrelief of symptoms despite tempo-rary increases in residual refractiveerrors.

The mean time betweenimplantation and explantation was9.14 months. Eight ReSTOR IOLssuccessfully underwent “in the bag”exchange with five ReZoom andthree monofocal IOLs. Despite tem-porarily increasing their residualrefractive error, all patients reportedcomplete subjective relief of theirsymptoms of VVD.

Pre-explant, eight of ninepatients had AK (astigmatic kerato-tomy) and all patients achieved

Figure 2: Typical symptoms and patient complaints associated with VVD

Figure 1: The overall incidence of explantation for the ReSTOR was 3% (9/300) and 0 for theReZoom

excellent Snellen acuity with mini-mal residual refractive error. Factorsnot correlating with VVD explanta-tion include: pre-op refractive error(five myopia, four hyperopia), pro-cedure type (five RL, four cataract),mesopic pupil size (five of nine < 5mm, four of nine > 6 mm) andopposite eye status (six pseudopha-kic, three phakic).

For severe VVD, explantation isnecessary. We have previouslyreported that 17 of 55 RS/RSpatients had severe intermediate

visual problems. None of thepatients undergoing explantationwere in the intermediate complaintgroup.

While the exact cause of VVD isnot known, this data should beconsidered when ophthalmologistsare reviewing multifocal options fortheir patients.

Frank A. Bucci Jr., M.D., is director of BucciLaser Vision Institute, Wilkes Barre, Pa. He canbe contacted at 570-825-5949 or at buccivi-sion@aol.com.

Patients immediately complain ofsmeary or waxy vision post-op

Vaseline vision dysphotopsia

by Frank A. Bucci Jr., M.D.

“ While the exactcause of VVD isnot known, thisdata should beconsidered whenophthalmologistsare reviewing mul-tifocal options fortheir patients”

Frank A. Bucci Jr., M.D.

“Vaseline Vision Dysphotopsia”

Multifocal Implants

EW Symposia

rePlaywww.EyeWorld.orgNEW ORLEANS – 2007

www.EyeWorld.org/ewsymposia

These activities have been approved for AMA PRA Category 1 Credits TM.

EDUCATIONAL SYMPOSIA

Recorded LiveSunday, November 11, 2007Sheraton New OrleansDefining State-of-the-Art Laser VisionCorrection: Providing Fully CustomizedTreatments through the Latest GenerationFemtosecond and Excimer Laser TechnologySupported by an unrestricted educational grant from Advanced Medical Optics, Inc. (AMO)

Program Chair: Steven J. Dell, MD

Recorded LiveMonday, November 12, 2007Sheraton New OrleansCustom Cataract Surgery: Selecting Premium Lens Technologies to Optimize Patient Refractive OutcomesSupported by an unrestricted educational grant from Advanced Medical Optics, Inc. (AMO)

Program Chair: Roger F. Steinert, MD

RP 07-24

rePlay Now Available Online atwww.EyeWorld.org/ewsymposia

These EyeWorld Symposia from the 2007 AAO meeting in New Orleans were captured live and are being made available to our readers to view in their entirety at no cost. Please view at your convenience.