Keratorefractive & Lenticular

SurgeryMichael Duplessie, MB, BCh

Indications for surgery: Patients who present with a history of or

clinical signs supporting a decrease in vision affecting the patients quality of life. This may be evaluated by: Reduced BSCVA Debilitating glare Monocular diplopia Debilitating halos { I can’t drive at night}

Cataracts:

Cataracts:

Trypan Blue for hypermature cataracts

Traumatic cataract and iridodialysis from Bungee cord inury

Many Corneas:

Corneal melt

Traumatic

Iatrogenic – Pseudophakic disastersAside from power calculation errors there can

be many problems with the lens

Clinical Evaluation

Get as much historical information as possible including: BCSVA pre treatment Pachymetry Ablation depth Flap thickness Pre operative k’s Anterior Chamber depth Axial length

Clinical Evaluation VA: UCVA, BCSVA Refraction

Manifest Cycloplegic Stability

Keratometry Pupillary Exam Pachymetry Anterior Chamber depth Axial length

Clinical Evaluation Slit lamp Tonometry Dilated Fundus examination Pachymetry by ultrasound Topography Placido Ring

Clinical Evaluation Evaluation of BSCVA loss

The etiology of the BSCVA loss or symptoms must be of keratorefractive or lenticular etiology

Retina input always encouraged

Introduction

Before the advent of small-incision cataract surgery, a primary goal of cataract surgery was the prevention and postoperative management of unwanted corneal astigmatism.

With the introduction of astigmatically neutral, small-incision cataract surgery, surgeons have now focused on the reduction or elimination of preexisting corneal astigmatism.

Between 15% and 20% of cataract patients present with more than 1.50 D of corneal astigmatism.

With the rule astigmatism

Against the rule astigmatism

Oblique Astigmatism

Corneal astigmatism in the complicated surgical patient

Options: various cataract incisions, relaxing corneal incisions { LRI, AK } toric intraocular lenses (IOLs), and excimer laser ablation

Endophthalmitis one of the most serious complications of

cataract extraction 95% postoperative cataract surgery.

68% yielded gram-positive coagulase-negative 22% yielded other gram-positive organisms, such

as streptococci and Straphylococcus aureus 6% showed gram-negative organisms. 4% of patients, more than one species was

confirmed

Upward trend in endophthalmitis.

Coincides temporally with the development of sutureless clear corneal incisions:

0.265% in the 2000-2003 period, 0.087% in the 1990s, 0.158% in the 1980s, and 0.327% during the 1970s.

3,140, 650 cataract extractions

Incidence of endophthalmitis

Clear corneal 0.189 – 0.269 %

Blue Line 0.074%

Intracameral 0.004 %

Are you putting yourself at risk ? Your co-managed patient is 67 times more

likely to get endophthalmitis if your surgeon does clear corneal surgery

Topical Antibiotics and Subconjunctival Injections

None of the topical agents penetrates the vitreous appreciably corneal epithelial barrier residual lens-iris apparatus anterior flow of aqueous

Post-operative AC antibiotics and anti-inflammatory medications

Routine Diabetic Retinopathy

0.15 cc 0.2 cc 0.4 cc

Indocin 0.06 mg 0.08 mg 0.161 mg

Ceftazadime 90 mcg 120 mcg 240 mcg

Vancomycin 149.9 mcg 199.8 mcg 399.6 mcg

Dexamethasone 18 mcg 24 mcg 48 mcg

Kenalog 1.5 mg 2.0 mg 4.0 mg

Toxic Anterior Segment Syndrome (TASS) Outbreak UpdateMay 22, 2006

February to May of 2006, over 82 centers in North America have reported cases of TASS following evidently uncomplicated

cataract surgery

To date, there has been no product usage pattern observed that points to any single product, product combinations, or

manufacturer of products used in cataract surgery.

May be related to any of the irrigating solutions, medications, or materials that gain access to the eye during anterior segment

surgery. In addition, factors related to the cleaning and sterilization of instruments.

TASS - common signs: blurred vision, marked increase in anterior segment

inflammation, including hypopyon formation as well as fibrin in the anterior chamber of the eye

Dislocated PCIOL repositioned with rhexis fixation of optic

Relaxing Incisions

Corneal Relaxing Incisions used since the 1970s Single or paired arcuate incisions 99% of the peripheral pachymetry measurements powerful tool limited predictability; often result in

overcorrections no longer "first-line"; patients with high

astigmatism.

Limbal Relaxing Incisions used with any type of cataract incision. easier to perform and more comfortable for the patient than

CRI more "forgiving" ; overcorrections are rare Precise placement "on-axis" is not as critical because the

length of an LRI ranges from 4 mm to 10 mm more forgiving of variation in depth than CRIs. Postoperative refractions are less variable LRIs combined with CRIs placed near the limbus can correct

even higher levels of astigmatism (up to 8 D)

LRI

Relaxing incisions being made prior to routine cataract operation:

Healed LRI

LRI - tools

Toric IOL

Toric IOLs No alteration of current surgical technique Reversible. Preset level of astigmatic correction or it

can be customized to meet the specific needs of a patient

Study Data

In 1994, Shimizu and colleagues the first clinical trial to evaluate toric IOLs.

Reduction of astigmatism in all but one of the eyes It was noted that the closer the IOL came to its

target axis, the greater was the reduction in astigmatism.

Average reduction of astigmatism for the IOL with 2 D and 3 D of astigmatic correction was approximately 1 D and 1.5 D, respectively.

Long-term rotational stability contributes to its success off-axis rotation has a deleterious effect

on visual acuity the maximum rotation of 30° where the

effective astigmatic correction is entirely negated

a toric IOL with postimplantation rotation of more than 30° should be rotated back.

Initial American experience Grabow. astigmatically neutral incision. 95% implanted IOLs remained within 30°

on the intended axis. No other adverse events related to the

insertion of these IOLs were reported

Calculations and alignment: The spherical power of the toric IOL is

calculated in the same way as for a conventional IOL.

Hash marks on the IOL allow this cylindrical power to be surgically aligned with the steeper "plus" axis of astigmatism

Toric IOL prior to insertion

Piggyback Toric IOLs

involves implanting two or more toric IOLs within the eye, in piggyback fashion

Back to back suturing of toric iol

IOL being inserted into the bag

Lens lying on axis in bag

Removal of viscoelastic behind lens

Pre-operative versus post operative cylindrical correction

Toric IOLs Combined with Relaxing Incisions combined to correct larger amounts of

astigmatism reduction in the amount of incisional

surgery required. For many cases of high astigmatism,

adding a toric IOL allows the use of limbal incision rather than corneal relaxing incisions.

Toric IOLs versus spherical IOL with LRIs Toric IOL

84% UCVA 20/40 or better

Spherical IOL/LRI

76% had 20/40 or better uncorrected visual acuity

Piggy Back IOL’s

Piggybacking IOL’s

Can be used to correct pseudophakic refractive errors.

Secondary IOL less traumatic than IOL exchange

IOL implanted anteriorly to the primary IOL

High rate of predictability The power of the secondary implant is

calculated purely by the patient's refraction Can never be certain of the power of the

original IOL. Cannot be confident that an exchanged IOL

would be placed in the same plane as the old IOL.

Lens selection for piggyback IOL AcrySof offers the advantage of a thinner,

6.5-mm optic

Any lens type can be secondarily piggybacked over any other type of IOL. Can use toric lenses.

Contraindications Progressive refractive error Cornea/Endothelial pathology Glaucoma Narrow AC angle Capsular opacification

Contraindications

History of: Iritis Synechiae Pigment dispersion Pseudoexfoliation

Low/abnormal endothelial cell count Keratoconus? (Toric ICL) Patients under age 21

Exam and Testing

Manifest and cycloplegic refraction Unaided and aided visual acuities Keratometry or corneal topography Gonioscopy Pachymetry-corneal thickness Pupil size in normal and mesopic

conditions (6mm or under mesopic)

Exam and Testing Anterior chamber depth Intraocular pressure (IOP) Biomicroscopy-dilated and undilated Opthalmoscopy-dilated Horizontal white to white-operating

microscope/caliper Endothelial cell count (if available)

Excimer laser phototherapeutic

keratectomy (PTK) and Piggyback IOL’s

Introduction a 193-nm argon-fluoride laser is used to

photoablate the affected areas and create a smooth transparent surface.

Compared to manual lamellar techniques, PTK results in controlled deposition of new extracellular matrix and basement membrane, reepithelialization, and stromal remodeling.

Ablation patterns Myopic Sphere Myopic Astigmatism Myopic Elipse

Patient Selection - Ideal candidates are patients with: significant visual compromise, pathology in the anterior one-third of the cornea, an elevated or flat opacity, and recurrent erosions not responsive to medical

therapy. Additional indications include postrefractive

surgery, stromal haze, and intraepithelial dysplasia.

Relative contraindications include: pathology deeper than one-third depth, corneas with central thickness is less than

250 mcg), and active ocular or adnexal infection or

inflammation

Testing includes best-corrected visual acuity, pinhole acuity, rigid gas-permeable contact lens over-refraction, glare testing, pupil diameter in different

illuminations, videokeratography, pachymetry, and, Slit lamp examination. Informed consent is obtained after a discussion of

risks, benefits, and alternatives

Case History Rev. GC 4/22/2002

K’s 41.75 x 9542.50 x 5

Post Op Refraction + 0.25

Chryseobacterium Indologenes Ubiquitous in nature, Chryseobacterium

species are found primarily in soil and water.

Can survive in chlorine-treated water Cause of cancer in plants

Case History Rev. GC 4/22/2002 41.75 x 95 42.50 x 5

Post Op Refraction + 0.25 Va 20/30

10/27/2005 31.6 x 31 36.5 x 12

Refraction + 7.00 with hard contact lens. 12D astigmatism in 3 & 5 mm zones Va LP

Piggyback IOL Current Rx: + 7.00 Desired Post Op Refraction - 1.00

+7 – {-1} x 1.5 = 12 Diopter IOL

11/11/05 12D Piggyback IOL placed12/2005 Therapeutic PTK

Rev. GC Last visit

- 3.00 – 1.50 x 170 20/40

Case History M.W.

7/12/2005 + 7.00 – 2.00 x 19 Va 20/200

7/28/2005 Piggyback IOL

7/29/2005 -0.25 – 1.50 x 105 Va 20/100

10/13/2005 PTK

11/30/2005 - 1.50 Va 20/70

LASER Improvements Tracking/scanning lasers Improved flaps

Femtosecond laser-IntraLase Custom ablations/topography Wavefront ablation

Biomask

Phakic IOLsThe Next Refractive Solution

Collamer Advantages Poly-HEMA based Collagen prevents coating Fibronectin monolayer formation High (1.453) index of refraction Foldable and highly elastic Many designs possible w/ lathe UV absorbing Optical properties closest to human

lens

Visian ICL

Collamer material Injector inserted through 2.8mm incision Current design (V4) is 5th generation Footplates rest in ciliary sulcus Absolute power range -30D to +30D Practical correction range -17.5D to +17D? Cylinder custom power to over 6.0D at any

axis

ICL Material, Designs and Specs

Myopic Visian ICLMyopic Visian ICLHigh Resolution Magnetic Resonance Images High Resolution Magnetic Resonance Images

Illustrates the Increased Vault with V4Illustrates the Increased Vault with V4

Version V3 Version V4

< 100 microns:

< 50 microns

500-600

microns

Vault Illustration

LASIK vs. ICLCONCURRENT COMPARATIVE

SERIES WITH 8-12 D OF PRE-OP MYOPIA

John A. Vukich, M.D.Donald R. Sanders, M.D., PhD.

BSCVA 20/20 or Better

0

20

40

60

80

100LASIK ICL

60%60%

76%76%82%82% 82%82%

75%75%

90%90%89%89%88%88%82%82%82%82%

PrePre

1Wk.

1Wk.

1 Mo.

1 Mo.

6 Mos.

6 Mos.

1 Yr1 Yr

%%Of Of CasesCases

*p *p 0.050.05**p **p 0.010.01

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