March 2011 Bascom Palmer Eye Institute University of Miami Elaine Wu, M.D. Ana Paula Canto, M.D. William Culbertson, M.D. Sonia Yoo, M.D. Financial disclosure: Dr. Sonia Yoo is a consultant for Carl Zeiss Meditec. Long-Term Outcomes of Myopic Correction Using the Excimer Femtosecond Laser System at One Institution

Study purpose and methods Purpose:Purpose: To evaluate the efficacy, stability of visual outcomes, and safety in patients who underwent myopic correction using the Carl Zeiss VisuMax femtosecond-MEL 80 excimer laser platform at Bascom Palmer Eye Institute. To evaluate the precision of flap thickness creation. Methods:Methods: Retrospective chart review of patients who underwent myopic correction with VisuMax- MEL 80 platform from 8/08-12/09 with at least 3 months follow-up. Demographics, preoperative and postoperative refraction/visual acuity, and complications were recorded. Postoperative data was collected for every postoperative visit. Where available, flap thickness as measured by anterior segment optical coherence tomography at cornea vertex was compared to intended thickness.

Comparison of excimer laser platforms ModelIndicationType of laser beam/FeaturesFDA approval year Alcon LADARVision & Custom cornea Myopia: up to -8D and to -4D of astigmatism Hyperopia: up to +5D and up to -3D of astigmatism Scanning spot (0.8mm) Wavefront Eye tracking 2002, 2004 (myopia) 2006 (hyperopia, mixed astigmatism) Bausch&Lomb Technolas Zyoptix Myopia: up to -12D and up to -3D of astigmatism (Wavefront guided: up to -7D and up to -3D of astigmatism) Hyperopia: up to +4D and up to +2D of astigmatism Scanning spot (2.0mm) Wavefront Eye tracking 2000, 2002 (myopia) 2003 (hyperopia) Nidek EC-5000Myopia: -1 to -14D and up to 4D of astigmatism Hyperopia: +0.5 to +5D and +0.5 to +2D of astigmatism Scanning slit Nidek Navex Quest which has wavefront capabilities is not approved in the U.S. yet (myopia) 2006 (hyperopia) Abbott Medical Optics Star S4 IR Myopia: up to -11D and up to -3D of astigmatism Hyperopia: up to +3D and up to +2D of astigmatism Variable scanning spot beam (0.65 to 6.5mm) Variable repetition rate Wavefront Eye tracking 2003, 2005 (myopia) 2004 (hyperopia) Alcon Wavelight Allegretto Wave Myopia: up to -12D and up to -6D of astigmatism (Wavefront guided: up to -7D and up to -3D of astigmatism) Hyoperia: up to +6D and up to +5D of astigmatism Scanning spot (0.95mm) Wavefront Eye tracking 2003, 2006 (myopia) 2003 (hyperopia) 2006 (mixed astigmatism) Carl Zeiss MEL 80Myopia: up to -7D and up to -3D of astigmatism Scanning spot (0.7mm) Wavefront Eye tracking 2006

VisuMax-MEL 80 platform features VisuMax Femtosecond laserVisuMax Femtosecond laser - 500kHz - efficient flap creation - “Gentle corneal interface” eliminates vision loss and high intraocular pressure during loss and high intraocular pressure during suction suction MEL 80 Excimer laserMEL 80 Excimer laser Hz repetition rate - Fast ablation (3.2 seconds per diopter, 22 seconds for -7.0D) (3.2 seconds per diopter, 22 seconds for -7.0D) - 0.7mm Gaussian beam, scanning spot - Pupil and limbus registration and tracking

Demographics 99 charts reviewed.99 charts reviewed. 52 patients included with at least 3 months follow-up (26 women).52 patients included with at least 3 months follow-up (26 women). 98 eyes - 6 patients had one eye treated; 6 eyes treated for monovision.98 eyes - 6 patients had one eye treated; 6 eyes treated for monovision. MeanRange Age Sphere-3.80 ± 1.45D-1.00 to -7.50D Cylinder+0.59 ± 0.46D0 to +1.75D Manifest refraction spherical equivalent ± 1.45D-0.50 to -7.38D Length of follow-up# of eyes% ≥ 3 months98100% ≥ 6 months5354% ≥ 12 months3031% Preoperative Manifest Refraction Spherical Equivalent

Postoperative Uncorrected Visual Acuity (UCVA) All eyes except one maintained best corrected visual acuity (BCVA) of 20/20. One eye lost BCVA (20/20 to 20/30 secondary to subepithelial haze following debridement for epithelial ingrowth). 18% 58% 62% 4% 15% 40% 51% 5% 3% 1% 46% 34% 12% 3% 2% 56% 3% 13% 28% 7% 35% POD 1 = postoperative day 1; POM 1 = postoperative month 1±2 weeks; POM 3 = postoperative month 3±1 month; POM 6 = postoperative 6±1 month. n=98n=80n=61n=32n=46

Target correction vs Achieved correction (at last visit) in diopters of spherical equivalent (SE) Overcorrected Undercorrected Overcorrected Undercorrected

Agreement of postoperative MRSE with target MRSE Undercorrected +/- 0.50D Overcorrected to -1.00D+0.51 to +1.00D>+1.00D 5.1% (5 eyes)85.7% (84 eyes)8.2% (8 eyes)1.0% (1 eye) 6 of the 14 eyes that did not achieve within 0.5D of target were symptomatic: In undercorrected eyes, 1 patient (both eyes undercorrected: residual MRSE -0.75D and D) was symptomatic with UCVA of 20/20.In undercorrected eyes, 1 patient (both eyes undercorrected: residual MRSE -0.75D and D) was symptomatic with UCVA of 20/20. In overcorrected eyes, 4 eyes were symptomatic:In overcorrected eyes, 4 eyes were symptomatic: - 1 eye residual +0.75D with UCVA 20/30. Underwent enhancement. Post-enhancement UCVA 20/25+, developed peripheral epithelial ingrowth. Post-enhancement UCVA 20/25+, developed peripheral epithelial ingrowth. - 2 eyes residual +0.75D with UCVA 20/20, but symptomatic at near. Will undergo enhancement. Will undergo enhancement. - 1 eye residual +0.75D with central epithelial ingrowth and UCVA 20/40. Underwent debridement. Post-debridement UCVA 20/30 with subepithelial haze. Underwent debridement. Post-debridement UCVA 20/30 with subepithelial haze.

Stability of correction In the 30 eyes with at least 1 year follow-up, refractive stability is seen fromIn the 30 eyes with at least 1 year follow-up, refractive stability is seen from postoperative month 1 (POM 1) through year 1 (POY 1). The difference is not postoperative month 1 (POM 1) through year 1 (POY 1). The difference is not statistically significant. statistically significant. Preop POM 1POM 3-6 POY 1

Flap thickness predictability Intended thickness# of eyesAchieved thickness* 100 µm10110 ± 11 µm 110 µm20112 ± 8 µm 120 µm2121 ± 4 µm 140 µm2124 ± 13 µm 160 µm1172 µm 10 *Measured at cornea vertex using anterior segment optical coherence tomography.

Postoperative events Adverse eventOverall # of eyes (%)Still present at POM 6 (%) Glare/halo45 (44%)9 (9%) Dry eyes26 (25%)10 (10%) All require only artificial tears. Light sensitivity4 (4%)2 (2%) Increased preexisting floaters 2 (2%) Microstriae2 (2%) No visual complaints 2 (2%) No visual complaints Epithelial ingrowth5 (5%) 4/5 peripheral ingrowth 1/5 needed debridement

Summary Our experience with the Carl Zeiss VisuMax femtosecond - MEL 80 excimer laser platform for myopic correction demonstrates efficacy, stability, and safety.Our experience with the Carl Zeiss VisuMax femtosecond - MEL 80 excimer laser platform for myopic correction demonstrates efficacy, stability, and safety. UCVA was ≥ 20/20 in 91% of eyes at POM 1, 80% at POM 3, 84% at POM 6 and 93% beyond POM 8. At all time points, all eyes except one attained UCVA ≥ 20/40. One eye at POM 3 had UCVA of 20/50 (52 year old patient target -1.75D for monovision, achievedUCVA was ≥ 20/20 in 91% of eyes at POM 1, 80% at POM 3, 84% at POM 6 and 93% beyond POM 8. At all time points, all eyes except one attained UCVA ≥ 20/40. One eye at POM 3 had UCVA of 20/50 (52 year old patient target -1.75D for monovision, achieved -1.50D however still required additional myopic correction to achieve BCVA of 20/20). 1/98 eyes (1%) lost BCVA secondary to epithelial ingrowth.1/98 eyes (1%) lost BCVA secondary to epithelial ingrowth. 86% achieved postoperative refraction within 0.5D of target. 6% were symptomatic from over- or undercorrection.86% achieved postoperative refraction within 0.5D of target. 6% were symptomatic from over- or undercorrection. Postoperative events such as halo/glare and dry eyes were common, however, resolved in most patients with time. Epithelial ingrowth occurred in 5% of eyes, requiring debridement in one eye (1%).Postoperative events such as halo/glare and dry eyes were common, however, resolved in most patients with time. Epithelial ingrowth occurred in 5% of eyes, requiring debridement in one eye (1%). Larger patient numbers may be needed to evaluate flap thickness predictability for intended thickness outside of μm.Larger patient numbers may be needed to evaluate flap thickness predictability for intended thickness outside of μm.