SurgiVision® DataLink Study Group Mixed Astigmatism Treatments With the Allegretto Laser Comparison of Hyperopic v. Crossed Cylinder Ablations Guy M. Kezirian, MD, FACS SurgiVision® DataLink Study Group December 20, 2007

Note to DataLink Users This presentation is based on data from 2 DataLink surgeons David Wallace, MD Robin Beran, MD The goal is to inspire other DataLink surgeons to assign mixed astigmatism eyes already entered into DataLink to either the “hyperopic” or “cross cylinder” cohort Please participate in this worthwhile project!

Introduction Mixed astigmatism exists when the sphere and cylinder components of a refraction are of opposite sign, and the cylinder magnitude is larger than the sphere Allegretto corrects mixed astigmatism using a myopic spherical ablation with a hyperopic cylinder ablation Some surgeons prefer a crossed cylinder approach Combined myopic and hyperopic astigmatism ablations

Ablation Effects Regardless of the treatment method, both approaches yield the same refractive change, the same central depth and the same postoperative K Cross cylinder ablations divide the peripheral ablation in 2 meridians, where the hyperopic approach puts it all in one meridian The following slides from Joachim Loeffler, formerly of WaveLight, illustrate these points

Treatment / Correction Options Example Mixed Astigmatism: -2 / +3 x 0° equals +1 / -3 x 90° Different treatment options: A) Plus Cylinder Sphere: -2 Cylinder: +3 x 0° B) Minus Cylinder Sphere: +1 Cylinder: - 3 x 90° C) Crossed Cylinder Cylinder1: -2 x 90° Cylinder2: +1 x 0° D) Split Cylinder Sphere: -0.5 Cylinder1: +1.5 x 0° Cylinder2: - 1.5 x 90° E) Any other split cylinder ….. All options create the same refractive change and the same resulting K‘s Courtesy of Joachim Loeffler

Courtesy of Joachim Loeffler Myopic Pure Sphere 2D Courtesy of Joachim Loeffler

Courtesy of Joachim Loeffler Myopic Pure Cylinder Courtesy of Joachim Loeffler

Courtesy of Joachim Loeffler Hyperopic Pure Sphere Courtesy of Joachim Loeffler

Hyperopic Pure Cylinder Courtesy of Joachim Loeffler

Courtesy of Joachim Loeffler Ablation Depths Treatment Profiles central periph. @ 0° periph. @ 90° Plus Cylinder Sphere -2 Cylinder +3 x 0° total 20µm 0µm 30µm Crossed Cylinder Cylinder1 -2 x 90° Cylinder2 +1 x 0° Total 10µm Courtesy of Joachim Loeffler

Ablation Characteristics Conclusions All approaches provide same final K’s and central curvatures Myopic sphere with hyperopic cyl takes more tissue in the periphery Hyperopic sphere with myopic cyl takes more tissue centrally Cross cyl divides the tissue between the two areas

What about the Allegretto? The Allegretto is programmed with the plus-cyl approach to mixed astigmatism correction Using cross-cyl requires double carding, interruption of treatment, manual calculations and a more complex nomogram FDA results with plus-cyl approach were excellent (better than any other platform) The following slides summarize the results for the FDA trial

FDA Cohort Description Female 48/142 (38%) : Male 94/142 (62%) Age: 40.2 ± 9.4 Years 75% wore no contact lenses Refractions Spheroequivalent: -0.22 ± 0.59 D Astigmatism: -2.52 ± 1.11 D Summary of FDA Mixed Astigmatism Results with the Allegretto (Hyperopic Cyl Approach)

46% Gained 1 or More Lines BSCVA All Safety Targets Met One eye lost 2 lines of BSCVA Had trauma 6 days after surgery Went from 20/15 to 20/25 46% Gained 1 or More Lines BSCVA Summary of FDA Mixed Astigmatism Results with the Allegretto (Hyperopic Cyl Approach)

UCVA Results Summary of FDA Mixed Astigmatism Results with the Allegretto (Hyperopic Cyl Approach)

Spheroequivalent Results Summary of FDA Mixed Astigmatism Results with the Allegretto (Hyperopic Cyl Approach)

Astigmatic Results Summary of FDA Mixed Astigmatism Results with the Allegretto (Hyperopic Cyl Approach)

Achieved v. Attempted Cylinder Summary of FDA Mixed Astigmatism Results with the Allegretto (Hyperopic Cyl Approach)

Doubled Angle Plots (M3) Summary of FDA Mixed Astigmatism Results with the Allegretto (Hyperopic Cyl Approach)

Glare and Night Driving   Preop Postop Delta Mean SD Night Driving 4.6 2.8 4.1 2.7 -0.5 3.6 Glare 4.9 2.6 4.3 2.4 -0.6 Overall average improved for both symptoms Summary of FDA Mixed Astigmatism Results with the Allegretto (Hyperopic Cyl Approach)

Change in Symptoms Summary of FDA Mixed Astigmatism Results with the Allegretto (Hyperopic Cyl Approach)

SurgiVision® Data Link Post-Approval Registry Results DataLink Analysis Cross v. Hyperopic Cylinder Treatments for Mixed Astigmatism SurgiVision® Data Link Post-Approval Registry Results

SurgiVision® Data Link Post-Approval Registry Results Current Analysis This analysis was performed to evaluate the objective outcome metrics using both approaches SurgiVision® Data Link Post-Approval Registry Results

SurgiVision® Data Link Post-Approval Registry Results Methods WaveLight surgeons using SurgiVision® DataLink software were asked to assign eyes entered for Mixed Astigmatism corrections to cohorts, depending on the treatment modality Results were analyzed for refractive and visual outcomes Month 3 outcomes were used for the analysis NOTE: Unable to perform stability analysis due to lack of long-term data SurgiVision® Data Link Post-Approval Registry Results

DataLink Surgeons: Please Assign Existing Data to the Cohorts Assign eyes to the appropriate cohort in the Preop form of DataLink

SurgiVision® Data Link Post-Approval Registry Results Total of 36 eyes were reported Cross cylinder approach: 25 (69%) Hyperopic cylinder approach: 11 (31%) 5 eyes operated with cross cylinder were operated using PRK Results did not differ from the LASIK eyes, so these results were pooled with the LASIK eyes Preoperative refractive features were similar for the two approaches Mean Preop Cyl was 3.2 ± 1.4 D for both groups SurgiVision® Data Link Post-Approval Registry Results

Uncorrected Visual Acuity 20/20 or Better Distance Targets Only SurgiVision® Data Link Post-Approval Registry Results

SurgiVision® Data Link Post-Approval Registry Results Spheroequivalent ± 0.50 D SurgiVision® Data Link Post-Approval Registry Results

Postop Cylinder (Mean/SD) SurgiVision® Data Link Post-Approval Registry Results

Doubled Angle Plot: Postop Cyl Hyperopic Cyl Approach 1 2 3 Very little scatter Centroid: (0.03, 0.05) SD 0.15 D SurgiVision® Data Link Post-Approval Registry Results

Doubled Angle Plot: Postop Cyl Cross Cyl Approach 1 2 3 Very little scatter Centroid: (-0.03, 0.03) SD 0.46 D SurgiVision® Data Link Post-Approval Registry Results

Attempted vs. Achieved Abs Cyl Hyperopic Cyl Approach SurgiVision® Data Link Post-Approval Registry Results

Attempted vs. Achieved Abs Cyl Cross Cyl Approach SurgiVision® Data Link Post-Approval Registry Results

SurgiVision® Data Link Post-Approval Registry Results Discussion Results in all categories are significantly better for hyperopic cyl Nomograms could potentially improve the cross-cyl accuracy However, the longer treatment time and interrupted treatment with cross-cyl approach is not amenable to nomogram improvement Results suggest that hyperopic cyl should be used to correct mixed astigmatism with the Allegretto More data could lead to other conclusions SurgiVision® Data Link Post-Approval Registry Results

SurgiVision® Data Link Post-Approval Registry Results Discussion Please update the “Cohort” field in the preop form for all mixed astigmatism corrections entered into DataLink Enter in the 3 month postop for these eyes, with a careful refraction This will allow me to supplement this analysis with more data SurgiVision® Data Link Post-Approval Registry Results

Comments Welcome DataLinkWLTForum@SurgiVision.net Guy1000@SurgiVision.net