Comparison of the Texture of Bowman’s Membrane in LASEK, PRK and Epi-LASIK

ASCRS April 3-9, 2009James S. Lewis, MD

Wills Eye Surgical Network, Philadelphia, PA

My travel expenses have been PAID by Moria, S.A. of Antony, France.

My travel expenses have been PAID by Moria, S.A. of Antony, France.

30 Consecutive EyesScheduled for

Advanced Surface Ablation were Randomized to

Epi-LASIK, PRK and LASEK

1080i Digital HD VIDEO

was captured in each case

video was passed thru a proprietary embossing filter

a representative swatch (like that on the right) was presented to three masked observers

images were graded 1-5

1: Smoothest 5: Roughest

procedureObserver

1Observer

2Observer

3Average Texture

LASEK 2 2.8 3 2.60

PRK 4.1 4 3.9 4.00

Epi-LASIK 1.6 1.3 1.2 1.36

Surgical Details

LASEK was performed with 30 seconds of exposure to a solution of 80 % BSS and 20% medical grade alcohol as described by Massimo Camellin

PRK was performed using a Hyperopic Amoil’s Brush

Epi-LASIK was performed using Moria’s Epi-K™

Motivations

Advanced Surface Ablation preserves the highest amount of corneal structural integrity

Bandage contact lenses, topical Mitomycin, cold BSS, NSAIDs, steroids, oral Vitamin Supplements and more homogeneous Excimer lasers have led to diminished scarring and haze

We strive to determine the smoothest possible surface to apply the refractive correction

Techniques and Alternatives

SEM distorts smoothness data by chemical post-processing

Drying artifacts thwart intraoperative measurement

Photography provides only a single image with variable lighting

EVI: Enhanced Video Imaging using uncompressed digital data and an embossing filter makes smoothness recognition easy

Conclusion

PRK using an Amoil’s brush provided the least smooth refractive surface (4.0 out of 5.0) for Excimer Laser Corneal Sculpting

LASEK produced a Bowman’s Membrane surface scored substantially better than PRK (2.6 out of 5.0)

Epi-LASIK scored a smoothness score of 1.36 out of 5.0

We suggest the best refractive results will arise from the smoothest refractive surface

Thanks

I gratefully acknowledge Massimo Camellin who suggested this study and who is responsible for our new commitment to advanced surface ablation.