Planned vs achieved stromal thickness reduction in femtosecond laser-assisted myopic LASIK and SMILE: an objective evaluation utilizing anterior segment OCT measurements

Session Details

Session Title: SMILE: Small Intrastromal Lenticule Extraction I

Session Date/Time: Sunday 11/09/2016 | 08:00-10:00

Paper Time: 09:20

Venue: Hall H1

First Author: : G.Pamel GREECE

Co Author(s): :    A. Kanellopoulos                    

Abstract Details

Purpose:

To objectively evaluate corneal stromal thickness reduction in myopic LASIK and Smile and compare attempted vs. achieved ablation depth in a consecutive retrospective study.

Setting:

LaserVision.gr Clinical and Research Eye Institute, Athens, Greece

Methods:

Stromal thickness reduction was retrospectively investigated in 205 consecutive myopic and myopic astigmatic LASIK eyes and 80 Smile eyes. Anterior-segment optical coherence tomography (AS-OCT, Rt-Vue-100, Optovue, Fremont, CA) was employed to provide pre-operative and three-month postoperative pachymetry maps. Stromal thickness change was evaluated as the difference between minimum thickness in pre- to post- pachymetry. The difference in epithelial thickness was also considered. The derived maximum stromal thickness reduction was then compared to the programmed (planned) maximum ablation depth. Deviations of planned vs. achieved maximum stromal thickness changes were correlated with residual refractive error.

Results:

The three-month stromal reduction was in average 86±28 μm, compared to the average programmed maximum ablation depth of 88±26 μm for LASIK and 96.01±26 μm -98 ±28 μm for the Smile cases respectively for the myopic corrections planned and achieved. The attempted vs. achieved thickness outliers correlated with deviations in achieved refractive correction.

Conclusions:

We introduce an objective technique for evaluation of actual stromal thickness reduction in myopic LASIK and Smile. Actual objective stromal thickness reduction following myopic LASIK and Smile correlates well with the attempted versus achieved refractive change.

Financial Disclosure:

NONE