Evaluation of Epithelial Cell Remodeling After a Lenticule Removal Procedure with a New Femtosecond Laser System

Abstract

Purpose : To assess epithelial cell remodeling after myopic laser vision correction with a new femtosecond laser for the correction of myopia and astigmatism through intrastromal lenticule removal procedure.

Methods : A prospective clinical study in myopic subjects ≥18 years is ongoing. 48 eyes of 24 myopic subjects were treated binocularly at 1 site for vision correction using a new femtosecond laser. Mean pre-operative Manifest Refraction Spherical Equivalent (MRSE) was -4.04 D and ranged from -2.00 D to -6.25 D (SD: 1.17 D). A lenticule removal procedure was used. The RTVue anterior segment Pachymetry + Cpwr scan (SW Ver. 6.11.0.12) was used to generate epithelial thickness maps comprised of 17 sectors over a 6 mm diameter circle. One central 2 mm diameter circular sector, 8 sectors within an annulus 2-5 mm diameter (ring-1), and 8 sectors within an annulus 5-6 mm diameter (ring-2). ANOVA with Tukey pairwise comparison was used to evaluate change in total epithelial thickness and change in superior versus inferior thickness from pre-operatively (44 eyes) to 1-day (42 eyes), 1-week (44 eyes), 1-mo (44 eyes), and 3-mo (17 eyes) post-operatively. A correlation between pre-operative MRSE and change in epithelial thickness was also evaluated.

Results : No significant change in epithelial thickness was found in the central sector at all time points. In ring-1, there was variability with significant thickening (1.47 µm) from pre-op to 1-day post-op followed by a significant thinning of 1.41 µm at 1-week and then continuous thickening at 1- and 3-mo post-op of 2.37 and 0.22 µm, respectively (p = 0.0001). In ring-2 there was a continuous thickening at 1- and 3-mo post-op of 1.47 and 1.08 µm, respectively (p = 0.0001). No significant change was observed between the superior vs. inferior sectors, and no correlation was found between pre-op MRSE and change in epithelial thickness (R² = 0.07, 0.05 for 1 and 3-mo post-op).

Conclusions : Significant change in epithelial thickness after lenticule removal with the new femtosecond laser was observed in rings 1 and 2. This thickening may be attributed to epithelial remodeling and is apparent at 1- and 3-mo post-op. No difference between superior and inferior change in thickness implies no effect of the lenticule entry cut on remodeling.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.