Three-Dimensional Epithelial Evaluation Following Myopic LASIK

Friday, April 25, 2014
KIOSKS (Boston Convention and Exhibition Center)
George Asimellis, PhD, Laservision.gr Eye Institute, Athens, Greece
A. John Kanellopoulos, MD, Laservision.gr Institute, Athens, Greece

Narrative Responses:

Purpose
To evaluate epithelial thickness profile changes following myopic femtosecond-assisted LASIK in relation to the degree of myopia corrected, evaluated with a spectral-domain anterior-segment optical coherence tomography system.

Methods
61 consecutive cases that were subjected to femtosecond LASIK myopic correction were investigated for corneal epithelial thickness distribution both pre-operatively as well as one-day, one-week, one-month and one-year post-operatively.  Epithelial thickness mapping over the 6 mm diameter corneal area was obtained with a commercially-available anterior-segment, spectral-domain optical coherence tomography (AS-OCT) system.  Descriptive statistics investigated pre- and post-operative epithelial thickness up to one year at the central 2 mm, the average over the central 6 mm area, and mid-peripherally at the 5 mm ring area.

Results
Preoperatively, pupil center epithelial thickness was 51.67±2.57 (45 to 56) μm, mean 51.76±2.66 (45 to 57) μm, mid-peripheral 51.78±2.71 (46 to 57) μm.  Epithelial thickness changed at the first postoperative day by -0.08, -0.34, and -0.39 μm, centrally, mean, mid-peripherally, then by -0.30, +1.07, +1.35 μm on the first week.  On the first month appeared increased by +1.58, +2.88, and +3.31 μm (p=0.0036, <0.001, and <0.001), and after one-year +1.42, +2.90, and +3.19 μm, (p=0.146, <0.001, and <0.001).  The correlation between epithelial increase at one-year and the amount of myopic correction showed a trend towards epithelial increase with myopic ablation.

Conclusion
This study suggests that there may be a very significant correlation of epithelial hypertrophy to degree of myopia corrected with LASIK, particularly in high myopic corrections.