PURPOSE. To investigate the changes in the epithelium and flap after laser in situ keratomileusis (LASIK), when measured with optical coherence tomography (OCT). METHODS. Twenty-eight eyes of 14 patients (age: 39.9 ± 8.6 years) underwent LASIK. The central thickness of corneal epithelium and flap were measured with a real-time 1310 nm OCT 1 day, 1 week, and 1 month after surgery. A custom software program was used to process multiple images of each eye on each visit. RESULTS. After surgery, the corneal epithelium changed significantly (ANOVA: F(3, 81) = 12.3, P = 0.000) with not statistically significant thinning at one day (mean ± SD: 57.8 ± 5.9 μm, P = 0.26, compared with baseline: 59.9 ± 5.9 μm) and statistically significant thickening at 1 week (60.8 ± 5.8 μm, P = 0.04, compared with 1 day) and 1 month (64.6 ± 6.1 μm, P = 0.008 compared with all others). There were statistically significant changes in the corneal flap thickness (ANOVA: F(2, 54) = 4.59, P = 0.01) with thickening in the intervals between 1 day (143.3 ± 20.6 μm) and 1 week (149.7 ± 24.6 μm, P = 0.12), and between 1 week and 1 month (152.7 ± 19.3 μm, P = 0.01). There was a strong correlation (r = 0.898) between the difference of corneal thickness before and after surgery and predicted laser ablation depth. CONCLUSIONS. OCT is a useful noncontact tool for thickness measurements of the epithelium, flap, and total cornea. After LASIK, the epithelium and flap showed thickening during the study period.
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience