In vivo confocal microscopic evaluation of corneal wound healing after epi-LASIK.

Purpose: To study the healing of corneal wounds after epikeratome laser-assisted in situ keratomileusis (epi-LASIK).
Methods: Twenty-seven patients who had undergone epi-LASIK for the treatment of myopia or myopic astigmatism in 46 eyes were enrolled. A single intraoperative application of 0.02% mitomycin C (MMC) for 20 to 30 seconds was used in 24 eyes with a refraction of no less than -6.0 D (MMC group). MMC was not given to eyes with myopia less than -6.0 D (non-MMC group). The eyes were examined by in vivo confocal microscopy at 1, 3, and 7 days after surgery and then weekly during the first month and once each at 3 and 6 months. Selected images of the corneal basal-apical surface epithelia and stromal reactions quantified by z-scan profile were evaluated.
Results: In vivo confocal microscopy showed that cells in most of the epithelial flaps were damaged during the first few days after surgery and were rapidly replaced by new growing cells. In the MMC and non-MMC groups, the corneal basal epithelial cells returned to their preoperative morphology in 0% and 13.6% of the eyes after 1 week, 37.5% and 36.4% after 2 weeks, and 87.5% and 86.3% after 1 month, respectively. The corneal apical surface epithelial cells in the MMC and non-MMC groups recovered their squamous morphology in 12.5% and 13.6% of the eyes at 2 weeks, 37.5% and 54.5% at 1 month, and 52.4% and 57.9% at 6 months, respectively. There was no difference in the stromal reaction between the groups at 1, 3, and 6 months after surgery.
Conclusions: Damage of the epithelial flaps after epi-LASIK was observed by in vivo confocal microscopy. MMC usage may cause more damage to the epithelial flaps. There was no difference in stromal reaction between the groups with and without MMC.