Keratocyte density in the retroablation area after LASEK for the correction of myopia

Purpose: During excimer laser photoablation keratocyte cell death is induced in the retroablation area. Afterwards this area is repopulated by keratocyte mitosis and migration from the adjacent stroma. The aim of this study was to investigate keratocyte density in the retroablation area and in the posterior stroma during the first year after LASEK for the correction of myopia. Methods: In a prospective study LASEK surgery was performed in 17 eyes of 10 consecutive patients for the correction of myopia (2.25 D to 9.0 D, mean 5.0 D). Confocal microscopy (Nidek Confoscan 2) was performed before surgery and 1 month, 3 months, 6 months and 12 months after LASEK. Keratocyte density was assessed in the anterior retroablation area at depths of 5 μm and 25μm and in the posterior stroma at distances of 5μm and 100μm from the corneal endothelium and compared with the corresponding area before surgery. Results: Keratocyte density was statistically significant reduced in the retroablation area at all timepoints after LASEK. At a depth of 5μm, cell densities were decreased by 64%, 47%, 43%, and 28% at 1 month, 3 months, 6 months and 12 months after LASEK compared with preoperative values. At a depth of 25μm, cell densities were decreased by 51%, 32%, 28%, and 18% at 1 month, 3 months, 6 months and 12 months after LASEK compared with preoperative values. In the posterior stroma no significant change in keratocyte density was observed at any time after LASEK. Conclusions: Keratocyte density in the anterior retroablation area recovers during the first year after LASEK for the correction of myopia, but does not go back to preoperative values.