Corneal sensation after laser epithelial keratomileusis for the correction of myopia

Background: Subepithelial nerve fibre bundles and stromal nerves are damaged during laser epithelial keratomileusis (LASEK). The aim of this study was to investigate the recovery of corneal sensation after LASEK for the correction of myopia. Methods: Corneal sensation was evaluated in 40 eyes of 20 patients using a Cochet-Bonnet aesthesiometer before surgery and 3 days, 14 days, 1, 3 and 6 months after LASEK for the correction of mild to moderate myopia (range -2.5 D to -8.0 D). At every examination corneal sensation was tested in the apex of the cornea and in one point each at the 12, 3, 6 and 9 o' clock positions 2mm from the centre of the cornea. Results: Corneal sensation was significantly reduced at 3 days and 14 days after surgery (P <0.01). The loss of corneal sensation was greatest 3 days after surgery and corneal sensation increased during the first month after LASEK. After 1 month, 3 months and 6 months no significant difference was found between preoperative and postoperative sensation. There was no significant difference in sensation between different areas of the cornea after LASEK. Conclusions: Corneal nerves are disrupted during LASEK surgery and the procedure results in a significant reduction in corneal sensation. During the first month after surgery the depressed corneal sensation improved and subsequently went back to preoperative values, staying stable 3 months and 6 months after surgery.