Comparison of tear film stability and corneal sensitivity between laser-assisted subepithelial keratectomy with laser in situ keratomileusis

Objective:To compare the changes in tear film stability and corneal sensitivity after laser-assisted subepithelial keratectomy (LASEK) and laser in situ keratomileusis (LASIK). Methods: Forty eyes of 20 patients underwent LASIK and 40 eyes of 20 patients underwent LASEK to correct mypia. The patients were observed for corneal sensitivity, tear break-up time (BUT) and Schirmer test under local anesthesia before and 1, 3 and 6 months after operation. The results were analyzed statistically. Results: The tear film stability and corneal sensitivity were decreased to some extent in both groups after operation. Compared with before operation, there were significant differences in corneal sensitivity 1, 3 and 6 months after operation and in BUT 1. 3 months after operation in LASIK group (P0. 05); there were also significant differences in corneal sensitivity 1, 3 months after operation and in BUT 1 month after operation in LASEK group (P0. 05). The corneal sensitivity and BUT values were obviously different between the 2 groups 1, 3 months after operation (P0. 05), with the decrease of corneal sensitivity and BUT values more significant in LASIK group. There was no significant changes in Schirmer test results before and after operation in both groups (P0. 05). Conclusion: Both LASIK and LASEK influence the corneal sensitivity and tear film stability after operation; the influence diminishes with the recovery of the cornea. The influence in LASIK group is more serious and more persistent than that in LASEK group.