Comparison of dry-eye disease severity after laser in situ keratomileusis and laser-assisted subepithelial keratectomy

PURPOSE: To evaluate the effects of laser in situ keratomileusis (LASIK) and laser-assisted subepithelial keratectomy (LASEK) on dry-eye disease markers including tear osmolarity, Schirmer testing, and the ocular surface disease index (OSDI). SETTING: Laser Suite, Mater Private Hospital, Dublin, Ireland. DESIGN: Prospective controlled cross-sectional observation study. METHODS: In a single center, consecutive eyes that had LASIK or LASEK had dry-eye disease markers assessed preoperatively and 3, 6, and 12 months postoperatively. RESULTS: In LASIK eyes (n = 50), the mean tear osmolarity was significantly elevated (by 2.8%) at 12 months (P=.009, Student t test). The mean Schirmer test values were not significantly altered postoperatively in either group. The mean OSDI was maximum in LASIK eyes at 3 months (mean follow-up 7.2 months +/- 8.2 [SD]) and in LASEK eyes (n = 35) preoperatively (mean follow-up 9.1 +/- 9.7 months). CONCLUSIONS: There were no significant differences in dry-eye disease markers or tear osmolarity between LASIK and LASEK patients at any stage after surgery up to 1 year. Although tear osmolarity remains one of the highest predictive tests of dry eye, it is complementary with other diagnostic criteria in the context of dry eye after refractive surgery.