PURPOSE: To monitor tear volume and tear film stability before and after LASIK. METHODS: Tear meniscus height at the mid-point above the lower eyelid and tear thinning time were measured using videokeratography in both eyes before bilateral LASIK and at 1, 3, and 6 months postoperatively. Patients predisposed to dry eye before surgery were excluded. RESULTS: Twenty-six patients (52 eyes) were monitored. Mean tear meniscus height values were: preoperative, 0.26 +/- 0.09 mm; 1 month, 0.24 +/- 0.07 mm; 3 months, 0.26 +/- 0.07 mm; and 6 months, 0.26 +/- 0.06 mm. The differences were not significant. Change in tear meniscus height at 1 month was 0.1395-0.601 [preoperative tear meniscus height] (r = -0.701, P < .0001, n = 52). On average, tear thinning time was not affected by LASIK. When preoperative tear thinning time was < 20 seconds, individual changes in tear thinning time at 3 and 6 months were significant (P < .05) but not at 1 month (P = .206). CONCLUSIONS: Average tear meniscus height and stability are not affected by LASIK; however, there is considerable variability between individual eyes.
PURPOSE: To monitor tear volume and tear film stability before and after LASIK. METHODS: Tear meniscus height at the mid-point above the lower eyelid and tear thinning time were measured using videokeratography in both eyes before bilateral LASIK and at 1, 3, and 6 months postoperatively. Patients predisposed to dry eye before surgery were excluded. RESULTS: Twenty-six patients (52 eyes) were monitored. Mean tear meniscus height values were: preoperative, 0.26 +/- 0.09 mm; 1 month, 0.24 +/- 0.07 mm; 3 months, 0.26 +/- 0.07 mm; and 6 months, 0.26 +/- 0.06 mm. The differences were not significant. Change in tear meniscus height at 1 month was 0.1395-0.601 [preoperative tear meniscus height] (r = -0.701, P < .0001, n = 52). On average, tear thinning time was not affected by LASIK. When preoperative tear thinning time was < 20 seconds, individual changes in tear thinning time at 3 and 6 months were significant (P < .05) but not at 1 month (P = .206). CONCLUSIONS: Average tear meniscus height and stability are not affected by LASIK; however, there is considerable variability between individual eyes.