Decreased tear secretion after laser in situ keratomileusis for high myopia

PURPOSE: To investigate the changes in tear secretion and tear film stabili ty after excimer laser in situ keratomileusis (LASIK) for high myopia. METHODS: One eye of 28 patients underwent unilateral LASIK for the correcti on of myopia with spherical equivalent refractions ranging from -6.37 to -1 8.25 D (mean, -11.98 +/- 3.45 D). Schirmer tear test values without anesthe sia at 5 minutes and tear break-up time values were measured 4 weeks after LASIK. Unoperated contralateral eyes were used as a control for each patien t. The Schirmer tear test and tear break-up time values were analyzed stati stically using the independent t-test. RESULTS: The mean Schirmer tear test value was 16.17 +/- 2.50 mm in the ope rated eyes and 21.07 +/- 7.03 mm in the unoperated (control) eyes of the sa me patients (P = .001). The mean tear break-up time value was 21.0 +/- 3.55 seconds in the operated eyes and 21.27 +/- 6.79 seconds in the control eye s (P = .85). CONCLUSION: Tear secretion decreased following LASIK probably due to decrea se in corneal sensitivity, but tear film stability appeared unaltered.