Decreased tear secretion after laser in situ keratomileusis for high myopia.

PURPOSE To investigate the changes in tear secretion and tear film stability after excimer laser in situ keratomileusis (LASIK) for high myopia. METHODS One eye of 28 patients underwent unilateral LASIK for the correction of myopia with spherical equivalent refractions ranging from -6.37 to -18.25 D (mean, -11.98 +/- 3.45 D). Schirmer tear test values without anesthesia 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 patient. The Schirmer tear test and tear break-up time values were analyzed statistically using the independent t-test. RESULTS The mean Schirmer tear test value was 16.17 +/- 2.50 mm in the operated eyes and 21.07 +/- 7.03 mm in the unoperated (control) eyes of the same 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 eyes (P = .85). CONCLUSION Tear secretion decreased following LASIK probably due to decrease in corneal sensitivity, but tear film stability appeared unaltered.