PURPOSE: To analyze the changes in corneal sensitivity and tear secretion after "laser in situ keratomileusis" (LASIK). METHODS: Thirty-eight eyes from nineteen patients, 9 men and 10 women, were submitted to myopic LASIK. The mean spherical equivalent before surgery was -3.79D (± 1.29). Corneal sensitivity was measured with a Cochet-Bonnet esthesiometer in the central region of the cornea. Tear secretion was evaluated by the Schirmer test, basal secretion, breakup time test and symptoms. Examinations were performed before and 7, 30, 90, 180, and 270 days after surgery, or until full recovery. RESULTS: Median preoperative corneal sensitivity was 60 mm (range, 50 to 60 mm); median Schirmer test was 21.5 mm (range, 10 to 30 mm); median basal secretion was 11.5 mm (range, 6 to 20 mm); median breakup time test was 16.0 seconds (range, 8 to 22 seconds). All patients recovered their preoperative corneal sensitivity and tear secretion values between 90 to 180 days after surgery. During 9 months of follow-up, 5 patients (10 eyes) did not present any dry eye symptom. CONCLUSION: After LASIK, the corneal sensitivity and tear secretion are decreased as long as for 6 months. During the postoperative period, 73.6% of the patients had dry eye symptoms. Further studies are required to best evaluate the effects on the corneal physiology.
Myopia; Laser in situ keratomileusis; Postoperative complications; Dry eye syndromes; Tears; Cornea
