Study of tear function before and after laser-assisted keratomileusis.

Purpose: This work assesses the change in tear function after LASIK surgery.

Methods: This prospective, observational study was conducted in the Refractive Clinic of a tertiary care rural hospital. Tear dysfunction symptoms and the tear function tests were assessed in 269 eyes of 134 patients, OSDI score was used to document the tear dysfunction symptoms. Tear function was assessed by tear meniscus height, tear film break-up time (TBUT), Lissamine green staining, corneal fluorescein staining, Schirmer test 1 without anesthesia before and at 4-6 weeks and 10-12 weeks after LASIK surgery.

Results: Preoperatively OSDI score was 8.54 ± 7.71. It increased to 15.11 ± 9.18 postoperatively at 4-6 weeks after LASIK surgery and 13 ± 9.56 at 10-12 weeks after LASIK surgery Mean TBUT preoperatively was 7.82 ± 3.57 sec which decreased to 5.34 ± 2.56 sec at 4-6 weeks and to 4.53 ± 2.63 sec at 10-12 weeks postoperatively. The number of eyes with clear secretion decreased from 40.5% preoperatively to 23.4% at 4-6 weeks and to 22.3% at 10-12 weeks postoperatively, whereas the granular and cloudy secretions increased significantly in eyes after LASIK surgery. The prevalence of eyes with Lissamine green score >3 (dry eye) increased from 17.1% preoperatively to 27.9% at 4-6 weeks and to 30.5% at 10-12 weeks. Similarly, the number of eyes showing positive fluorescein corneal staining increased from 5.6% preoperatively to 19% postoperatively at 4-6 weeks. Mean Schirmer score was 28.83 ± 6.39 mm preoperatively, 22.47 ± 5.38 mm at 4-6 weeks, and 21.27 ± 4.99 mm at 10-12 weeks after LASIK surgery.

Conclusion: The prevalence of dry eye increased after LASIK as was assessed by an increase in the tear dysfunction symptoms using OSDI score and the deranged values of various tear function tests after LASIK surgery.