Comparison of Ocular Surface Changes Following Laser-Assisted in Situ Keratomileusis and Photorefractive Keratectomy: Cross-Sectional Study

Abstract

Objective: To compare the ocular surface changes fol- lowing Femtosecond laser in situ keratomileusis (Femto-LASIK) and photorefractive keratectomy (PRK). Material and Methods: TThis prospective study included 74 eyes of 37 patients: 34 were in the Femto-LASIK group, and 40 were in the PRK group. Schirmer test, tear break-up time, and conjunctival impression cytology (CIC) were used to determine ocular surface changes before and 1 month, and 3 months after PRK or Femto-LASIK.Results: There were no significant differences between PRK and LASIK group in mean CIC scores in the first month (p > .05, for each). However, a significant difference ob- served at goblet cell density (GCD) at the third month between PRK and LASIK group (p =0.008). Comparing of the CIC scores between first month and the third month of PRK group showed significant im- provements in the GCD and epithelial cell sheet (p =0.005, p =0.001, respectively). However, no significant changes occurred in the Femto- LASIK group between first month and the third month (p > .05, for each). Conclusion: We observed histopathological changes in the per- ilimbal conjunctiva in the PRK and LASIK groups at the first month after surgery. It was observed that these changes continued in the 3rd postoperative month. Although GCD improved significantly in the PRK group, it was still lower than preoperatively. We can say that these changes play a primary role in the pathogenesis of dry eye and even cause a more severe course of DED in LASIK patients.