Analysis quantitative and qualitative of the tear film in patients undergoing PRK and LASIK with femtosecond

Abstract

Purpose: To evaluate tear film stability, ocular surface staining and tear secretion in patients undergoing PRK and femtosecond laser LASIK. Methods: Twenty eyes of 10 patients submitted to femtosecond laser LASIK and 11 eyes of the 6 patients submitted do PRK underwent tear film break-up time (TBUT), Schirmer's basal and lissamine green staining measurements pre and postoperatively on days 15 (PO 15) and 30 (PO 30). Results: When grouping all eyes TBUT was reduced on PO 15 (p=0.025) and on PO 30 (p=0.001) compared to preoperative values. No difference was found between PO 15 and PO 30 (p=0.219). Compared to preoperative measurements, lissamine green test demonstrated a significant increase in score on PO 15 (p=0.021) and a significant reduction on PO 30 (p=0.010), when both groups were analyzed together (all 42 eyes). No changes in Schirmer's basal test were detected in all 3 time periods (p=0.107). TBUT, lissamine green and Schirmer's basal measurements were no different in all 3 time periods when both groups (PRK and femtosecond laser LASIK) were compared. Conclusion: TBUT and lissamine green measurements were altered after refractive surgery regardless the technique (PRK or femtosecond laser LASIK). When comparing one technique to the other, no difference was found in all measurements.