Dry eye after small incision lenticule extraction and LASIK for myopia.

PURPOSE: To compare the effects of small incision lenticule extraction (SMILE) and LASIK with either femtosecond laser or mechanical microkeratome on dry eye. METHODS: A total of 176 patients (338 eyes) who underwent refractive procedures for myopia were observed in this nonrandomized, interventional, prospective study. To evaluate dry eye, the Schirmer secretion test without anesthesia, tear break-up time, and the McMonnies questionnaire were used preoperatively and at 1, 3, and 6 months postoperatively. RESULTS: In all groups, there was no significant decrease in the results from the Schirmer secretion test without anesthesia after surgery. The value in the LASIK group was significantly lower than any other group at 3 and 6 months postoperatively. In all groups, the tear break-up time decreased significantly after surgery and did not return to preoperative levels within 6 months; the SMILE group time lasted significantly longer than the LASIK group at 1 month. The McMonnies score increased significantly in all groups after surgery. The preoperative levels returned within 6 months in all groups except the LASIK group. The mean McMonnies score in the SMILE group was better than other groups. CONCLUSIONS: Dry eye after corneal refractive surgery usually occurs transiently. The SMILE procedure had better dry eye parameters and relatively fewer subjective symptoms than LASIK.