To compare effects of small-incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (F-LASIK) on corneal sensation and dry eye parameters.
In this prospective, randomized, contralateral-eye study, 28 patients with myopia or myopic astigmatism in both eyes were enrolled. One eye of each patient was treated by SMILE, and the fellow eye was treated by F-LASIK. Mean outcome measures Cochet-Bonnet esthesiometry, Schirmer test with anesthesia, tear breakup time, and tear film osmolarity were evaluated preoperatively as well as 1 week, 1 month, 3 months, and 6 months after surgery.
Corneal sensation was reduced after both SMILE and F-LASIK surgeries 1 week, 1 month, and 3 months after surgery (p < 0.05 in both groups). Corneal sensation was significantly lower after F-LASIK than after SMILE at postoperative 1 week, 1 month, and 3 months (p < 0.01 for all points). Dry eye parameters such as tear breakup time, Schirmer test, and tear film osmolarity did not change significantly in any of the procedures and were not significantly different between the procedures at any follow-up visits.
The findings of the study revealed that, although both F-LASIK and SMILE procedures changed the corneal sensation 1 week, 1 month, and 3 months after surgery, they did not affect the dry eye parameters at any point.