Dry Eye Disease after Refractive Surgery

Purpose To compare small incision lenticule extraction (SMILE) versus LASIK for post-refractive dry eye disease. Design Prospective, comparative, nonrandomized clinical study. Participants Thirty patients scheduled for bilateral myopic SMILE and 30 age-, sex-, and refraction-matched patients scheduled for bilateral myopic LASIK were enrolled and followed for 6 months after the surgery. Methods Complete evaluation of dry eye disease was performed at 1 and 6 months postoperatively, which included vision-related quality of life (Ocular Surface Disease Index [OSDI]), clinical examinations (tear film breakup time [TBUT], Schirmer I test, corneal staining), and tear osmolarity measurements, together with an overall severity score. Function and morphology of the corneal innervation were evaluated by corneal esthesiometry and subbasal nerve imaging using in vivo confocal microscopy (IVCM). Main Outcome Measures Overall analysis of dry eye disease and corneal innervation. Results High incidence of mild to moderate dry eye disease was observed in both groups 1 month postoperatively, which remained significantly higher in the LASIK group than in the SMILE group 6 months after surgery (overall severity score [0–4]: 1.2±1.1 vs. 0.2±0.4, respectively, P P R ² = 0.48, P R ² = 0.50, P R ² = 0.21, P Conclusions The SMILE procedure has a less pronounced impact on the ocular surface and corneal innervation compared with LASIK, further reducing the incidence of dry eye disease and subsequent degradation in quality of life after refractive surgery.