Ten-year evaluation on efficacy, safety, and predictability of femtosecond laser corneal small incision lenticule extraction for correction of myopia and myopic astigmatism: a case series

Objective: The objective was to evaluate the 10-year long-term outcomes of patients undergoing small incision lenticule extraction (SMILE).

Methods: In this continuous case series, the authors enrolled a total of 113 patients (208 eyes) who underwent SMILE 10 years prior. Measured parameters included uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), and cycloplegia spherical equivalent error (SER).

Results: One hundred thirteen patients were enrolled in this study. Patients' age ranged from 18 to 44 years (mean: 30.2 years). One hundred ninety-three eyes (92.8%) and 176 eyes (84.6%) had an UCVA≥20/20 at 3 months and 10 years postoperatively. The mean efficacy index, measured at 3 months and 10 years postoperatively, were 1.041 and 1.023, respectively; the difference was not statistically significant. Three months after the operation, best-corrected visual acuity (BCVA) decreased by 1 line in 19 eyes (9.1%), remained unchanged in 158 eyes (76.0%), and increased by ≥1 line in 31 eyes (14.9%). Ten years after operation, BCVA decreased by 2 lines in 15 eyes (7.2%) and by 1 line in 35 eyes (16.8%); remained unchanged in 142 eyes (68.3%); increased ≥1 line in 16 eyes (7.7%). The mean safety index, measured at 3 months and 10 years postoperatively, were 1.147 and 1.331, respectively; the difference was not statistically significant. The mean SER at 3 months and 10 years postoperatively was -0.112 and -0.276, respectively; the difference was statistically significant.

Conclusion: There was a decrease in SER 10 years after SMILE surgery compared with 3 months postoperatively, there was no significant decrease in the efficacy index or safety index.