The Clinical Study Of Femtosecond Laser Small Incision Lenticule Extraction For Myopia

Objective:To investigate the clinical safety, efficacy, predictability and stability of femtosecond laser small incision lenticule extraction (SMILE) for myopia.Methods This is a prospective study involved 94 patients (170 eyes) with myopia, including 34 males (62 eyes) and 60 females (108 eyes).The patients’ average age was 26.8±4.7(range 18 to 44)years. The mean preoperative spherical equivalent(SE) was -6.20±1.37 diopters (D) (from -3.25 to -9.13 D).The mean myopic astigmatism was -0.75 (0.75) D (from 0.00 to -3.25 D).The mean corneal thickness was 554.7±27.5μm(range 484 to 600μm).Routine ophthalmologic examinations including uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, intraocular pressure, corneal topography, and slitlamp examination were done. The patients received routine SMILE procedure and were followed up from 6 months to 2 years. The results were analyzed with the paired t test and linear regression analysis. P<0.05 was considered statistically significant.Results All procedures were completed successfully without complications. By the end of follow-up 97% of eyes had a UCVA of 1.0 or better, and 100% of eyes had a UCVA of 0.8 or better. BCVA was equal to or better than the preoperative BCVA in 100% of eyes,35% gained one line, and 10% gained two lines of BCVA. The residual spherical equivalent was -0.01±0.45 D and 87% and 100% were within ±0.50 and ±1.00 D of attempted correction. Higher order aberrations (HOA)、spherical aberrations and coma significantly (P<0.05) increased 0.15±0.12μm、0.04±0.11μm、 0.14±0.14μm after surgery.Conclusions SMILE was safe, effective, predictable and stable for myopia. The change of spherical aberrations was small whereas HOA increased after SMILE.