15-Month Visual Outcomes and Corneal Power Changes of SMILE in Treating High Myopia With Maximum Myopic Meridian Exceeding 10.00 D

PURPOSE: To evaluate the long-term visual and refractive outcomes, optical quality, and stability of the cornea and axial length after small incision lenticule extraction (SMILE) for the correction of high myopia with a maximum myopic meridian exceeding 10.00 diopters (D). METHODS: Via a prospective cohort study, 53 eyes (53 patients) with a maximum myopic meridian exceeding 10.00 D were corrected with a VisuMax femtosecond laser (version 3.0; Carl Zeiss Meditec AG, Jena, Germany) at the Zhongshan Ophthalmic Center of Sun Yat-sen University. Refractive outcomes, aberrations, axial length, and corneal curvature were evaluated preoperatively and at 1, 3, and 15 months postoperatively. RESULTS: At 15 months postoperatively, the efficacy and safety indexes were 0.91 ± 0.25 and 1.15 ± 0.18, respectively. A total of 72% of eyes were within ±0.50 D and 89% were within ±1.00 D of the attempted spherical equivalent, respectively. From 1 to 15 months postoperatively, the significant regression was −0.24 ± 0.28 D ( P < .001) on manifest refraction and −0.43 ± 0.54 D ( P < .001) on anterior corneal curvature. In addition, a significant increase of 0.20 µm ( P = .016) was observed in the spherical aberration. No significant change was observed in posterior corneal curvature ( P > .999), including mean keratometry or astigmatism, or in the ocular axis length from 1 to 15 months postoperatively (26.82 ± 0.93 and 26.82 ± 0.95 mm, respectively, P > .99). CONCLUSIONS: SMILE had long-term safety, efficacy, and predictability when treating high myopia with a maximum myopic meridian exceeding 10.00 D. Both a manifest refraction regression of −0.24 D and a significant spherical aberration increase of 0.20 µm were observed between 1 and 15 months postoperatively, due to the increased anterior corneal curvature. [ J Refract Surg . 2019;35(1):31–39.]