Comparison of the Visual Outcomes and Optical Quality of Small Incision Lenticule Extraction and Toric Implantable Collamer Lens Implantation to Correct High Astigmatism

Purpose To compare 6-month visual outcomes and optical quality after small incision lenticule extraction (SMILE) and toric Implantable Collamer Lens (ICL) (STAAR Surgical Company) implantation for high myopia astigmatism. Methods This was a prospective non-randomized study. Overall, 88 eyes of 88 patients with high astigmatism (≥ 2.00 diopters [D]) were enrolled, comprising 42 and 46 eyes in the SMILE and toric ICL groups, respectively. Uncorrected distance visual acuity, corrected distance visual acuity, subjective manifest refraction, and higher order aberrations (HOAs) were examined before and 6 months after surgery. The astigmatism outcomes were further analyzed using Alpins vector analysis. Results The preoperative astigmatism was −3.20 ± 0.58 D in the SMILE group and −3.09 ± 0.81 D in the toric ICL group ( P = .495), respectively, and the postoperative astigmatism was −0.58 ± 0.39 and −0.72 ± 0.41 D ( P = .099) in the SMILE and toric ICL groups, respectively, at the 6-month visit. Surgically induced astigmatism, correction index, difference vector, the magnitude of error, and index of success were comparable between the two groups ( P > .05). The Alpins vector analysis indicated a significant difference in absolute values of the angle of error between the two groups (SMILE: 3.05 ± 2.98°, toric ICL: 4.70 ± 3.84°; P = .027). Compared with the SMILE group, the toric ICL group exhibited significantly fewer HOAs at the 6-month follow-up visit, including total HOAs, total coma, horizontal coma, vertical coma, and spherical aberrations. Conclusions Both SMILE and toric ICL implantation showed satisfactory efficacy and safety in correcting high myopia astigmatism, whereas toric ICL implantation induced fewer HOAs, leading to better postoperative visual quality. [ J Refract Surg . 2024;40(12):e916–e925.]