Management of low astigmatism in implantable collamer lens surgery: opposite clear corneal incisions vs toric implantable collamer lens

Abstract

Purpose: To compare 2 techniques to correct low astigmatism during implantable collamer lens (ICL) surgery: astigmatic opposite clear corneal incisions (OCCIs) and toric ICL (T-ICL).

Setting: Arruzafa Ophthalmological Hospital, Cordoba, Spain.

Design: Randomized prospective comparative study.

Methods: The study comprised 152 myopic eyes undergoing ICL surgery. Patients were separated into 2 groups: Group 1 (57 patients; 76 eyes) received a spherical ICL with OCCIs and Group 2 (53 patients; 76 eyes) received a T-ICL. The inclusion criteria were refractive astigmatism up to 1.50 diopters (D), regular corneal astigmatism up to 2.00 D (Sim K, Pentacam), and agreement between the refractive and topographic corneal cylinders (discrepancies less than 30 degrees axis or 0.50 D). The outcomes were evaluated after a 1-month follow-up.

Results: The T-ICL group achieved a mean postoperative spherical equivalent refraction and refractive astigmatism of -0.04 ± 0.17 D and -0.03 ± 0.12 D, respectively, vs -0.14 ± 0.33 D and -0.20 ± 0.36 D, in the OCCI group ( P < .001). Postoperative refractive astigmatism of less than 0.25 D was achieved in 94.74% of cases in the T-ICL group vs 73.68% in the OCCI group. Undercorrection of corneal astigmatism occurred in the OCCI group with a surgically induced astigmatism of 0.48 ± 0.24 D and correction index = 0.46.

Conclusions: Both the T-ICL and OCCI techniques provided excellent results in terms of safety and efficacy. T-ICL surgery was shown to be more predictable and accurate for correcting low astigmatism with a lower postoperative spherical equivalent and less residual astigmatism compared to incisional management.