Efficacy and safety after posterior chamber Implantable Collamer Lens implantation according to preoperative anterior chamber depth: Short-term comparative study

Purpose: To compare visual, refractive, and safety outcomes of posterior chamber Implantable Collamer Lens (ICL) implantation for the correction of myopia according to the preoperative anterior chamber depth (ACD). Methods: Retrospective, comparative study, patients submitted to implantation of myopic posterior-chamber phakic Implantable Collamer Lens (ICL), model V4C/V5, minimum follow-up of 12 months; two groups were created: Group 1 (ACD 2.80 to 2.99 mm) and Group 2 (ACD equal to or greater than 3.00 mm). The parameters evaluated were uncorrected and corrected visual acuity, subjective refraction, efficacy and safety index, predictability, endothelial cell density, central vault, anterior chamber angle and postoperative complications. A total of 558 eyes from 298 patients were evaluated: 111 eyes (19.9%) in group 1 and 447 eyes (80.1%) in group 2. Results: At 12 months, the efficacy index was similar in both groups ( p= 0.264); the safety index was higher in group 1 (p= 0.031); the mean central Vault was significantly lower in group 1 (212.8 vs 410.6 mu m; p < 0.001). Respectively, 93 (83.8%) and 366 (84.1%) eyes were within +/- 0.50 D of targeted refraction. Anterior chamber angle significantly decreased during follow-up in both groups ( p < 0.001; p < 0.001). Intraocular pressure did not change significantly ( p= 0.310 and p= 0.446, respectively). There were no significant differences in endothelial cell density loss ( p= 0.278) or in the rate of complications observed (p= 0.733). Conclusions: ICL implantation is an effective and safe procedure in eyes with shallow anterior chambers, with visual and refractive results and complication rates identical to those obtained in deeper anterior chambers.