Four-year follow-up of posterior chamber phakic intraocular lens implantation for moderate to high myopia.

Objective: To assess the long-term clinical outcomes of implantation of a lens consisting of a biocompatible collagen copolymer (Visian implantable Collamer lens [ICL]; STAAR Surgical, Nidau, Switzerland) for moderate to high myopia.

Methods: We evaluated 56 eyes of 34 patients with myopic refractive errors of -4.00 to -15.25 diopters (D) who underwent ICL implantation and routine postoperative examinations. Before and 1, 3, and 6 months and 1, 2, and 4 years after surgery, we assessed the safety, efficacy, predictability, stability, and adverse events of the surgery.

Results: Mean (SD) logMAR uncorrected and best spectacle-corrected visual acuities were -0.03 (0.23) and -0.21 (0.09), respectively, at 4 years after surgery. The mean (SD) safety and efficacy indexes were 1.19 (0.25) and 0.83 (0.29), respectively. At 4 years, 44 (79%) and 52 (93%) of the eyes were within +/-0.5 and +/-1.0 D, respectively, of the targeted correction. Mean (SD) manifest refraction changes of -0.24 (0.57) D occurred from 1 month to 4 years after surgery. No vision-threatening complications occurred during the observation period.

Conclusion: Implantation of ICLs is safe and effective and provides predictable and stable refractive results in the treatment of moderate to high myopia during a 4-year observation period, suggesting its viability as a surgical option for the treatment of such eyes.