Risk factors for explantation of iris-fixated phakic intraocular lenses

Abstract

To determine risk factors for explantation of iris-fixated phakic intraocular lenses (pIOLs) with a maximum 17-year follow-up. University Eye Clinic Maastricht, Maastricht UMC+, the Netherlands. Prospective case series. Eyes that had implantation of 1 of various iris-fixated pIOL models from 1998 to 2016 were evaluated. Primary outcome measures were the rate and proportion of pIOL explantations and the survival time (ie, time to pIOL explantation) in general and specifically as a result of cataract formation or endothelial cell loss (ECL). The study comprised 1037 eyes. The mean follow-up was 69.3months±52.8 (SD) and the mean preoperative age, 40.2±10.9years. The overall explantation rate was 12% after a mean of 166.1months±3.0 (standard error). Phakic IOL explantations were performed in 59% of eyes because of cataract formation and in 32% because of ECL. Shorter survival was seen with a higher preoperative age (hazard ratio [HR], 1.07/y; P<.001), longer axial length (AL) (HR, 1.10/mm; P=.009), and smaller anterior chamber depth (ACD) (HR, 4.47/mm; P<.001). Factors for shorter survival resulting from cataract were older preoperative age, longer AL, and larger ACD. Risk factors contributing to shorter survival resulting from ECL were a smaller ACD, lower endothelial cell density, and implantation with an Artisan hyperopia (toric) or Artiflex myopia (toric) IOL. The explantation rate of iris-fixated pIOLs was 12% after almost 14 years of follow-up, with 59% of pIOL explantations caused by cataract formation and 32% caused by ECL. An older preoperative age, longer AL, and smaller ACD were risk factors for a shorter survival.