Cornea Endothelial Cell Loss Before and After Explantation of Artisan and Artiflex Iris-Fixated Phakic Intraocular Lenses

Abstract

Purpose: To investigate the risk factors for corneal endothelial cell density (ECD) loss of 2 types of iris-fixated phakic intraocular lenses (pIOL) and indicate the cutoff values for preventing irreversible ECD loss after explantation.

Design: The retrospective, comparative, clinical cohort study.

Methods: Total 114 eyes of 61 patients were included in this study. Fifty-five eyes with Artisan pIOL and 59 eyes with Artiflex pIOL had undergone explantation of pIOLs due to continuous ECD loss. Correlation analysis was performed to assess the ocular parameters associated with ECD loss. Receiver operating characteristic (ROC) curve was performed to set cutoff values of ocular parameters to prevent ECD loss after explantation.

Results: The mean ECD before explantation was 1637 cells/mm² in Artisan group and 1769 cells/mm² in Artiflex group. The distance of cornea endothelium to IOL center and edges were all significantly higher in Artisan group (P < .05). The risk factor of decreased ECD in Artisan group were small anterior chamber angle (ACA), and distance of nasal edge of IOL to endothelium and iris fixation to nasal limbus distance, and differences of fixation length. In Artiflex group, ACA, distance of nasal edge of IOL to endothelium, both limbus to IOL fixation length, fixation length, iris pigmentation grading were the risk factors. At 1 year after the pIOL removal, the population demonstrating ΔECD >10% were significantly higher in Artisan group than Artiflex group (P < .05). In ROC curve analysis, the cutoff value of preoperative ECD to prevent significant postexplantation ECD loss was 1683.5 cells/mm² in Artisan group and 1648 cells/mm² in Artiflex group.

Conclusions: This study examined the existing explantation guidelines for these lenses. In analyzing the longterm prognosis of cornea ECD with Iris-fixated phakic intraocular lens, it is important to identify the relevant anatomical factors. Small ACA, and short distances from IOL to endothelium and from limbus to iris fixation especially in the nasal region were significant risk factors to continuous ECD loss in both lenses. To minimize irreversible ECD loss after explantation, it is important to determine the optimal period of explantation by observing both ECD and structural changes.