Pathology of 157 human cadaver eyes with round-edged or modern square-edged silicone intraocular lenses: analyses of capsule bag opacification

Purpose: To assess the degree of capsular bag opacification in human cadaver eyes with silicone intraocular lenses (IOLs), specifically comparing the differences between round-edged IOLs and modern square-edged IOLs.

Setting: John A. Moran Eye Center, University of Utah, USA.

Design: Experimental study.

Methods: The eyes were immersed in 10% formalin on enucleation. They had anterior segment scanning with a very-high-frequency ultrasound (Artemis). After the eyes were sectioned at the equator, gross examination of the anterior segment was performed from the posterior aspect to assess the degree of capsular bag opacification, coverage of the IOL edge by the anterior capsule, and IOL fixation. Selected eyes also had histopathologic examination.

Results: Eighty-seven eyes with a 3-piece round-edged IOL, 43 with a 3-piece square-edged IOL, 26 with a 1-piece plate IOL, and 1 with an accommodating IOL design were included in the analyses of capsular bag opacification. Comparison between 3-piece round-edged IOLs and square-edged IOLs showed statistically significant differences in central posterior capsule opacification (PCO) (P=.0001687) and peripheral PCO (P<.0001). In eyes with square-edged IOLs, PCO had a tendency to start in areas without capsulorhexis coverage of the optic. Twenty-one of 26 eyes with a silicone plate IOL had a neodymium:YAG posterior capsulotomy for dense PCO.

Conclusions: This first study using pseudophakic human cadaver eyes that includes a significant number of modern 3-piece silicone IOLs with square optic edges confirmed the role of this design in the prevention of PCO.

Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.