Evaluation of 3 modern single-piece foldable intraocular lenses

PURPOSE: To assess the development of posterior capsule opacification (PCO) with 3 modern single-piece foldable intraocular lenses (IOLs) in a histopathological study and to compare the potential preventive effects of the IOL design and biomaterial in retarding PCO. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: Thirty-one rabbit eyes were randomly operated on with phacoemulsification and implantation of 3 single-piece foldable lenses: a hydrophilic acrylic design, the Rayner Centerflex 570H (n = 11); a hydrophobic acrylic design, the Alcon AcrySof SA30AL (n = 10); and a silicone large-hole plate design, the Staar AA-4203VF (n = 10). Central PCO (CPCO), peripheral PCO (PPCO), and Soemmering's ring formation were evaluated 3 weeks after surgery using the Miyake-Apple posterior photographic technique. Histological sections of each globe were prepared to document capsular bag status and performance of IOL geometry. RESULTS: The acrylic IOLs (Centerflex and AcrySof) had lower CPCO and PPCO scores than the silicone plate IOL (P <.05). There was no significant difference in Soemmering's ring formation among the 3 models. Pathological evaluations revealed effective blockage of migrating lens epithelial cells (LECs) at the site of the truncated optic edge of the Centerflex and AcrySof IOLs, even in the presence of large amounts of retained/regenerative cortical material. CONCLUSIONS: The AcrySof IOL has a hydrophobic surface and the Centerflex a hydrophilic surface, but no correlation to these characteristics could be identified. The single-piece AcrySof optic geometry created a clear-cut barrier effect equal to that of its 3-piece predecessor. The anatomic profile of the Centerflex IOL shows the same characteristics. The optics of both acrylic lenses have square truncated edges that functionally block ingrowth of migrating LECs toward the central visual axis, leaving clear posterior capsules. The square optic edge was an appropriate geometric configuration to create a barrier effect. There was no effect of the biomaterial on PCO prevention.