DYSTROPHIC CALCIFICATION OF AN IMPLANTED HYDROXYETHYLMETHACRYLATE INTRAOCULAR-LENS

Hydroxyethylmethacrylate is a biomaterial still under clinical trial f or use in foldable intraocular lenses. We observed a patient in whom a geographic opacification developed within an implanted hydroxyethylme thacrylate lens, together with granular deposits on the posterior lens capsule and in the scar of a paracentesis. The intraocular lens and p osterior lens capsule were removed because of impaired visual acuity. Light and scanning electron microscopy disclosed nodular calcification s within the intraocular lens and granular, partially crystalline, cal cifications on the posterior lens capsule. Energy-dispersive x-ray ana lysis and x-ray diffraction showed the deposits in the intraocular len s to consist of calcium hydroxyapatite. We presume this mineralization to be dystrophic, with calcium derived from lens remnants and phospho rus possibly derived from a thymoxamine solution used briefly during t he cararact operation. Our observation suggests caution in the use of phosphated solutions together with hydroxyethylmethacrylate intraocula r lenses and may warrant reconsideration of the suitability of hydroxy ethylmethacrylate intraocular lenses, should additional similar cases be reported.