Dystrophic calcification of an implanted hydroxyethylmethacrylate intraocular lens
P. J. Bucher, E. R. Buchi and B. C. Daicker
University Eye Hospital, Basel, Switzerland.
Hydroxyethylmethacrylate is a biomaterial still under clinical trial for
use in foldable intraocular lenses. We observed a patient in whom a
geographic opacification developed within an implanted
hydroxyethylmethacrylate lens, together with granular deposits on the
posterior lens capsule and in the scar of a paracentesis. The intraocular
lens and posterior lens capsule were removed because of impaired visual
acuity. Light and scanning electron microscopy disclosed nodular
calcifications within the intraocular lens and granular, partially
crystalline, calcifications on the posterior lens capsule.
Energy-dispersive x-ray analysis and x-ray diffraction showed the deposits
in the intraocular lens to consist of calcium hydroxyapatite. We presume
this mineralization to be dystrophic, with calcium derived from lens
remnants and phosphorus possibly derived from a thymoxamine solution used
briefly during the cataract operation. Our observation suggests caution in
the use of phosphated solutions together with hydroxyethylmethacrylate
intraocular lenses and may warrant reconsideration of the suitability of
hydroxyethylmethacrylate intraocular lenses, should additional similar
cases be reported.
