[Light and electron microscopy of the human, anterior cataract capsule]

Forty-three anterior lens capsules and epithelium from cataract patients extracted during extracapsular cataract surgery were examined by light microscopy and morphometry. An additional 15 lens capsules were examined by transmission electron microscopy. Morphometric examination revealed a positive correlation between age and the lens capsule thickness of 0.08 micron/year. The medium lens-capsule thickness of a 65-year-old human being was 8.65 microns. Light microscopy of cataractous anterior lens capsule and epithelium demonstrated proliferative changes with a multilamellar arrangement of the lens epithelial cells and an increase in the pleomorphic appearance of the cell and nucleus. Examination of the lens capsule revealed intracapsular foamy and vacuolic deposits with a localized splitting of the lens capsule. Transmission electromicroscopy established certain aspects of the lens capsule and epithelium. We found intracytoplasmatic single cilia and fibrillar intracytoplasmatic structures, with a diameter of 12-20 nm arranged in a pseudocrystalline fashion. The anterior lens capsule demonstrated similarly localized deviations from the normal homogeneous structure of type IV collagen, resulting in intracapsular deposition of fibrillar material. These observations suggest that cataractogenesis is associated with ultrastructural metaplastic and degenerative alteration of the lens epithelium and capsule.