Calcification in the human lens.
A calcified cataractous lens from a 12 year old boy suffering from chronic uveitis was analysed using a microradiographic technique, X-ray crystallography and transmission electron microscopy. A 0.2 mm thick shell of calcified tissue was found in the subcapsular cortex. The mineral consisted of well-crystallized hydroxyapatite with a random orientation of the crystals. The underlying cortex consisted of a fibrous matrix containing collagen fibers. In the matrix, single or groups of epitheloid cells and fibroblast-like cells were found. Membrane-enclosed vesicles were found scattered in the matrix. The content of these vesicles had a wide range of electron density. A cell-induced mechanism for calcification is suggested.
D002114:Calcinosis / Q000150:complications / Q000473:pathology*; D002386:Cataract / Q000150:complications / Q000473:pathology*; D002387:Cataract Extraction / Q000379:methods; D002648:Child; D002675:Child, Preschool; D003461:Crystallography / Q000379:methods; D006801:Humans; D007905:Lens Diseases / Q000473:pathology*; D007908:Lens, Crystalline / Q000032:analysis* / Q000648:ultrastructure; D008297:Male; D008852:Microradiography / Q000379:methods; D008854:Microscopy, Electron; D014605:Uveitis / Q000150:complications