Cataracta ossea - Ultrastructural and specimen analysis.

BACKGROUND

Although intraocular osseous metaplasia is a well-known phenomenon, ossification of the lens is a rare phenomenon nowadays.

MATERIAL AND

METHODS

An enucleated phthisical eye showed a rock-hard intraocular particle. Lens status after a trauma 36 years ago had been unclear. Differential diagnosis included an intraocular foreign body or ossification of the lens. X-ray diffraction analysis showed microcrystalline apatite indicating a mineralized structure. Histologic specimens revealed a mineralized lens that underwent secondary osseous metaplasia.

CONCLUSIONS

Due to the small number of cases, the mechanisms and preconditions of osseous metaplasia of the lens are not understood in detail, but injury to the lens capsule and availability of blood supply are being discussed. Both were present in this case, in which the luxated lens ended up in the ciliary body region. The mechanism resembled enchondral ossification rather than intramembranous ossification, which is seen in osseous metaplasia of other intraocular structures.