Cataracta ossea - Ultrastructural and specimen analysis

Background: Although intraocular osseous metaplasia is a well-known phenomenon, ossification of the tens 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 tens. X-ray diffraction analysis showed microcrystalline apatite indicating a mineralized structure. Histologic specimens revealed a mineralized tens that underwent secondary osseous metaplasia. Conclusions: Due to the small number of cases, the mechanisms and preconditions of osseous metaplasia of the tens are not understood in detail, but injury to the tens capsule and availability of blood supply are being discussed. Both were present in this case, in which the luxated tens 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. (C) 2009 Elsevier GmbH. All rights reserved.