Yonago Acta medica 1996;39:59-64

Histopathological Study of a Doughnut-Shaped Lens Luxated in the Vitreous in a Case of Blunt Ocular Trauma

Shigeru Takagi, Sayo Tsunematsu, Masao Nagata, Keiko Sasaki, Yoshihiro Murata, Ryoko Ishihara and Akihiko Tamai

Department of Ophthalmology, Faculty of Medicine, Tottori University, Yonago 683, Japan

A peculiarly shaped lens extracted from the vitreous cavity was histopathologically examined by light microscopy, transmission electron microscopy and scanning electron microscopy. The subject patient (49-year-old male) had suffered from blunt ocular trauma 40 years before. The lens seemed to have dropped into the vitreous after the injury. The surgically removed lens showed a "doughnut appearance", with a central thin membrane and an equatorial ring-shaped mass. The lens epithelial cells were almost normally arranged at the equatorial region, but fell off at the membranous portion. The ring-shaped mass consisted of normally arranged epithelial cells and degenerated lens fibers, accompanied by a very hard central core. These results indicate that the lens capsule was ruptured in the central portion by some blunt trauma, and that the lens cortex at the central region was gradually absorbed. Incidentally, it is surmised that the epithelial cells remaining at the equatorial region formed new lens fibers, resulting in the doughnut-shaped lens.

Key words: blunt ocular trauma; doughnut-shaped lens; histopathology; lens epithelial cells; surgically removed lens