Posterior lens rupture in rats

Rupture of the posterior lens capsule with extrusion of lens fibers or entire lens cortex and nucleus was found in Sprague-Dawley rats. The lesion was detected during an ophthalmoscopic examination as round shadows that interfered with the view of the fundus. By slit-lamp biomicroscopic and dissecting microscopic examinations, the shadows were related to opaque plaques located on the posterior capsule. By light microscopic examination, the posterior lens capsule was ruptured and lens fibers extruded into the vitreous. Mononuclear and multinucleared giant cells were present at the site of rupture, however, few other inflammatory responses were present. Although the incidence and pathogenesis of the lesion is unknown, the lesion should be considered along with other spontaneous ocular changes when evaluating safety assessment studies.