[Iris degeneration in the Royal College of Surgeons rat].

The pathologic changes in the iris epithelial cells of the Royal College of Surgeons (RCS) rat are reported. Light microscopy demonstrated progressive thinning of the iris tissue of the RCS rat after 3 month of age. Transmission electron microscopy showed cellular degenerative changes in both the anterior and the posterior iris epithelium. It is possible that these changes in the iris are the result of the same type of genetically determined defect of the retinal pigment epithelial cells that characterizes this animal model for retinal degeneration.