Screening for mouse retinal degenerations. II. Molossinus MOLC and MOLD strains.

Using screening techniques of indirect ophthalmoscopy, electroretinography, and histology, we found inbred strains of Mus musculus molossinus to have a variable onset of retinal degeneration, which may present with early loss of outer segments and photoreceptor nuclei. The early affected mice have constricted vessels, optic atrophy, and markedly abnormal electroretinograms. An intermediate form of retinal degeneration was identified with slight arterial narrowing on ophthalmoscopy and electroretinogram amplitudes approximately 50% of normal. From this preliminary study the hereditary pattern is unclear. The mice with early onset of retinal degeneration share features seen in rd mice, but in a number of the molossinus the degeneration is slower with only a partial loss on electroretinogram amplitude.