Progress in histopathologic and pathogenetic research in a retinitis pigmentosa model.

Retinitis pigmentosa is a major cause of visual impairment and blindness, affecting millions of people worldwide. The mechanisms of and effective treatments for the disease, however, remain to be further investigated. The Royal College of Surgeons rat is one of the most widely used animal models for the study of retinal degeneration diseases. The mutation in the mer tyrosine kinase proto-oncogene of this model leads to deficient phagocytosis in the retinal pigment epithelium cells and the accumulation of photoreceptor out segments in the subretinal space, ultimately resulting in retinal degeneration. The retina begins to change as early as 17 days after birth and becomes gradually thinner with the death and remodeling of cells and blood vessels. Retinal cell apoptosis plays a dominant role in this degeneration, with some cells being activated by the secondary alterations of the retinal neurotransmitter and other related factors.