Intense Cyclic Light–Induced Retinal Degeneration in Rats

Retinal degenerations, including retinitis pigmentosa and age-related macular degeneration (AMD), affect the sight of nearly 10 million people in the United States, and treatment options for those affected are limited to nonexistent. The understanding of retinal degenerations has been greatly enhanced through the use of environmental exposures that result in damage to photoreceptors or the Bruch membrane. Environmentally induced retinal degenerations, such as exposure to intense constant light or laser photocoagulation, in normal rodents1 have provided useful models for the study of retinal degeneration and choroidal neovascularization. Studies of light exposure in rodents with mutations that cause photoreceptor degeneration have provided further insight into the complex relationship between light exposure and retinal degeneration (reviewed by Wenzel et al2 and Paskowitz et al3).