Various factors are thought to cause the development and progression of disease in macular
degeneration, diabetic retinopathy, and retinitis pigmentosa. Some of the deleterious
processes include oxidative stress, hypoxia, metabolic derangement, genetics, and
vasculopathy. In this review, we present a unified theory for the pathophysiology of several
retinopathies based on the unique and intense metabolism of rod photoreceptors.