Sudden painless visual loss: retinal causes.

Sudden painless visual loss occurs in retinal disorders that reflect primary ocular disease, as well as systemic disease. This article reviews vitreous and retinal detachment and macular degeneration as ocular causes of sudden visual loss. Retinal changes that are caused by systemic disease, including infectious retinitis, occlusion of retinal vessels, and proliferative new vessel formation, are reviewed. In each instance, the retinal examination should provide the ocular or systemic diagnosis or lead to the diagnosis.