Distinguishing Characteristics of Primary Retinal Vasculitis from Eales Disease

Retinal vasculitis is a poorly characterized, potentially sight-threatening, inflammatory ocular condition that occurs when there is the presence of abnormal blood vessels in the retina. The annual incidence of retinal vasculitis in the United States is estimated at 1-2 per 100,000 with variation between regions. Because it is not well understood, the definition of “retinal vasculitis” is not well established. Currently, the Standardization of Uveitis Nomenclature Working Group considers “perivascular sheathing and vascular leakage/occlusion on fluorescein angiogram as evidence of retinal vascular disease” in classifying retinal vasculitis [1]. There are two main causes of retina vasculitis: primary ocular vasculitis, occurring as an isolated condition or secondary retinal vasculitis, caused by an inflammatory systemic condition. Common systemic diseases associated with retinal vasculitis include Behcet’s disease, sarcoidosis, multiple sclerosis, systemic lupus erythematosus, Wegener granulomatosis, polyarteritisnodosa and other rheumatologic conditions. Infectious agents may also cause retinal vasculitis such as syphilis, tuberculosis, and Lyme disease. Common diseases associated with isolated conditions of retinal vasculitis include primary retinal vasculitis, Eales disease, pars planitis, birdshot retinochoroidopathy, and Fuchs uveitis syndrome. Many autoimmune manifestations have been seen with retinal vasculitis when no systemic diseases are present; however, the exact etiology is unclear [1,2].