Clinical Diagnosis and Classification in Central Retinal Vein Occlusion and Macular Edema

Central retinal vein occlusion (CRVO) is a common and dramatic cause of sudden, painless, and unilateral visual loss. The vast majority of vision loss associated with CRVO results from the macular edema and neovascularization. The diagnosis is generally based upon the history and fundus examination. Common clinical evaluations include fluorescein angiography (FA) and optical coherence tomography (OCT). According to retinal perfusion status, CRVO is classified into two clinical types, and it is important to differentiate between the more common nonischemic type and the less common ischemic type. It is possible to detect the peripheral ischemic areas with wide angle FA, while the perfusion status of the macula is evaluated by OCT angiography, which takes place in our daily practice.