Vitrectomy With Intrasurgical Control of Ocular Hypotony as a Treatment for Central Retina Artery Occlusion.

Vitrectomy With Intrasurgical Control of Ocular Hypotony as a Treatment for Central Retina Artery Occlusion Central retinal artery occlusion (CRAO) is an ocular emergency usually caused by blockage of a vessel by a thrombus or embolus. The central retinal artery supplies the inner two thirds of the retina; the occlusion of this vessel causes ischemia and subsequent necrosis. Experimental studies have shown that irreversible retina damage can occur 240 minutes after CRAO. Clinically, the patient experiences a sudden painless and unilateral loss of vision. The natural course of CRAO is devastating: 92% of patients have a visual acuity of counting fingers or worse. However, up to 8% of patients have improved visual acuity because of spontaneous remission of the occlusion. There are numerous treatments for CRAO, but none have proved to be successful. Conventional conservative options include carbogen inhalation, acetazolamide infusion, ocular massage and paracentesis, and intravenous glyceryl trinitrate. However, none have been able to alter the natural history of the disease. There has been recent interest in other techniques: the use of tissue plasminogen activator, intraarterial thrombolysis, surgical embolus removal, Nd:YAG laser embolysis, systemic prostaglandin E1, and vitreous surgery with direct central retinal artery massage or intraarterial verapamil and alteplase infusion. However, these treatments have shown only limited efficacy in improving vision. As CRAO is the ocular equivalent of a cerebral stroke, the risk factors for this occurrence are the same as for stroke or heart disease. It is important to manage these risk factors as they may lead to other vascular conditions.