Acute retinal necrosis

Varicella zoster virus is the most frequent cause of acute retinal necrosis (ARN) followed by herpes simplex virus. Retinal ischemia and optic nerve atrophy are the main causes of the frequently poor final visual outcome in severe cases of ARN. The clinical diagnosis of ARN should be made as early as possible. Acyclovir should be administered intravenously due to its unreliable oral bioavailability. Systemic corticosteroids should be applied to suppress tissue damage caused by the host's inflammatory response. Severe cases of ARN should be treated by early vitrectomy with diagnostic vitreous biopsy, intravitreal aciclovir lavage, intraoperative laser retinopexy and silicone oil tamponade. The role of prophylactic laser retinopexy for prevention of secondary retinal detachment remains to be determined. The cause of different degrees of severity of ARN is unknown. The degree of severity of ARN is probably an independent predictor of the functional outcome.