Acute retinal necrosis: a case series with clinical features and treatment outcomes

PURPOSE: To determine clinical features, viral aetiology and treatment outcomes of eyes with acute retinal necrosis (ARN). METHODS: Retrospective, interventional, non-comparative case series. RESULTS: Twenty-two patients (23 eyes) were identified between 1996 and 2007. Varicella zoster virus was the causative agent in 12 patients (nine confirmed by polymerase chain reaction), herpes simplex virus type 1 in six (five polymerase chain reaction-confirmed) and unknown in three patients. Five patients had documented herpes zoster infection in the month prior to the onset of ARN. Twelve patients (55%) had identifiable (clinical or subclinical) immune dysfunction. At 6 months, 3 out of 15 eyes (20%) maintained vision 6/12 or better and 7 (47%) were 6/60 or worse. Median final VA was 6/60. Nine eyes developed retinal detachment and two-thirds of these had received prior barrier laser. Poor prognostic factors for severe visual loss by univariate analysis were male gender (P = 0.019), and the development of retinal detachment (P = 0.05). Delay between onset of symptoms and diagnosis was associated with moderate visual loss (P = 0.018). Barrier laser did not reduce the risk of retinal detachment. CONCLUSIONS: Acute retinal necrosis still has poor visual prognosis. Early diagnosis and initiation of treatment may improve outcome.