Acute retinal necrosis: an unusual presentation.

Acute retinal necrosis (ARN) is a visually devastating disease consisting of necrotizing retinitis in healthy patients. The retinitis usually begins in the midperiphery to periphery and may spread to the posterior pole. Milder cases of ARN involving the posterior pole have been described. However, these cases never progress to full-blown ARN and have relatively good visual outcomes. A case is reported of a young, white woman with ARN that originally presented in the posterior pole. Unlike mild cases, spread to the midperiphery and periphery ensued until full-blown ARN occurred. This disease may present not only as an acute mid-peripheral to peripheral retinitis, but it also must be considered in the differential diagnosis of patients with multifocal, punctate areas of retinitis in the posterior pole.