Foveal-Onset Acute Retinal Necrosis Associated With Varicella-Zoster Virus and Delayed Peripheral Retinitis: A Case Report

Acute retinal necrosis (ARN) usually begins in the peripheral retina, but atypical cases may initially involve the posterior pole. A 63-year-old man with no evidence of immunodeficiency presented with decreased vision and ocular hypertension in the left eye. The earliest optical coherence tomography (OCT) image showed a lesion centered on the fovea. At a subsequent examination, a whitish foveal lesion was associated with marked hyperreflectivity involving nearly the entire inner retina, posterior shadowing, and ellipsoid zone disruption. Dilated peripheral retinal examination and widefield fundus photography at the referring hospital showed no visible peripheral necrotizing retinitis; scleral depression was not performed. OCT angiography showed no detectable perfusion abnormality within the acquired 6 x 6-mm macular scan in either the superficial or deep retinal slab. Fine keratic precipitates, increased aqueous flare, and ocular hypertension raised concern for herpetic retinitis, and oral valacyclovir was started. At the first visit to our hospital, aqueous humor was collected while no peripheral lesion was visible. Four days later, an approximately four-disc-diameter inferotemporal lesion with vascular sheathing, punctate hemorrhages, and vitreous opacity appeared. On the same day, the 24-target multiplex PCR result from the aqueous sample collected at the first visit became available and was positive only for Varicella-zoster virus (VZV) DNA. Antiviral therapy with systemic corticosteroids led to regression of the retinal lesions. At 42 weeks, best-corrected visual acuity had improved to 0.6, with no retinal detachment or recurrence. This case suggests that VZV-associated ARN may initially present as an isolated foveal lesion. The OCT morphology was not typical of paracentral acute middle maculopathy because the hyperreflectivity was not confined to the middle retinal layers.