The initial color fundus photographs of the left eye show a placoid area of retinal whitening below the inferotemporal arcade and many spots and dots of retinal whitening. There is chorioretinal scarring in the temporal and inferonasal periphery, and a spot of chorioretinal scarring beyond the midperiphery at 2:30. Fluorescein angiography reveals staining of the whitish placoid lesion but little or no staining or leakage at the multiple whitish spots and dots. Near the placoid lesion, there are many focal areas of perivascular staining and leakage, primarily of arteries. There is moderate disc leakage, which would be expected in any infectious or inflammatory process. The color fundus photograph of the left eye one month later shows resolution of the retinal whitening and multiple areas of chorioretinal scarring, particularly below the inferotemporal arcade.
Our patient had an infectious process with multifocal areas of retinal whitening and an associated uveitis. Clinically, our patient’s presentation was consistent with acute retinal necrosis (ARN), which is most often caused by varicella-zoster virus (VZV) and less commonly caused by Herpes simplex virus (HSV) 1 or 2. Laboratory work up was remarkable for a positive varicella-zoster IgG titer of 1122 (negative less than 135), unremarkable CBC and basic metabolic panel, negative T. pallidum Ab, negative HIV-1 and HIV-2 Ab, and negative HSV-1 and HSV-2 DNA. For unclear reasons, the laboratory was unable to do VZV or HSV testing on a fluid sample from the anterior chamber. The elevated serum IgG for VZV demonstrates only prior infection from this virus and does not prove that VZV caused the acute ocular infection or the infection at age 9. The peripheral chorioretinal scarring and the history of an ocular infection indicates that there was a prior episode of ARN in the left eye, and the most recent infection was likely a reactivation.
Our patient was treated with 2 gm valacyclovir TID for 1 month, which resulted in clinical control of the infection. He then received 1 gm TID for one month, and he has been on 1 gm QD maintenance therapy subsequently. Most patients receive prophylactic treatment for 6-12 months.
ARN often involves the contralateral eye, usually within weeks or months of involvement of the first eye but sometimes years later.1 Recurrences are uncommon.2 There was no recent COVID-19 infection, but some COVID-19 infections are asymptomatic and reactivation of ARN after COVID-19 infection has been reported.3 Though our patient had congenital immune system deficiencies, ARN typically occurs in immune-competent, young adults. It is a vision-threatening condition that typically starts in the retinal periphery and can rapidly extend posteriorly. Uncommonly, the macula can be directly involved. Patients often have uveitis, and some patients have scleritis and eye pain. It often has a perivascular distribution, and there can be associated vascular occlusions that can cause significant loss of vision. ARN patients are at high risk of retinal detachment, which typically begins at the border of necrotic retina and healthy retina. There is no consensus among experts about the value of prophylactic laser retinopexy placed posterior to the border of necrotic tissue.
1. Rabinovitch T, Nozik RA, Varenhorst, MP. Bilateral acute retinal necrosis syndrome. American Journal of Ophthalmology 1989;108:735-6.
2. Donovan CP, Levison AL, Lowder CY, Martin DF. Delayed recurrence of acute retinal necrosis (ARN): A case series. Journal of Clinical Virology 2016; 80:68-71.
3. Gonzales MP, Rios R, Pappaterra M, et al. Reactivation of acute retinal necrosis following SARS-CoV-2 infection. Case Reports in Ophthalmological Medicine 2021; pp 1-4.
