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To the Editor I read with interest the article titled “Progressive Outer Retinal Necrosis (PORN): A Catchy Acronym But Is the Anatomy Correct? The Salient Observation of Lorenz E. Zimmerman, MD.”1 In 1996, my colleagues and I reported the first series of patients, to our knowledge, with the diagnosis of PORN who were successfully treated as defined by at least 1 eye retaining useful visual acuity.2 One of the patients had a retinal biopsy with electron and light microscopic examination, including immunohistochemistry. This patient had an extremely depressed CD4+ T-lymphocyte count and a chronic multidermatomal eruption of shingles on his back and buttocks. Although he had a typical appearance of PORN, the retinal biopsy showed full-thickness retinal necrosis. There were no cytoplasmic inclusions, and the patient had eosinophilic nuclear inclusions. Electron microscopy showed intranuclear inclusions of nucleocapsids typical of herpesvirus. Immunohistochemical staining was negative for cytomegalovirus and herpes simplex virus but there was diffuse reaction product in all layers of the retina for varicella-zoster virus. The predominant infiltrates in the retina were CD8+ lymphocytes, and these primarily were found in the inner retina, not the outer retina. A biopsy of one of the patient’s numerous skin lesions showed findings of a chronic varicella-zoster virus infection. Animal models of herpes retinitis, referenced in that article,2 suggested CD4+ cells were necessary to efficiently clear herpesvirus from the retina. The predominant lymphocyte found, CD8+ cells, may have been less efficient, allowing the infection to progress in this at-risk patient. This article was not referenced by Margo and Friedman.
Spaide RF. Vintage Progressive Outer Retinal Necrosis. JAMA Ophthalmol. 2015;133(2):230-231. doi:10.1001/jamaophthalmol.2014.4486