Progressive outer retinal necrosis (PORN) syndrome is a form of chorio-retinitis, an infection in the retina, the back of the eye. The disease is most commonly caused by the Varicella zoster virus and is found almost exclusively in patients with HIV/AIDS (acquired immunodeficiency syndrome). Progressive outer retinal necrosis is the second most common opportunistic retinal infection in North America among people with AIDS. The reason this disease process is considered opportunistic is precisely because it only presents in patients with AIDS, a disease that attacks and weakens the immune system, making space for other infections, like Varicella zoster virus (VZV) and Herpes simplex virus (HSV), to attack the body. The syndrome, PORN, falls under the umbrella of Necrotizing Herpetic Retinopathy, along with Acute Retinal Necrosis (ARN). Although fairly similar processes, the two forms of retinopathy have different presenting symptoms. Acute Retinal Necrosis, or ARN, is damage more central in the retinal portion of the eye with dead or necrotic areas well defined. ARN also presents with inflammation within the eye and is often painful. Progressive outer retinal necrosis (PORN) is a chorioretinitis presenting with multiple lesions in the peripheral retina. Unlike ARN, this disease process has no signs of intraocular inflammation, the hallmark feature, or vascular involvement. Presentation (Signs and Symptoms) The presentation of the disease is dependent on the patient's AIDS prognosis. If the immune system has been significantly weakened by AIDS, a patient will likely present with worse and faster progressing PORN. Commonly presenting symptoms of PORN include: Blurry vision Acute onset bilateral visual loss OR painless progressive visual loss Decreased vision with pain Floaters Headaches Diagnosis The diagnosis of Progressive outer retinal necrosis (PORN) syndrome is made primarily through history and physical exam. A patient's medical history of AIDS increases the likelihood of PORN as the diagnosis. An eye exam will show specific hallmark features, including opacified lesions in the peripheral retina without inflammation. There are medical tests that can aid in diagnosing the severity of the disease process, however are not necessary for initial diagnosis. Imaging studies: may help diagnose the extent of retinal involvement Optical coherence tomography (OCT): this test allows ophthalmologists to look at outer and inner layers of the retina Fundus autofluorescence: shows areas of unhealthy cells in the retina Blood work: the labs can show how immuno-compromised an individual is Vitreous Tap: Analysis of the fluid in the eye can show the