Progressive outer retinal necrosis (PORN) syndrome is a form of chorioretinitis, 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).

[4] 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.

An eye exam will show specific hallmark features, including opacified lesions in the peripheral retina without inflammation.

[6] When AIDS first became a diagnosis, ophthalmologists began seeing patients with infectious processes such as Progressive outer retinal necrosis (PORN).