HIV Retinopathy

Abstract

Human Immunodeficiency Virus (HIV) retinopathy, also called Acquired Immunodeficiency Syndrome (AIDS) retinopathy, is a noninfectious retinal microvasculopathy and the most common ocular manifestation of HIV infection. Its primary significance is the strong correlation with the degree of immunosuppression, occurring in over 50% of patients with AIDS (acquired immunodeficiency syndrome). While HIV retinopathy does not by itself constitute AIDS, it is typically found in patients with a CD4+ T-lymphocyte count (CD4+ count) of <200 cells/mL, which is an AIDS-defining condition and a level of immunosuppression at which ocular opportunistic infections such as cytomegalovirus (CMV) retinitis become much more common. HIV retinopathy is characterized by cotton wool spots (the most common manifestation), dot-blot and flame-shaped hemorrhages, white-centered hemorrhages, and capillary nonperfusion. Cotton wool spots have a white, feathery appearance, may be single or multiple, and usually vary from 150 to 350 microns in size and are confined to the posterior pole. They are usually asymptomatic. HIV retinopathy has a lengthy differential diagnosis. Reversal of HIV retinopathy may be a helpful sign of a positive response to combination antiretroviral therapy (cART), and widespread use of cART since the 1990s has resulted in a much lower incidence of both HIV retinopathy and ocular opportunistic infections. However, as AIDS has evolved from a terminal into a chronic and manageable disease, it is clear that HIV infection causes chronic inflammation and immune activation that may cause accelerated aging despite continued viral suppression. Accelerated biological aging may include a neurocognitive decline in HIV-infected individuals. Functional and structural retina changes in the absence of ocular opportunistic infections or visible noninfectious HIV retinopathy may manifest as subtle diminution in contrast sensitivity, visual field defects, and thinning of the peripapillary retinal nerve fiber layer, collectively known as "HIV-associated neuroretinal disorder" (HIV-NRD). Studies have suggested that HIV-NRD increases the risk for visual impairment, blindness, decreased quality of life, and even mortality. Thus, techniques for identifying HIV-NRD will become increasingly important in the management of individuals living with HIV/AIDS.