HIV/AIDS and blindness.

Nearly 34 million people are currently living with HIV/AIDS: ocular complications are common, affecting 50% to 75% of all such patients at some point during the course of their illness. Cytomegalovirus retinitis is by far the most frequent cause of vision loss in patients with AIDS. Although the prevalence of cytomegalovirus retinitis is decreasing in industrialized countries because of the widespread availability of highly active antiretroviral therapy, between 10% and 20% of HIV-infected patients worldwide can be expected to lose vision in one or both eyes as a result of ocular cytomegalovirus infection. Less frequent but important causes of bilateral vision loss in patients with HIV/AIDS include varicella zoster virus and herpes simplex virus retinitis, HIV-related ischaemic microvasculopathy, ocular syphilis, ocular tuberculosis, cryptococcal meningitis, and ocular toxic or allergic drug reactions. At present, most patients with HIV/AIDS in developing countries who lose their vision have a very limited life expectancy. As antiretroviral therapy makes its way to these countries, however, both life expectancy and the prevalence of blindness related to HIV/AIDS can be expected to increase dramatically.