Causes of visual acuity loss among HIV-infected patients with cytomegalovirus retinitis in the era of highly active antiretroviral therapy in Chiang Mai University Hospital.

Abstract

To quantify the frequencies of the common causes of visual acuity loss for HIV-infected patients with cytomegalovirus retinitis (CMVR) in the era of highly active antiretroviral therapy(HAART). The present prospective observational study comprised 113 patients (184 eyes) with newly diagnosed CMVR, from May 2008-March 2010. Each patient was followed-up every 3 months with medical history and ophthalmologic examination. Patients were divided as visual impairment and legal blindness. The majority of the patients were native Thai (91%), while the rest was of hill tribe origin. 55% were females with age ranged between 14-57 years (average of 39). The main cause of HIV infection was heterosexual contact (90%), followed by homosexual contact (7%). It was found that 68% had CD4 T-cell count less than 50 cells/microl and that 46% had bilateral CMVR. Major causes of visual impairment were CMVR zone 2&3, CMVR zone 1 and cataract, respectively. Major causes of legal blindness were CMVR zone 2&3, CMVR zone 1 and retinal detachment, respectively Retinal detachment was a major risk factor in both groups. Even when surgery was successful, the visual acuity was not significantly improved, indicating a permanent loss of vision. In the HAART era, immune recovery of HIV patients also helps restoring specific anti-CMVimmunity. HAART reduces occurrence of visual impairment to 0.10/eye-year (EY) and legal blindness to 0.15/EY, compared to the pre-HAART figures of 0.94-0.98/EY and 0.47-0.49/EY respectively. However, it did not completely eliminate the occurrence. CMVR and cataract remain the most common causes of visual acuity loss followed by retinitis-related retinal detachment, and optic nerve atrophy respectively.