PATTERN ELECTRORETINOGRAMS AND VISUAL-EVOKED POTENTIALS IN HIV-INFECTION - EVIDENCE OF ASYMPTOMATIC RETINAL AND POSTRETINAL IMPAIRMENT IN THE ABSENCE OF INFECTIOUS RETINOPATHY

Retinal microangiopathy associated with HN infection is usually asympt omatic and escapes detection unless funduscopic examination is perform ed when evanescent cotton-wool spots are present. The aim of this stud y was to assess retinal and optic nerve/retrochiasmal function in HIV infection by means of electrophysiologic techniques that are sensitive to the detection of subclinical visual impairment. We studied transie nt and steady state pattern electroretinograms (PERGs) and pattern-rev ersal visual evoked potentials (PVEPs) in 21 HIV-negative controls and 33 HIV-positive subjects (16 with CD4 greater than or equal to 200/mL and 17 with CD4 < 200/mL) without visual symptoms or infectious retin opathy. HIV-positive subjects with CD4 greater than or equal to 200/mL had reduced amplitude of the transient PERG P1 potential, but no othe r latency or amplitude abnormalities. The HIV-positive group with CD4 < 200/mL had reduced P1 transient PERG amplitude, as well as latency d elay of the transient PVEP. These findings suggest that HIV infection is associated with subclinical retinopathy and that, when severe immun osuppression occurs, both retinopathy and optic nerve/retrochiasmal dy sfunction are present. Transient PERGs are more sensitive measures of visual system disease in HIV infection than are steady state responses .