Objective analysis of vision loss in HIV–positive patients in the HAART era using OCT.

Abstract

Abstract: : Purpose: Patients with HIV disease without retinitis have been shown to have vision loss. We hypothesized that the site of this loss is at least partially in the inner retina and therefore wished to assess the retinal nerve fiber layer (RNFL) in such patients. Methods: A case control study at the Acquired Immunodeficiency Syndrome Ocular Research Unit at the University of California, San Diego was conducted in 48 eyes of 26 patients. Retinal nerve fiber layer thickness along the circumference of a circle with 3.4 mm diameter centered on the optic nerve head was evaluated using third generation optical coherence tomography (Stratus OCT). Patients in group 1 (23 eyes of 12 patients) consisted of HIV–negative controls. Group 2 (15 eyes of 8 patients) consisted of HIV–positive patients with no prior history of cytomegalovirus (CMV) retinitis and CD4 counts consistently above 100. Group 3 (10 eyes of 6 patients) consisted of HIV–positive patients with no prior history of CMV retinitis but a history of CD4 count < 100 at some point in time. Results: The average RNFL thicknesses in groups 1, 2 and 3 were 108.50 ± 14.24 µm (median 105.49µm), 103.48 ± 15.73 µm (median 96.53 µm), and 86.09 ± 21.78 µm (median 81.07 µm), respectively. The RNFL thicknesses among the three groups were statistically different, p<0.01 (Tukey–Kramer test). The low CD4 HIV–positive group 3 had significantly thinner RNFL than either of the groups 1 and 2, p<0.05. Conclusions: Significant thinning of RNFL occurs in HIV–positive patients without history of CMV retinitis and with low CD4 counts in comparison to the same subgroup of patients with CD4 count increased above 100 and HIV–negative controls. We have previously shown that vision loss and a reduction in optic nerve axon counts of up to 40% occurs in CMV retinitis negative HIV patients with low CD4 cell counts; these studies will help define it's pathoanatomic basis. OCT may be of clinical use in the diagnosis of early subclinical HIV–associated visual functional loss.

Keywords: AIDS/HIV • clinical (human) or epidemiologic studies: systems/equipment/techniques • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)