Neuroretinal degeneration in HIV

Abstract

Purpose: To detect possible neuro-retinal degeneration in HIV-positive patients by SD-OCT and contrast sensitivity tests.

Methods: One hundred and one HIV-positive patients and 71 HIV-negative control subjects were enrolled from the prospective AGEhIV cohort study on age-associated non-communicable co-morbidity in Amsterdam. All participants underwent a complete ophthalmological examination.Participants with a history of any disease known to influence the retina were excluded (n=20). Macular and optic disc 3D volume OCT scans were made with SD-OCT (Topcon). Mean thickness of each layer in the macula and the peripapillary retinal nerve fiber layer (RNFL) thickness were measured. Spatial (Pelli-Robson charts) and temporal contrast sensitivity (assessed with the C-Quant) were measured. Ocular straylight was also assessed with the C-Quant. Multivariable mixed linear regression was used to assess associations between several HIV related factors and ocular examinations.

Results: Correcting for age, spherical equivalent, and OCT image quality, we did not find a significant difference in retinal layer thickness between HIV-patients and controls. Patients had a significantly lower, although small (1 letter) difference in spatial contrast sensitivity compared with controls, but no differences in temporal contrast sensitivity. Straylight values were significant higher in patients compared to controls. In the patients, we observed a significant negative association between CD8 counts at time of examination and RNFL and GCL thickness. Other investigated potential determinants were not associated with RNFL and GCL thickness: current CD4 count and %, CD8 %, CD4/8-ratio and markers of inflammation (soluble CD14 and CD163); nadir CD4 count; duration of immunodeficiency; prior AIDS diagnosis; documented duration of HIV-infection; duration of anti-retroviral therapy; prior use of d4T/ddC/ddI.

Conclusions: In contrast to other reports, no significant difference was observed in retinal structure measured with OCT between HIV-positive patients and HIV-negative controls. Only the absolute CD8 count was negatively associated with RNFL and GCL thickness in HIV-positive patients. Higher CD8 counts in HIV-infection are associated with residual HIV-replication, chronic antigenic stimulation, and chronic T-cell activation, which may all play a role in retinal degeneration. The slightly lower spatial contrast sensitivity in HIV-patients could be explained by higher glare values.

Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 688 retina • 415 AIDS/HIV