A Pilot Study of Retinal Vessel Calibre and Its Potential Link to Cardiovascular Risk in HIV

This pilot study investigates the effects of HIV and antiretroviral therapy (ART) on retinal vessel calibre in immunocompetent people living with HIV (PLHIV). Changes in vessel calibre in HIV-positive individuals may serve as biomarkers of iBRB integrity and endothelial dysfunction.

This was a cross-sectional study. Fundus photography was conducted in three groups: HIV-positive individuals on ART (HIV-ART, n=62 eyes), HIV-positive ART-naïve individuals (HIV-NART, n=20 eyes), and a comparison group of HIV-negative controls (n=82 eyes). We evaluated retinal vessel calibres (Arteriolar widths, venular widths, central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), arteriole-venule ratio (AVR) using VAMPIRE software. Association models included Multivariable regression, generalized estimated equations, and mixed effects models.

The mean venular width was significantly greater among PLHIV compared to HIV-negative controls (p=0.003). Longer ART duration was associated with the narrowing of venules in the HIV-ART group, particularly affecting mean venular width (β=-1.40 μm, p=0.02) and CRVE (β=-4.44 μm, p=0.05). The generalized model showed longer ART duration was positively associated with wider arteriolar calibre (β=7.09 μm for CRAE, p=0.001). The HIV-NART group had a significantly higher odds of abnormal CRAE (OR=3.00; p=0.033) compared to controls.

This study provides a novel perspective on the probable link between retinal vessel calibre and systemic HIV factors, suggesting a possible relationship to systemic vascular health. All health clinicians should be aware of the potential for ART to influence retinal microvasculature. Future research should focus on larger cohorts and longitudinal studies to track changes in vessel calibre over time.