Carotid intima-media thickness in relation to primary open-angle glaucoma: epidemiological and structural evidence from a cross-sectional study.

Abstract

Objective: Keen interest exists in the relationship between carotid atherosclerosis and primary open-angle glaucoma (POAG), with prior studies yielding inconsistent findings. This study aims to quantify the association between carotid intima-media thickness (CIMT) and POAG using data from a large cohort.

Methods and analysis: In this cross-sectional analysis, we used data from 47 595 participants in the UK Biobank. CIMT was assessed using carotid ultrasound, while POAG was diagnosed based on health records and self-reported information. Logistic regression was used to detect CIMT-POAG association, after adjusting for potential confounders. Additionally, relationships with POAG-related endophenotypes, including intraocular pressure (IOP), macular retinal nerve fibre layer (mRNFL) thickness, macular ganglion cell-inner plexiform layer thickness and retinal vascular features, were examined through linear regression.

Results: A greater CIMT, evaluated per SD increment, was associated with a 10% increased risk of POAG (OR 1.10, p=0.004). The CIMT-POAG relationship exhibited an approximately linear pattern (p non-linear=0.797). This association was more pronounced in women (OR 1.18, p=0.003) and in individuals with a high genetic predisposition to POAG (OR 1.14, p=0.004). Furthermore, higher CIMT was significantly correlated with increased IOP (β=0.14, p=0.007) and decreased mRNFL thickness (β=-0.16, p=0.030). Additionally, higher CIMT was found to co-occur with retinal vascular impairments, including a decrease in fractal dimension, an increase in vessel tortuosity and a narrower central retinal arteriole (all false discovery rates<0.05).

Conclusion: This study observes an association between increased CIMT and POAG, especially in women and individuals with genetic susceptibility. These findings suggest that CIMT may be a useful biomarker with potential clinical relevance and propose possible vascular mechanisms underlying disease progression.