The Effect of Carotid Atherosclerosis on the Risk for Open-Angle Glaucoma.

Purpose: There is evidence that patients with open-angle glaucoma (OAG) have altered hemodynamic parameters of the carotid and retinal arteries. We investigated the effect of carotid artery atherosclerosis on incident OAG, intraocular pressure (IOP), and macular retinal nerve fiber layer (mRNFL) in the general population. Methods: We analyzed data from the Rotterdam Study, a large prospective population-based cohort study. Carotid atherosclerosis was assessed by measuring the carotid intima-media thickness (cIMT). We used multivariable Cox proportional hazard models to estimate the effect of cIMT on OAG risk, and linear mixed models for IOP and mRNFL. Linear and logistic regressions were used to analyze within participants with OAG the effect of cIMT on age at diagnosis and the requirement for glaucoma surgery. Results: Among 9652 participants, 193 developed OAG during 89,665 person-years of follow-up (mean follow-up = 10.5 years). Each standard deviation increase in cIMT was associated with a 17% higher risk of developing OAG (adjusted hazard ratio = 1.17, 95% confidence interval [CI] = 1.00 to 1.36, P = 0.047). Although no association between cIMT and IOP was found, the mRNFL thickness decreased by an average of 0.17 µm (95% CI = 0.01 to 0.34) for each standard deviation increase in cIMT. Among participants with OAG, an increased cIMT was also associated with a younger age at diagnosis (beta = -1.01 years, 95% CI = -1.84 to -0.17), and more frequent requirement of glaucoma surgery (odds ratio [OR] = 1.93, 95% CI = 1.07 to 3.50). Conclusions: Among participants with OAG, an increased cIMT was associated with a younger age at diagnosis. In patients with OAG and unexplained continuous progression, a screening ultrasound examination of the carotid arteries might be considered.