To investigate the relationships between optic nerve cupping and total and regional brain volumes.
Secondary analysis of randomized clinical trial data.
Women, aged 65 to 79, without glaucoma with cup-to-disc ratio (CDR) measurements from the WHI Sight Examination study and MRI-based total and regional brain volumes from the WHI Memory Study MRI-1 were included. Large CDR was defined as 0.6 or greater in either eye. Generalized estimating equation models were used to account for intra-brain correlations between the right and left sides. The final analysis was adjusted for demographic, clinical characteristics, and total brain volume (for regional analyses).
Final analyses included 471 women: the mean age ± standard deviation was 69.2 ± 3.6 years; 92.8% of subjects were white. 34 of 471 (7.2%) women had large CDR. Controlling for total brain volume, demographic, and clinical characteristics, lateral ventricle volume was 3.01 cc larger for those with large CDR compared to those without large CDR (95% CI: 0.02, 5.99; p-value=0.048). Furthermore, frontal lobe volume was 4.78 cc lower for those with large CDR compared to those without (95% CI: -8.71, -0.84; p-value=0.02), and occipital lobe volume was 1.86 cc lower for those with large CDR compared to those without (95% CI: -3.39, -0.3; p-value=0.02).
Our analysis suggests that in women aged 65+, large CDR is associated with lower relative total brain volume and absolute regional volume in the frontal and occipital lobes. Enlarged CDR in individuals without glaucoma may represent a sign of optic nerve and brain aging, although more longitudinal data is needed.
Copyright © 2023. Published by Elsevier Inc.
