Abstract
Purpose: :
To investigate the age-related morphological changes of optic nerve head, retinal nerve fiber layer (RNFL) thickness, cup/disc ratio and visual field progression in women and men aged 60 years or higher with primary open angle glaucoma (OAG).
Methods: :
Baseline data from 116 patients with OAG from the Indianapolis Glaucoma Progression Study was used in this analysis. Data from patients over the age of 60 (n=90) were used to explore the effects of gender on the relationship between age and optic nerve head structure and retrobulbar blood flow. Color Doppler imaging for peak systolic (PSV) and end diastolic (EDV) blood flow velocities and vascular resistance (RI) in the ophthalmic (OA) and central retinal arteries (CRA) was examined. A multivariate linear regression analysis was performed.
Results: :
In patients over 60, age negatively correlated with OA EDV in both women and men (r=-0.281, P=0.048 and r=-0.328, P=0.039, respectively). RNFL cross-section area decreased, and vertical and horizontal optic cup/disc ratios increased with age in women only (P=0.036, 0.048 and 0.033, respectively). The mean and maximum optic cup depth decreased with aging in men only (P=0.048 and 0.032, respectively). Moreover, RNFL cross-sectional area correlated negatively with the vertical and horizontal optic cup/disc ratios in women (r=-0.340, P=0.016 and r=-0.317, P=0.025, respectively). Mean and maximum optic cup depth did not correlate with RNFL cross-section area in men (r=0.006, P=0.972 and r=0.104, P=0.528, respectively).The regression model was insignificant when the entire patient population (men and women) was included (adjusted r2=0.021 P=0.218). However, dividing the patients based on gender revealed that the independent variables in the question could explain 11.5% of variance in baseline AGIS score in women, while their contributions to AGIS score in men was insignificant. In women, CRA RI was independently and negatively associated with baseline AGIS score (partial rho=-0.298, P=0.016).
Conclusions: :
In female OAG patients, the optic cup widens in the vertical and horizontal axes with aging; this change is associated with RNFL loss. In male OAG patients, however, optic nerve depth (anteroposterior axis) increases with aging, and this change is not associated with significant RNFL loss.
Keywords: optic nerve • blood supply • visual fields