Retrobulbar Blood Flow Correlates With Visual Field Damage in Glaucoma Subjects

Abstract

Purpose: : To examine the relationship between retrobulbar blood flow and visual field damage in primary open angle glaucoma (OAG) patients.

Methods: : An analysis of 99 OAG patients (mean age 65.8 (10.4); 53 female) participating in the Indianapolis Glaucoma Progression Study (IGPS) was performed. Color Doppler imaging (CDI) of the ophthalmic (OA), central retinal (CRA) and nasal and temporal short posterior ciliary arteries was performed after Humphrey Visual Field Analyzer 24-2 standard automated perimetry (SITA) during a single visit. We investigated the relationship between the peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) within those 4 vessels and the mean defect (MD) and pattern standard defect (PSD) for each patient. The strength of the linear association among all of these parameters was assessed using the Pearson Correlation Coefficients and P<0.05 were considered statistically significant.

Results: : Both nasal and temporal short poster ciliary artery PSV were significantly correlated with visual field MD (r=0.16, p=0.014; r-0.17, p=0.01). EDV was also significantly correlated with MD (r=0.23, p=0.0008; r=0.15, p=0.02) while RI was negatively correlated (r=0.20, p=0.003; r=0.1, p=0.09) in both vessels. PSD was also significantly correlated with nasal short poster ciliary artery PSV (r=0.2, p=0.003) and EDV (r=0.2, p=0.003) and temporal PSV (r=0.20, p=0.003). The OA and CRA did not significantly correlate to PSD or MD.

Conclusions: : In this cohort of patients with OAG, visual field damage was found to be correlated with both nasal and temporal short poster ciliary artery blood flow. The lack of correlation in the OA and CRA with visual field testing suggests that the short poster ciliary arteries which perfuse the pre-laminar and laminar regions of the optic nerve head are associated with visual field outcomes.

Keywords: blood supply • visual fields • ischemia