Changes in Retrobulbar Blood Flow Correlate to Changes in Optic Disc in Patients with Glaucoma

Abstract

Purpose: : To examine changes over two years in retrobulbar blood flow in relation to changes in optic nerve structure in patients with open angle glaucoma (OAG).

Methods: : 98 patients with OAG were examined at baseline and following 2 years follow up for retrobulbar blood flow and optic nerve structure as measured by color Doppler imaging (CDI) and optical coherence tomography (OCT) respectively. Associations between the changes in optic nerve structure and blood flow parameters were evaluated using Pearson correlation coefficients.

Results: : Retinal and optic nerve perfusion through the central retinal artery (CRA), nasal short posterior ciliary artery (NPCA), and temporal short posterior ciliary artery (TPCA) were negatively correlated with optic cup area. Specifically, as CRA end diastolic velocity (EDV), NPCA peak systolic velocity (PSV), NPCA EDV, and TPCA PSV decreased, optic cup area increased (r=-0.21, p=0.0380; r=-0.24, p=0.0185; r=-0.29, p=0.0040; r=-0.21, p=0.00387).

Conclusions: : Decreased perfusion in the retina and optic nerve is associated with an increase in optic cup area in this cohort of patients with OAG. Retrobulbar vessels including CRA, NPCA, and TPCA showed this positive correlation. Thus, decreasing retinal blood flow may increase optic nerve damage as defined by optic cup area in patients with OAG.

Keywords: optic nerve • blood supply • optic disc