Relationship Between Cerebral Blood Flow and Central Visual Function in Primary Open–Angle Glaucoma

Abstract

Purpose: : To investigate the relationship between middle cerebral artery (MCA) blood flow velocities and central visual function.

Methods: : Fifteen primary open–angle glaucoma (POAG) patients were recruited. The eye with the more severe visual field defect (full threshold 24–2) and/or optic disc damage was chosen. Measurements included brachial arterial pressure, heart rate, visual acuity (logMAR), contrast sensitivity (CSV–1000), central visual field (Humphrey SITA 10–2), foveal cone electroretinogram (ERG), and transcranial Doppler (TCD). Statistical analysis was performed using regression analysis with p<0.05 regarded as significant.

Results: : Visual field was successfully done in twelve eyes. In one patient we were unable to obtain ERG responses and middle cerebral artery velocity readings. A significant correlation was observed between MCA mean flow velocity and focal cone ERG amplitude (r² = 0.47, p = 0.009), but correlation between mean foveal cone ERG implicit time and middle cerebral was not statistically significant (r²=0.013). A significant correlation was also observed between MCA mean flow velocity and mean sensitivity (r² = 0.57, p = 0.005), and mean defect (r² = 0.54, p = 0.007) of the central visual field, logMar visual acuity (r² = 0.32, p = 0.036), and contrast sensitivity (r² = 0.37, p = 0.027).

Conclusions: : Central visual function was found to be related to cerebral hemodynamics. Some POAG patients present with abnormal central visual function. This study suggests that these abnormalities are, at least in part, related to cerebrovascular insufficiency.

Keywords: electroretinography: clinical • visual fields • blood supply