Peripapillary and Macular Vessel Density in Glaucoma Patients With Single-Hemifield Visual Field Defect
Ophthalmology, May 2017
Yarmohammadi et al. compared hemifield differences in the vessel density of the peripapillary and macular regions in open-angle glaucoma eyes with a visual field (VF) defect confined to 1 hemifield. Using optical coherence tomography angiography (OCT-A), they found that vessel density was higher in the intact hemiretina than in the affected hemiretina; however, both values were lower than in control patients.
This cross-sectional study included 58 eyes of 58 glaucoma patients with VF loss confined to a single hemifield and 28 healthy eyes. Retinal vasculature information was summarized as circumpapillary vessel density (cpVD) and perifoveal vessel density (pfVD). In addition, circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell complex (mGCC) thicknesses were calculated with spectral-domain optical coherence tomography.
The researchers found that mean cpVD and pfVD in the intact hemiretinas of glaucoma eyes (59.0% and 51.1%, respectively) were higher than in the affected hemiretinas (54.7% and 48.3%, respectively) but were lower than in healthy eyes (62.4% and 53.8%, respectively). Similar differences in cpRNFL and mGCC thickness were found in affected versus intact hemiretinas within glaucoma patients and between patients and controls.
The strongest associations between mean sensitivity (MS) in the affected hemifields were found for cpVD, followed by pfVD, cpRNFL, and mGCC in the corresponding hemiretinas. Moreover, in the intact hemifields, correlations between MS and cpVD and pfVD were higher than those between MS and cpRNFL and mGCC thickness measurements.
The researchers concluded that among glaucomatous eyes with a single-hemifield VF defect, reduced peripapillary and macular vessel density was detectable in the perimetrically intact hemiretina as well as the affected hemiretina. Further, vessel density was associated with the extent of VF deficiency in the corresponding hemifields. They noted that OCT-A shows promise in identifying glaucomatous damage before focal VF defects are detectable.
The original article can be found here.