Macula Vessel Density and Foveal Avascular Zone Parameters in Exfoliation Glaucoma Compared to Primary Open-Angle Glaucoma

Abstract

Purpose The purpose of this study was to explore macula vessel density and foveal avascular zone (FAZ) parameters in exfoliation glaucoma (XFG) compared to primary open-angle glaucoma (POAG) using optical coherence tomography angiography (OCTA). Methods This was a cross-sectional observational study. Twenty-six XFG and 28 POAG patients with comparable visual field defects on Humphrey 24-2 and 10-2 perimetries were recruited. OCTA scans (3 × 3 mm) centered on the fovea were obtained. Built-in software was used to measure superficial capillary plexus (SCP) vessel density at different quadrants of the macula. Custom software was then used to create a full-thickness image. The FAZ was manually delineated, and large vessels were removed. Vessel density in eight concentric rings with increments of 200-μm diameters from the delineated FAZ was measured. FAZ parameters were calculated using the custom software. Results SCP density was significantly lower in the superior (mean difference [MD] = −4.32, 95% confidence interval [CI] = −7.02, −1.61, P = 0.003) and nasal (MD = −3.00, 95% CI = 05.22, −0.77, P = 0.010) quadrants in XFG versus POAG. SCP vessel density using the concentric ring approach revealed significantly decreased values at all eight rings in XFG versus POAG. In the full-thickness analysis, density was significantly less in the XFG group in all rings except the initial 200 μm. No significant differences existed in FAZ parameters between the groups. Conclusions Despite the presence of comparable central visual field defects, the macula vessel density was predominately lower in XFG compared with POAG in our sample of patients. Further studies are warranted to investigate the consistency of our results.

Macular vessel density and foveal avascular zone parameters in patients after acute primary angle closure determined by OCT angiography

“…Physiological evidence also supports that the macula is more sensitive to hypoxia and ischaemia because it consumes more oxygen than other tissues in the body 17 . Subsequently, macular VD and foveal avascular zone (FAZ) metrics were regarded as potential biomarkers in the clinical evaluation of early glaucoma in recent studies 18 – 20 . However, few researches have examined macular vasculature in PACG.…”

Peripapillary Perfused Capillary Density in True Versus Pseudoexfoliation Syndrome: An OCTA Study

“…21,22 The mechanism of glaucomatous optic neuropathy in eyes with PEX-related glaucoma is due to mechanical damage by elevated intraocular pressure, which results in death of retinal ganglion cells 23 with primary open-angle glaucoma, which constitutes evidence for vasculopathy in eyes with PEX. 25 Conversely, there is no evidence to support reduction of optic nerve head blood flow in eyes with TEX.…”

Peripapillary perfused capillary density in true versus pseudoexfoliation syndrome: An OCTA study

“…This vasculopathy may produce synergistic effect on the natural course of PEX-related glaucoma, which may result in greater intraocular pressure fluctuation, more severe clinical manifestations, and greater recalcitrance, compared with primary open-angle glaucoma. Shawn et al found lower macula vessel density in eyes with pseudoexfoliation glaucoma than in eyes with primary open-angle glaucoma, which constitutes evidence for vasculopathy in eyes with PEX [ 25 ]. Conversely, there is no evidence to support reduction of optic nerve head blood flow in eyes with TEX.…”