Quantitative Optical Coherence Tomography Angiography of Radial Peripapillary Capillaries in Glaucoma, Glaucoma Suspect, and Normal Eyes

• Published in: American journal of ophthalmology Vol. 170; pp. 41 - 49
• Main Authors: Mammo, Zaid, Heisler, Morgan, Balaratnasingam, Chandrakumar, Lee, Sieun, Yu, Dao-Yi, Mackenzie, Paul, Schendel, Steven, Merkur, Andrew, Kirker, Andrew, Albiani, David, Navajas, Eduardo, Beg, Mirza Faisal, Morgan, William, Sarunic, Marinko V.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2016; Elsevier Limited
• Subjects: Adult; Aged; Automation; Capillaries - diagnostic imaging; Capillaries - pathology; Cross-Sectional Studies; Female; Fluorescein Angiography - methods; Funding; Glaucoma; Glaucoma - physiopathology; Healthy Volunteers; Humans; Intraocular Pressure; Male; Medical imaging; Medical research; Methods; Middle Aged; Nerve Fibers - pathology; Ocular Hypertension - physiopathology; Ophthalmology; Optic Disk - blood supply; Optic nerve; Optics; Retinal Ganglion Cells - pathology; Retinal Vessels - diagnostic imaging; Retinal Vessels - pathology; Tomography, Optical Coherence - methods; Visual Fields - physiology; Young Adult; Canada
• DOI: 10.1016/j.ajo.2016.07.015
• ISSN: 0002-9394

To evaluate the quantitative characteristics of the radial peripapillary capillary (RPC) network in glaucoma, glaucoma suspect, and normal eyes using speckle variance optical coherence tomography angiography (OCT-A). To determine correlations between RPC density, nerve fiber layer (NFL) thickness, and visual field indices. Cross-sectional study. OCT-A images of RPCs were acquired at a single institution using a custom-built 1060 nm system from 3 groups: unilateral glaucoma (10 eyes from 5 subjects), glaucoma suspects (6 eyes from 3 subjects), and normal control eyes (16 eyes from 9 normal subjects). Peripapillary NFL thickness measurements were determined using spectral-domain optical coherence tomography. Glaucoma and glaucoma suspects also underwent automated 30-2 Humphrey visual field analysis. Manual tracing techniques were used to quantify RPC density in the OCT-A images. Data were analyzed using a linear mixed model with 1 fixed-effect covariate. Correlations between main outcome measures (RPC density, NFL thickness, and visual field index) were determined. Mean age was not significantly different between the 3 groups (P = .25). The density of RPCs was significantly lower in glaucomatous eyes compared with matched-peripapillary regions in the fellow eye, glaucoma suspect group, and normal group (all P < .001). RPC density was strongly correlated with NFL thickness (P < .001) and visual field index (P < .001). Significant reductions in RPC density were correlated with sites of NFL decrease and visual field loss in glaucoma. Speckle variance OCT-A allows visualization and quantification of RPCs and may therefore be a useful tool for indirectly quantifying and monitoring retinal ganglion cell axonal injury in glaucoma.