To assess optic nerve head (ONH) and peripapillary microvasculature in primary open-angle glaucoma (POAG) of mild to moderate severity using swept-source optical coherence tomography angiography (OCTA).
In a cross-sectional study, swept-source OCTA images were analyzed for 1 eye from each of 30 POAG patients with glaucomatous Humphrey visual field loss and 16 controls. The anatomic boundary of ONH was manually delineated based on Bruch’s membrane opening and large vessels were removed from en face angiography images to measure vessel density (VD) and the integrated OCTA by ratio analysis signal (IOS), suggestive of flow, in the ONH and peripapillary region. POAG subgroup analysis was performed based on a history of disc hemorrhage (DH) matched by visual field mean deviation (MD).
POAG (mean MD±SD, −3.3±3.0 dB) and control groups had similar demographic characteristics and intraocular pressure on the day of imaging. Groups did not differ in superficial ONH VD or flow indicated by IOS (P≥0.28). POAG eyes showed significantly lower VD (39.4%±4.0%) and flow (38.8%±5.6%) in deep ONH, peripapillary VD (37.9%±2.9%) and flow (43.6%±4.0%) compared with control eyes (44.1%±5.1%, 44.7%±6.9%, 40.7%±1.7%, 47.8%±2.5%, respectively; P≤0.007 for all). In the subgroup analysis, POAG eyes with (n=14) and without DH (n=16) had similar measured OCTA parameters (P>0.99 for all).
The image processing methodology based on the anatomic boundary of ONH demonstrated compromised microvasculature in the deep ONH and peripapillary region in eyes with mild to moderate POAG, regardless of the history of DH.
*Department of Ophthalmology, Massachusetts Eye and Ear
‡Channing Division of Network Medicine, Brigham and Women’s Hospital, Boston, MA
§Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY
†University of Sao Paulo, Sao Paulo, Brazil
Supported by the Harvard Glaucoma Center of Excellence, the Miller Research Funds at the Massachusetts Eye and Ear and the Topcon Research Foundation.
Disclosure: L.Q.S. is a consultant for Genentech and Topcon. L.R.P. is a consultant for Bausch & Lomb and Eyenovia. The remaining authors declare no conflict of interest.
Reprints: Lucy Q. Shen, MD, Department of Ophthalmology, Massachusetts Eye and Ear, 243 Charles St., Boston, MA 02114 (e-mail: firstname.lastname@example.org).
Received July 27, 2018
Accepted December 8, 2018