Researchers representing the AAO conducted a retrospective review of 60 peer-reviewed journal articles to determine the benefits of optical coherence tomography angiography (OCTA) examination in the diagnosis of primary open-angle glaucoma (OAG). The researchers found evidence that OCTA can detect decreased capillary vessel density within the peripapillary nerve fiber layer and macula in patients with suspected glaucoma, preperimetric glaucoma, and perimetric glaucoma. The degree of vessel density loss correlates significantly with glaucoma severity both overall and topographically. For differentiating glaucomatous from healthy eyes, some studies found that peripapillary and macular vessel density measurements by OCTA showed a diagnostic ability (area under the receiver operating characteristic curve) comparable with structural OCT retinal nerve fiber and ganglion cell thickness measurements, whereas other studies found that structural OCT measurements performed better. Choroidal or deep-layer microvasculature dropout, as measured by OCTA, was also associated with glaucoma damage. Lower peripapillary and macular vessel density and choroidal microvasculature dropout were associated with faster rates of disease progression.

The researchers concluded that vessel density loss associated with glaucoma can be detected by OCTA. Peripapillary, macular, and choroidal vessel density parameters may complement visual field and structural OCT measurements in the diagnosis of glaucoma.