Purpose: To quantitatively evaluate the superficial microvasculature in the macular and peripapillary areas in glaucomatous and healthy eyes using optical coherence tomography angiography (OCT-A).
Methods: We enrolled 26 eyes of medically managed primary open-angle glaucoma patients and 27 eyes of healthy subjects were enrolled in this prospective study. Measurements of OCT-A vessel density were acquired both in the macular and peripapillary areas. We compared vessel density values, the circumpapillary retinal nerve fiber layer (cpRNFL), the ganglion cell complex (GCC), and standard automated perimetry (SAP) parameters across study groups. Areas under the receiver operating characteristic (AUROC) curves were used to evaluate diagnostic accuracy. Quadratic regression models were used to determine the correlations between SAP severity and outcome measures.
Results: The whole image vessel density (wiVD) in glaucomatous eyes was lower than that in healthy eyes in the macular (38.5% ± 2.2% vs. 43.2% ± 2.3%, P < 0.001) and peripapillary areas (43.8% ± 5.7% vs. 53.3% ± 3.0%, P < 0.001). The circumpapillary vessel density (cpVD) was also lower in glaucomatous eyes (53.3% ± 7.0% vs. 61.5% ± 3.2%, P < 0.001). We found the AUROCs for discriminating between glaucomatous and healthy eyes were highest for cpRNFL (0.95) and GCC (0.95); followed by macular wiVD (0.94); peripapillary wiVD (0.93); and cpVD (0.89). The correlations between SAP severity were strongest with peripapillary wiVD (R2 = 0.58); followed by cpVD (R2 = 0.55); GCC (R2 = 0.51); cpRNFL (R2 = 0.42); and macular wiVD (R2 = 0.36).
Conclusions: Medically managed glaucomatous eyes show sparser superficial microvasculature in the macular area than do healthy eyes. The measurement of the macular superficial vessel density had similar diagnostic accuracy to peripapillary RNFL and macular GCC thickness for differentiating between glaucomatous and healthy eyes.