Purpose: To assess quantitatively the choriocapillaris (CC) perfusion area in the macular area of healthy eyes, eyes with primary open-angle glaucoma, and eyes with ocular hypertension using optical coherence tomography angiography (OCTA).

Methods: A consecutive series of healthy individuals and patients with glaucoma and ocular hypertension were recruited prospectively in this single-center, cross-sectional study based in Milan, Italy. OCTA was performed in the morning and evening, along with a complete ophthalmologic examination. Macular superficial capillary plexus vessel density (SCP-VD) and the thicknesses of the retina and ganglion cell complex (GCC), as well as their fluctuations, were investigated.

Results: Thirty-nine eyes from 24 individuals with glaucoma (mean age= 58.79±6 years), 43 eyes from 27 individuals with ocular hypertension (59.19±6 years), and 54 eyes from 35 controls (58.27±6 years) were enrolled. The mean CC perfusion area values were not significantly different among the three groups in the morning or evening (P≥ 0.47). In contrast, SCP-VD, retinal thickness, and GCC thickness were statistically different among the groups (P≤ 0.016), except for the foveal SCP-VD (P≥ 0.19) and the evening foveal thickness (P= 0.57). Diurnal changes in the CC perfusion area, SCP-VD, retinal thickness, and GCC thickness were not statistically significant (P≥ 0.16). Systemic hypertension, sex, age, axial length, and diurnal changes in intraocular pressure were not significantly associated with morning or evening measurements, or with diurnal fluctuations (P≥ 0.07).

Conclusions: The macular CC flow perfusion area appears unaffected in eyes with primary open-angle glaucoma. No significant diurnal changes were observed in any of the parameters investigated.