Comparative study of retinal microcirculation in primary angle closure disease and early primary open-angle glaucoma

Abstract

To compare microcirculatory changes in patients with early stages of primary angle closure disease (PACD) and primary open-angle glaucoma (POAG). The study retrospectively analyzed the clinical data of 60 eyes with PACD, 30 with initial POAG, and 30 eyes without any ophthalmic pathologies. Vessel density (VD) in the optic nerve head and peripapillary retina (wiVD Disc), as well as in the inner layers of fovea and parafovea (wiVD Macula) and their different sectors were determined in all patients by optical coherence tomography angiography (OCTA). The correlation of VD with axial length (AL), anterior chamber depth (ACD), lens thickness (TL), and corneal-compensated intraocular pressure (IOPcc) was assessed. The wiVD Disc in PACD (42.47±4.23%) was lower than in POAG eyes (47.46±2.10%), p<0.001, but the difference for wiVD Macula was not significant: 41.71±4.55% and 39.29±2.46%, respectively (p=0.47). In both PACD and POAG, all OCTA parameters were lower than in normal eyes: p=0.000 for both wiVD Disc and wiVD Macula. WiVD Disc correlated with ACD both in PACD (r=0.724, p=0.012) and in POAG (r= 0.685, p=0.012), but a correlation with IOPcc was found only in PACD (r= -0.670, p=0.033). The largest number of inverse correlations was found between TL and VD both for wiVD Disc (r= -0.714, p=0.006) and the parameters of macular area (in para- and perifovea). OCTA parameters differ significantly from the norm even in the early stages of both PACD and POAG. In PACD, there was a significant decrease in microcirculation in the peripapillary retina compared to POAG, which had an inverse correlation with IOPcc; there was also an inverse correlation of OCTA parameters in the optic nerve head and macula with lens thickness.