Comparison of retinal microvascular changes in eyes with high-tension glaucoma or normal-tension glaucoma: a quantitative optic coherence tomography angiographic study.

PURPOSE: The aim of this study is to determine and compare the changes in the retinal vasculature in eyes with high-tension glaucoma (HTG) or normal-tension glaucoma (NTG).

METHODS: The right eyes of 43 HTG subjects, 33 NTG subjects, and 51 age- and sex-matched normal subjects were included in this cross-sectional study. Signals were projected from the internal limiting membrane to retinal pigment epithelium. The retinal perfused vessel densities in the peripapillary and parafoveal regions were measured automatically with optic coherence tomography angiography and the split-spectrum amplitude-decorrelation angiography algorithm.

RESULTS: Compared with normal eyes, glaucomatous eyes had a smaller retinal nerve fibre layer (RNFL) thickness, smaller full parafoveal retinal thickness, and lower retinal perfused vessel density (PVD) in the peripapillary and parafoveal regions (all P < 0.01). The visual field, RNFL and retinal thicknesses, and PVD in the parafoveal region in the HTG eyes were similar to those in the NTG eyes. However, the NTG eyes had a significantly lower mean PVD than the HTG eyes in the peripapillary region. When the different sectors of the peripapillary region were studied, the difference was still significant in most sectors (all P < 0.05), except the inferotemporal sector (P = 0.676).

CONCLUSIONS: The retinal perfused vessel density is significantly reduced in HTG and NTG eyes, and more prominently in the peripapillary region in NTG eyes.