Analysis of Retinal Capillary Using Optical Coherence Tomographic Angiography of Unilateral Normal Tension Glaucoma

Purpose: The purpose of this study was to analyze retinal capillary parameters using optical coherence tomography angiography (OCTA) of the affected eye and the fellow eye of unilateral normal tension glaucoma (NTG) patients and compare the findings with eyes from a normal control group. Methods: A retrospective cross-sectional study was carried out on patients diagnosed with unilateral NTG (24 affected eyes and 24 fellow eyes each) and normal individuals (29 eyes, the control group). OCTA was used to measure the vascular density (VD) and perfusion density (PD) of the macular area and the peripapillary area. Results: In the superficial capillary plexus, the fellow eye group of unilateral NTG patients showed a decrease in VD of the inner-inferior and PD of the inner-inferior and outer-average peripapillary area, compared with the normal control group (p = 0.008, p < 0.001, and p = 0.001). In the affected NTG eye group, the VD (p = 0.014, p = 0.011, p < 0.001, p < 0.001, and p < 0.001) and PD (p = 0.017, p = 0.023, p < 0.001, p = 0.001, and p < 0.001) of the total, inner-average, inner-inferior, and outer-inferior peripapillary area, and the outer-inferior macular area decreased compared to the fellow eye and normal control group, as well as the VD of the outer-average peripapillary area (p = 0.010). The PD of the outer-average peripapillary area (p = 0.003); the VD (p = 0.041, p = 0.008, p = 0.006) and the PD (p = 0.013, p < 0.001, p = 0.001) of the total, inner-inferior, and outer-average macular area; and the PD of the outer-temporal macular area (p = 0.003) were lower than the normal control group. There was no difference in the VD or PD obtained from the deep capillary plexus of the macular area among the groups. Conclusions: It is useful to observe retinal capillary parameters using OCTA for patients with unilateral NTG.