Intereye Comparison of the Characteristics of the Peripapillary Choroid in Patients with Unilateral Normal-Tension Glaucoma

To compare the characteristics of the peripapillary choroid (PPC) between the 2 eyes of patients with unilateral treatment-naïve normal-tension glaucoma (NTG). Observational case series. Sixty-nine patients (138 eyes) with treatment-naïve unilateral NTG. The characteristics of PPC vasculature were evaluated by measuring PPC thickness and assessing the presence of parapapillary deep-layer microvasculature dropout (MvD). Peripapillary choroid thickness was measured by enhanced depth imaging OCT. Microvasculature dropout was assessed using OCT angiography. The area and maximum radial width of β-zone parapapillary atrophy (PPA) were measured on infrared images using the built-in caliper tool of the Spectralis OCT (Heidelberg Engineering). Between-eye differences in PPC thickness, MvD frequency, and the area and maximum width of β-zone PPA. Eyes with NTG showed higher intraocular pressure (IOP), longer axial length, thinner PPC, larger area and maximum radial width of the β-zone PPA, and more frequent MvD (P < 0.01 for each) than contralateral healthy eyes. Multivariate conditional logistic regression analysis revealed that higher IOP, thinner PPC, larger maximum radial width of β-zone PPA, and the presence of MvD were associated independently with the risk of NTG (P < 0.03 for each). In eyes with NTG, MvD location and retinal nerve fiber layer defect were correlated topographically. Peripapillary choroid vasculature characteristics are significantly more compromised in eyes with NTG than in contralateral healthy eyes of patients with unilateral NTG.