Associations between changes in radial peripapillary capillaries and occurrence of disc hemorrhage in normal-tension glaucoma

Purpose In order to clarify the association between peripapillary vascular changes and disc hemorrhage (DH) occurrences over time, we analyzed the density of radial peripapillary capillary (RPC) and clinical parameters during follow-up periods in patients with normal-tension glaucoma (NTG). Methods Seventy-seven eyes of 77 NTG patients were subjected to analysis. We selected patients who had an initial optical coherence tomography angiography (OCTA) scan in 2015 and who had another OCTA scan in 2018 with both OCTA scans showing good-quality images. We investigated the relationships between DH occurrence and each of the following parameters: RPC density, circumpapillary retinal nerve fiber layer (cpRNFL) thickness slope and total deviation (TD) slope. Results In the period between the initial and final OCTA, we categorized the patients into 53 sides with DH (DH group) and 101 sides without DH (non-DH group). The Delta RPC density of sides with DH was significantly greater than that of sides without DH (DH, - 4.42 +/- 6.43%; without DH, - 2.48 +/- 5.29%; p = 0.0469). The cpRNFL thickness slope of sides with DH was significantly faster than that of sides without DH (DH, - 2.85 +/- 3.17; without DH, - 0.74 +/- 2.46 mu m/y; p < 0.0001). The TD slope of sides with DH was significantly faster than that of sides without DH (DH, - 0.50 +/- 0.77; without DH, - 0.22 +/- 0.53 dB/y; p = 0.0163). As DH occurrence increased, the RPC density significantly decreased (r = -0.255, p = 0.0014). Stepwise multiple regression analysis to identify factors influencing RPC changes showed that frequency of DH (beta = - 0.224, p = 0.008) and central corneal thickness (beta = - 0.220, p = 0.009) were significantly associated with RPC changes. Conclusions DH occurrence may prompt the structural and vascular deterioration of NTG.