The occurrence of optic disc haemorrhage in primary open‐angle glaucoma eyes with lower normal pressure and its relating factors

Purpose To report the occurrence probability of disc haemorrhage (DH) and risk factors for it in otherwise healthy Japanese normal-tension glaucoma (NTG) patients who had lower normal intraocular pressure (IOP) and were followed without treatment for 5 years. Methods A prospective observational study. Normal-tension glaucoma (NTG) patients with IOP consistently ≤15 mmHg without treatment were enrolled. The presence or absence of DH was checked semi-annually on the fundus photographs by three independent observers, while patients were followed without treatment. Cox proportional hazards model taking inter-eye correlation into consideration was adopted to identify risk factors for DH occurrence. The main outcomes were DH occurrence probability during 5-year period and its risk factors. Results One hundred seventeen eyes of 90 patients with mean age of 54.1 years, mean deviation value of -3.6 decibels and mean IOP during follow-up of 12.4 mmHg were included. Disc haemorrhage (DH) was observed at least once in 34 eyes and more than twice in 15 eyes during the follow-up. The DH occurrence probability at 5 years was 31% (95% confidence interval: 21-40%), and lower myopic refraction (HR = 1.18; p = 0.018), higher IOP during follow-up (HR = 1.35; p = 0.047) and presence of DH at baseline (HR = 4.19; p = 0.002) were its risk factors. Conclusion Disc haemorrhage (DH) occurrence probability of Japanese healthy NTG patients with mean IOP of 12.4 mmHg and no systemic and/or topical treatment was 31% at 5 years. Lower myopic refraction, higher IOP and its existence at baseline were its risk factors.