Aim To evaluate the effect of intravitreal injection of erythropoietin for the treatment of non-arteritic anterior ischaemic optic neuropathy (NAION).

Methods In this prospective interventional case series, 31 eyes of 31 patients with NAION were included. Patients received intravitreal injection of 2000 unit (0.2 cm³) of erythropoietin within 1 month of the onset of the disease. Visual acuity and visual field were recorded before injections and 1 week, 1 month, 3 months and 6 months after the injections.

Results The mean duration of symptoms before injections was 11.2±5.5 days. Six months after injections, visual acuity improved in 27 eyes (87%), and 17 eyes (54.8%) had ≥3 lines of visual improvement. The mean preinjection visual acuity was 1.01±0.88 logMAR and 0.58±0.58 logMAR (p<0.001) at last follow-up. Visual acuity improvement occurred in 61.2% of patients within the first month. It followed a biphasic pattern in which there was continuous improvement up to 3 months and then started to deteriorate, although it remained significantly better than baseline until the last follow-up. No patient lost any lines of visual acuity compared with the baseline values. The mean of mean deviations of visual field was −19.6±5.7 dB at baseline and −18.6±6.3 dB (p=0.6) at last follow-up.

Conclusions Intravitreal injection of erythropoietin may be safe and effective in the treatment of NAION. The effect may last for a few months and then decline.