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Objective: There has long been a great interest in neuroprotection therapy for ischaemic stroke and various types of optic neuropathies. In view of that, I reviewed the literature on the role of neuroprotection for non-arteritic anterior ischaemic optic neuropathy (NA-AION)., Methods: The review is based on a PubMed search of literature about the use of neuroprotectors in stroke and optic neuropathies and about current clinical trials of RPh201 and QPI-1007 in NA-AION., Results: Several neuroprotection agents for ischaemic stroke and various types of optic neuropathies have been evaluated extensively in experimental studies in animals and benefits claimed. However, translation of therapeutic strategies for neuroprotection from experimental research to humans has invariably been fraught with failure. Two currently ongoing studies dealing with neuroprotection by RPh201 and QPI-1007 in NA-AION may have limitations in their rationale and study designs., Conclusions: Unfortunately, in spite of all the experimental and clinical research on neuroprotection agents in NA-AION so far, we have no scientifically proven evidence of neuroprotection agents showing any benefit in the human clinical studies so far., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Ciliary neurotrophic factor (CNTF) has been shown to protect retinal ganglion cells (RGCs) in traumatic optic nerve injury. We sought to evaluate this neuroprotective effect of CNTF after an ischaemic event using rodent anterior ischaemic optic neuropathy (rAION), a mouse model of non-arteritic anterior ischaemic optic neuropathy (NAION)., Methods: We induced rAION in Thy1-cyan fluorescent protein (CFP) transgenic mice by exposing the optic nerve to frequency doubled neodymium yttrium aluminium garnet laser pulses following intravenous rose bengal injection. One day after rAION induction, an intravitreal injection of 0.75 μg CNTF or vehicle (sham injection) was given. Animals were euthanised on day 15 after induction, tissues isolated and CFP cells in the RGC layer were counted using stereology in flat-mounted retina. The average number of CFP-positive (CFP+) cells was determined for each study group and the percentages of RGC loss were compared between the different groups., Results: Two weeks after rAION induction, significantly more (CFP+) cells were preserved in CNTF-treated eyes than in sham-injected controls. Sham-treated animals showed a 58% loss of CFP+ cells. In contrast, CFP+ cell density in CNTF-treated eyes decreased by only 10%, when compared with untreated control eyes. This increased survival was statistically significant (p<0.05)., Conclusions: CNTF exerts a neuroprotective effect in ischaemic optic nerve injury and promotes RGC survival, suggesting that CNTF may be effective in the clinical treatment of human NAION., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

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.

Background/aims: Preclinical data suggest that intravitreally administered erythropoietin (EPO) is both neuroprotective and safe. In a small pilot series, we intended to assess the feasibility of intravitreal EPO injections in humans., Methods: Three patients with acute vascular occlusion of the posterior pole received a single intravitreal EPO injection of 2000 U. Immediately before the injection and over the ensuing 3 months, these patients were closely monitored by measuring visual acuity, visual fields, intraocular pressure, the electroretinogram, the haematocrit and serum EPO levels., Results: Over the observational period, most parameters remained unchanged except for a short-term rise of serum EPO levels, which, however, did not exceeded normal serum levels. No injection-related toxicity was observed., Conclusion: Based on this limited set of data, a single EPO injection of 2000 U, a dose adapted from previous in vivo studies, is feasible and seems to induce no obvious damage. Hence, further investigations of this therapeutic approach appear justified.