Feasibility of intravitreal erythropoietin injections in humans.

Abstract

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. 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. 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. 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.