Effects of topical erythropoietin on healing experimentally-induced avascular scleral damage in a rabbit model

The present study was designed to investigate the effect of topical erythropoietin on the healing process of induced necrotizing scleritis and to evaluate the ocular side effects of this treatment modality in a rabbit model. Necrotizing scleritis was induced in 8 New Zealand albino rabbits. The animals were then randomly divided into one of two groups: a treated group administered a topical erythropoietin-containing cellulose-based gel every 8 h or a control group treated with a cellulose-based gel without erythropoietin every 8 h. The sizes of the lesions measured at different time points were compared between the groups. After three months, the rabbits' eyes were enucleated and histologically and immunohistochemically evaluated for angiogenesis and apoptosis. The lesions were completely vascularized in all eyes of the treated group and 50% of eyes of the control group. The mean interval from the induction of scleral necrosis to a complete improvement was 28 days in the treated group and 62.5 days in the control group (P = 0.04). Histological examination revealed that erythropoietin enhanced the improvement of necrotizing scleritis by stimulating angiogenesis and reducing apoptosis. Neovascularization of the cornea, iris, or retina was not observed in the treated group. We observed a significantly faster recovery to complete improvement of necrotizing scleritis in rabbit eyes treated with erythropoietin compared to those of the control group. Treated eyes had a higher rate of complete healing and had no ocular safety concerns. This therapeutic modality represents a promising treatment for scleral necrosis following various types of ocular surgery.