Effects of Local Administration of Interferon- β on Proliferation of Retinal Pigment Epithelium in Rabbit After Laser Photocoagulation

Abstract

Purpose: To investigate whether local administration of interferon (IFN)-β promotes proliferation of the retinal pigment epithelium (RPE) in vivo. Methods: Following local injection of IFN-β into the sub-Tenon space of rabbit eyes, the penetration of IFN-β into various intraocular areas was determined by means of enzyme-linked immuno-adsorbent assay. Retinal lesions were produced by laser photocoagulation (PC), and IFN-β (1 × 10 6 IU, 1 × 10 5 IU, or 1 × 10 4 IU) was administered into the sub-Tenon space. Physiological saline was substituted for IFN-β in controls. The proliferation of RPE cells was inspected histopathologically. Results: After IFN-β administration, IFN-β was found in all intraocular areas examined, with the highest concentration detected in the choroid. After PC, profuse proliferation of RPE cells began earlier in the rabbits that received the highest dose of IFN-β than in the control rabbits; repair of the central part of the coagulated lesion in those rabbits was complete within 7 days after PC. In control rabbits, the histopathologic wound repair process proceeded more slowly and to a limited extent. Proliferation of RPE cells in the low and medium dose IFN-β-treated rabbits was similar to that in the control rabbits. Conclusion: The present study demonstrates that repair of the PC-induced retinal lesions, particularly the proliferation of RPE cells, is promoted in vivo by local administration of IFN-β.