Octreotide Inhibits Choroidal Neovascularization in Rats

Abstract

Aims: Octreotide exhibits anti-angiogenic activity in animal models of retinopathy of prematurity and in clinical cases of proliferative diabetic retinopathy. In this study, we tested the applicability of using octreotide for inhibiting experimental choroidal neovascularization (CNV) in rats. Methods: Of 15 adult rats used, 3 served as non-laser-treated controls. CNV was induced in the right eye of the remaining 12 rats by laser photocoagulation. These 12 rats were divided into two groups (n = 6 each) which were retrobulbarly injected with octreotide (50 μg/kg) or phosphate-buffered saline (PBS) (0.15 ml) immediately and on day 3 after the first injection. Fluorescein angiography and quantitative analysis of the retinal pigment epithelium (RPE)-choroidal flat mounts were performed 14 days after the operation to evaluate the changes in the CNV lesions. Quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) was used to compare the changes shown by the octreotide-, PBS-, and non-laser-treated rats (n = 3 each) with regard to mRNA levels of the vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF)-1 in the RPE-choroidal complex. Results: Octreotide treatment significantly inhibited fluorescein leakage and the extent of neovascularization as was observed in the flat mounts of choroidal tissue derived from the rats with induced CNV. The VEGF and IGF-1 mRNA levels were reduced following treatment with octreotide. Conclusion: The retrobulbar administration of octreotide may be an effective new therapeutic strategy for CNV.