RETINAL TOXICITY OF INTRAVITREOUS OCTREOTIDE IN THE RABBIT

Objective: To evaluate the ocular toxicity of intravitreous octreotide . Design: New Zealand white rabbits weighing approximately 2 kg were g iven 5 mg (group 1, two eyes), 2 mg (group 2, four eyes), 1 mg (group 3, four eyes), 0.5 mg (group 4, two eyes), 0.3 mg (group 5, two eyes) or 0.1 mg (group 7, two eyes) of octreotide acetate, two doses of 0.3 mg 1 week apart (group 6, four eyes) or 0.1 mL of balanced salt soluti on (group 8 [control group], two eyes). Outcome measures: Findings on clinical examination and electroretinography, performed before and 10 days after injection, and on light microscopy. Results: Cataracts deve loped in groups 1 and 2. No clinical changes were found in groups 3 to 8. Electroretinography showed various degrees of decrease in the b-wa ve amplitude in groups 1 and 2; the results were normal in groups 3 to 8. Histologic examination showed macrophage and monocyte infiltration in the vitreous and retina in group 1. No histologic change was seen in the eyes in groups 2 to 8. Conclusions: Octreotide injected intravi treally is safe at dosages of 1 mg or less.