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 given 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 solution (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 developed in groups 1 and 2. No clinical changes were found in groups 3 to 8. Electroretinography showed various degrees of decrease in the b-wave 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 intravitreally is safe at dosages of 1 mg or less.