Objective: To determine the retinal toxicity of triamcinolone acetonide at different doses in vitrectomized, silicone-filled rabbit eyes.
Materials and methods: Vitrectomy with silicone oil placement was performed in 32 rabbit eyes. A dosage of 1 mg/0.025 mL, 2 mg/0.05 mL, or 4 mg/0.1 mL of triamcinolone acetonide was injected intravitreally in the study group eyes; the control group received 0.1 mL of sterile saline. Electroretinography and retinal histology were performed to evaluate toxicity.
Results: No retinal toxicity was seen in the groups given 1, 2, and 4 mg of triamcinolone acetonide or in the control group. ERG and histologic sections in all groups were normal. No drug was visible in the vitreous cavity at the end of the 140-day period (average) in eyes injected with 4 mg of triamcinolone acetonide.
Conclusions: Up to 4 mg of triamcinolone acetonide can be safely injected in silicone-filled, vitrectomized eyes without any significant retinal toxicity.