Abstract
Purpose: :
The purpose of this study was to determine the intravitreous pharmacokinetic profile of benzyl alcohol triamcinolone acetonide formulation, and preservative-free triamcinolone acetonide formulation, and evaluate potential signs of toxicity to the retina.
Methods: :
Fifty New Zealand male white rabbits, divided in two groups, were enrolled in the study. In group I, 25 rabbits received 4 mg (0,1 ml) of preservative benzyl alcohol triamcinolone acetonide formulation into the vitreous of the right eye. In group II, 25 rabbits received 4mg (0,1ml) of preservative-free triamcinolone. Five rabbits of each group was euthanized at 3, 7, 14, 21 e 28 days after injections, and intravitreal drug levels were determined by enzyme linked immunosorbent assay (ELISA). Ocular pressure of the experimental eye was measured preoperatively, postoperatively, and on 14 and 28 days after injection. Five animals in each group were randomly chosen 27 days after injection for light microscopy examination. Eletroretinography (ERG) was performed on both eyes of each five rabbits of group I and II at baseline and 27 days after injection.
Results: :
At 7 days after injection, the mean triamcinolone intravitreous concentration in the group I was higher than group II. In the other days the mean concentration observed was the same in both groups. There was no evidence of toxic effects on both groups based on histological and ERG findings.
Conclusions: :
Our findings showed that preservative benzyl alcohol triamcinolone acetonide formulation and preservative-free triamcinolone acetonide formulation had the different vitreous concentration just at seven days after intravitreous injection. No toxic reactions in the retina were observed in both groups.
Keywords: retina • inflammation • drug toxicity/drug effects