Vehicle used for triamcinolone acetonide is toxic to ocular tissues of the pigmented rabbit.

PURPOSE: To investigate the potential toxicity of the vehicle used for triamcinolone acetonide (TA) to the cornea, lens, ciliary body, and retina of pigmented rabbits.

METHODS

Forty chinchilla rabbits (40 eyes) were divided into four groups: group A (control group) eyes received an intravitreal injection of 0.1 ml sterile saline solution; group B eyes received 0.1 ml (1.3 mg) TA plus vehicle; group C eyes received 0.1 ml (1.3 mg) TA alone (vehicle eliminated); group D eyes received 0.1 ml vehicle only. Intraocular pressure (IOP) was measured pre-injection and at 1, 7, 14, 30, and 90 days post-injection. Scotopic and photopic electroretinograms (ERG) were examined pre-injection and 7, 30, and 90 days post-injection. Animals were sacrificed 7, 30, and 90 days post-injection. Eyes were enucleated and examined by light microscopy (LM) and electron microscopy (EM).

RESULTS

The IOP of groups B and C was higher than that of other groups on days 1, 7, and 14 post-injection (p < 0.05). ERG amplitudes of groups B and D were lower than those of other groups on days 7 and 30 post-injection (p < 0.05). Histopathological sections indicated morphologic changes in the ciliary body, lens, and retina of eyes in groups B and D.

CONCLUSIONS

Vehicle used for TA is toxic to the lens, ciliary body, and retina of pigmented rabbit eyes after injection of intravitreal TA.