The Lack Of Toxicity Of Intravitreally Administered Triamcinolone Acetonide

Purpose To evaluate the toxicity of intravitreal triamcinolone acetonide (TA) on rabbit retina.Methods we drew-off 0.1 mL of aqueous humor of all rabbits and then gave one eye of 40 pigmented rabbits an intravitreal injection of 4 mg/0.1 mL of TA as study group;the other eye received an injection of an equal volume of saline solution as a control.Results of slit-lamp examinations ,ophthalmoscopy , intraocular pressure, electroretinography , light microscopy, the contents of NO and Na+-K+-ATPase of retina,and the glutamate levels of vitreous,which were all assayed in 1,2,4,8,12 weeks after injection and before,demonstrated the lack of ocular toxicity of triamcinolone aceronide in the rabbit.Results No obviously ophthalmoscopic change and retinal toxicity was seen in the each surveying group.ERG and histologicsections in all groups were not significantly changed. The levels of NO, Na+-K+-ATPase and glutamate were not significantly changed after injection.Conclusion Single intravitreal injection of 4 mg of TA in short period,which about three months,did not produce toxicity. However, long-term toxicity studies should carry out before this therapy becomes more widely used.