Triamcinolone acetonide concentration of aqueous humor after decanted 20-mg intravitreal injection

To characterize the concentration-time profile of triamcinolone acetonide (TA) in human aqueous after a single, 20-mg, intravitreal injection.

Case series.

Seven patients and 10 eyes that received intravitreal injection of the decanted 20 mg of TA.

Fifty microliters of aqueous were sampled from each intravitreally TA-injected eye at postinjection monthly interval and the samples were subjected to liquid chromatography coupled with tandem mass spectrometric detection for TA.

The TA concentration in the aqueous.

The TA was cleared from the aqueous in a monoexponential manner with a half-life of 29.6 days and clearance coefficient of 0.0234 (1/day). The extrapolated maximum TA concentration in aqueous was about 3312 ng/ml and the area under the curve was 74,017 day x ng/ml.

The TA concentration in human aqueous could stay above therapeutic concentration for 150 days (5 half-lives with remaining TA concentration of 104 ng/ml) after a 20-mg intravitreal injection, suggesting an even longer therapeutic concentration of TA in vitreous.