Background: To evaluate the intraocular concentration of triamcinolone acetonide after intravitreal injection.
Methods: The prospective clinical interventional case series study included 17 patients who had received a 20 to 25-mg intravitreal injection of triamcinolone acetonide as treatment for exudative age-related macular degeneration, diffuse diabetic macular edema, or retinal vein occlusions. During a secondary intraocular surgery taking place 4.1 weeks to 25.7 months after the intravitreal injection, aqueous humor samples were obtained. None of the eyes were vitrectomized.
Results: In the aqueous humor samples, triamcinolone acetonide was in low, but measurable, concentrations detected up to 1.5 years after the intravitreal injection. Concentrations found in samples obtained during the first 6 months, or 7 to 12 months, respectively, after the injection ranged between 3.0 microg/l and 436 microg/l, and between 0.0 microg/l and 11.2 microg/l, respectively.
Conclusions: After injection of triamcinolone acetonide, triamcinolone can be present in measurable concentrations up to 1.5 years after the application.