Related Experiment Video
Updated: Aug 20, 2026
Use of Rabbit Eyes in Pharmacokinetic Studies of Intraocular Drugs
Published on: July 23, 2016
Intravitreal concentration and clearance of triamcinolone acetonide in nonvitrectomized human eyes
John O Mason1, Mamta D Somaiya, Ravinder J Singh
1Retina Consultants of Alabama, P.C., Department of Ophthalmology, Callahan Eye Foundation Hospital, University of Alabama at Birmingham, USA.
Purpose:
To determine the intravitreal concentration and clearance of triamcinolone acetonide at various intervals after intravitreal injection into nonvitrectomized eyes.
Methods:
Six participants were administered 4 mg (0.1 cc) of triamcinolone acetonide ophthalmic suspension. All six eyes underwent therapeutic pars plana vitrectomy with membranectomy at various post injection intervals ranging from 1.25 to 5 months from the intravitreal injection. Undiluted specimens of vitreous overlying the macula and of aqueous humor were submitted for analysis. Vitreous and aqueous humor concentrations of triamcinolone were measured by high performance liquid chromatography.
Results:
Four eyes demonstrated detectable intravitreal concentrations of triamcinolone acetonide between 1.25 and 2.75 months after a single injection. Two eyes had an undetectable level of triamcinolone in both the vitreous and aqueous at 3 and 5 months post single injection.
Conclusions:
The intravitreal concentration of triamcinolone acetonide is detectable up to 2.75 months post a single 4 mg injection in nonvitrectomized eyes. A reinjection interval of 3 months may be needed to achieve sustained measurable levels of triamcinolone in nonvitrectomized patients.
