Intravitreal pharmacokinetics after posterior subtenon triamcinolone acetonide injection in vitrectomized rabbit eyes.
OBJECTIVE
To investigate the intraocular pharmacokinetics of triamcinolone acetonide (TA) injected into the posterior subtenon of vitrectomized rabbit eyes.


METHODS
Vitrectomy was performed on the right eyes of 35 rabbits. Triamcinolone acetonide (40 mg/mL) was injected into the posterior subtenon space of both eyes. Five rabbits each were killed at days 1, 3, 7, 14, 28, 56, and 84. Both eyes were enucleated. The vitreous was isolated, and TA concentration was measured.


RESULTS
In vitrectomized eyes, the intravitreal concentrations of TA were 1763, 822.9, 321.5, 113.3, 35.5, 14.4, and 6.7 ng/mL, respectively, at the time points indicated above; the concentrations in nonvitrectomized eyes were 397.8, 360.4, 154.4, 48.5, 30.7, 15.2, and 8.0 ng/mL, respectively. Triamcinolone acetonide concentrations were significantly higher in the vitrectomized eyes at days 1, 3, 7, and 14. The terminal half-life of intravitreal TA was 23.3 days in the vitrectomized eyes and 28.9 days in the nonvitrectomized eyes.


CONCLUSIONS
Intravitreal absorption and excretion of TA in the posterior subtenon space are increased after vitrectomy. Although the terminal half-life of TA was shorter, higher early concentration and similar effective duration were achieved in the vitrectomized eyes.
*Department of Ophthalmology, College of Medicine, Pusan National University, Yangsan, Korea; †Research Institute of Convergence of Biomedical Science and Technology, Yangsan Pusan National University Hospital, Yangsan, Korea; and ‡Medical Research Institute, Pusan National University Hospital, Busan, Korea.
Hyun Jun
HJ
Park
Ji Eun
JE
Lee
Sung Il
SI
Kim
Kang Yeun
KY
Pak
Boo Sup
BS
Oum
Jong Su
JS
Lee
Jae Ho
JH
Jung
Ji-Eun
JE
Lee
D000818:Animals; D001682:Biological Availability; D002853:Chromatography, Liquid; D005938:Glucocorticoids / Q000493:pharmacokinetics*; D006207:Half-Life; D056965:Injections, Intraocular; D013058:Mass Spectrometry; D011817:Rabbits; D058475:Tenon Capsule / Q000378:metabolism; D014222:Triamcinolone Acetonide / Q000493:pharmacokinetics*; D014821:Vitrectomy; D014822:Vitreous Body / Q000378:metabolism*
D005938:Glucocorticoids; D014222:Triamcinolone Acetonide