title: Distribution of Triamcinolone Acetonide after Intravitreal Injection into Silicone Oil-Filled Eye.
abstract: There is increasing use of the vitreous cavity as a reservoir for drug delivery. We study the intraocular migration and distribution of triamcinolone acetonide (TA) after injection into silicone oil tamponade agent during and after vitrectomy surgery ex vivo (pig eye) and in vitro (glass bottle). For ex vivo assessment, intraocular migration of TA was imaged using real-time FLASH MRI scans and high-resolution T2W imaging and the in vitro model was monitored continuously with a video camera. Results of the ex vivo experiment showed that the TA droplet sank to the interface of silicone oil and aqueous almost immediately after injection and remained inside the silicone oil bubble for as long as 16 minutes. The in vitro results showed that, after the shrinkage of the droplet, TA gradually precipitated leaving only a lump of whitish crystalline residue inside the droplet for about 100 minutes. TA then quickly broke the interface and dispersed into the underlying aqueous within 15 seconds, which may result in a momentary increase of local TA concentration in the aqueous portion and potentially toxic to the retina. Our study suggests that silicone oil may not be a good candidate as a drug reservoir for drugs like TA.
authors: Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong.
authors: Ma
authors: 0000-0002-3542-7798
authors: M
authors: Da
authors: Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong; Department of Ophthalmology, United Christian Hospital, Kwun Tong, Kowloon, Hong Kong.
authors: Kenneth K W
authors: 0000-0001-9440-8063
authors: KK
authors: Li
authors: Departments of Ophthalmology and Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA; Laboratory of Biomedical Imaging and Signal Processing, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong.
authors: Kevin C
authors: 0000-0003-4012-7084
authors: KC
authors: Chan
authors: Departments of Ophthalmology and Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA; Laboratory of Biomedical Imaging and Signal Processing, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong.
authors: Ed X
authors: EX
authors: Wu
authors: Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong.
authors: David S H
authors: DS
authors: Wong
mesh_terms: D000818:Animals; D016503:Drug Delivery Systems / Q000379:methods; D058449:Intravitreal Injections / Q000379:methods; D007908:Lens, Crystalline / Q000378:metabolism*; D012160:Retina / Q000378:metabolism*; D012827:Silicone Oils / Q000008:administration & dosage* / Q000378:metabolism; D013552:Swine; D014018:Tissue Distribution / Q000502:physiology*; D014222:Triamcinolone Acetonide / Q000008:administration & dosage* / Q000378:metabolism*
chemical_list: D012827:Silicone Oils; D014222:Triamcinolone Acetonide