Intraocular steroids have shown promise in treatment of intraocular proliferation such as seen in penetrating injuries and massive periretinal proliferation. In this study we will measure the distribution and persistence of a radioactive labelled steroid (H3 radio-labelled Triamcinoline acetonide) in both vitrectomized and non-vitrectomized rabbit eyes. Following intravitreal injection, the radioactivity in vitreous, retina and pigment epithelium, choroid, sclera, lens, iris and ciliary body, and cornea will be counted in a liquid scintillation counter at various time intervals (1 day, 7 days, 30 days, 90 days). This information will be valuable in determining the amount of steroid delivered to tissues responsible for proliferation (retina, pigment epithelium, choroid, sclera) and the persistence of the drug in tissues. The levels in other tissues potentially harmfully affected by the drug will be investigated (lens, cornea). Also whether vitrectomy affects distribution and persistence will be investigated. Long term objectives will be to determine if active steroid, metabolite, or breakdown products reach the tissues by using high performance liquid chromatography, and to test distribution and persistence of intravitreal steroids and antibiotics in experimental retinal detachment, perforating injury, and endophthalmitis.