Ustekinumab (STELARA) for the Treatment of Active Sight-Threatening Uveitis (STAR Study)

Background: Uveitis is an inflammation of the eye that can cause vision loss. It is treated with medications and sometimes surgery. However, in many people, treatment does not always prevent loss of vision. A new medication, ustekinumab, reduces inflammation in patients with other inflammatory diseases. Therefore, it might be helpful in treatment of uveitis. Objective: To see if ustekinumab is safe and can help people with uveitis. Eligibility: People ages 18 and older with uveitis Design: Participants will be screened with: Medical and eye disease history Physical exam Eye exam: The pupil is dilated with eye drops. A machine scans the back of the eye. Pictures are taken of the inside of the eye. Blood and urine tests Tuberculosis test Participants will have 6 clinic visits over 28 weeks. Visits lasts 2-3 hours and include: * Medical and eye disease history * Physical and eye exams * Blood and urine tests * Fluorescein angiography: A needle guides a thin plastic tube into an arm vein. A dye is injected into the tube. The dye travels through the veins up to the blood vessels in the eyes. A camera takes pictures of the dye as it flows through the blood vessels in the eyes. * Cohort 1 - Ustekinumab injections at Weeks 0, 4, and 8: The injection is under the skin of the upper arm, leg, or abdomen. Participants will have their uveitis monitored and receive standard uveitis care during the study. * Cohort 2 - Ustekinumab injections via intravenous (IV) injection at first visit, followed by a single 90 mg injection of ustekinumab under the skin of the upper arm, leg or abdomen. For the IV injection a needle will be used to guide a thin plastic tube (catheter) into one of the arm veins. The needle will be removed, leaving only the catheter in the vein.