Patients will be followed at 1 week and 2 weeks after the procedure, then monthly for 6 months, again at 9 months and 1 year. Follow-up will continue at 1-year intervals in patients in whom the treatment is successful. During each follow-up visit patients will have 2 to 3 tablespoons of blood drawn for tests. A small biopsy (about 1/4 inch) of transplanted cells will also be done at 1 week, 1 month, 3 months, 6 months, 1 year, and each year or so thereafter. These tests will evaluate whether the treated skin cells are producing the deficient OAT enzyme and, if so, how much and for how long. They will also indicate whether the enzyme produced is sufficient to lower ornithine blood levels. Patients will also undergo various eye examinations before grafting and at scheduled follow-up visits. These tests may include electrophysiologic (ERG) testing, fundus photographs, scanning laser ophthalmoscope, visual field test, fluorescein angiogram, visual acuity, and manifest reaction.