When the above tests are completed, patients will be scheduled for surgery to place the implant. The procedure will be done under either local or general anesthesia. Follow-up visits will be scheduled 1, 2, 4, and 6 weeks after surgery, then at 3 and 6 months after surgery, and then every 6 months until the implant is depleted of medicine or is removed. Several of the exams described above will be repeated during the follow-up period to evaluate the treatment and side effects, if any.