New Cysteamine Eye Drops Formulation to Treat Corneal Crystals in Cystinosis

This study will evaluate the safety and effectiveness of a new formulation of eye drops used to treat cystine crystals that form in the corneas of patients with cystinosis. Cystinosis is an inherited disease caused by a defective enzyme, in which excessive amounts of the amino acid cystine accumulate in the body. Among others, symptoms include poor growth and development of kidney failure. In addition, after 10 to 20 years, the cornea-the outside covering of the eye over the iris and pupils-becomes so packed with cystine crystals that small, painful breaks may develop. This corneal condition is treated with cysteamine eye drops. This study is designed to provide additional information about this medication that the Food and Drug Administration requires before approving it for marketing. The study will examine, in two separate but simultaneous investigations, the safety and effectiveness of a new cysteamine formulation. In both studies, before treatment begins, patients will have a complete eye examination, and photographs of the eye will be taken using a bright flash. Safety Study Children and adults currently enrolled in a cystinosis study at the National Institutes of Health may participate in this trial. They will receive the current cysteamine formulation in one eye and the new preparation in the other eye. The drops will be given every hour during waking hours. Patients will be observed daily for the first week of treatment and will be called at 2 weeks and 4 weeks to check on side effects, if any. At 6 months, they will undergo a repeat eye examination. Patients (or their parents) will keep a daily diary recording the condition of each eye. Effectiveness Study Children and adults from Ann Arbor, Michigan, LaJolla, California, and the NEI clinic may be enrolled in this study. Participants will receive medication as described above for the safety trial. They will be observed daily for the first week and will have repeat eye examinations, including photograp