Cysteamine Eye Drops to Treat Corneal Crystals in Cystinosis
Status:
Completed
Trial end date:
2013-07-01
Target enrollment:
Participant gender:
Summary
Cystinosis is an inherited disease that results in poor growth and kidney disease, among
other things. The damage to the kidneys and other organs is thought to be due to accumulation
of cystine inside the cells of various body tissues. This chemical also accumulates in the
cornea-the covering of the eye over the pupil and iris. After 10 to 20 years, the corneas of
some patients become so packed with crystals that the surfaces may become irregular,
occasionally causing small, painful breaks.
Patients enrolled in a NIH study on cystinosis are receiving the drug cysteamine. Taken by
mouth, this drug reduces cystine in some tissues, but not in the cornea. This study began in
1986 to test whether cysteamine eye drops could prevent or reduce corneal cystine crystals in
these patients. The drops have been very effective in removing crystals and reducing pain in
patients who take the medication as directed. Patients who do not take the medication as
prescribed do not benefit.
After the effectiveness of the drops was proven, the main purpose was modified to continue to
evaluate the long-term safety and effectiveness of cysteamine eye drops for treating cystine
crystals in the corneas of patients with cystinosis until the drops are approved by the Food
and Drug Administration (FDA). When the New Drug Application (NDA) for the Sigma-Tau standard
formulation is granted, this protocol will be terminated.