Removal of Corneal Crystals by Topical Cysteamine in Nephropathic Cystinosis

Abstract

In patients with nephropathic cystinosis, corneal crystals develop by one year of age; they progressively accumulate and eventually cause recurrent corneal erosions and photophobia. After an in vitro study of cystinotic corneal stromal cells showed cystine depletion by cysteamine and after topical cysteamine was determined to be nontoxic in rabbits, we performed a controlled double-blind clinical trial of 10 mM cysteamine eyedrops in young patients with cystinosis, using one eye for treatment and the other as the control. Two children begun on the protocol before two years of age had a striking decrease in the number of corneal crystals in the cysteamine-treated eye within four to five months of entering the study.