A multicentre randomised double masked clinical trial of a new formulation of topical cysteamine for the treatment of corneal cystine crystals in cystinosis.
OBJECTIVE
To evaluate the safety and efficacy of a new topical cysteamine formulation, stable at room temperature, for the treatment of corneal cystine crystals in cystinosis.


METHODS
20 study subjects were enrolled in the safety study and 16 in the efficacy study. Both studies were randomised and double blind. The primary outcome for the safety study was the occurrence of predefined serious adverse reactions over 6 months and for the efficacy study the reduction of corneal cystine crystal score (CCCS) by 1.00 or more units on photographs graded by a reading centre using a standardised protocol.


RESULTS
No study subject developed any serious adverse reactions. In the efficacy study, 47% of eyes receiving the standard formulation experienced a reduction in the CCCS of >/=1.00 after 1 year, while 7% of eyes on the new formulation experienced such a decrease (p=0.04).


CONCLUSIONS
Although no serious adverse reactions were observed with either formulation, the new formulation was not as effective as the standard formulation.
Tsilou
E T
ET
Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA. tsiloue@nei.nih.gov
Thompson
D
D
Lindblad
A S
AS
Reed
G F
GF
Rubin
B
B
Gahl
W
W
Thoene
J
J
Del Monte
M
M
Schneider
J A
JA
Granet
D B
DB
Kaiser-Kupfer
M I
MI
D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003316:Corneal Diseases / Q000188:drug therapy* / Q000473:pathology; D003543:Cysteamine / Q000008:administration & dosage* / Q000009:adverse effects; D003554:Cystinosis / Q000188:drug therapy* / Q000473:pathology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011837:Radiation-Protective Agents / Q000008:administration & dosage* / Q000009:adverse effects; D016896:Treatment Outcome
D011837:Radiation-Protective Agents; D003543:Cysteamine