Efficacy of Topical Cysteamine in Nephropathic Cyctinosis

Study Overview
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Brief Summary
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The aim of this study is to evaluate the efficacy of topical cysteamine eye drops in the treatment of corneal cystine crystals deposits in patients with nephropathic cystinosis.

Detailed Description
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A total of 26 patients with nephropathic cystinosis were included in this prospective study. Patients were evaluated for improvement of corneal cysteine deposits crystals and photophobia following treatment with topical 0.55% cysteamine eye drops.

Conditions
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Nephropathic Cyctinosis, Corneal Cystine Crystals

Intervention / Treatment
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* Drug: Cysteamine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients with confirmed diagnosis of nephropathic cystinosis leucocyte cystine concentration level of more than 2.0 nmol half-cystine/ mg protein clinical evidence of tissue deposition of cystine and tissue damage due to cystinosis Exclusion Criteria: Allergy to cysteamine

Ages Eligible for Study
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Minimum Age: 8 Months
Maximum Age: 19 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: cysteamine eye drops<br>Patients used cysteamine eye drops every 2 hours while awake to both eyes. | Drug: Cysteamine<br>* Patients were asked to use topical cysteamine 0.55% eye drops every 2 hours while awake to both eyes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with improvement of photophobia, corneal cystine crystals and visual acuity following treatment with topical cysteamine 0.55% eye drops in patients with nephropathic cystinosis. | Patients had a baseline ophthalmic examination before initiation of topical cysteamine 0.55% eye drops and subsequent monthly follow up exams. The following parameters were recorded pretreatment, on each monthly visit and post treatment at last follow up visit: photophobia, slit lamp assessment of corneal cystine crystals and visual acuity. Photophobia was classified as grade 0 (none) for no photophobia, grade 1 (mild) for photophobia in bright light, grade 2 (moderate) for photophobia in room light and grade 3 (severe) for photophobia in dim light. Corneal cystine crystals were graded as Grade 0 = None, Grade 1 = 1-10 crystals/mm, Grade 2 = 11- 50 crystals/mm, Grade 3 = more than 50 crystals/mm. The level of cystine in the corneal layers was recorded and the location whether peripheral or central was also identified. Visual acuity was measured by Snellen chart at 20 feet with best distance correction. | Photophobia, slit lamp assessment of corneal cystine crystals and visual acuity are recorded pretreatment, on each monthly visit up to 48 months. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cysteamine, nephropathic cystinosis, cystine crystals