Corneal Collagen Cross-linking With Hypotonic Riboflavin in Corneas Thinner Than 400 Microns

Study Overview
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Brief Summary
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Corneal ectasia is a relative weakness in the structure of the cornea, which produces a progressive change in its shape which results in visual distortion. It is known that collagen cross-linking in the cornea occurs naturally with age, and in diabetes, both of which seem to prevent progressive ectasia. Corneal collagen cross-linking with riboflavin on corneas thicker than 400 microns has been shown to stabilize the cornea in keratoconus, and prevent progression of the disease. The purpose of this study is to determine whether corneal collagen cross-linking with riboflavin in a hypotonic solution, with UV light, on corneas less than 400 microns thick, leads to stabilisation of corneal ectasia.

Detailed Description
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When cross-linking corneas of > 400 microns, riboflavin in a solution with high molecular weight dextran T500 is used to prevent corneal swelling during the administration of the drops and the UV treatment. However if riboflavin is applied to a cornea in a hypotonic solution (saline), then transient corneal oedema is created with thickening of the corneal stroma. In this way it is thought that the temporarily thickened cornea can be treated with UV whilst still providing a sufficient thickness to absorb the UV to an extent that endothelial cell damage is avoided.

Official Title
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Collagen Cross-linking With Riboflavin in a Hypotonic Solution, With UV Light, on Corneas Less Than 400 Microns Thick: an Exploratory Study.

Conditions
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Keratoconus

Intervention / Treatment
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* Procedure: Collagen cross-linking with hypotonic riboflavin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Keratoconus Corneas thinner than 400 microns, but thicker than 250 microns Exclusion Criteria: Evidence of other corneal disease in the eye to be treated (e.g., Herpes simplex keratitis) Women who are pregnant or nursing at the time of the initial treatment

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Study Arm<br>Exploratory | Procedure: Collagen cross-linking with hypotonic riboflavin<br>* Topical anaesthesia, corneal epithelial debridement, application of hypotonic riboflavin 0.1% solution (20 minutes), application of UV light (30 minutes).<br>* Other names: Medio-Cross® hypotonic solution;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in keratometry/corneal topography |  | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Corneal endothelial cell count |  | 3 months | 
| Visual acuity |  | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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keratoconus, collagen cross-linking, riboflavin, UV light