Keratoconus
Conditions
Keywords
keratoconus, collagen cross-linking, riboflavin, UV light
Brief summary
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
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.
Interventions
Topical anaesthesia, corneal epithelial debridement, application of hypotonic riboflavin 0.1% solution (20 minutes), application of UV light (30 minutes).
Sponsors
Study design
Eligibility
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
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Change in keratometry/corneal topography | 3 months |
Secondary
| Measure | Time frame |
|---|---|
| Corneal endothelial cell count | 3 months |
| Visual acuity | 3 months |
Countries
United Kingdom