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

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.