Bilateral RCT of tomography orientated corneal collagen cross linking
Research type
Research Study
Full title
A Randomised, Bilateral, Controlled, Prospective Study to Investigate the efficacy of Tomography-orientated versus standard axial Riboflavin/Ultraviolet A Corneal Collagen Cross-linking (CXL)\n
IRAS ID
242042
Contact name
David PS O'Brart
Contact email
Sponsor organisation
Guys and St Thomas' NHS Foundation Trust
ISRCTN Number
ISRCTN52187987
Clinicaltrials.gov Identifier
n/a, n/a
Duration of Study in the UK
1 years, 10 months, 31 days
Research summary
Keratoconus is a disease of the eye affecting the cornea (the transparent dome at the front of the eye) characterized by thinning and subsequent localized bulging (known as ectasia). The resultant irregular corneal shape results in reduced and distorted vision. \n\nRiboflavin (vitamin B2)/ultraviolet A (UVA) corneal collagen cross-linkage (CXL) is a treatment which halts the progression of keratoconus. It involves removing the central corneal surface cells (epithelium), applying riboflavin drops (which soak into the substance of the cornea, i.e. corneal stroma), and then shining ultraviolet light onto the cornea. This has been shown to increase the strength of the cornea by cross-linking the protein molecules within it, thus reducing progression.\n\nIn clinical studies, it has been shown to halt the progression of keratoconus in over 90% of eyes, as well as improve the overall corneal shape in the majority but not all eyes. In the standard technique the epithelium is removed, Riboflavin 0.1% is applied to the central cornea for sufficient time to allow complete stromal riboflavin uptake and the UV light shone at the central 8.0-9.0 millimetres of the corneal stroma. This occurs irrespective of the position on the cornea of the bulging (known as the cone) and therefore the location of abnormally weakened corneal tissue. Interestingly, it has been documented that better results tend to occur with more centrally located cones. This is perhaps because with centrally located cones, the conventional central treatment is directed towards the site of the problem rather than the entire cornea. \n\nThe aim of this study is to compare the efficacy in terms of visual, refractive and tomographic outcomes of tomography/topography orientated CXL, where the treatment is directed to the location of the main area of ectasia on the cornea (the cone), with the standard technique.
REC name
South West - Cornwall & Plymouth Research Ethics Committee
REC reference
18/SW/0156
Date of REC Opinion
22 Jun 2018
REC opinion
Further Information Favourable Opinion