Research recommendation(s) from an individual piece of guidance Guidance: Photochemical corneal collagen cross‑linkage using riboflavin and ultraviolet A for keratoconus and keratectasia Date issued: 25 September 2013 Research recommendations coming out of this guidance NICE encourages further research into CXL using riboflavin and UVA for keratoconus and keratectasia, especially epithelium-on (transepithelial) CXL and the combination (CXL-plus) procedures. Details of the techniques used should be clearly described. Reported outcomes should include visual acuity, corneal topography and quality of life. Data on long-term outcomes for all types of CXL using riboflavin and UVA for keratoconus and keratectasia would be useful – specifically data about prevention of progression to corneal transplantation and about repeat procedures and their efficacy.