The effects of riboflavin UV crosslinking on keratometric behaviour in keratoconus : a six-month follow-up study

Abstract: Ultraviolet riboflavin crosslinking (CXL) for keratoconus is a relatively new procedure done by ophthalmologists. It seems to be the only form of treatment available at present to stop the progression of keratoconus. As the progression of keratoconus results in a decrease of vision as well as the inability of vision to be adequately restored with spectacles or soft contact lenses, it is important to do the procedure as early as possible. Early CXL treatment seems to preserve the patient’s vision at a better level, it should only be done if progressive keratoconus has been established and if the cornea is not thinner than 400 μm. It has been found that keratometric measurements (K-readings) flatten or stabilise, or that the cornea tends to take on a more symmetric form after CXL. In a few rare cases a steepening of Kreadings might be found. The aim of this study was to analyse the change in K-readings (which are related to the shape or topography) of the cornea following CXL of keratoconic corneas over a six-month period. Participants undergoing CXL were examined to ensure that they qualify for the study. In the treatment group, fourteen eyes of eleven subjects were analysed. Fifty consecutive Kreadings were done with an autokeratometer before the procedure, at one week postoperatively, one month post-operatively and at six months post-operatively. Two keratoconic eyes in the keratoconic control group and twelve eyes (of six subjects) in the non-keratoconic control group were analysed. Both these groups underwent the same measurements on the same time line as the treatment group. A test eye was also analysed during the study period. The test eye was used to assess the accuracy and repeatability of the autokeratometer used in this study...M.Phil. (Optometry