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)