Rigid gas permeable lens highly influences the interpretation of CXL results

Wearing a rigid gas permeable lens can lead to improved topographic parameters and can significantly alter a number of study parameters, claims a paper published in the British Journal of Ophthalmology.

A prospective, non-comparative study led by Dr Koppen Carina, Department of Ophthalmology, Antwerp University Hospital, Belgium, comprised of 15 eyes without rigid gas permeable contact lens (CL) and 12 eyes fitted with a CL from 1 to 10 weeks after ultraviolet A/riboflavin cross-linking (CXL) for the stabilisation of progressive keratoconus.

Refractive sphere and cylinder, maximal keratometry value (K max), simulated keratometry steep, flat, astigmatism, refractive power (RP) steep, flat and astigmatism, I-S value on EyeSys, K max on Pentacam and change from baseline of best spectacle-corrected visual acuity (BSCVA) were all used to measure the effect of CXL treatment on patients. The results of the study were recorded pre-CXL and in 6 month intervals for 18 months post-CXL.

There were no study parameters that demonstrated a significant change from baseline results in eyes without CL.

However, in eyes fitted with CL post-CXL I-S value and K max on EyeSys at all time intervals, RP steep and simulated astigmatism at 6 and 12 months and RP flat at 12 months all showed significant improvement.

CL can greatly influence the interpretation of CXL results, with lens wear improving topographic parameters.