Nagoya, Japan Although previous studies suggest that orthokeratology contact lens wear slows the axial length growth of the eye in children with progressing myopia, some limitations in the methodology employed have been evident. Using a rigorous study design and precise optical measuring instruments, Menicon Co., Ltd and the Novovision Clinic in Madrid are undertaking the Myopia Control with Orthokeratology contact lenses in Spain (MCOS) study to compare the axial length growth between white European myopic children wearing orthokeratology contact lenses (OK) and distance single-vision spectacles (SP) over a 2 year period. In this prospective, single-centre clinical trial, sixty two subjects 6 to 12 years of age, and with myopia of -0.75 to -4.00 D and astigmatism = 1.00 D were randomly allocated wear OK or SP correction. Measurements of axial length (using partial coherence interferometry, Zeiss IOLMaster), anterior chamber depth, corneal topography, cycloplegic refraction and visual acuity are being performed at 6 month intervals. To date, no subjects have withdrawn from the study, no adverse events were evident and no contact lens fitting modifications were required in the OK group.
The MCOS study offers a number of notable features: a prospective design; well matched samples and high resolution ocular biometry measures, which collectively should elucidate whether OK contact lens wear is a feasible method of myopia control.
"The MCOS study aims, using a rigorous study design and precise optical measuring instruments, at elucidating whether orthokeratology lens wear slows the axial length growth of the eye in children with progressing myopia. This study is of special relevance taking into account that the prevalence of myopia has increased substantially over recent decades and now is approaching 10-25% and 60-80% in industrialized societies of the West and East, respectively", commented Dr Jacinto Santodomingo, Global Professional Relations Manager for Menicon Co., Ltd
"We have been fitting orthokeratology lenses in our clinic for several years, during which we observed that myopia tends to progress less in children wearing orthokeratology lenses compared to children wearing other modalities of visual correction. We are delighted to participate in this unique clinical trial, which should proof whether we are correct about our preliminary observations", added Mr César Villa, Director of Optometry at Novovision.