Comparison of accommodative lag in pre-adolescent myopes one year after wearing rigid gas permeable contact lenses,orthokeratology lenses or spectacles

Objective To discuss the differences in accommodative lag between pre-adolescent myopes who wore rigid gas permeable contact lenses(RGPCL),orthokeratology(Ortho-K) lenses or spectacles for a year.Methods Seventy pre-adolescent myopes aged 9 to 14 years were enrolled in the study.Every subject was measured for refraction with MPMVA,corneal curvature radius and corneal topography.Twenty-five subjects were selected to wear RGPCL,25 subjects were chosen to wear Ortho-K lenses and the other 20 subjects wore spectacles.According to the above measurements and the compliance of children and their parents.Regular after-care visits were made at 3-month intervals. Accommodative response(AR) was measured with an open field infrared autorefractor(WAM- 5500) in accommodative stimulus(AS) level of 2～5 D after one year.Accommodative lag and the AR/ AS slope were calculated by statistical methods.Results Fifty-seven subjects completed the experiment. The results demonstrate no significant difference in accommodative lag between RGPCL,Ortho-K lens and spectacle wearers for the 2 D AS level(P0.05),while for the 3 D,4 D and 5 D AS levels,there were significant differences in accommodative lag among the three groups(F=4.373,P0.05;F=5.833,P0.01;F=6.157,P0.01),the smallest for Ortho-K,then RGPCL.The AR/AS slope demonstrated the same trend with accommodative lag,but the differences were not significant (P0.05).Conclusion Compared to spectacles,there is an obvious decrease in accommodative lag in pre-adolescent myopes one year after wearing RGPCL and Ortho-K lenses,which strongly suggests that RGPCL and Ortho-K lenses can control the development of myopia in pre-adolescents.