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 in- tervals. 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 experi- ment. The results demonstrate no significant difference in accommodative lag between RGPCL, Ortho- K lens and spectacle wearers for the 2 D AS level (P>0.05), 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, P 0.05). 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-adoleseents. Key words: Contact lens,rigid gas permeable; Orthokeratology; Accommodative lag; Myopia, preadolescent