Abstract
Purpose :
To compare the variation of objective cycloplegic refraction and axial length (AL) between 2 kinds of different orthokeratology (ortho-k) contact lenses and to examine their effect on suppressing the progression of myopia.
Methods :
In this prospective study, 68 eyes of 34 Japanese children [mean age: 9.1±1.6 years; cycloplegic refraction: -3.61±0.80 diopters (D); AL: 21.85±0.52 mm] were randomly assigned to wear ortho-k contact lenses made by Alpha Corp. (Alpha Group: 30 eyes of 15 children) or by Technopia Co., Ltd. (Techno Group: 38 eyes of 19 children). In this study, there was no significant difference between the two groups in regard to age, objective cycloplegic refraction, AL, and the ratio of boys to girls (unpaired t-test, one-way analysis of variance). Measurements of objective cycloplegic refraction by ARK-730A AUTO REF/KERATOMETER (NIDEK) and AL by IOL Master (Carl Zeiss Meditec) were obtained at every 6-month period for 2 years and at 3-weeks post discontinuance of the ortho-k lens wear when the schoolchildren returned for examination of corneal topography. The variation of objective cycloplegic refraction and AL pre and post ortho-k lens wear was also compared in both groups.
Results :
Over the 2-year follow-up period, objective cycloplegic refraction variation was -0.20±0.60D and -0.42±0.62D in the Alpha Group and Techno Group, respectively, with no significant difference found between the two groups (p=0.25, unpaired t-test), and AL variation was 0.52±0.07mm and 0.50±0.08mm in the Alpha Group and Techno Group, respectively, with no significant difference found between the two groups (p=0.88).
Conclusions :
The findings of this study showed equivalent variation of objective cycloplegic refraction and AL between these two types of ortho-k lens, thus suggesting that there is no difference between them in their effect of suppressing the progression of myopia.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.