Defocus Incorporated Soft Contact (DISC) lens
Summary
Purpose
DISC lens is a concentric bifocal contact lens, combining myopia correction and constant myopic defocus. We investigate the effects of wearing time, eye dominance and pupil size on myopia control with DISC lens.
Methods
128 children completed a 2-year double masked randomized clinical trial of myopic control (65 in DISC lens and 63 in single vision contact lenses). Refraction and axial length were measured with cylcoplegic autorefraction and IOL Master. Ocular dominance was determined with the Miles and Porta tests. Pupil images were captured by EAS-1000 (Nidek) for children wearing the DISC lens, the area ratio of the two optical zones was then calculated.
Results
Those who have worn the DISC lens for 8 hours daily reached a 60% reduction in myopia progression. There were no significant differences in eye dominance with refractive changes (t-test), association between myopic progression (chi-square test) and correlation between the zones ratio at pupil and myopic progression (multiple linear regression analysis).
Conclusions
We identified a dosage effect on the DISC lens in slowing myopia progression. Ocular dominance and pupil size do not have any effect on myopia control using the DISC lens.
