Extended depth-of-focus contact lenses can slow the rate of progression of myopia

Abstract

Purpose: We investigated the effects of two different, novel design, extended depth-of-focus (EDOF) contact lenses (CL) and a commercially-available single vision control CL on the rate of myopia progression in Chinese children.

Methods: A prospective, double-masked, randomized clinical trial was initiated at the BHVI China research clinic in January 2014 to enrol 270 Chinese children, aged 8 to 13 years, with spherical equivalent refractive error between -0.75D and -3.50D. Enrolled patients were randomized into one of the following: a single vision control CL, EDOF1 or EDOF2 prototype CL. The primary outcome measures, cycloplegic autorefraction (AR, Shin-Nippon, Japan) and axial length (AL, Lenstar, Switzerland), were measured at baseline, and were scheduled to be measured every 6 months for at least 3 years. Each group was matched for age, gender, parental myopia, AL and refractive error. Exclusion criteria included previous treatment for myopia and systemic or ocular disease.

Results: To date, approximately twenty children in each group have completed the 6 months visit. The mean rate of myopia progression for the control group was AR: -0.49D ± 0.29 and AL: 0.17mm ± 0.09. Statistically significant reduction in the rate of myopia progression (p<0.001) was achieved in children wearing both types of EDOF lenses; EDOF1: AR -0.24D ± 0.28 (51% reduction) and AL 0.07 mm ± 0.08 (58% reduction); EDOF2: AR -0.23D ± 0.28 (53% reduction) and AL 0.08 mm ± 0.09 (53% reduction). The outcome measures obtained with two EDOF lenses were not significantly different between eachother (p>0.05).

Conclusions: The EDOF lenses significantly slowed the rate of progression of myopia in children. Longer term results with greater number of participants will be needed to substantiate the results obtained at the 6-month visit.