Peripheral Defocus Profile of Multifocal Minus Contact Lenses

Purpose: Numerous studies have proven that emmetropization in young animals including humans is regulated by visual input. It has long been hypothesized that peripheral myopic defocus may act as a stop signal to reduce myopia progression and axial elongation. As such, multifocal soft contact lenses (MFCLs) have been utilized for myopia control in school-aged children, with variable efficacies. One potential explanation is that the actual peripheral myopic defocus an eye experiences during MFCL wear may not be identical to the Add power and not sufficient to reduce myopia progression. Our study investigated and compared the peripheral power profiles of myopic eyes when they were uncorrected and wore single vision contact lenses (SVCLs) and MFCLs of different Add powers.

Methods: Subjects with -1.00 D to -10.00 D of myopia (SE, determined with manifest refraction) were custom fit with both single vision (SV) and MFCLs (+2.00 and +4.00 D Add; provided by Specialeyes) in both eyes. These Specialeyes MFCLs had an aspheric design with a standard total optical zone of 8.0mm. Cycloplegic central autorefraction was conducted with both Grand Seiko WAM-5500 open-field auto-refractor (Grand Seiko Co Ltd) and OPD OPD-Scan III Wavefront Aberrometer (Marco) on the subjects in the following conditions: (1) no CLs, (2) SVCLs, (3) MFCLs (+2.00D Add), and (4) MFCLs (+4.00D Add). Relative peripheral power profiles were measured using the OPD under the same 4 conditions after cycloplegia. Data in the right eye was used for analysis.