Peripheral defocus and myopia progression in myopic children randomly assigned to wear single vision and progressive addition lenses

Abstract

Purpose: To determine the effect of progressive addition lenses (PALs) and single vision lenses (SVLs) on peripheral defocus in myopic children, and to compare the effect of myopic versus hyperopic peripheral defocus on foveal myopia progression.

Methods: Eighty-four myopic children aged 6 to 11 years with spherical equivalent (SE) cycloplegic autorefraction between -0.75 diopters (D) and -4.50 D were randomly assigned to wear SVLs or PALs. Aberrometry measurements of the eye and spectacles were made centrally, 30° nasally, temporally, and superiorly, and 20° inferiorly on the retina using a Complete Ophthalmic Analysis System for Vision Research (COAS-VR). The association between peripheral defocus and the 1-year change in central myopia was investigated.

Results: SVLs caused a hyperopic shift in peripheral defocus at all locations (all P ≤ 0.0003). PALs caused a myopic shift in peripheral defocus in three of four locations measured (all P ≤ 0.01) with the greatest shift superiorly due to the PAL addition (-1.04 ± 0.30 D). Superior retinal defocus when wearing either SVLs or PALs was associated with the 1-year change in central myopia. The adjusted 1-year change in central SE myopia was -0.38 D for children with absolute superior myopic defocus (n = 67) and -0.65 D for children with absolute superior hyperopic defocus (n = 17; difference = 0.27 D; P = 0.002).

Conclusions: PALs caused a myopic shift in peripheral defocus. Superior myopic defocus was associated with less central myopia progression. These data support the continued investigation of optical designs that result in peripheral myopic defocus as a potential way to slow myopia progression. (ClinicalTrials.gov number, NCT00335049.).

Keywords: children; myopia progression; peripheral defocus; progressive addition lenses; single vision lenses.

Figure 1.

The difference in spectacle RPD (i.e., the change in the eye's RPD caused by the spectacle lens) between PALs and SVLs by retinal location in Year 1 of the study. Values are mean ± SE.

Figure 2.

Mean 1-year change in central spherical equivalent refractive error for children with hyperopic RPD on the superior retina and children with myopic RPD on the superior retina during the first study year when children wore either SVLs or PALs. Annual progression is adjusted for baseline refractive error, baseline age, sex, and ethnicity. Error bars represent SE.

Figure 3.

Mean 1-year change in central spherical equivalent refractive error during the first study year (wearing either SVLs or PALs) for children with absolute peripheral defocus (as measured by the aberrometer) that was hyperopic versus myopic on the (A) superior retina and (B) temporal retina. Annual progression is adjusted for baseline refractive error, baseline age, sex, and ethnicity. Error bars represent SE.