Myopia treatment with defocus incorporated multiple segments (DIMS) lenses can create hyperopic relative peripheral refraction (RPR) reductions in children previously treated with single vision lenses, according to research published in Ophthalmic and Physiological Optics. These findings indicate differences in retinal shape and eye growth patterns among these individuals compared with patients treated with DIMS who never underwent treatment with single vision lenses, the report shows.
Researchers included 130 children with myopia in the double-masked, randomized controlled trial and randomly assigned them to treatment with DIMS (n=65) or single vision lenses (n=55). Participants in the single vision cohort switched to treatment with DIMS after 2 years while individuals in the DIMS group continued to receive the same treatment throughout the 3-year study duration. The team performed central and peripheral refractions and measured axial length every 6 months during the investigation.
Participants who were treated with DIMS did not experience any significant changes in RPR or clinically meaningful differences between the nasal and temporal retina during the course of the study. The children treated with single vision lenses experienced asymmetric RPR changes evidenced by hyperopic RPR increases at 20° and 30° nasally (mean difference: 0.88 and 1.07, respectively; P <.001 for both). After switching to treatment with DIMS, these individuals experienced significant reductions in hyperopic RPR in the same eccentricities (mean difference: -1.14 and -1.07, respectively; P <.001 for both). No significant differences between RPR changes in the nasal and temporal retina were noted at the study conclusion.
“The uniform changes in RPR revealed the proportional changes in peripheral refraction and myopic shifts, which results in an overall uniform and slow eye growth after wearing DIMS,” according to the study authors. “In contrast, the asymmetrical hyperopic shifts in RPR resulted in faster on-axis axial length growth compared with the peripheral retina. This local and non coordinated eyeball expansion could also be a trigger for myopia progression.”
Study limitations include failure to measure peripheral refraction across the vertical median.
Zhang HY, Lam CSY, Tang WC, Lee PH, Tse DY, To CH. Changes in relative peripheral refraction in children who switched from single-vision lenses to defocus incorporated multiple segments lenses. Ophthalmic Physiol Opt. Published online December 30, 2022. doi:10.1111/opo.13086