Long-term Effect of Dual-focus Contact Lenses on Myopia Progression in Children: A 6-year Multicenter Clinical Trial

Abstract

SIGNIFICANCE:Treatment of myopic children with a dual-focus soft contact lens (DFCL; MiSight 1 day) produced sustained slowing of myopia progression over a 6-year period. Significant slowing was also observed in children switched from a single vision control to treatment lenses (3 years in each lens).PURPOSE: This study aimed to evaluate the effectiveness of DFCLs in sustaining slowed progression of juvenileonset myopia over a 6-year treatment period and assess myopia progression in children who were switched to a DFCL at the end of year 3. METHODS: Part 1 was a 3-year clinical trial comparing DFCLs with a control contact lens (Proclear 1 day) at four investigational sites. In part 2, subjects completing part 1 were invited to continue for 3 additional years during which all children were treated with MiSight 1 day DFCLs (52 and 56 from the initially treated [T6] and control [T3] groups, respectively). Eighty-five subjects (45 [T3] and 40 [T6]) completed part 2. Cyclopleged spherical equivalent refractive errors (SEREs) and axial lengths (ALs) were monitored, and a linear mixed model was used to compare their adjusted change annually.RESULTS: Average ages at part 2 baseline were 13.2 ± 1.3 and 13.0 ± 1.5 years for the T6 and T3 groups, respectively. Slowed myopia progression in the T6 group observed during part 1 was sustained throughout part 2 (mean ± standard error of the mean: change from baseline SERE [in diopters], −0.52 ± 0.076 vs. −0.51 ± 0.076; change in AL [in millimeters], 0.28 ± 0.033 vs. 0.23 ± 0.033; both P > .05). Comparing progression rates in part 2 for the T6 and T3 groups, respectively, indicates that prior treatment does not influence efficacy (SERE, −0.51 ± 0.076 vs. −0.34 ± 0.077; AL, 0.23 ± 0.03 vs. 0.18 ± 0.03; both P > .05). Within-eye comparisons of AL growth revealed a 71% slowing for the T3 group (3 years older than part 1) and further revealed a small subset of eyes (10%) that did not respond to treatment.CONCLUSIONS: Dual-focus soft contact lenses continue to slow the progression of myopia in children over a 6-year period revealing an accumulation of treatment effect. Eye growth of the initial control cohort with DFCL was slowed by 71% over the subsequent 3-year treatment period.

The effect of peripheral defocus on axial growth and modulation of refractive error in hyperopes

“…The power of the central portion of the lens was selected to correct distance refractive error while simultaneously exposing the retina to relative peripheral hyperopic defocus from the outer distance zone (see Figure 1 ). A +2.00 D add was selected in line with previous refractive error modulation studies 21 , 22 , 28 to strike a balance between ensuring adequate visual performance 29 while imposing peripheral defocus at a level sufficient to test the hypothesis. 24 Participants aged between 8 and <16 years‐of‐age were recruited for this arm of the study.…”

“…The progression of myopia and axial growth can be modulated in children and adolescents using soft multifocal or dual‐focus contact lenses 21–24 …”

“…The progression of myopia and axial growth can be modulated in children and adolescents using soft multifocal or dual‐focus contact lenses. 21 , 22 , 23 , 24 These contact lenses are designed to correct distance refractive error through the central optic zone, while simultaneously imposing myopic defocus through the outer optic zone. For hyperopes, using centre‐near bifocal soft contact lenses to correct distance refractive error through the central optic zone, while simultaneously imposing hyperopic defocus through the outer optic zone, could provide a stimulus to axial growth, thereby increasing the rate of axial elongation and subsequently reducing refractive error.…”

Additive effects of narrowband light and optical defocus on chick eye growth and refraction

“…Full-time wearing of dual-focus soft contact lens also slowed myopia progression and axial elongation [ 25 , 28 , 29 , 31 , 32 ]. The effect was sustainable and may further slow myopia progression in subsequent full-time lens wearing period [ 25 , 28 , 30 ]. The protective effect was more effective for lens with high add power (+ 2.0 D) when compared with medium add power (+ 1.5 D) [ 31 ].…”

Multifocal Contact Lenses and 0.01% Atropine Eye Drops for Myopia Control Study: Research Protocol for a 1-Year, Randomized, Four-Arm, Clinical Trial in Schoolchildren

“…The potential of the optical approach has been demonstrated in the use of progressive addition spectacles, 8,9 orthokeratology (OK), 10,11 and multifocal soft contact lenses (MFCLs) for myopia control. [12][13][14][15][16][17][18][19] Of these optical modalities, MFCLs have also a considerable efficacy in the reduction of both axial elongation and myopia progression, making it one of the most promising tools for the reduction of myopia progression and axial elongation. 16,17 Commercially available MFCLs have various optical designs; however, the concentric designs seem to be more efficacious than the continuous aspheric ones.…”