July 1, 2025
By Kevin Chan, OD, MS, FAAO, IACMM
Photo Credit: Getty Images
A recent study conducted by the Bifocal Lens In Nearsighted Kids (BLINK) Study group aimed to investigate physiologic or structural changes in subfoveal choroidal thickness and area in children wearing soft multifocal contact lenses (MFCL) for myopia management. A deeper understanding of lens-induced choroidal changes would help elucidate the intricate relationship between multifocal signals and retinal responses, which thereby drives novel potential of treatment interventions in slowing myopia progression.
Methodology
The study employed a robust experimental design, which involves:
- Participants: 281 children with myopia aged 7 to 11 years
- Randomized cohorts: 1) +1.50D add, 2) +2.50D add distance-centered MFCL, or 3) single vision contact lens (SVCL) or spectacle wear as control group
- Measurement Techniques: Spectral-domain optical coherence tomography (OCT) to assess choroidal thickness and structural changes
- Duration: Longitudinal assessment at baseline, after two weeks of lens wear, and later annually for three years consecutively.
Physiologic Choroidal Changes—Short-term Only
The study revealed several key findings:
- Children in the +2.50D MFCL group showed statistically significant response in subfoveal choroidal thickness (p=0.003) and area (p=0.002).
- Changes in choroidal structure appeared to be localized, suggesting a targeted response to specific optical power distribution in multifocal contact lenses.
- After two weeks of treatment, axial length elongation associated with the +2.50D MFCL group compared to the SVCL or spectacle group were found to be proportionally less.
- Throughout the three-year period, the duration of treatment response was maintained. However, treatment effects induced by the choroidal parameters can only account for a small portion of the entire physiologic changes.
Key Limitations
- Choroidal changes are highly variable and poorly related to treatment responses by each child.
- No age- or ethnicity-related choroidal responses were examined.
- Choroidal changes are not universally thickened in response to MFCL; both thinning and thickening effects have been found within each cohort group.
- The study did not account for diurnal variations in the choroid.
- The accuracy of the study could be skewed because other factors, such as prior near work, water intake, caffeine, and blood pressure, were not studied and controlled.
Clinical Implications—Long-term Predictability
- Multifocal lenses could influence choroidal behavior in human eyes—yet only temporarily as the initial changes tended to diminish after prolonged use.
- Long-term adaptation is likely warranted to ensure choroidal health in children wearing multifocal contact lenses.
- Potential target in modulating choroidal thickness and area highlights novel opportunities to optimize long-term treatment efficacy and outcomes.
- Choroidal changes do not solely account for axial length variations. Other unknown factors are likely involved in affecting axial length elongation and, therefore, treatment success by multifocal contact lenses.
- Treatment efficacy should not be predicted solely by choroidal responses.
- Further studies are warranted to explore other biomarkers to predict long-term axial length growth in each child.
Abstract
Three-Year Change in Subfoveal Choroidal Thickness and Area With Multifocal Contact Lens Wear in the Bifocal Lenses in Nearsighted Kids (BLINK) Study
Maria K. Walker; David A. Berntsen; Matt L. Robich; Rachel L. Fenton; Anita Ticak; Justina R. Assaad; Hope M. Queener; Stephanie J. Chiu; Sina Farsiu; Donald O. Mutti; Lisa A. Jones-Jordan; Jeffrey J. Walline; for the BLINK Study Group
Purpose
To evaluate changes in subfoveal choroidal thickness and area in children wearing soft multifocal contact lenses (MFCLs) for myopia control.
Methods
Analyses included 281 myopic children aged 7 to 11 years in the Bifocal Lenses in Nearsighted Kids (BLINK) Study randomly assigned to wear single vision contact lenses (SVCLs), +1.50 D add, or +2.50 D add center-distance MFCL. Subfoveal choroidal thickness and choroidal area were measured using spectral-domain optical coherence tomography before and after 2 weeks of lens wear, and then annually for 3 years. Repeated measures linear regression was used to determine the effect of contact lens wear on the choroid and test the association between choroidal changes and axial elongation.
Results
After initiating contact lens wear, mean ± SE subfoveal choroidal thickness and choroidal area increased in the +2.50 D MFCL group compared with the SVCL group by 8 ± 3 µm (P = 0.003) and 0.07 ± 0.02 mm2 (P = 0.002), a difference maintained throughout the 3-year study (P ≥ 0.55). Increased choroidal thickness and area after 2 weeks in the +2.50 D MFCL group vs. SVCL group were associated with less axial elongation over 3 years (β = −0.0058 mm/µm and −0.947 mm/mm2; P = 0.02 and P = 0.006; 20% and 29% of total treatment effect, respectively).
Conclusions
The choroid increased in subfoveal thickness and area after 2 weeks of +2.50 D MFCL wear, which was maintained for 3 years and was associated with slower axial elongation. However, only a portion of the treatment effect can be accounted for by the choroidal parameters.
doi:https://doi.org/10.1167/iovs.66.5.5
