January 15, 2025
By Dwight Akerman, OD, MBA, FAAO, Dipl AAO, FBCLA, FIACLE
In the article, “Comparison of the Performance of Myopia Control in European Children and Adolescents with Defocus Incorporated Multiple Segments (DIMS) and Highly Aspherical Lenslets (HAL) Spectacles,” authors Andrea Lembo, Irene Schiavetti, Massimiliano Serafino, Roberto Caputo, and Paolo Nucci present a comprehensive retrospective cohort study aimed at evaluating the effectiveness of two innovative spectacle lens designs for controlling myopia progression in a European pediatric population. This study addresses a critical gap in the existing literature, which has primarily focused on Chinese populations and shorter follow-up durations, typically only one year.
The prevalence of myopia among children and adolescents in Europe is estimated to be approximately 22.6%. As myopia becomes increasingly common, particularly among youth, optimizing treatment strategies is crucial to mitigate its progression and the potential long-term complications associated with high myopia. The two lens types examined in this study, DIMS (Hoya MiyoSmart) and HAL (Essilor Stellest), have demonstrated promise in previous research. However, direct comparisons within such a significant demographic as European children had not yet been conducted.
The methodology employed in this study involved a cohort of participants aged 6 to 17 years who had experienced myopia progression. Each child in the study had worn either DIMS or HAL spectacles for a minimum of two years. To assess the progression of myopia, key measures, including axial length (AL) and cycloplegic autorefraction (measured as spherical equivalent refraction, SER) were recorded at baseline and after one and two years of spectacle wear.
The findings revealed slight differences in the mean changes of SER and AL between the two lens types over both one- and two-year periods. For instance, after one year, the mean SER change for DIMS was -0.34D (±0.46 SD), while for HAL, it was -0.30D (±0.30 SD). Over a two-year period, the SER changes continued, with DIMS showing a mean change of -0.50D (±0.64) and HAL -0.63D (±0.56). Similarly, AL changes were recorded, with increases of 0.19 mm (±0.56) for DIMS and 0.15 mm (±0.47) for HAL after the first year, and 0.29 mm (±0.63) and 0.32 mm (±0.72) after two years, respectively.
The analysis employed statistical tests, including the Mann-Whitney U test and linear mixed model analysis, to determine the significance of the differences observed. Ultimately, the study concluded that there were no statistically significant differences between DIMS and HAL in terms of their ability to control myopia progression, with both lens types proving to be equally effective. However, it was noted that a larger percentage of children using DIMS (38.4%) exhibited no progression in SER after two years compared to those using HAL (21.9%), a finding noted in a significant p-value of 0.047.
The implications of this study are particularly pertinent for clinicians and parents who are faced with the decision of which myopia control lenses to choose. Given that both DIMS and HAL lenses have been found to be equally effective in a European context, stakeholders can be reassured that either option can be safely prescribed according to individual patient needs, preferences, and unique circumstances.
In conclusion, both DIMS and HAL spectacle lenses can slow myopia progression in children, but research directly comparing these lens types is limited to Chinese children and generally has only a one-year follow-up. This retrospective study directly compares DIMS and HAL in a European child and adolescent population over two years of spectacle wear. In this European population, DIMS and HAL spectacle lenses are equally effective in slowing myopia progression during a two-year follow-up period. Based on this study, parents and caregivers, along with clinicians, can confidently choose between DIMS or HAL lenses for myopia control, knowing that both lens types will be equally effective for a European population.
Abstract
Comparison of the Performance of Myopia Control in European Children and Adolescents with Defocus Incorporated Multiple Segments (DIMS) and Highly Aspherical Lenslets (HAL) Spectacles
Andrea Lembo, Irene Schiavetti, Massimiliano Serafino, Roberto Caputo, Paolo Nucci
Purpose: A performance comparison of two myopia control spectacle lens designs, defocus incorporated multiple segments (DIMS) and highly aspherical lenslets (HAL), at slowing myopia progression in a European child/adolescent population. Previous research directly comparing these designs has been limited to Chinese participants and 1-year follow-up. The prevalence of myopia in European children/adolescents has been estimated at 22.60%.
Methods: Retrospective cohort study of individuals (6-17 years) with myopia progression. Participants wore DIMS (Hoya MiyoSmart) or HAL (Essilor Stellest) spectacles for a minimum of 2 years. Axial length (AL) and cycloplegic autorefraction (spherical equivalent refraction (SER)) were measured at baseline and 1 and 2 years.
Results: Mean 1-year SER changes for DIMS were -0.34D (±0.46 SD) and HAL -0.30D (±0.30); 2-year changes for DIMS were -0.50D (±0.64 SD) and HAL -0.63D (±0.56). Mean 1-year AL increases for DIMS were 0.19 mm (±0.56) and HAL 0.15 mm (±0.47); 2-year increases for DIMS were 0.29 mm (±0.63) and HAL 0.32 mm (±0.72). For equivalence margins of 0.25D and 0.50D for SER at 1 and 2 years, respectively, and similarly 0.20 mm and 0.30 mm margins for AL, DIMS, and HAL lenses were equivalent apart from AL at 1 year where the 0.21 mm 95% CI upper limit just exceeded 0.20 mm. At both 1 and 2 years, none of the differences in mean SERs or ALs between DIMS and HAL were clinically or statistically significant (p≥0.05 Mann-Whitney U test). Using linear mixed model analysis, the interaction between lens type and time did not significantly affect SER or AL at 1- or 2-year follow-up (p≥0.05). 38.4% of children/adolescents with DIMS had no SER progression at 2 years, compared with 21.9% with HAL (p=0.047).
Conclusion: In a European population, DIMS and HAL lenses are essentially equivalent in their ability to reduce myopia progression and AL elongation over a 2-year follow-up period.
Lembo, A., Schiavetti, I., Serafino, M., Caputo, R., & Nucci, P. (2024). Comparison of the performance of myopia control in European children and adolescents with defocus incorporated multiple segments (DIMS) and highly aspherical lenslets (HAL) spectacles. BMJ Paediatrics Open, 8(1).
DOI: https://doi.org/10.1136/bmjpo-2024-003187
