Purchase this article with an account.
Han Yu Zhang, Carly S Y Lam, Wing Chun Tang, Chi Ho To; Impact of Defocus Incorporated Multiple Segments (DIMS) spectacle lenses on Relative Peripheral Refraction (RPR): a 2-year randomized clinical trial. Invest. Ophthalmol. Vis. Sci. 2019;60(9):3898. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To compare the changes of relative peripheral refraction (RPR) associated with myopia progression by wearing DIMS and SV spectacle lens in Hong Kong Chinese children over 2 years.
A 2-year double-blind randomized controlled trial was conducted in 183 children aged 8–13 years with myopia between −1.00 and −5.00 Diopters (D) and astigmatism≤1.50 D. Subjects were allocated to the DIMS spectacle lens (n=93) or SV spectacle lens (n= 90) group. The DIMS spectacle lens comprises of a central correction zone surrounded by multiple segments of constant myopic defocus (+3.50D). Central and peripheral refraction, axial length (AXL) after cycloplegia were monitored by Shin-Nippon NVision K5001 autorefractor and IOL Master every 6 months over 2 years.
Subjects wearing the DIMS lens showed significantly less myopia and AXL elongation over 2 years. Within the DIMS group, there was a decrease in hyperopic RPR at 10 degrees of the nasal visual field (N) compared with baseline (p=0.007), while the SV showed a significant increase of hyperopic RPR at 10 N and 20 N (p<0.0001). There was a significant difference of changes in RPR at the nasal visual field between DIMS (10N: -0.13±0.43 D, 20N: -0.10±0.62 D) and SV (10N: 0.34±0.77 D, 20N: 0.84±0.92 D) groups (p<0.0001). Changes of RPR at 20N showed a significant correlation with myopia progression in DIMS (p=0.004 r=-0.327), while no significant relationship showed in SV (p=0.156). In a subgroup analysis, 47 subjects from the DIMS (n=23) and SV (n=24) groups were matched for axial length at 2 years. There were significant reductions of RPR at 20N in DIMS compared with SV after 2 years (mean difference= 1.12±0.19 D, p<0.0001).
By exposing myopic defocus signal in both the central and peripheral retina, DIMS lenses showed significant myopia control effects in Hong Kong Chinese schoolchildren, and more myopic RPR at the nasal visual field was observed after treatment. Further understanding of the mechanism is needed.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
This PDF is available to Subscribers Only