Developing treatments that reduce one’s overall myopia long-term is of the utmost importance, given estimates that by the year 2050 roughly half of the world’s population will be myopic.¹ Even a small reduction can be beneficial, as supported by modeling data that suggests reducing one’s refractive error by just 1.00 D may reduce one’s risk of future visual comorbidities by roughly 40%.²

Spectacles have long been evaluated as a solution for mitigating myopic progressing. An early strategy included under correcting a myopic patient’s spectacle prescriptions.^3,4 Trials that evaluated under correction, unfortunately, failed to find a clinically meaningful slowing of myopic progression, and in one instance this strategy may have even resulted in faster myopic progression.^3,4 This and other myopia control strategies are typically based upon reducing peripheral retinal hyperopic defocus.^5,6 Specifically, even when a myopic patient is being optically corrected at the fovea with spectacles or contact lenses, these interventions still produce peripheral retinal hyperopic defocus (image behind retina), which is thought to be a myopic growth signal.⁷

However, when interventions, such as spectacles, bring the peripheral retinal image shell within the eye (myopic defocus), it is thought to be a stop signal for myopic growth.⁷ Interestingly, the Correction of Myopia Evaluation Trial (COMET) study, which was another early spectacle-based treated approach, used progressive addition lenses and found a significant reduction in myopic progression, yet this reduction was not clinically meaningful.⁸ Nonetheless, this gave some credence to using spectacles for myopia control, and it has since spurred other much more successful approaches.

In this article, I review the latest research on some of the upcoming spectacle designs that will soon be available in the United States.

Aspherical lenslets

Bao J et al have developed a spectacle-based myopia control platform that utilizes aspherical lenslets.⁹ The authors based their approach on research that suggests the retina responds most strongly to myopic defocus when regulating eye growth.^9,10 The authors specifically created spherical front surface spectacles with “11 concentric rings formed by contiguous aspherical lenslets” with lenslets that were 1.1 mm in diameter. The center portion of the lens was void of lenslets and provided distance vision. This arrangement is supported by Li X et al who determined that aspherical lenslets arranged in a concentric ring pattern could improve a patient’s visual acuity and contrast sensitivity.¹¹

Bao J et al’s study randomized 170 subjects in a double-masked manner and found during the first 12 months of the study that the highly and slightly aspherical lenslets significantly reduced refractive error and axial length progression, without impacting distance or near visual acuity.⁶ Bao J et al has since reported the 2-year results from this same study, with the authors finding cumulative reduction in both refractive error and axial length among both aspherical lenslet groups; however, the authors found that most of the benefit with the slightly aspherical lenslets occurred during the first year of treatment.

Li X et al have since reported the 3-year results from this same trial,¹¹ which again found that the highly aspherical lenslets were able to reduce myopic progression with there being no difference in progression among the three highly aspherical lenslets groups. This study also demonstrates that starting treatment at a later age provides meaningful benefit.

Diffusion optics spectacle lenses

Rappon J et al recently reported on diffusion optics spectacle lenses, which utilize lenslets that alter retinal contrast.¹² This technology was based upon literature that suggests that the eye’s L and M cone cells may affect emmetropization and that these cells are important for high-contrast visual acuity.

Each diffuser within the lens has a diameter of 0.14 mm and a height of 0.2 mm. This lens also uses two different refractive indexes (1.50 and 1.53) within the lens to scatter light, with the intent of reducing contrast and activity differences between L and M cones.¹² Rappon J et al tested this technology by randomizing 258 subjects in a 3-year trial to lenses with diffusers that were spaced 0.365 mm or 0.240 mm apart or to single vision lenses. The study lenses were also designed to have a 5 mm central distance vision zone.

The authors have since published their 1-year interim results with the study determining that both diffuser lens designs were able to significantly reduce refractive error and axial length progression compared to the control group. The study likewise determined that subjects were able to wear their spectacles for 10 or more hours per day. The coming study years are needed to fully understand the durability of this treatment, but it shows great promise.

DIMS

Developed by Lam CSY et al, the Defocus Incorporated Multiple Segments (DIMS) design is composed of about 400 defocus segments (1.03 mm diameter) with each segment having a power of +3.50 D. The defocus segments are arranged in a honeycomb pattern that is 33 mm in diameter with a central 9 mm zone that is free of defocus segments for distance vision.¹³

The authors of this study found that the DIMS lens significantly reduced refractive error and axial length in subjects, with no significant difference in regards to visual acuity or accommodation. Subjects wore the DIMS lenses for over 15 hours per day.^13,14

The authors overall found that the DIMS lens slowed myopic progression in both the original DIMS group and a group who switched to the DIMS lens, with the two DIMS group having a similar reduction in myopic progression in the third year of the study. These data suggest that subjects who start with the DIMS lens at a later age can receive a similar slowing of myopic progression to the children who start the treatment at a younger age.

Technology maturing

Myopia control spectacle technology is maturing. As more designs are fully vetted this technology will likely transcend pediatric vision care worldwide. While spectacles have many benefits, the subject’s overall lifestyle preferences, as always, will need to be considered before making final treatment approach given that there are multiple myopia management modalities in the market. OM

References

1. Holden BA, Fricke TR, Wilson DA, et al. Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology. 2016;123:1036-1042. doi: 10.1016/j.ophtha.2016.01.006.
2. Bullimore MA, Brennan NA. Myopia Control: Why Each Diopter Matters. Optom Vis Sci 2019;96:463-465. doi: 10.1097/OPX.0000000000001367.
3. Chung K, Mohidin N, O’Leary DJ. Undercorrection of myopia enhances rather than inhibits myopia progression. Vision Res 2002;42:2555-2559. doi: 10.1016/s0042-6989(02)00258-4.
4. Adler D, Millodot M. The possible effect of undercorrection on myopic progression in children. Clin Exp Optom 2006;89:315-321. doi: 10.1111/j.1444-0938.2006.00055.x.
5. Smith EL, 3rd, Ramamirtham R, Qiao-Grider Y, et al. Effects of foveal ablation on emmetropization and form-deprivation myopia. Investig Ophthalmol Vis Sci 2007;48:3914-3922. doi: 10.1167/iovs.06-1264.
6. Smith EL, 3rd, Hung LF, Huang J. Relative peripheral hyperopic defocus alters central refractive development in infant monkeys. Vision Res 2009;49:2386-2392. doi: 10.1016/j.visres.2009.07.011. Epub 2009 Jul 24.
7. Flitcroft DI. The complex interactions of retinal, optical and environmental factors in myopia aetiology. Prog Retin Eye Res 2012;31:622-660. doi: 10.1016/j.preteyeres.2012.06.004. Epub 2012 Jul 4.
8. Gwiazda J, Hyman L, Hussein M, et al. A randomized clinical trial of progressive addition lenses versus single vision lenses on the progression of myopia in children. Investig Ophthalmol Vis Sci 2003;44:1492-1500. doi: 10.1167/iovs.02-0816.
9. Bao J, Yang A, Huang Y, et al. One-year myopia control efficacy of spectacle lenses with aspherical lenslets. Br J Ophthalmol. 2022;106:1171-1176. doi: 10.1136/bjophthalmol-2020-318367.
10. Arumugam B, Hung LF, To CH, Sankaridurg P, Smith EL, III. The Effects of the Relative Strength of Simultaneous Competing Defocus Signals on Emmetropization in Infant Rhesus Monkeys. Investig Ophthalmol Vis Sci. 2016;57:3949-3960. doi: 10.1167/iovs.16-19704.
11. Li X, Ding C, Li Y, et al. Influence of Lenslet Configuration on Short-Term Visual Performance in Myopia Control Spectacle Lenses. Front Neurosci 2021;15:667329. doi: 10.3389/fnins.2021.667329. eCollection 2021.
12. Rappon J, Chung C, Young G, et al. Control of myopia using diffusion optics spectacle lenses: 12-month results of a randomised controlled, efficacy and safety study (CYPRESS). Br J Ophthalmol 2022. doi: 10.1136/bjo-2021-321005. Online ahead of print.
13. Lam CSY, Tang WC, Tse DY, et al. Defocus Incorporated Multiple Segments (DIMS) spectacle lenses slow myopia progression: a 2-year randomised clinical trial. Br J Ophthalmol 2020;104:363-368. doi: 10.1136/bjophthalmol-2018-313739.
14. Lam CS, Tang WC, Lee PH, et al. Myopia control effect of defocus incorporated multiple segments (DIMS) spectacle lens in Chinese children: results of a 3-year follow-up study. Br J Ophthalmol 2022;106:1110-1114. doi: 10.1136/bjophthalmol-2020-317664.

DR. PUCKER is the senior director of clinical and medical sciences at Lexitas Pharma Services. He earned his OD, MS, and PhD degrees from The Ohio State University, and he is the former director of the UAB Eye Care Myopia Control Clinic. He has received research or consulting support from Alcon Research, LLC, Art Optical, and Haymarket Media, Inc. in the past year.