Can Glasses Slow Down Myopia?

At the time of writing this article, only 2 treatments are FDA approved for myopia management and both are contact lenses. Myopia management is the process of slowing down the worsening of near-sightedness in children. Studies show that on average, children with myopia will worsen by -0.50D per year (and -0.75D per year for children of Asian descent) until they are done growing (around age 17 for most). This prescription worsening is associated with actual elongation of the eye ball, called axial length. Faster axial length growth (0.2 mm or more in childhood) is considered rapidly progressive and associated with the risk of much higher prescriptions and higher risks for associated eye diseases, including retinal detachment, glaucoma, and myopic maculopathy. You can read more about the FDA approved myopia management contact lens options here: MiSight soft multifocal contact lenses and Abiliti orthokeratology lenses. But not every parent (or child) is eager to start contact lens wear; are there approaches to slow down myopia progression with glasses? 

Bifocals and Progressive Addition Lenses (PALs)

Childhood myopia is caused by a complex combination of factors, including genetics, reduced outdoor time, and increased near work. When prescribing glasses for children, doctors measure not just what it takes to make distance vision clear, but also the strength of the focusing system of the eye. Children with reduced accommodation (ability to focus on near tasks like reading) or with convergence inefficiencies (eyes that can't comfortably maintain coordination of gaze when looking at near tasks) have increased strain on their eyes when performing near tasks, and theoretically could be at more risk of worsening myopia, but research shows it's much more complicated than this. 

With this theory of near strain being a potential factor in worsening myopia, several studies have investigated if there is any benefit to prescribing glasses with a near addition to reduce strain on the eyes with reading or close tasks through the use of bifocals or progressive glasses. A 2014 study of 135 children with at least -0.50D of myopia between the ages of 8 and 13 showed that those who wore +1.50 add executive bifocals experienced statistically significantly less myopia progression and axial elongation over a 3 year period than their peers who were prescribed normal single vision distance glasses. Average myopic progression over 3 years was -2.06D for the control group and -1.25 D for the bifocal group (a myopia control rate of 39.3%); average axial length progression over 3 year was 0.82 mm of the control group and 0.57 mm for the bifocal group (a myopia control rate of 30.4%). Note that these myopia control rates are less than those reported by the FDA approved contact lenses for myopia management (59% control of spherical prescription change), but still statistically significant.

Interestingly this study found that the myopia management rate was slightly more effective if the children who were prescribed bifocal glasses also had a lower lag of accommodation (more strain on their eye muscles at near) and were also prescribed 3 prism units of base in prism on eye eye. The prism cohort of children had a myopia progression rate of -1.01D over 3 years (a 51% myopia control rate) and 0.54 mm of axial length growth over 3 years (a myopia control rate of 34%). The study authors concluded that executive lined bifocals were effective for myopia management, and that prism lined bifocals were more effective if the child also had accommodative dysfunction. 

So we know executive lined bifocals have some effect, though less than the FDA approved contact lens options. But what if your child doesn't want a huge line going across the middle of their glasses? Would an invisible line bifocal (called a progressive addition lens or PAL) work as well?

The Hong Kong Progressive Lens Myopia Control study investigated just that: 153 myopic children between the ages of 7 and 10.5 were followed over a 2 year time frame. Half were prescribed progressive glasses with +1.50 D of near add, and the other half were in the control group, prescribed normal single vision distance glasses. Over the 2 year study period, the control group had an average -1.26 D increase in myopia and the progressive group had a -1.12 D increase (a modest 11.11% myopia control effect that was not statistically significant). Axial elongation was also measured and the control group had an average 0.63 mm increase in axial length after two years versus a 0.61 mm increase in the progressive group; again not statistically significant. 

The COMET (Correction of Myopia Evaluation Treatment) Study also explored the benefit of progressive lenses. This study followed 469 'ethnically diverse' patients with myopia (-1.25 to -4.50 D) between the ages of 6 and 11 for 5 years. The children were randomly assigned to either progressive addition lenses with +2.00D of add or single vision distance lenses. After 3 years, the average amount of myopia worsening was -1.48D in the control group and -1.28D in the progressive group, a modest but statistically significant myopia control effect of 13.5%. Axial length elongation was on average 0.75 mm in the control group and 0.64 mm in the progressive group, a modest but statistically significant 14.67% myopia control effect. 

The largest myopia management benefit was experienced in the first year, and as the study progressed the effect dwindled more and more. After 5 years, the average amount of increased myopia was -2.10D in the control group and -1.97D in those wearing progressives - not statistically significant. 

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Researchers concluded that even the small benefit seen early in the study was not significant enough to warrant a change in clinical management of myopic patients away from single vision glasses to progressive lenses.  

Myopia Management Glasses Are Coming to the US

While not yet available in the United States, glasses that are specifically approved for myopia management are coming and are already available in Canada, Europe, and Asia. Studies have shown these glasses work very effectively at reducing myopic progression both of prescription and axial length! Both of these technologies work by incorporating high plus power 360 degrees throughout the lens and maintaining clear central distance vision. With executive bifocal and progressive addition lenses, the high plus power is only being processed by the eye with inferior gaze and is thus more limited in it's ability to actually induce peripheral defocus (see this blog post for more insight into how peripheral defocus is essential to myopia control). 

Defocus Incorporated Multiple Segments (DIMS): This unique design found in Hoya's MiyoSmart myopia management lenses uses 400 individual peripheral lenslets of +3.50D scattered throughout the lens. A study published in 2020 followed 183 Chinese children between the ages of 8 and 13 with -1.00 to -5.00D of myopia. On average the control group wearing single vision glasses progressed -0.85 D in that time, and the DIMS group progressed -0.4 D, a 52% myopia control effect. There was also a 62% reduction in axial length progression in the DIMS group compared to control. 

Unlike the COMET study of progressive glasses outlined above where there was waning benefit, studies have shown that DIMS technology continues to achieve statistically significant results. In a 3 year follow-up study of 128 children, kids that had been wearing the DIMS lenses for the prior 2 years continued to do so, and kids that had been wearing single vision distance lenses now switched into DIMS. This study proved that the myopia control effect achieved in myopic prescription change and axial length was stable and maintained over time. Children that switched from control to DIMs group also achieved the same myopia management effect as children enrolled initially in the DIMs group in their first year. The repeatability and consistency of results has garnered a lot of attention that this technology has become our first truly effective glasses option for myopia management. 

Highly Aspheric Lenslet Target (HALT): This unique design is found in Essilor's Stellest myopia management lenses and uses 11 concentric rings of over 1000 lenslets with varying powers. 2 year study data was published in March 2022 following 157 Chinese children between the ages of 8 and 13 with -0.75D to -4.75D of myopia. On average the control group wearing single vision glasses progressed -1.04 D in that time, and the HALT group progressed -0.66D, a 55% myopia control effect. There was also a 51% reduction in axial length progression in the HALT group compared to control. Interestingly, kids who wore their HALT glasses more had an even better myopia management effect. Children who wore their HALT glasses 12 hours or more per day, every day achieved a 67% reduction in myopic progression and a 60% reduction in axial elongation. 

Stay tuned! While neither of these myopia management glasses solutions are available in the United States now, they should be coming soon!