The long and short of myopia management
As our dependence on technology progresses, we have seen tremendous impact on all aspects of our lives—including our kids’ eyes and vision.
It is no secret that the technology era we live in will only lend itself to additional advancements. In keeping with the typical expectation of taking the good with the bad, we will undoubtedly see a rise in nearsightedness as a direct result of our increased screen time.
As such, the World Health Organization projects that over 50% of our global population will be nearsighted by the year 20501—an increase of nearly 30% from the year 2000. Parents and optometrists around the world all face the challenge of managing and balancing the right amount of screen time, both recreational and educational.
The concern among those in the eye care professional community is that high or progressive myopia can be associated with an increased prevalence of primary open-angle glaucoma, higher rates of cataract growth requiring surgical intervention, retinal thinning, and macular pathology. Fortunately, because of the progress of research in vision science, eye care professionals are now able to make use of many tools to manage and somewhat control the progression of myopia.
First options include technology that is available to aid in decreasing screen time. Apple’s screen time insights, the GizmoWatch, and the Yeux app are all helpful and effective as they promote taking breaks from screens and provide reminders to engage in other activities.
Additional technologies begin with our simplest of tools: the phoropter. Refraction is 1 of our 2 most important data points as we consider the need for and best mechanism to manage the progression of myopia; it is also going to be the most effective tool in monitoring progression and evaluating efficacy of our treatment plans.
The other important tool is axial length measurement. The challenge in monitoring axial growth rate is in understanding the consistency of its inconsistency. It has been noted that axial growth rate of 0.33 mm/year is typically found in the year before the onset of myopia and it is expected that this rate of growth declines to less than 0.10 mm per year by age 12. By aged 14 to 16 years, even emmetropic eyes continue to progress, but at a much-reduced rate: 0.03 mm/year to 0.06 mm/year in girls.2,3
With that, it can be somewhat difficult to interpret and evaluate the efficacy of a myopia control treatment plan using axial length progression alone—particularly in growing, younger children. Of course, as we monitor progression and efficacy of any of our management tools, we will consider the relationship between refractive error and axial length elongation.
Management options
At present, there are many spectacle lens options available for myopia management, including the following:
1. defocus incorporated multiple segments technology employed by the Hoya MiyoSmart lens;
2. highly aspherical lenslet target technology utilized in the Essilor Stellest lens; and
3. MyoKids and MyoVision Pro by Zeiss.
Each, utilizing its own proprietary technology, effectively focuses light to specific areas of the retina and defocuses in other areas to decrease the pace of axial length elongation.
1. The MiyoSmart, the first lens of its kind, has proven to yield a decrease in progression of myopia by an average of 50% and axial length by 60%.4
2. The Stellest lens has also shown itself to effectively yield a decrease in the progression of myopia; in this case, touting an average decrease in refractive error by approximately 70% and axial length by 60%.5
3. The MyoVision Pro also employs peripheral defocus technology and has proven to decrease myopic progression by stabilizing axial length growth. The MyoKids lens takes a different approach to the process of slowing down nearsightedness by decreasing accommodative lag, thereby reducing the progression of myopia by approximately 30%.
With each of these lenses, the expectation is that the glasses are worn for approximately 12 hours per day.
Similar to the use of spectacle correction, there has been progress in research that has afforded the opportunity to slow the progression of nearsightedness by correction with soft contact lenses. When worn 6 days per week, the MiSight 1 day lens (CooperVision) has shown a reduction in axial elongation by an average of 52% and refractive error by 59%.
These lenses utilize a similar principal to many of the spectacle lenses: peripheral defocus, in order that they may allow for focus of light on the central retina, thereby leading to slowed lengthening of the eye. Using a similar principal, the more recently developed Abiliti lens (Johnson & Johnson Vision) provides an additional daily disposable lens option for patients who would benefit from myopia management.
Pharmacological therapeutics have also been found to be an effective tool in myopia management. Atropine, which has other uses in ocular health management, has been successful when used in low dosages, typically 0.01% or 0.05%, before bed each night. These doses have minimal effects on pupil size and less of an impact on near vision.
While 0.01% atropine has shown to have the least side effects,6 a more recent study has shown that there is a dose-dependent effect and that 0.05% atropine has a greater influence on slowing down the progression of myopia given its greater impact on axial elongation over time.7 Both have proven a decrease of progression of refractive error by 59%.
An additional option in the world of myopia control is corneal reshaping, a process most commonly described as orthokeratology or ortho-K. For many years now, rigid gas-permeable lenses have been available for overnight wear for the purpose of flattening the cornea.
The result of this reshaping is a change to how light is received in the eye, therefore leading to a change in focus and ultimately, a decrease in the pace of myopic progression. While risks have proven to be minimal, it is important that corneal evaluations are done regularly to ensure that proper ocular health is maintained.8
With all of this technology available, the obvious question is how do we decide which option to select to serve our patients? Very simply stated, it depends on your patient and it depends on your available resources as a practitioner. Corneal topographers, interferometry, or ultrasonographers can all be somewhat cost prohibitive for the optometrist; some of our offices may not even have the space to house them.
And from the patient perspective, it is always important to consider how lifestyle will be impacted. Some children may be more resistant to the idea of a nightly eye drop while others may welcome the ease of a soft lens that fits into their daily routine.
While I always consider and explore all of the available options for my patients, I generally appreciate and support the ease of a pair of glasses that can aid in slowing the progression of myopia provided that the spectacle prescription falls within the available parameters, ie, total combined power of –7.00D.
Considering all of this, patient and parent communication is the critical step in myopia management. As is the case with management of any ocular health condition, the child must be seen regularly and at appropriate intervals to monitor progress. Treatment may need to be altered according to response and once the child reaches their late teens, a clinical judgment needs to be made as to whether treatment should be stopped.
With numerous technological advancements and available options to manage myopia, eye care professionals around the world have tremendous opportunity to battle the myopia epidemic. Of course, our most valuable tool is the knowledge that we have to share with our patients. With effective use of the tools around us and continual advancements in optometric research and technology, we can decrease the prevalence of myopia-associated risk in young patients in each of our communities.
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(5):1036-1042. doi:10.1016/j.ophtha.2016.01.006
2. The collaborative longitudinal evaluation of ethnicity and refractive error (CLEERE) study. ClinicalTrials.gov. Updated June 24, 2005. Accessed June 24, 2005. https://clinicaltrials.gov/ct2/show/NCT00000169
3. Mutti DO, Jordan LA, Zadnik K. (2021). Predicting the onset of myopia in children: results from the CLEERE study. BMC Ophthalmol. 2021;21(1):279. doi:10.1186/s12886-021-02036-9
4. 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(3):363-368. doi:10.1136/bjophthalmol-2018-313739
5. Bao J, Huang Y, Li X, et al. Spectacle lenses with aspherical lenslets for myopia control vs single-vision spectacle lenses: a randomized clinical trial. JAMA Ophthalmol. 2022;140(5):472-478. doi:10.1001/jamaophthalmol.2022.0401
6. Chia A, Lu QS, Tan D. Five-year clinical trial on atropine for the treatment of myopia 2: myopia control with atropine 0.01% eyedrops. Ophthalmology. 2016;123(2):391-399. doi:10.1016/j.ophtha.2015.07.004
7. Yam JC, Li FF, Zhang X, et al. Two-year clinical trial of the low-concentration atropine for myopia progression (LAMP) study: phase 2 report. Ophthalmology. 2020;127(7):910-919. doi: 10.1016/j.ophtha.2019.12.011.
8. Walline JJ, Rah MJ, Jones LA. The children’s overnight orthokeratology investigation, (COOKI) pilot study. Optom Vis Sci. 200481(6):407-413. doi:10.1097/01.opx.0000135093.77007.18
