It is estimated that by 2050, the number of myopes will double worldwide.1 In other words, nearly 5 billion people and 1 billion people will have myopia or high myopia, respectively. That means in 25 years, 50% of the world is expected to be myopic!2
Based on this data, it is not surprising that myopia control is one of the fastest-growing specialties in optometry. However, if you are unsure where to begin, have no fear, this article will serve as a primer to myopia management.
We will review the risk factors and co-morbidities associated with myopia, how to diagnose and assess the risk of myopia, current treatment options, and when to know if the treatment is effective as well as future potential treatments.
The current state of myopia
In 2016, Brien Holden came together with the World Health Organization to establish a universal definition of myopia. Myopia was defined as any refractive error ≥-0.50D and high myopia ≥-6.00D.3
Furthermore, uncorrected myopia has become the leading cause of visual impairment worldwide.3 Although myopia has often been referred to as a “simple” refractive error, even lower amounts can increase the risk of serious eye disorders.
Factors that can influence myopia
Co-morbidities
It is well-established that high myopia increases the risk of ocular diseases such as cataracts, glaucoma, retinal detachment, and myopic maculopathy.4
Furthermore, high myopia (≥-6.00D) increases the risk of myopia maculopathy and retinal detachment 40x and 20x, respectively.5 Both these diseases can lead to irreversible blindness.
Myopia risk factors
There are three main risk factors that indicate the likelihood of progression to myopia:
- Parental myopia
- Age of onset
- Amount of myopia
Age of onset of myopia
Age is by far the most significant factor in determining how myopic the child will become. Hyman et al. extrapolated data from the 2001 COMET study to determine if baseline age was a significant factor in how fast the child progresses.
They divided subjects based on age (6 to 11 years) with baseline refractive errors between -2.00D to -2.50D (fairly similar). They found that children in the 6- to 7-year-old range progressed 2x as fast as 11-year-olds after the 3-year visit.6
Parental myopia
Kurtz et al. also used data from the 2001 COMET study to investigate the likelihood of a child developing myopia based on parental myopia. They found that the number of myopic parents was directly correlated to the myopia progression in children.
Children with two myopic parents demonstrated a statistically significant likelihood of becoming myopia compared to zero parents. Children with only one or myopic parent showed no difference in myopia progression from children with zero parents. Furthermore, if both parents had high myopia (≥-6.00D), there was a high risk their child would also become a high myope.7
Amount of myopia
Gwiazda et al. then took the same children from their 2001 COMET study and followed them for an additional 7 years. Similar-age patients were separated by the amount of myopia (either >-2.25D or <-2.25D). The probability of developing myopia (>-6.00D) was significantly higher in those patients starting with higher myopia at baseline.8
Can genetics be the only risk factor for myopia?
Myopia numbers are rising at such a fast rate, genetics are unlikely to be the only factor influencing refractive error and myopia progression.9 Numerous investigators have been exploring whether other environmental factors, such as amount of near-work or time spent outside, also play a role in the rapid increase in myopia.
Many researchers hypothesized that the substantial increase in the amount of near-work post-COVID-19 was to blame for the increasing trends of myopia. Li et al. investigated the correlation between myopia progression and near-work. They found a significant association only when reading was very close (<20cm) and for continuous periods of time (>45 minutes), not total time spent on near activities.10
Time spent outdoors has also been an area of interest when considering risk for myopia onset and progression.11,12 A well-known study by Rose et al. demonstrated a protective effect on myopia onset. Based on their results, they concluded that 90 minutes/day for at least 14 hours per week is optimal to prevent myopia onset.13
In a more recent study by Wu et al., outdoor time for at least 11 hours/week was reported to slow myopia progression in children. This is a huge breakthrough because for many years it was believed that outdoors could not only prevent the onset but slow myopia.14
We may not be 100% certain on the reason why outside time can help to prevent/slow myopia, but we can be confident when educating parents that the more outdoor time for their children the better!
Myopia diagnosis and assessment
We have already reviewed the risk factors for myopia onset/progression. However, how do we as practitioners know when it is time to consider myopia control treatment?
In 2015, Zadnik et al. created a guideline for practitioners as to what age and level of nearsightedness treatment should be considered.15 The study focused on children ages 6 to 11 years and the presenting refractive error that would lead to significant myopia in the future.
Table 1 displays the conclusions this study came to on guidelines for when to initiate myopia management based on age and presenting refractive error.15 As well, they reported that if myopia increases >0.50D annually, myopia control should be initiated.15
| Age | Presenting Refractive Error |
|---|---|
| Grade 1 (age 6) | <+0.75D |
| Grades 2 and 3 (ages 7 to 8) | <+0.50D |
| Grades 4 and 5 (age 9 and 10) | <+0.25D |
| Grade 6 (age 11) | <0.00D |
| Progression (refractive error) | >-0.50D/year |
| Progression (axial length) Before 10 years old/After 10 years old | >0.2 mm/year / >0.1 mm/year |
Table 1: Courtesy of Zadnik et al.
Furthermore, the authors established that before age 10, the normal axial length change in emmetropization ranges from 0.1 to 0. mm/year. After age 10, a change of 0.1mm/year or less is considered normal.15
The goal of myopia management
It can be difficult to know whether myopia control treatment is effective, how often to monitor the patient, and when to discontinue treatment.
This section will help provide a guideline for managing myopia once treatment has been initiated.
Measuring refractive error progression
The level of refractive error progression often depends on the type of myopia control treatment being implemented and the age of the child being treated.
Through a large meta-analysis, Donovan et al. were able to determine the average rate of change in a myopic child depending on age with no myopia control intervention.16 In 2023, Gifford et al. compiled data from Brennan et al. (which reviewed the efficacy of myopia treatments) to illustrate the expected change in refractive error and axial length (see Table 2 below).17,18
Table 2 lists the expected change in refractive error with various myopia management strategies.16,17,18
| Age of Patient | Expected Change Per Year w/o Myopia Control | Expected Change per Year w/ Stellest, MIYOsmart, MiSight, NaturalVue, Ortho-k, Atropine 0.05% | Expected Change per Year w/ Bifocals, Prism bifocals, Biofinity +2.50 MF, Atropine 0.025% | Expected Change per Year w/ PALs, Atropine 0.01% |
|---|---|---|---|---|
| <9 years | -1.00D | -0.50D | -0.37D | -0.25D |
| 9 to 11 years | -0.75D | -0.67D | -0.50D | -0.37D |
| 12 to 16 years | -0.50D | -0.75D | -0.67D | -0.33D |
Evaluating axial length
Below is a breakdown of the expected axial length change per year in emmetropes versus uncorrected myopes. The goal is to keep axial length change to around 0.1mm or less/year and below 26mm as anything above that can increase the risk of ocular comorbidities mentioned above.19,20,21,22
Table 3 summarizes the expected axial length change per year based on myopia status and age.19,20,21,22
| Age of Patient | Expected Change Per Year in Emmetropes | Expected Change per Year in Uncorrected Myopes |
|---|---|---|
| 7 to 10 years | 0.1 to 0.2mm | 0.3mm |
| 11 to 16 years | 0.1mm | 0.2mm |
Available myopia treatment options
There are numerous treatment options available for all ages, lifestyles, level of myopia, astigmatism, etc. A summary of the available options is included below.
Orthokeratology
Most orthokeratology (ortho-k) lenses are FDA-approved to correct up to 6.00D of myopia and up to -3.50D of astigmatism (with toric lens parameters).23,24 Although orthokeratology has been used for decades to correct vision, researchers have discovered that orthokeratology can slow myopic progression based on the “peripheral refraction theory.
The theory states that orthokeratology reduces stimuli for axial elongation via decreasing peripheral hyperopic defocus and increasing peripheral myopic defocus.25 Studies have observed patients as young as 6 years old, but success with ortho-k is also dependent on maturity level, ability to handle lenses, and parental supervision.26
A meta-analysis by Si et al. included seven studies, a total of 218 ortho-k wearers, and 217 controls. They found 0.27mm less change in axial length over 2 years compared to non-ortho-k wearing controls, or about a 45% reduction in axial length growth.27
Furthermore, ortho-k is extremely safe despite wearing the lenses overnight. The risk of microbial keratitis was only around one to two cases per 2,000 wearers per year.28
For a point of reference, the incidence of microbial keratitis for daily wear soft contact lenses ranges from 1.9 to 6.4 per 10,000 patient years with a mean weighted by the number of cases of 3.1 per 10,000 patient years.29
Currently available ortho-k lenses
There are numerous orthokeratology lenses on the market now, from Paragon CRT to Euclid and Dream lenses. However, most of these are used off-label for myopia control.
In 2021, the FDA approved ACUVUE Abiliti™ Overnight Therapeutic Lenses for Myopia Management to reduce refractive error up to 4.00 diopters (and up to 1.50D of astigmatism).30 The range of these lenses was expanded in September 2022 to an increased refractive error of 6.00D.31
One of the unique features about the Abiliti lens is not only the lens itself but the FitAbiliti app that comes with customized lens-fitting software to help inexperienced practitioners fit their patients with 90% success.
Some of its features include:
- Simulate FL patterns
- Troubleshoot fits
- Calculate power changes
- Determine optimum lens
- Order the lens
Not only does the Abiliti lens have an app for practitioners, but they also have an app for parents called SeeAbiliti which allows parents to track outdoor time and set reminders for insertion and removal of lenses as well as myopia resources.
Soft multifocal contact lenses for myopia management
There are numerous soft contact lens options available for myopia management, which we will review briefly below.
Biofinity (CooperVision)
This was the first lens to be studied for myopia control and is the only monthly lens available for myopia management (off-label use). Biofinity multifocal lenses come in both near- and distance-centered lenses.
The distance-centered multifocal lens with +2.50 add power was used in order to create a peripheral myopic defocus (mentioned in the orthokeratology section above) and therefore signal the eye to slow growth.
In the BLINK study, 294 children ages 7 to 11 with myopia from -0.75D to -5.00D with ≤1.00D astigmatism were recruited. The authors found a 50% reduction in refractive error and a 29% reduction in axial elongation compared to the control group over a 3-year period.32
MiSight (CooperVision)
MiSight 1 day is still the only treatment FDA-approved to slow the progression of myopia (ages 8 to 12 and -0.75 to -4.00D with ≤0.75D astigmatism at the start of treatment). It has a dual focus design, which creates a point of focus in front of the peripheral retina (peripheral myopic defocus) to signal the eye to slow as well as a point of focus on the macular so the patient can see distance clearly. It is also a daily disposable lens, and is available up to -10D in some markets.
CooperVision has recently released 7 years of data which is broken down below. Initially, 144 children ages 8 to 12 years with refractive errors of -0.75 to -4.00D and ≤0.75D astigmatism were recruited.33,34,35
- First 3 years: MiSight vs. Proclear 1 day
- Results showed a 0.73mm (59%) reduction in refractive error and 0.32mm (52%) less axial length growth compared to control
- Subsequent 3 years: Switch Proclear 1-Day to MiSight
- Subjects who switched from Proclear 1-Day to MiSight illustrated the similar axial length change as subjects already in MiSight, confirming that MiSight can still be effective at a later age
- Final year
- All children were switched from MiSight to Proclear 1 Day and monitored for a year
- Authors found no significant rebound effect (however, children were older at this time, average of 11 years)
NaturalVue (Visioneering Technologies, Inc.)
NaturalVue was originally indicated for presbyopes. It has unique Neurofocus optics that allows for a streamlined depth of focus over larger ranges (easier to adapt). The lens ranges from +4.00 to -12.25D in 0.25 steps and can correct (not mask) up to -1.75D astigmatism.
A study by Cooper et al., recruited 196 subjects, over 15 practices, ages 5 to 20, over a 6-year period. They found an average axial length change of 0.10mm/year (similar to emmetropic eyes).36
The PROTECT study 1-year interim data was just released in 2023. It is the company’s first prospective study look at 144 myopes ages 7 to 13 years and refractive error of -0.75D to -5.00D. So far they have found a treatment effect of 0.41D (refractive error) and 0.17mm (axial length) compared to the control group.37
Abiliti 1-day lens (Johnson & Johnson): New lens alert (not available in US yet)
Not only has Johnson & Johnson recently released an orthokeratology lens, but they have also produced a new daily disposable soft myopia control lens. This lens utilizes a unique ring focus design that allows for myopia correction zones and annular treatment zones.
Instead of “point” of focus in front of the retina (dual-focus design) there is instead a RING of focus slightly off-center to the visual axis. The parameters range from -0.25 to -8.00D in 0.25 steps (only spherical).38
A study by Cheng et al. recruited 200 children aged 7 to 12 years old between -0.75D and -4.50D. Although the study is still in its early stages, the 6-month data has already shown a reduction of axial elongation on average by 0.15mm.39
The latest on atropine for myopia management
Three large studies have investigated the effectiveness of various atropine concentrations. Although we are unsure of the exact mechanism of atropine, researchers have postulated it may stimulate the dopamine receptors in retina, which have shown to slow axial length, or via scleral remodeling.40,41
Please note as of now all atropine is considered off-label for myopia management.
ATOM (Atropine for Treatment of Myopia) 1 study
This was the first study to explore the potential use of atropine in managing myopia. Authors compared 1.0% atropine to control (saline). Results showed a reduction in refractive error and axial length by nearly 50%.
However, there were some serious side effects, such as pupil dilation, reduced accommodation, and blurry vision. Furthermore, the authors found after discontinuing there was a large rebound effect.42
ATOM 2 study
After the results of the ATOM 1 study were published, researchers then decided to test lower concentrations of atropine in order to reduce side effects but still effectively slow myopia. Authors investigated various levels of atropine concentrations (0.01%, 0.1%, 0.5% and 1.0%) compared to the control group from the ATOM 1 study.
All concentrations of atropine demonstrated a similar and significant refractive error reduction compared to the control group. The only concentration that did not show significant axial length reduction was 0.01% atropine.43
LAMP (Low-concentration Atropine for Myopia Progression) study
In 2019, Yam et al. explored 0.01%, 0.025% and 0.05% atropine concentrations with the intention of finding an atropine concentration that was effective in slowing both refractive error and axial length.
They determined that 0.05% showed the largest reduction in refractive error and axial length compared to all other concentrations without the side effects seen with 1.0% atropine.44
CHAMP (Childhood Atropine for Myopia Progression): New study
Currently being investigated is a preservative-free atropine option called Vyluma. The CHAMP study by Zadnik et al., investigated the effectiveness of 0.01% and 0.02% atropine.
The 3-year results showed that 0.01% atropine was effective in slowing both refractive error and axial length change compared to the control group. However, 0.02% atropine only demonstrated a significant reduction in axial length.45
Based on all these studies combined, it seems that atropine 0.025% or 0.05% would be the best concentrations to begin with since 0.01% did not demonstrate any reduction in axial length progression and 1.0% resulted in significant side effects.
Glasses for myopia management
Myopia control spectacles are not currently available in the US. However, they are being utilized in Europe and Asia and have shown up to an average of 50% reduction in refractive error and axial length.
Lenses include MyoVision (Zeiss), MyopiLux (Essilor), Stellest (Essilor), MiyoSmart (Hoya) and SightGlass (Coopervision). MiyoSmart has just released data that demonstrated both significant axial length and refractive error reduction sustained over 6 years.46
Red light therapy for myopia management
Repeated low-level red light (RLRL) therapy has been used for decades in Asian countries but is just gaining waves in Europe, Japan and Australia. The device known as the Eyerising emits a wavelength of 650nm at a laser power of 0.29W going through a 4mm pupil and used for 180 seconds 2x day for 5 days per week.
The mechanism of action is still not determined; however, studies have found that red light therapy can reduce the risk of myopia onset,47,48 as well as slow the rate of myopia.49 Axial length stability and sometimes shortening (due to choroidal thickening) was found.50 Furthermore, Xiong et al. found a significant rebound effect after discontinuing RLRL therapy after 1 year.51
Only one adverse event was reported by Liu et al., in which a female experienced bilateral vision loss for 2 weeks (20/30) after 5 months of RLRL therapy. After 3 months without RLRL therapy, there was partial recovery of retinal damage (PIL line) and BCVA improved to 20/25 both eyes.52
Combination therapy for myopia management
There has been some short-term data on utilizing combination therapy of either orthokeratology and atropine 0.01% or soft multifocal contact lenses and atropine 0.01%.
Orthokeratology and atropine 0.01%
So far, there was only minimal benefit found, and if any significance was determined, it was only in the first 6 to 12 months.53,54,55,56
Soft multifocal contact lenses and atropine 0.01%
The BAM study explored combining distance soft multifocal contact lenses with 0.01% atropine. The study’s findings revealed that over a 3-year period, there was no significant difference in myopia progression between the two groups. Therefore, the addition of 0.01% atropine to soft multifocal contact lenses did not have an additive effect.57
A 3-year retrospective study investigating the MiSight lens combined with 0.01% atropine reported that combination therapy showed no significant difference to monotherapy alone.58
Are contact lenses for myopia a feasible option?
It is one thing for contact lenses to be an effective myopia control treatment option in laboratory settings, however, we as ECPs must also consider the time and effort that it requires to fit and monitor contact lenses, especially in children.
A study by Walline et al., known as the CLIP study investigated the chair time required for fitting and follow-ups of contact lenses for children between the ages of 8 to 12 and 13 to 17 years old. The amount of time required for fitting, application and removal, and follow-up visits were measured individually and added for total chair time.
Total chair time was approximately 15 minutes longer than teens but most of that difference was due to longer application and removal time. In most offices, application and removal is taught by staff members, so ECP chair time is relatively the same.59
Therefore, practitioners can feel confident that they are sacrificing very little chair time when fitting contact lenses, even with young children.
Tools to predict and monitor myopia
A tool for practitioners to use for themselves or to educate parents on myopia progression is the Brien Holden Myopia Calculator. Practitioners can use the app or website to input the patient's age (6 to 16 years), current refractive error (-0.50 to -7.00D), ethnicity (Asian vs. Caucasian).
The calculator will then predict the level of myopia progression up to 17 years of age based on data aggregated from multiple different studies. Although this calculator tends to overestimate myopia progression for less myopic children, approximately 36% of subjects were within target of the calculator, 33% became less myopic, and 31% more myopic.60
When it comes to monitoring myopia progression for both refractive error and axial length there are three types of instruments currently available: interferometry, a-scan ultrasonography and combination of both.
Current interferometry instruments include Zeiss IOL Master, Oculus 3-1, and Pentacam AXL. What is great about interferometry is the doctor can obtain axial length, refractive error, IOL measurements and keratometry. This type of device has been shown to have high repeatability and accuracy but can be very expensive.59
A-scan ultrasonography is found more often in a lab/academic setting. It requires anesthesia of the eye and multiple measurements, which can make it harder for children. However, it is the most accurate of all the types discussed.61
Two devices that combine the accuracy of the A-scan ultrasonography without contact required include the Oculus Myopia Master and Tomey OA 2000. Results of these instruments have been found to be similar to the IOL Master,62 yet they are targeted more towards primary eye physicians in terms of price and ease of use.
If you do not have access to any of these instruments, you can consider asking your local ophthalmologist who often already has one of these devices. However, if you do not have access to any axial length devices you can still monitor refractive error.
Monitor/follow up time frame for myopia patients
The International Myopia Institute (IMI) Clinical Management Guidelines recommend that the monitoring schedule described in Table 4 be followed in the initial year of myopia management.63
| Treatment Modality | Initial Year Follow-Up Schedule | Second Year and Beyond |
|---|---|---|
| Multifocal Soft Lenses | 1 week, 1 month, 6 months | 6 months |
| Orthokeratology | 1 day, 1 week, 3 months, 6 months | 6 months |
| Spectacles | 1 month, 6 months | 6 months |
| Atropine | 1 week, 1 month, 3 months, 6 months | 6 months |
Table 4: Courtesy of Sel et al.
Cycloplegic refractions and axial length measurements (if accessible) should be performed on a yearly basis at minimum.64 If the patient is showing >0.50D/year or 0.1mm/year change (based on Zadnik et al. guidelines), the patient should be monitored every 6 months.
What’s in the myopia pipeline?
Many of the future treatment options have already been used for many years in other countries (spectacle lenses, red light therapy). However, with FDA in the United States having strict guidelines, practitioners are patiently waiting to obtain access to these myopia management options.
In the future we hope to have a myopia control toric soft contact lens option. As of now there is no word of any companies releasing this type of lens anytime soon, however, there is a large demand for it.
Preservative-free atropine options are currently being studied (such as the CHAMP study mentioned earlier). Another product known as Sydnexis (SYD-101) is a preservative-free atropine formulation which has a unique ingredient that stabilizes atropine at a comfortable and closest-to-physiologic pH, which helps keep it stable and maximize efficacy.
The STAR study is underway which is about 50% larger than the CHAMP study (nearly 850 patients enrolled). Authors will be analyzing the safety and efficacy of SYD-101 0.01% and 0.03% atropine over a 3-year period (unpublished data).
Conclusion
Many people, including practitioners, view myopia as an inconvenience rather than a sight-threatening disease; however, the World Health Organization has now recognized it as a global epidemic, and we as eyecare professionals must too.
What makes myopia control so special is that we can actually prevent/slow a disease at an early age and save our patients from potentially permanent visual loss.
Myopia management may seem intimidating, but it is well worth the pursuit and with a combination of education and enthusiasm, you can gain the skills and confidence needed to help tackle this growing condition.
