There have been alarming predictions regarding the rate of increase of myopia for the next three decades. Of particular concern is the predicted increase in high myopia, with reports that almost 10% of the world’s population will exhibit myopia in excess of -5.00 D by 2050.¹ Given the abundance of evidence in the literature that shows myopia progression can be reduced, practitioners need to be proactive with their young patients and introduce the concept of myopia control as soon as there is evidence of a myopic refractive error. Additionally, practitioners need to be familiar with the treatment options available.

Currently, there is no specific indication for the most appropriate myopia management option based on the clinical presentation of the patient. However, many factors need to be taken into consideration in choosing the management option. These include the patient’s age, rate of myopia progression, presenting refractive error and the consideration of the likelihood of tolerance and compliance with the management option under consideration.

There are three basic categories of myopia management: spectacles, pharmaceuticals and contact lenses:

SPECTACLES

The simplest option for myopia correction (and myopia management) is spectacles, especially for young patients who may not be ready for other management options. Undercorrection of myopia to slow progression has been discussed for decades and is often requested by anxious parents. In animal models, it has been shown that imposed myopic defocus slows the rate of eye growth.² Therefore, it would seem reasonable to assume that undercorrection of refractive error in spectacles, thereby creating myopic defocus, could support this concept and lead to a slowed progression of myopia. Indeed, in recent surveys of ophthalmologists and optometrists, both groups reported that they consider undercorrection of refractive error in spectacles as a strategy for their myopic patients (8.2% and 20.4%, respectively).^3,4 However, a systematic review by Logan and Wolffsohn demonstrates clearly that undercorrection of myopia is not a strategy to be adopted for myopia management.⁵ Indeed, studies demonstrate that undercorrection could actually lead to an increase in myopia progression.^6,7

Currently, the scientific evidence on the efficacy of spectacle lenses for myopia management is not as compelling as that for other options. Studies using PAL or bifocal spectacle lenses show variable success, with some evidence that patients who have binocular vision or accommodative issues may benefit more than those with no binocular vision issues.^8,9

Novel spectacle lens options from large commercial companies, such as Zeiss and Essilor, are marketed for myopia management. Relatively encouraging company-generated data (reportedly around 30% to 60% slowing of progression) supports their use for myopia management.

Of note are some recent promising spectacle lens designs not yet available in the United States: The Defocus Incorporated Multiple Segments (DIMS) lens, developed in Hong Kong and only available in Asia (Myo Smart, Hoya), is shown to reduce myopia progression by around 50%.¹⁰ The design principle is one of a central clear zone surrounded by a multizone area of defocus, which appears well tolerated by patients.¹¹ Additionally, SightGlass Vision, based in California, recently announced promising interim results from a randomized clinical trial of their spectacle lens design and have also presented positive data on patient tolerability.¹²

At this time, there is limited global availability of spectacle lens products for myopia control and limited data from well-controlled, randomized control trials. However, this landscape is changing, so practitioners can expect that, in the not-too-distant future, there will be spectacle lenses widely available that have good scientific evidence to support their prescribing for myopia control.

PHARMACEUTICALS

Atropine is the most widely used pharmaceutical with respect to myopia management, in both clinical trials and in clinical practice. Atropine has been widely adopted by eye care practitioners globally, and it is the main method of choice for ophthalmologists.³

A major debate exists around the most appropriate concentration to use clinically. Following the pivotal Atom 1 and Atom 2 studies, it was widely accepted that 0.01% atropine was the concentration of choice, as this was shown to have a significant impact (around 60%) on the progression of refractive error, without the loss of accommodation and pupil dilation that occurred with higher concentrations.^13,14 However, a mismatch has been shown between the impact on refractive error compared with that on axial length progression, with axial length progressing at a similar rate to untreated age-matched control groups.¹⁵

Other studies advocate for the use of higher concentrations of atropine (at 0.05%), with evidence of a similar effect at this concentration on both refractive error (66%) and axial length (51%).¹⁶ See Table 1 for the comparison of effect of atropine on refractive error progression and axial length progression.

Regardless of the concentration used, the recommended dosage of atropine is one drop, each eye, daily.

Another topic of debate concerns the rebound effect when atropine therapy ceases. This is of particular concern at higher concentrations, with studies suggesting a progression of myopia at a greater rate to a matched untreated control group.^17,18 (See also “Communicate Myopia Management Options,” by Dr. Jeffrey Cooper at bit.ly/myopiacooper .)

Ongoing clinical trials’ results will inform practitioners of the most appropriate atropine concentration to use, as well as address concerns related to rebound. One report concludes that the minimum concentration should be 0.025%, with 0.05% likely being more effective, but resulting in increased side effects (mydriasis, and cycloplegia).¹⁹ Side effects are certainly worthy of consideration when prescribing a myopia management strategy. In this case, if the side effects of atropine use become intolerable, compliance will likely be compromised.

In Singapore, 0.01% atropine has been authorized for use by the Singapore Health Sciences Authority and is commercially available. Elsewhere, low-dose atropine for myopia control is used in an off-label capacity and has to be compounded by a pharmacist to the required concentration. This provides the eye care practitioner with choices of concentration to prescribe and adds a complexity of consistency in preparation. (See “O.D.s Discuss How They Acquire Atropine,” p.12.)

SOFT CONTACT LENSES

Soft contact lenses are increasingly used as a myopia management option, with solid scientific evidence to support their use. There are two main options to consider:

• Center distance multifocal soft lenses. Originally intended for the correction of presbyopia, these are shown to have a positive effect on myopia progression when fit on young myopes.^20,21
• Lenses specifically designed for myopia control (broadly two designs). Dual focus lenses and extended-depth-of-focus lenses have both been shown to slow myopia progression.^22-24;25,26

Regardless of the lens design, the principle used is effectively the same: central clear distance vision with myopic defocus in the peripheral retina created by an increase in positive power away from the center of the lens.

The results from clinical studies have been promising, with myopia progression being slowed in the range of 40% to 60%. The majority of products in this category are used in an off-label capacity when prescribed for myopia control. However, products that have an indication and regulatory authorization for myopia control globally are: NaturalVue (Visioneering Technologies, Inc.), MiSight (CooperVision) and Mylo (mark’ennovy). (Only the MiSight lens has cleared the FDA for the treatment of myopia in the United States.)

All soft lens options are worn on a daily wear basis, with replacement frequency varying from daily to monthly, depending on the product chosen. Practitioners should consider the pros and cons of the particular lens modality prior to recommending an option.

ORTHOKERATOLOGY

Orthokeratology (ortho-k) has been used as a method to correct myopia for more than 50 years. In recent years, growing evidence indicates that ortho-k can successfully slow the rate of progression of myopia.^27-30 With the introduction of reverse geometry lens designs and high permeability materials, ortho-k has become a very popular myopia management option. The myopia control effect is similar to soft multifocal lenses, with 30% to 80% slowing of axial elongation.^27,28 Ortho-k effectively eliminates the refractive error, such that no correction needs to be worn during the day. Toric ortho-k lenses are available for patients who have significant amounts of astigmatism.³¹

The question of safety of ortho-k as a modality has been raised and addressed in numerous studies, with the conclusion that the risks of wearing overnight ortho-k are similar to other overnight modalities and with appropriate compliance can be considered a safe option for patients.^32-34

COMBINATION THERAPIES

It would be reasonable to assume that if myopia control is modulated by different mechanisms (see “Diagnose Myopia,” p.22), combining treatments may be more effective than a single method. The obvious option would be to combine atropine with either ortho-k or multifocal soft lenses.^35,36 Currently, there is insufficient evidence in the literature to recommend this as a first-line treatment option, but such an approach could be valuable in patients who continue to experience progression at a rapid rate using a single treatment.

Practitioners and parents need to work together to decide on the best management option for the patient and to ensure that patients comply with the prescribed therapy. Patients must be monitored carefully to ensure that the chosen strategy has the desired outcome.

Most of the management methods described above provide a similar level of myopia control, with inherent variations from patient to patient. Therefore, the management option will likely be chosen based on other factors, such as lifestyle, familiarity with a specific management option (e.g., rigid lens vs. soft lens), cost, age and maturity of the child, time commitment, availability of a particular product and practitioner experience and confidence.

Practitioners have the tools available for incorporating myopia management options into their practice; now is the time to use them. OM

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DR. JONES is a clinical professor at the School of Optometry & Vision Science at the University of Waterloo and clinical scientist at the Centre for Ocular Research & Education (CORE).