Myopia, more commonly known as nearsightedness, is a condition due to the physical length of the eye being relatively too long for its refractive components. Despite its strong family trait, juvenile myopia has been considered as a combined product of environmental influence and genetic predisposition, with factors such as lack of outdoor exposure, active use of handheld devices, and sustained near activities playing primary role in the etiology of the condition.
To Intervene or Not to Intervene?
There's some debate as to whether myopia is a benign refractive condition or a disease that significantly benefits from early intervention.
The perception of myopia as a simple refractive error versus a disease that can lead to irreversible loss varies significantly based on the patients and parents' cultural background. In general, Asian parents view myopia as much more than just a refractive problem and instead see it as a progressive condition that can lead to vision loss. Similarly, the condition is much better recognized as a disease among eye care practitioners in Asia. This is partially attributable to the higher prevalence and severity of myopia, hence the much higher incidences of blinding retinal complications seen by the eye care practitioners.
It is important to note that even though the risks of myopia-related complications -- such as myopic maculopathy, retinal detachment, primary open angle glaucoma, or early onset cataract -- increase exponentially with the severity of myopia, lower myopes are not immune from such risks. In fact, because there are so many more lower myopes in the population, the complications in myopic eyes less than -3D contribute to more than 40% of all cases. Additionally, despite the major advancement of using anti-VEGF treatment in many types of chorioretinal neovascularization, the long-term outcome of such treatment in myopic maculopathy remains equivocal, as the complication is an end-product of excessive scleral stretching and thinning at the advanced stage of the irreversible axial elongation. Consequently, early interventions that slow the axial growth and prevent excessive stretching of the posterior sclera will likely provide the best accumulative outcome in minimizing the risk of vision loss due to myopia complications.
Recent evidence from both animal and clinical studies clearly demonstrates that myopia, as well as the associated axial elongation, is controllable, especially during the early stage of visual development. Common evidence-based treatments that offer both statistically significant and clinically meaningful efficacies include daytime multifocal soft contact lenses (MFSCL), overnight orthokeratology (ortho-k), and topical low dose atropine (LDA). Novel spectacle lenses also showed a promising myopia-inhibiting effect, albeit with limited availability in U.S. at the current moment. On average, these options slow myopia progression by 30-70% compared to conventional single vision glasses or contacts. With properly selected early interventions, not only the development of myopia stabilizes at younger ages, the endpoint of the progression is also much lower, resulting in significantly lower risk of complications. Furthermore, with lower level of myopia at stabilization, many myopic patients could be good candidates for refractive surgery with given corneal thickness.
Myopia Treatment Is Good for Individual and Public Health
Permanent vision loss related to pathological myopia accounts for up to 25% of all low vision cases. Comparing to other priority eye conditions such as age-related macular degeneration, glaucoma, cataract, and diabetic retinopathy, vision loss related to myopia complications tend to have much younger age of onset, bilateral presentation, and bias toward populations with higher educational levels. As a result, its impacts on quality of life and productivity are likely much higher. With myopia becoming the most prevalent ocular condition globally, a small reduction either in the prevalence or the severity of myopia carries a huge public health benefit.
Even for myopes without permanent vision loss, the choices of optical correction reduce significantly and the cost for spectacles and contact lenses increases dramatically with increasing level of myopia. Additionally, aesthetics, optical distortion, and the field of view from high prescription are all significantly impacted.
Integrating Myopia Control
One question that arises is whether myopia control treatments should be considered as concierge service or implemented in the form of traditional primary care. The answer is both.
Evidence-based myopia control treatments include a wide variety of options including daytime MFSCL, overnight ortho-k, LDA eyedrops, or novel glasses. Despite the differences in treatment efficacies, decisions regarding treatment are also influenced by the patients' age, cultural background, lifestyle, visual needs, and the parents' knowledge of the long-term safety of the options, among other factors. The necessity for easy accessibility to practitioners, and the flexibility of office visits is highly dependent on the particular type of treatment. For options such as LDA eyedrops or novel glasses, the treatments can be offered by eye care practitioners in all settings without the need for advanced training, and the risk of serious side effects due to the treatments is minimal. Considering the tremendous size of the target patient population (i.e. children with progressive myopia), it is critical that these treatment options are available at as many practices as possible. On the other hand, it is critical to ensure easy accessibility especially after regular clinic hours, the continuity of follow-up care, as well as frequent and flexible office visits for options involve contact lens wear in children -- especially the overnight modality of the ortho-k treatment -- to minimize the risks of serious complications related to contact lens wear.
In summary, juvenile myopia is a combined product of genetic predisposition and environmental influences. Early interventions that target not only correcting myopia but also slow the excessive axial elongation and scleral stretching are critical in minimizing the risks of complications that may lead to irreversible vision loss. Myopia control options need to be prescribed with a custom-tailored approach with some options readily available in traditional primary care settings, and others more properly offered as concierge services, depending on the level of complexity of the treatment, advanced training required, and the risks of treatment related complications.
Maria Liu, OD, PhD, MPH, MBA, is an associate professor of clinical optometry and founder and chief of the Myopia Control Clinic at University of California Berkeley Optometry.
Disclosures
Liu receives consulting fees from CooperVision and Essilor.
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