Myopia in Children

The World Health Organization (WHO) generally defines high myopia as a refractive error of

≤-5.00 Diopters (D), or in a local context we call this 500 degrees. This classification emphasizes the increased risk of sight-threatening diseases, such as retinal detachment, glaucoma, and myopic maculopathy, which are significantly more likely when the eye is highly elongated in high myopia (often >26mm).

Prevalence of Myopia in Children in Singapore

Myopia, or nearsightedness, is a common refractive error in which distant objects appear blurry while close objects are seen clearly. In Singapore, myopia has become an increasingly prevalent condition among children. Studies show that approximately 80-90% of teenagers in Singapore are affected by myopia by the time they reach 18 years old. This high prevalence is linked to a combination of genetic factors and environmental influences, particularly prolonged near work such as reading and using electronic devices.

The rapid increase in myopia cases has raised concerns about the long-term implications for eye health. Singapore has become one of the countries with the highest rates of myopia in the world, prompting a strong focus on strategies for myopia control to reduce its progression in children.

Negative Effects of Myopia on Eye Health in Adulthood

As myopia progresses, it typically worsens during childhood and adolescence, stabilizing in early adulthood. However, high levels of myopia (usually defined as greater than -5.00 or -6.00 diopters) can lead to serious complications later in life. These complications include:

Retinal Detachment: The retina becomes more stretched and thin in highly myopic eyes, increasing the risk of retinal tears or detachment, which can lead to permanent vision loss if not treated promptly.

Glaucoma: High myopia increases the risk of developing glaucoma, a condition where increased intraocular pressure can damage the optic nerve and cause permanent vision loss.

Macular Degeneration: Myopia, particularly high myopia, can lead to degeneration of the macula, the central part of the retina, leading to significant central vision loss.

Cataracts: Myopic individuals are more likely to develop cataracts at an earlier age compared to those without myopia.

The risk of these conditions increases as the degree of myopia increases, which is why controlling the progression of myopia during childhood is crucial.

Myopia Control Options for Children

Several approaches have been developed to manage the progression of myopia in children. These include:

Orthokeratology (Ortho-K): Special contact lenses are worn overnight to temporarily reshape the cornea and correct myopia. This can slow down myopia progression and reduce the need for glasses or contact lenses during the day.

Multifocal Contact Lenses: These lenses have different zones that focus light in different ways, which can help reduce the progression of myopia by altering the way light is focused on the retina.

Atropine Eye Drops: One of the most promising treatments for myopia control in children is the use of low-dose atropine eye drops. Atropine is a medication that dilates the pupil and reduces the focusing power of the eye, which can help slow down the progression of myopia.

Myopia Control Spectacle Lenses: Specially designed spectacle lenses are also available to control the progression of myopia in children. These lenses incorporate features like dual-focus or peripheral defocus to help reduce the strain on the eye that contributes to myopia progression. These lenses have been shown to slow myopia progression by altering the way light is focused on the peripheral retina, which can reduce the stimulus for the eye to elongate. Examples include myopia control designs like Hoya's MiYOSmart lenses and Essilor's Stellest Lenses. These lenses have become a popular, non-invasive option for children who may not be comfortable with contact lenses or atropine drops.

Low-Dose Atropine for Myopia Control

Atropine has been used for myopia control for several years, and recent studies have focused on the efficacy of low-dose atropine (0.01%, 0.1%, and 0.5%). The goal of using low doses is to reduce the side effects of high-dose atropine, such as light sensitivity and blurred near vision, while still effectively slowing myopia progression.

Efficacy of Low-Dose Atropine

1. 0.01% Atropine: This low dose has shown remarkable effectiveness in controlling myopia progression with minimal side effects. A landmark study published in the American Journal of Ophthalmology (2015) found that children treated with 0.01% atropine experienced a 50% reduction in myopia progression compared to the placebo group. Importantly, this dose had minimal side effects, with few complaints about light sensitivity or blurred near vision.

2. 0.1% Atropine: A study published in The Lancet (2019) reported that 0.1% atropine was effective in reducing myopia progression by approximately 60-70% over a two-year period. However, some children experienced mild side effects, such as light sensitivity and near-vision blur.

3. 0.5% Atropine: Although more effective in slowing myopia progression (up to 80-90%), higher doses of atropine, such as 0.5%, can cause more pronounced side effects, including significant difficulty with near vision and light sensitivity. These side effects have led to a preference for lower doses in clinical practice.

Studies on Efficacy

• The Atropine for the Treatment of Myopia (ATOM) Study (2006): This large study demonstrated the efficacy of 1% atropine in slowing the progression of myopia by about 77% over two years. Although this dosage is not commonly used today due to side effects, it laid the foundation for further research into lower doses.

  
  

• ATOM 2 Study (2012): This follow-up study found that 0.01% atropine was the most effective low-dose regimen, reducing myopia progression by 50% over two years with minimal side effects.

In conclusion, 0.01% atropine appears to be the most effective low-dose treatment for myopia control with the least number of side effects, making it the preferred option in clinical practice today.

Conclusion

Myopia is a growing concern among children in Singapore, with a significant percentage of children becoming myopic by their teenage years. The long-term risks of myopia, including retinal detachment, glaucoma, and macular degeneration, make it crucial to control its progression during childhood. Low-dose atropine, particularly 0.01% atropine, has emerged as one of the most effective and well-tolerated treatments for slowing myopia progression, with substantial evidence supporting its efficacy. In addition to atropine, myopia control spectacle lenses and contact lenses are valuable, non-invasive options for children. Early intervention, alongside these myopia control strategies, can help mitigate the risks of high myopia in later life and preserve long-term eye health.