Understand the different categories and the management considerations for pre-myopia. Stop myopia in its tracks early.
Imagine taking your child for an eye exam and discovering that they have pre-myopia. However, your eye doctor only suggests keeping a close watch and returning for a check-up in one year. As a concerned parent, you may be left wondering if there is anything you can do to prevent myopia onset.
Myopia is grouped into three categories: pre-myopia, low myopia, and high myopia. And having pre-myopia indicates an increased risk of developing myopia.
In this article, we will explore pre-myopia and how to manage the condition.
How does myopia develop?
It was only 50 years ago that myopia was believed to be mainly driven by genetics. However, research since then has shown that the development and progression of myopia are influenced by multiple factors, including genetic and environmental ones.
Studies demonstrated strong correlations between myopia and education, near-work, and higher occupational status. Interestingly, experimental models showed that myopia might develop as an adaptation to environmental visual conditions through the same internal mechanisms that your body utilized for emmetropization.
In a normal eye, eye growth proceeds from being hyperopic to emmetropic, a process known as emmetropization. During this process, the eye adjusts so that the eye's optical power matches its axial length leading to the appropriate focusing of the light on the retina. This process occurs rapidly within the first year of life and then more slowly until emmetropia, 20/20 sight, is achieved in mid-childhood.
However, in myopia, this process is accelerated and overshoots emmetropization. This means that children who become myopic experience significantly more axial elongation up to 3 years before onset and up to 5 years after onset. It's interesting to note that axial elongation during emmetropization occurs more rapidly in younger children (6-10 years) than in older children (12-16 years).
What are the stages of myopia?
The International Myopia Institute (IMI) has classified myopia into three categories: pre-myopia, low myopia, and high myopia.
Pre-myopia | A refractive state of an eye of ⩽ +0.75 D and > −0.50 D in children where a combination of baseline refraction, age, and other quantifiable risk factors provide a sufficient likelihood of the future development of myopia to merit preventative interventions. |
Myopia | A condition in which the spherical equivalent refractive error of an eye is ⩽ −0.50 D when ocular accommodation is relaxed. |
Low myopia | A condition in which the spherical equivalent refractive error of an eye is ⩽ −0.50 and > −6.00 D when ocular accommodation is relaxed. |
High myopia | A condition in which the spherical equivalent refractive error of an eye is ⩽ -6.00 D when ocular accommodation is relaxed |
Additionally, a US-based study with more than 4,500 children identified the following refractive error levels that may lead to an increased risk of becoming myopic for different age groups:
- 6 years old: < +0.75 D
- 7-8 years: ⩽ +0.50 D
- 9-10 years: ⩽ +0.25 D
- 11 years: ⩽ 0 D
In a nutshell, pre-myopia is determined by multiple factors. And it includes refraction in the hyperopic range, which means even before our child needs glasses!
However, since pre-myopia indicates a higher likelihood of developing myopia in the future, discussing preventive measures with a healthcare professional is recommended.
How to treat pre-myopia?
Two medical society-supported approaches to reduce the likelihood of myopia onset are low-concentration atropine and increased outdoor time. In fact, in the Refractive Errors Practical Practice Patterns in 2022, the American Academy of Ophthalmology (AAO) recommended the use of low-concentration atropine and increased outdoor time for myopia prevention.
In a research study, 0.05% atropine treatment was found to have a significantly lower progression rate vs placebo. After two years, only 28% of pre-myopes who received 0.05% atropine treatment progressed to myopia, while 53% of those who had placebo treatment developed myopia. In other words, 0.05% atropine treatment reduces the risk of developing myopia by about 47% compared to placebo.
Additionally, a meta-analysis examining the relationship between outdoor time and myopia development indicated that an increase of 1.25 hours/day would result in a 50% reduction in the occurrence of myopia compared with controls. Based on multiple studies, an IMI and European Society of Ophthalmology guidance on the management of myopia suggested a minimum of 8 to 15 h of outdoor activity per week, with more time the greater protection.
In the unfortunate event that your child has already developed myopia, there are also treatments available to control its progression. For example, the AAO recommended the use of atropine eye drops, myopia control glasses and contact lenses, as well as overnight orthokeratology, to stop or slow down myopia progression in children, which ultimately would reduce the risk of long-term eye complications, such as macular degeneration, glaucoma, cataracts, or retinal detachment.
As with any treatment, there are benefits and risks. It is important to discuss treatment options with your healthcare provider to find the most effective and appropriate option.
New insights on treating pre-myopia with Stellest lenses
A study published in August 2024 tested Stellest glasses to see if they could help prevent myopia in 108 Chinese children aged 6 to less than 10 years who were at high risk of developing the condition. The children were divided into two groups: one wore Stellest glasses, and the other wore regular single vision lenses (SVL) for at least 5 days a week and 4 hours a day. After one year, children who wore Stellest glasses for more than 30 hours a week had significantly slower eye growth (0.11 mm) compared to those wearing SVL lenses (0.27 mm). Although changes in vision were not significant, the reduced eye growth -- eye axial length -- suggests that Stellest glasses may be a new approach to lower the risk of developing myopia in children.
Key takeaways
In summary, if your child has pre-myopia or has been diagnosed with myopia, it’s essential to work closely with your eye doctor to develop an effective management plan.
The good news is that increasing outdoor time is a simple, cost-free way to help prevent the onset or progression of myopia. For children at higher risk, your doctor may also recommend treatments such as low-dose atropine eye drops or Stellest glasses, which have been shown to slow eye growth and reduce the chances of progression.
To protect your child’s eye health, encourage them to spend more time outdoors with proper sun protection, and take proactive steps to manage their vision.
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