Understanding High Myopia and Its Risks
Myopia, commonly known as nearsightedness, affects millions of people worldwide. However, when myopia progresses to an advanced stage, it becomes more than just a simple vision problem. High myopia is associated with many potential complications that can significantly impact eye health and vision quality.
What is High Myopia?
High Myopia is an advanced form of nearsightedness characterized by a refractive error of -6.00. This condition goes beyond a simple error and involves considerable structural differences compared to the typical eye’s structure.
With high myopia, the eyeball becomes elongated beyond the normal range. A typical eye measures between 23mm and 23.5mm, while myopia occurs at lengths over 24mm. Eyes with advanced myopia often continue to grow to 26mm or more, which can cause thinning of the retina and choroid.
This elongation causes light to focus in front of the retina rather than on the retina, resulting in significantly blurred distance vision. Due to the stretching of the ocular tissues, high myopia is associated with an increased risk of several ocular diseases later in life.
What Are the Options for Managing High Myopia in Children and Young Adults?
Regular eye examinations with an eyecare practitioner familiar with the patient’s condition are vital to tracking myopia progression and detecting signs of complications. An eyecare practitioner will devise a management and treatment plan that suits their patient’s unique eyes and lifestyle to give them the best chance of maintaining long-term vision and ocular health.
Managing high myopia involves several strategies to correct vision and slow the progression of the condition. Here are some common options:
Orthokeratology (Ortho-K): This involves wearing specially designed rigid contact lenses overnight to temporarily reshape the cornea. This can reduce myopia for the following day without the need for glasses or contact lenses. Orthokeratology has been shown to effectively slow the pression of myopia in children and teenagers.
Atropine Eye Drops: Low-dose atropine eye drops have been used to slow the progression of myopia in children. The exact mechanism isn’t fully understood.
Center-distance Multifocal Contact Lenses: These offer a center zone that corrects the distance vision and a second multifocal zone which helps slow elongation of the eye. They can be beneficial for myopia management
What Causes Advanced Myopia?
Several studies show the increased prevalence of myopia in children in East Asia. According to one study, the rise of myopia in many Asian countries may be due to the prolonged use of near work in children such as computers, tablets and phones. Genetics also play a role in the chances of a child developing myopia and myopia progression, which in turn also affects the rising rate of myopia worldwide.
Children with one myopic parent are at greater risk of developing myopia as well, and this risk increases considerably if both parents are myopic. As the growing number of myopic adolescents grow up and have their own children, their chances of passing on their myopia are further increased.
Concerning environmental factors, prolonged time doing near work can profoundly affect developing eyes. Unmoderated time spent reading, writing, drawing, and using digital devices, in conjunction with a lack of exposure to natural light, can have negative consequences for children who may already be predisposed to myopia.
Children in every country spend less time playing outdoors during their most crucial developmental years as indoor activities like video games and social media become more popular. If academic pursuits are prioritized, this leads to even more time inside. Minimal exposure to natural light may increase axial growth of the eye.
What are the Symptoms of High Myopia?
The symptoms of mild and high myopia are similar, but the degree of severity is substantially higher with advanced myopia. Patients with high myopia may regularly notice themselves squinting or straining to see objects in the distance. Squinting is a subconscious attempt to improve focus and can cause severe eye strain and frequent headaches.
Blurred distance vision is the defining factor of myopia, and in patients with high myopia, this blurriness can affect quality of life. Children may struggle to participate in class because they can’t clearly see the board.
High myopia progresses quickly, which can lead to the need for frequent prescription changes.
What are the Risks Associated with High Myopia?
- Retinal detachment. The elongation of the eyeball puts stress on the retina, increasing the risk of tears and detachment. Detachment is an emergency that can cause permanent vision loss if not treated immediately.
- Cataracts are a common issue for older people, but for those with high myopia, they can occur earlier in life. Cataracts present when proteins and fibrous tissue in the eye break down, causing clouds that disrupt vision.
- Macular degeneration. This condition is more common for patients with high myopia because their eyes are weakened due to the excessive elongation. Macular degeneration can cause central vision loss.
- Glaucoma, damage to the optic nerve caused by the intraocular pressure being too high for the optic nerve to tolerate. This condition is more prevalent in those who have higher levels of myopia.
Moving Forward with High Myopia
High myopia is a complex condition that goes beyond mere difficulty in seeing distant objects. Its impact on eye health and overall quality of life can be profound, making regular monitoring and proper management vital.
While the increasing prevalence of myopia is concerning, continuous advancements in eye care provide hope. By understanding the symptoms and causes and being aware of potential risks, patients can take proactive steps to manage their condition and protect their future vision.