Why control myopia?
Myopia — or short-sightedness — refers to poor distance vision but clear near vision. This occurs when the eyeball grows too long in relation to the power of the eye’s lenses. The light rays then focus at a point in front of the retina, rather than directly on its surface.
The main reason to control myopia is the risk of blinding conditions that escalates as myopia increases.
Progression and associated risks
Adult-onset myopia (developing after 20 years of age) can progress over time, though youth-onset (before 20 years) generally shows more aggressive progression which continues until the eye stops growing. Typical sufferers are highly dependent on high-powered glasses or contact lenses and require frequent replacements as the condition escalates.
Myopia usually appears in childhood. The condition does run in families; however, some children are becoming short-sighted even though their parents have no distance vision problems. Genetics is therefore not the only contributing factor.
All levels of myopia increase the chance of blinding conditions such as retinal detachment, cataracts, glaucoma and myopia retinal degeneration later in life.
This risk escalates as the level of myopia increases. Myopic maculopathy, a progressive condition causing holes in the retina due to overstretching, is the fourth most common cause of visual impairment in the UK, ahead of diabetic eye disease.
Studies show the risk factor for eye disease due to myopia is comparable to the risk of cardiovascular disease due to untreated high blood pressure. The risk for glaucoma and cataract due to myopia compares to the risk of stroke from smoking over 20 cigarettes per day. For retinal detachment and myopic maculopathy, myopia carries a risk far more than any identified population risk factor for cardiovascular disease. Given that higher levels of myopia entail a higher risk of these conditions, halting this progression can broadly prevent a significant level of blindness.
A chart showing the increased risk of different eye disease with higher levels of short-sightedness. Courtesy of the OSO
The increase in myopia cases is worryingly high. While we don’t have accurate data at this stage, it is believed to have a prevalence in New Zealand of 25-40%, similar to North America and Australia. There are approximately 1.4 billion people worldwide with myopia, by 2050 over 50% of the world’s population is expected to have short-sightedness.
Studies have shown that 93% of 18-year-old girls in Taiwan are myopic. In Singapore, seven out of ten college graduates have the condition, and China is experiencing rates up to 78% among 15-year olds in urban areas. Closer to home in Australia, 30% of teenagers finishing school are myopic — and this percentage is on the rise.
More than just genetics?
The development of myopia seems to also be influenced by environmental factors, such as near work.
Studies show that the more near work performed, the more likely your child will become near-sighted.
In one study, boys in Orthodox Jewish schools were found to have a higher rate of myopia (81.3%) compared with boys in general Jewish schools (27.4%). The boys in the Orthodox schools spent upwards of 16 hours a day studying.
Lack of time spent outdoors has also been implicated.
What can be done?
At Visique we take a pro-active approach to controlling myopia progression.
Prescribing standard spectacle lenses or contact lenses for your child or teenager won’t do anything to slow the progression of short-sightedness. As a result, frequent changes to their glasses will be needed and they will be put at risk of sight-threatening problems in the future. Unfortunately, the lengthening of the eye which causes myopia cannot be reversed, making it critical to control myopia sooner rather than later.
The good news is that there is conclusive evidence that certain treatments can slow and even halt the progression of myopia.
At Visique we ensure we are up to date with the latest research in this area and we will recommend the most appropriate myopia control methods for your child or teenager, depending on a range of factors.