‘All males have to join the army in Singapore at age 18,’ explains Dr Koh Liang Hwee, former president of Singapore Optometric Association, ‘and over 80% of these adult males have myopia.’
Singapore is a small, economically developed nation that sits near the top of the table in terms of myopia rates in young adults. More than four in five adult Singaporeans are myopic, a figure that dwarfs rates in the UK, where around 30% of adults are.
Rates of myopia are on the rise in the UK however, with one study demonstrating that rates have more than doubled in the past 50 years from 7.2% of children in the 1960s to 16.4% today. Singapore provides an example of what the future could look like in the UK in terms of myopia rates, but also demonstrates how optometry in the UK could develop myopia management strategies to control the most severe cases.
Root causes
The causes of myopia are not fully understood, although studies have shown that extra hours of schooling and time spent inside correlate with higher rates, while patients with one or two myopic parents are also more likely to develop myopic vision.
Singapore’s high levels of economic development are often attributed to its focus on education, in which it comes first for primary and secondary schools in the Organisation for Economic Cooperation and Development’s school performance rankings. This, however, may contribute to its high levels of myopia.
Koh explains: ‘In Singapore we emphasise how important education is from a young age, and we study very hard with a lot of near work from when children are very young. Many Singaporeans develop myopia at a very young age, which can make the progression much worse, and because study happens indoors most of the time we spend less time outdoors, which doesn’t help.’
Dr Koh Liang Hwee at his practice, Pearl’s Optical
High rates of myopia in Singapore may also result from the country’s demography. Around three-quarters (74.1%) of the country’s residents are of Chinese descent, which Koh believes exacerbate rates of myopia: ‘The genetic factor is important, most of us are Chinese and the Chinese are more prone to myopia, similar to Taiwanese, Japanese and Korean people.’ While ethnic origin has not been proven as a causal factor in myopia, a systematic review and quantitative meta-analysis of myopia prevalence in children published in the British Journal of Ophthalmology demonstrated that ethnic differences in myopia prevalence exist among populations drawn from the same living environment.
The same paper adds that children of Indian ethnic origin living in Singapore had myopia rates more similar to those of ethnic Chinese Singaporean children than to Indians in India, evidencing the fact that genetic differences are not sufficient to explain such large differences in myopia rates between different populations.
Public health
Whether the result of nature or nurture, the rates at which Singaporeans experience myopia necessitate that the situation is treated as a public health issue. As Koh explains, myopia presents risks to health that go beyond the need for vision correction. ‘In cases of severe myopia the greatest risks are retinal detachment or macular degeneration,’ he says, ‘but the public are generally not aware of these risks, and it’s important that we explain them.’
One of the difficulties of explaining the need for any preventative treatment, including myopia control, is communicating that the problem may become much worse despite its less severe presentation in the present. Koh and other optometrists in Singapore grapple with this problem regularly. ‘One issue is that myopia has become so common in Singapore that it is no longer seen as a handicap, many people believe that as long as they can see with their glasses they will be okay,’ he says. ‘We try to fight this attitude with a complete optical profile that includes a myopia history of patient’s parents and siblings. At the end of an examination with a myopic child we explain the risks of letting it develop, but ultimately it’s up to them to decide whether they proceed.’
Expectations around the results of myopia management must also be managed, explains Koh: ‘Some parents expect too much, they feel that once their child is being treated with myopia management methods that it shouldn’t increase at all. After one year they can be disappointed, so it’s important to manage this expectation.’
Communicating with patients and increasing awareness of the risks of myopia is not left entirely up to the optical profession in Singapore, however. The country’s government has recognised the public health implications of allowing such high levels of the condition to go untreated and produces awareness campaigns that are broadcast on TV. ‘The government has been pushing knowledge of the risks and have national campaigns to encourage students to spend time outdoors more often,’ says Koh.
Attacking the problem
Awareness of the risks is not enough to deal with such high rates of myopia, and Singapore’s efforts to combat the condition do not end with broadcast campaigns. Koh explains: ‘Children are screened for eyesight problems by their regional authority starting at four years old up until they are six. After that their primary school will screen them every year from seven years old until they are 16.’
Once eyesight problems are detected in a child the school health service will then send a letter to their parents explaining that a full eye examination is required. Koh says: ‘Parents then have to bring the child to an optometrist for the eye check. Once the check is completed, the optometrist has to reply to the school health service explaining any prescriptions and that the child has been checked at the practice.’
Screening services are provided by the government, although optometry is primarily a private service in Singapore. The government does provide subsidised myopia management at a national myopia management clinic, the Myopia Centre. Once an optometrist identifies myopia in a child the patient can be referred to the dedicated clinic, which can then refer patients to private practices for certain prescriptions. Koh says: ‘The government set up the Myopia Centre specifically to monitor myopia progression, screen for eye diseases and prescribe atropine to slow down the progression. They don’t prescribe Ortho-K or special ophthalmic lenses at the centre, so they refer patients to other optometrists for this service while we refer their patients there for atropine therapy.’
Benefits all round
Myopia management is a long-term therapy that patients and their parents must commit to with the knowledge that there will be no instant results. Convincing patients of its benefits can be difficult, but doing so is incredibly beneficial for both their health and the practitioner.
Koh explains that different patients can be managed differently, based on their motivation levels. ‘Highly motivated patients or those who want to go spectacle-free in the daytime can be prescribed Ortho-K, while ophthalmic lenses can be recommended where parents are worried about sensitivity or infections. Atropine therapy can also be used in more severe cases.’
That myopia rates in Singapore are so high is taken as a result of the nation’s lifestyle, and management of the condition simply seeks to reduce the amount of high myopes to minimise health complications. Treatment takes place over many years and continues until the development stabilises in early adulthood.
Such a long-term treatment presents both clinical and financial opportunities for practitioners, as Koh explains: ‘We have to care for myopic patients over a long period in order to protect their health, it’s a kind of speciality that optometrists can easily adopt. This also has benefits in terms of business profitability too, treating patients over many years means you’ll be well compensated.’