I have worn glasses and contact lenses for most of my life to correct my ever-worsening myopia (short-sightedness). I’m by no means alone as about one in three people are affected by myopia in the UK, and about 1 in10 are genetically pre-disposed to severe short-sightedness.
It’s not been a big hindrance to my life (I’m fortunate to have been able to afford good eye care), although I don’t care to think about how much time I have wasted looking in vain for my glasses! That said, I have always wondered if some kind of intervention in my childhood could have minimised or even prevented the gradual deterioration of sight I have experienced since my early teens.
Currently, predicting myopia in children would involve instigating a screening regimen of cycloplegic autorefraction, which involves the use of a computer-controlled machine to provide an objective measurement of the eye’s refractive error, on the basis that low hyperopic refractive error may be predictive of myopia at an age before symptoms typically manifest. However, such a screening regimen would be both resource and time expensive and may still detect at-risk children too late to instigate a prophylactic intervention.
It is therefore interesting to see a recent publication from researchers at Cardiff and Bristol Universities describing a genetic test that could help to identify children at risk of developing short-sightedness. While no prophylactic treatment intervention is currently available, interventions for slowing childhood myopia progression have shown success in randomized clinical trials. Moreover, as myopia is associated with an increased risk of sight-threatening diseases such as glaucoma, maculopathy, and retinal detachment, the development of a genetic test for myopia is a welcome advance in this field and may represent a significant step towards the generation of personalized treatments for these conditions.
Notably however, further development of the test is required before it is suitable for use in clinical practice. This will require substantial investment in further research and product development and this raises an interesting issue. As I have discussed in a previous article, in recent years it has become increasingly difficult to obtain and enforce patents in the US (and some other countries) directed to methods of diagnosis, particularly where the diagnostic method is based on detecting or measuring a naturally-occurring biomarker, e.g. genetic tests. The uncertainty surrounding the ability to secure patent protection for innovations relating to diagnostics in an important market, such as the US, can make it difficult to secure investment to develop these tests.
On a positive note, there is now some movement in the US to overturn the current case law relating to diagnostic methods, although this would need to come either through the Supreme Court or new legislation. Given the time-frame involved in developing diagnostic tests, innovators must hope that prudent investors will continue to recognise the value in investing early in the development process, the potential returns available and the possibility that changes to the law in the US, and the existing law in other countries, such as in Europe, will allow their investments to be safe-guarded by protecting diagnostic inventions through IP.
As for my own eyesight, it would seem that my extended years in education may have had a detrimental effect – the same Cardiff and Bristol team has shown previously that every year of education increases the risk of developing short-sightedness. Clearly I should have spent more time outdoors as a child, which is the current recommendation for children at risk of myopia. Maybe I should send my own children to an outdoor school…just in case.
"A genetic test can be carried out at any age, so a test like this - for a high risk of myopia - could give children who are likely to become very short-sighted a head start if carried out when they are young and if there are effective suitable treatments." Prof Jeremy Guggenheim, from Cardiff University's School of Optometry and Vision Sciences, said: "Knowing a child is at high risk would help parents and clinicians decide if treatment should be started."