Identifying genetic risk factors for myopia and retinal detachment
- Grant holder: Dr Véronique Vitart,Group Leader, MRC Human Genetics Unit and MRC Institute of Genetics & Molecular Medicine
- Institution: University of Edinburgh
- Grant award: £70,000
- Start date: July 2019
- End date: March 2021
Why is this research needed?
Retinal detachment is a serious, and common, sight-threatening condition. It happens when the retina – the light-sensitive layer of tissue at the back of the eye – is pulled away from its normal position. The most common causes of retinal detachment are aging or injury, but some eye conditions, including diabetic retinopathy and extreme short-sightedness (myopia), can also increase the risk of this condition.
Myopia occurs when the eyeball grows too long during childhood. The longer shape of the eyeball means that, as light enters the eye, instead of focusing on the retina at the back of the eye, it focuses in front of it, causing blurred vision. In people with severe or “high myopia”, the eyeball becomes very long from front to back, not only making it hard to see at a distance, but increasing the risk of eye conditions such as retinal detachment, cataracts, and glaucoma.
What is the aim of the project?
Dr Vitart’s team at the University of Edinburgh were the first to discover that certain genetic mutations associated with myopia, in particular those within and close to a gene called BMP3, increase the risk of retinal detachment. As the protein produced by BMP3 stimulates cell growth, their theory is that BMP3 affects the growth of the eyeball. The aim of this project is to better understand the role of BPM3 within the eye, in the hope that the knowledge could point the way towards new treatments for retinal detachment.
Using cells grown in the laboratory, the team will seek to establish which of the genetic mutations in BMP3 are significant in influencing myopia, and what effects they have. Using a process called gene editing, the team will replicate the same genetic mutations found in patients within their own cell cultures, and will measure the effects on the function of the cells in their model.
The team has also observed that genetic mutations around two other genes – BMP2 and BMP4 – are associated with short-sightedness and could indicate a risk of increased retinal detachment. These two genes are involved in retinal development, and they are also known to block the function of the gene BMP3 within bone, but their relationship to BMP3 within the eye has not been examined.
An important part of drug development is understanding the pathways – or series of chemical reactions – that happen within cells. Identifying what genes, proteins, and other molecules are involved in a biological pathway is fundamental to understanding the causes of disease and how they might be treated or prevented. Drugs already exist that can modify the BMP pathway, but BMP genes are involved in many other diseases and processes, and so a better understanding of their role within the eye is needed to inform the development of therapies that could help to treat severe myopia and retinal detachment.
How will this research help to beat sight loss faster?
Myopia is becoming more prevalent across the globe. If current trends continue, over the half the world’s population will be myopic by 2050, and one tenth will have high myopia, which carries and increased risk of developing sight-threatening conditions, such as cataracts or myopic macular degeneration.
In the UK, the incidence of myopia in children has more than doubled over the last few decades, and now stands at 20%. In furthering our understanding of the underlying biology of myopia, this project will help to point the way towards new and more effective drug therapies that could be used to treat the condition and stop its severe complications.
Professor Jeremy Guggenheim at the University of Cardiff led another research project, funded by Sight Research UK, that explored the interaction between genetic and environmental risk factors for myopia. You can read about what he discovered here. We are also supporting Dr Denize Atan at the University of Bristol, which is examining the effect of insulin in the body on myopia, and how that relationship is further influenced by environmental and genetic factors.
Not everyone who is severely short-sighted will develop other eye conditions, and for most people, their eyes will be healthy. The best way for everyone to look after their eyes is to have regular eye tests. An optician can spot early signs of eye conditions before you experience any symptoms, many of which can be treated if detected early enough. You can read about what’s involved in having an eye test here.
You can find more about the causes and symptoms of myopia and pathological myopia here.
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