Visionary science

 

Our eyes are not just windows into the soul, they are also windows onto the world. Of all the senses, sight arguably gives us the most mastery over our environment, helping us to connect with the people and landscapes that surround us.

And so, for those who suffer from vision impairment, sight loss can have far-reaching consequences. There are many different types of sight loss and symptoms range in severity, from mild blurring or blank spots to total blindness. There are many possible causes, but some of the most common are glaucoma, cataracts and deterioration related to age or diabetes.
 
According to the Royal National Institute of Blind People (RNIB), around two million people in the UK suffer from sight loss: that’s 1 person in 30. And vision impairment is not just practically debilitating, it also can also have a profound impact on sufferers’ mental health, personal relationships and ability to find employment. Many cases can already be improved by medical interventions – but for those cases that are harder to treat, scientists are working to uncover more about the sub-microscopic mechanisms that can damage our sight.
 
Thanks to modern technology we can now study the structure and composition of the eye in more detail than ever before: and this is heralding a swathe of new research into sight loss.
On one of Diamond’s crystallography beamlines, I02, scientists are creating a map of the tiny fibres that make up the eyeball’s protective outer coating. As small as they are, these fibres may be a trigger for glaucoma, and studying them could provide new medical clues.
 

The basic architecture of our eyes is created by a structural protein called collagen. The most abundant protein in our body, collagen is essentially the glue that holds us together – that’s why it’s so popular as a tool for cosmetic surgery: it gives the skin strength – helpful if you want to prevent wrinkles.

But collagen has a much more important purpose, particularly when it comes to our eyes: it determines the shape and resilience of our eyeballs. Because of the pull of the muscles that move our eyes and internal pressure from the fluid that fills our eyeballs, our eyes are under continuously changing forces.

The millions of tiny collagen fibres that make up the eyeball coating must all be aligned in just the right direction to provide the necessary strength and support. But if these fibres become misaligned then it can cause real problems. The eyeball may not be able to function correctly, meaning that it can weaken and even change its shape. This can lead to a range of issues, including myopia: an inability to focus on distant objects. Scientists also believe that poor collagen fibre alignment may lead to glaucoma, and they’re using Diamond to investigate.
 
Supported by Diamond’s Professor Thomas Sorensen and his team, Dr Craig Boote and Professor Keith Meek from Cardiff University are leading the search for links between the eye's collagen fibres and glaucoma.
 
 

 Thomas Sorensen, Principal Beamline Scientist on I02

  

More than 500,000 people in the UK suffer from glaucoma, and we’re still not completely sure what’s behind it. It’s often caused by a build-up of pressure in the eye, and this can be addressed with eye drops and surgery. But some people develop glaucoma symptoms at normal eye pressure – and this makes things more complicated.
 
But as Craig explains, the Cardiff group have a theory about what could be behind these mysterious glaucoma cases: “We believe that misaligned collagen fibres could be causing the back of the eye to weaken and lose its ability to protect the optic nerve, leaving the eye more susceptible to developing glaucoma. Usually the collagen around the optic nerve would prevent this from happening, but if the fibres are misaligned, the nerve simply doesn’t have the support it needs”.
 
By scrutinising the orientation of these minute fibres, the team hope to identify a causal link between collagen misalignment and glaucoma. If their hunch is right, this early-stage work could ultimately help to generate specialised treatments based on enhancing collagen structure within patients’ eyes.
Our sight is so much more than the basic reality of what we see: it’s fundamental to how we experience the world. Sight loss can be devastating, but scientists like Thomas, Craig and Keith are committed to uncovering why these conditions develop and what can be done to prevent them.
 
This is vital work. Every move towards better understanding the workings of the eye is a step forward in the fight against sight loss. And, in time, millions of people around the world will enjoy better sight thanks to scientists’ vision.
 
 

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