Fight for Sight PhD students tackle the silent thief of sight
Developing new tests for detecting and monitoring glaucoma and understanding the condition in it rare and most common forms
National Glaucoma Awareness week 2016, runs from 6 – 12 June. Glaucoma is a major cause of blindness worldwide, second only to cataract. Sight lost to glaucoma cannot be recovered, so research to understand, treat and prevent the condition is vital.
Fight for Sight has added 4 new PhD studentship projects to our strong glaucoma research programme. They start with the academic year this October. Here’s what they’re about.
Unblocking the drain to lower eye pressure
High pressure in the eye is an important risk factor for primary open-angle glaucoma – the most common form of the condition. High intraocular pressure happens when it becomes harder than usual for the fluid that fills the eye (aqueous humour) to drain away. In a healthy eye there is a balance between the rate at which the eye makes and drains the fluid.
When intraocular pressure is high, it can damage the optic nerve. This is the specialised cable that send visual information from eye to brain.
Current treatments for glaucoma target high eye pressure, but this is not the root cause that can lead to damage. So in this project, Professor Colin Willoughby is leading research at the University of Liverpool to try to improve the eye’s drainage system so that high pressure doesn't happen in the first place.
A patient-friendly test of useful vision in moderate and advanced glaucoma
Standard tests used in UK clinics to measure how much of the world people with glaucoma can see (their ‘visual field’) were designed for people in the condition’s early stages. They don’t work as well for people who have already had significant sight loss and their results can vary a lot. This makes it hard to monitor how well treatment is working.
In a study at Plymouth University, Professor Paul Artes and team aim to develop a test that’s more patient-friendly. Current tests can’t give much information about the peripheral (side) vision that’s useful for day-to-day tasks and may be frustrating if the test points keep falling inside patient’s blind spots.
The team will build a computer programme designed to work out the most useful and reliable test measures. They will then see how the results match up to people’s ability to get around in their everyday living.
The genetics of a rare form of glaucoma that affects younger men
Pigmentary glaucoma is a rare form of the condition in which the optic nerve is damaged by high pressure in the eye that’s due to scattered pigment from the iris. Scattered pigment blocks the eye and prevents aqueous humour from draining away.
Professor Chris Hammond and team at Kings College London will be looking for any genetic variations in people’s DNA that are linked to pigmentary glaucoma and whether there are any genetic links to other common eye conditions. Although we don’t yet know the cause, the fact that pigmentary glaucoma runs in families points to it being largely genetic. The team wants to identify the genes that can alter the risk of developing the condition.
There are no symptoms in the early stages of pigmentary glaucoma and so it is often diagnosed after permanent damage has been done. Results from the project could lead to earlier diagnosis, before sight loss occurs.
Imaging changes in the visual brain in people with glaucoma
Glaucoma is sometimes called the silent thief of sight because it can be hard to notice that your field of view is shrinking until the conditon is quite advanced. This is because people with glaucoma see blurred patches or details missing from a whole image rather than their vision becoming full of dark spots. In turn this could be because perts of the brain that process vision are compensating for the eye by ‘filling in’ the scene.
Dr Tony Redmond and team at Cardiff University have found that nerve cells in the visual brain might reorganise themselves in response to damage in the eye. If so, this could be the brain’s way of making the most of the vision that is left. So in the project the team will study this in more detail, in people with and without glaucoma. Results from the project may lead to a better way to pick up glaucoma early if there are changes that can be measured in the brain that are a closer match to the actual amount of sight loss.