Posted November 29, 2018 07:24:20For decades, scientists have been using a mathematical formula to predict how much damage to the retina can occur during a winter storm.
It’s called the “radial eye deficit” or RAD.
But scientists are not sure what causes this problem.
Now a new study by University of Queensland researchers has suggested it’s due to changes in the structure of the retina, which can cause damage to its surface and can increase the risk of eye problems.
The RAD is caused by the accumulation of damage to a material called vitreous, which is the fluid that surrounds the retina.
As the fluid changes, it’s constantly absorbing more light.
“The amount of light in the vitreos is increasing, and that increases the surface area of the vitres [the inner layer of the lens],” says Dr Jennifer Biermann, from the Queensland University of Technology’s Department of Ophthalmology and Vascular Biology.
“That increases the chance that there will be a damage to these cells.”
Dr Bierman and her colleagues found that during a storm, when the temperature is between -2C and +2C (-4C to -10C), the surface of the eye is less than 3 per cent of normal.
This results in a layer of fluid called vitriculitis.
“We found that the RAD was much more common in the winter and in conditions of low moisture, such as during the monsoon,” Dr Biermans said.
“This is a good example of why people are more likely than not to lose their sight if they have RADs, because they can see less than their normal vision.”
The researchers used a new technique called the radial occlusion technique, which uses lasers to “influence” the lens of a macaque’s eye.
This allows them to measure the amount of surface area in the retina in the centre of the image, compared with a normal area.
“It’s really important to understand the mechanism behind what causes the RADs,” Dr Jennifer said.
“The main problem we have is the damage to this vitreo [the outer layer of a lens], and it’s not clear how this damage is repaired.”
It’s not just vitreas that can be damaged.
Other macaques have been found to have different types of damage, and some have developed eye conditions such as vitiligo, which affects the lens itself.
Dr Biersman said the findings were important because they could lead to new therapies for RADs.
“There’s no cure for RAD,” she said.
But this study suggests there’s an opportunity for better treatment, because a number of macaques in this study showed improvements in eye function, including the ability to distinguish colours and see in low light.
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