Link found between blue light and age-related macular degeneration
- Author:Ella Cai
- Release on:2018-08-10
“We are being exposed to blue light continuously, and it’s no secret that blue light harms our vision by damaging the eye’s retina,” said University of Toledo researcher Dr Ajith Karunarathne (pictured). “Our experiments explain how this happens, and we hope this leads to therapies that slow macular degeneration.”
The mechanism identified involves a vitamin A related chemical called ‘retinal’ (aka retinaldehyde, retinene, vitamin A aldehyde).
“You need a continuous supply of retinal molecules if you want to see,” said Karunarathne. “Photoreceptors are useless without retinal, which is produced in the eye.”
The finding is that blue light exposure causes retinal to trigger reactions that generate poisonous molecules in the eye’s photoreceptor cells.
“If you shine blue light on retinal, the retinal kills photoreceptor cells as the signalling molecule on the membrane dissolves,” said researcher Kasun Ratnayake. “Photoreceptor cells do not regenerate in the eye. When they’re dead, they’re dead for good.”
When retinal was introduced to other cell types in the body – such as cancer cells, heart cells and neurons, said the University – the cells died when exposed to blue light. However, there was no effect on the cells when exposed to blue light alone or retinal alone.
“No activity is sparked with green, yellow or red light,” said Karunarathne. “The retinal-generated toxicity by blue light is universal. It can kill any cell type.”
A vitamin E derivative called alpha tocopherol stops the cells from dying. “However, as a person ages or the immune system is suppressed, people lose the ability to fight against the attack by retinal and blue light,” said the University. “That is when the real damage occurs,” added Karunarathne.
Are screens having an effect?
The University is measuring light coming from televisions, phones and tablet screens to get a better understanding of how the eye cells respond.
“If you look at the amount of light coming out of your phone, it’s not great but it seems tolerable,” said Toledo researcher Dr John Payton. “Some phone companies are adding blue-light filters to the screens, and I think that is a good idea.”
To protect your eyes from blue light, Karunarathne advises, wear sunglasses that can filter both UV and blue light outside, and avoid looking at phones or tablets in the dark.
The work is published in Nature Scientific Reports as ‘Blue light excited retinal intercepts cellular signaling‘ – available in full on that link.
The mechanism identified involves a vitamin A related chemical called ‘retinal’ (aka retinaldehyde, retinene, vitamin A aldehyde).
“You need a continuous supply of retinal molecules if you want to see,” said Karunarathne. “Photoreceptors are useless without retinal, which is produced in the eye.”
The finding is that blue light exposure causes retinal to trigger reactions that generate poisonous molecules in the eye’s photoreceptor cells.
“If you shine blue light on retinal, the retinal kills photoreceptor cells as the signalling molecule on the membrane dissolves,” said researcher Kasun Ratnayake. “Photoreceptor cells do not regenerate in the eye. When they’re dead, they’re dead for good.”
When retinal was introduced to other cell types in the body – such as cancer cells, heart cells and neurons, said the University – the cells died when exposed to blue light. However, there was no effect on the cells when exposed to blue light alone or retinal alone.
“No activity is sparked with green, yellow or red light,” said Karunarathne. “The retinal-generated toxicity by blue light is universal. It can kill any cell type.”
A vitamin E derivative called alpha tocopherol stops the cells from dying. “However, as a person ages or the immune system is suppressed, people lose the ability to fight against the attack by retinal and blue light,” said the University. “That is when the real damage occurs,” added Karunarathne.
Are screens having an effect?
The University is measuring light coming from televisions, phones and tablet screens to get a better understanding of how the eye cells respond.
“If you look at the amount of light coming out of your phone, it’s not great but it seems tolerable,” said Toledo researcher Dr John Payton. “Some phone companies are adding blue-light filters to the screens, and I think that is a good idea.”
To protect your eyes from blue light, Karunarathne advises, wear sunglasses that can filter both UV and blue light outside, and avoid looking at phones or tablets in the dark.
The work is published in Nature Scientific Reports as ‘Blue light excited retinal intercepts cellular signaling‘ – available in full on that link.
