Staring at a deep red light for three minutes a day
can significantly improve declining eyesight, finds a new UCL-led study, the
first of its kind in humans.
Scientists believe the
discovery, published in the Journals of Gerontology,
could signal the dawn of new affordable home-based eye therapies, helping the
millions of people globally with naturally declining vision.
In the UK there are currently around 12 million people
aged over 65: in 50 years this will increase to around 20 million and all will
have some degree of visual decline because of retinal ageing.
Lead author, Professor Glen Jeffery (UCL Institute of
Ophthalmology) said: “As you age your visual system declines significantly,
particularly once over 40.
“Your retinal sensitivity and your colour vision are
both gradually undermined, and with an ageing population, this is an
increasingly important issue.
“To try to stem or reverse this decline, we sought to
reboot the retina’s ageing cells with short bursts of longwave light.”
In humans around 40 years-old, cells in the eye’s retina
begin to age, and the pace of this ageing is caused, in part, when the cell’s
mitochondria, whose role is to produce energy (known as ATP) and boost cell
function, also start to decline.
Mitochondrial density is greatest in the retina’s
photoreceptor cells, which have high energy demands. As a result, the retina
ages faster than other organs, with a 70% ATP reduction over life, causing a
significant decline in photoreceptor function as they lack the energy to
perform their normal role.
Researchers built on their previous findings in mice,
bumblebees and fruit flies, which all found significant improvements in the
function of the retina’s photoreceptors when their eyes were exposed to 670
nanometre (long wavelength) deep red light.
“Mitochondria have specific light absorbance
characteristics influencing their performance: longer wavelengths spanning 650
to 1000nm are absorbed and improve mitochondrial performance to increase energy
production,” said Professor Jeffery.
The retina’s photoreceptor population is formed of
cones, which mediate colour vision and rods, which provide peripheral vision
and adapt vision in low/dim light.
For the study, 24 people (12 male, 12 female), aged
between 28 and 72, who had no ocular disease, were recruited. All participants’
eyes were tested for the sensitivity of their rods and cones at the start of
the study. Rod sensitivity was measured in dark adapted eyes (with pupils
dilated) by asking participants to detect dim light signals in the dark, and
cone function was tested by subjects identifying coloured letters that had very
low contrast and appeared increasingly blurred, a process called colour
contrast.
All participants were then given a small LED torch to
take home and were asked to look into its deep red 670nm light beam for three
minutes a day for two weeks. They were then re-tested for their rod and cone
sensitivity
Results
Researchers found the 670nm light had no impact in
younger individuals, but in those around 40 years and over, significant
improvements were obtained.
Cone colour contrast sensitivity (the ability to
detect colours) improved by up to 20% in some people aged around 40 and over.
Improvements were more significant in the blue part of the colour spectrum that
is more vulnerable in ageing.
Rod sensitivity (the ability to see in low light) also
improved significantly in those aged around 40 and over, though less than
colour contrast.
Professor Jeffery said: “Our study shows that it is
possible to significantly improve vision that has declined in aged individuals
using simple brief exposures to light wavelengths that recharge the energy
system that has declined in the retina cells, rather like re-charging a
battery.
“The technology is simple and very safe, using a deep
red light of a specific wavelength, that is absorbed by mitochondria in the
retina that supply energy for cellular function.
“Our devices cost about £12 to make, so the technology
is highly accessible to members of the public.”
Journal article: https://academic.oup.com/biomedgerontology/article-abstract/doi/10.1093/gerona/glaa155/5863431?redirectedFrom=fulltext
Source: https://myfusimotors.com/2020/07/07/declining-eyesight-improved-by-looking-at-deep-red-light/
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