Page 26 - The Indian Optician Digital Edition May-June 2023

SCIENTISTS were fed omega-3 supplements such as fish oil and krill oil, did not
DEVELOP
NEW OMEGA-3
SUPPLEMENT
Blindness that can result due
to Alzheimer’s disease can now
be prevented with the help of a
new omega-3 supplement that
can cross the retina.
This is the first time such
a fatty acid supplement has
been developed. The research,
presented at the annual meeting
of the American Society for
Biochemistry and Molecular
Biology in Seattle, USA, revealed
that the new dietary supplement
was adept at overcoming both
intestinal and blood retinal
barriers to improve retinal
function.
Speaking on the occasion, Dr
Sugasini Dhavaman, research
assistant professor at the
University of Illinois at Chicago,
said that the supplement
could prove to be beneficial for
various forms of retinopathy in
patients. “This provides a novel
therapeutic approach for the
prevention or mitigation of
retinal dysfunction associated
with Alzheimer’s disease and
diabetes,” said Dr Dhavaman.
The omega-3 fatty acid
docosahexaenoic acid
(DHA) levels were tested in
mouse models of early-onset
Alzheimer’s disease who were
given the supplement daily. The
study results revealed that the
mice who got the supplement
showed 96% improvement
in retinal DHA content after a
period of six months. Others who
22 | THE INDIAN OPTICIAN | MAY-JUNE 2023
experience a change in their retinal DHA levels.
More studies are required to confirm that the new supplement is
equally safe and effective for humans.
LAB-GROWN RETINAL CELLS SET
FOR HUMAN TRIALS
Since the last ten years, researchers from the University
of Wisconsin-Madison have been working on the theory that
retinal cells grown from stem cells can reach out to connect with
neighbouring cells in a unique “handshake.” Such a happening
would mean that the cells are ready for trials in humans with
degenerative eye disorders.
The UW–Madison researchers developed a way to grow organised
clusters of cells, called organoids that resemble the retina, the light-
sensitive tissue at the back of the eye, about a decade back. “We
wanted to use the cells from those organoids as replacement parts
for the same types of cells that have been lost in the course of retinal
diseases. But after being grown in a laboratory dish for months as
compact clusters, the question remained — will the cells behave
appropriately after we tease them apart? Because that is key to
introducing them into a patient’s eye,” said Professor David Gamm
from the UW–Madison’s McPherson Eye Research Institute.
In order to confirm that their lab-grown retinal cells had the
capacity to replace diseased cells and carry sensory information
like healthy ones, the researchers wanted to show that they could
make synapses. Professor Xinyu Zhao, UW–Madison professor
of neuroscience and co-author of the new study, worked with
the Gamm lab’s cells to help study their ability to form synaptic
connections. This was done with the help of a modified rabies virus
to identify pairs of cells that could form the means to communicate
with each other.
The retinal organoids were broken into individual cells, and then
left for a week to enable them to extend their axons and make new
connections, following which they were exposed to the virus. The
end result was that many retinal cells were marked by a fluorescent
colour indicating a rabies infection had infected one across a synapse
successfully formed between neighbours.
Once they established the presence of synaptic connections, the
researchers analysed the cells involved and found that the most
common retinal cell types forming synapses were photoreceptors –
rods and cones – which are lost in diseases like retinitis pigmentosa
and age-related macular degeneration.
“That was an important revelation for us. It really shows the
potentially broad impact these retinal organoids could have,”
summed by Prof Gamm.
OPHTHALMIC NEWS