Tackling Dementia with AI Powered Eye Care
around 200 years ago
london became the largest city in the
world this was an exciting time
the first railways were introduced the
national gallery was built
and the city established itself as a
global hub of trade
however it was a place tormented by
frequent epidemics
some of these were well recognized
infections of the day
like smallpox or cholera but one of them
had doctors scratching their heads
hundreds of patients were being admitted
with unexplained headaches
vomiting seizures and swelling of the
legs
some of them strangely were also going
blind
often hours before their death now it
might surprise you to hear
that the culprit of this was no
infection
rather it was something that we couldn’t
yet detect
but affect many of us to some extent
today
high blood pressure what dr richard
bright revealed to us
in these descriptions was perhaps one of
the earliest hints
that the eyes could harbor diseases
outside of the eyes
the problem was that technology hadn’t
kept up with scientific understanding
and we had to wait several decades
before the invention of
this the ophthalmoscope when we could
reliably distinguish what was causing
vision loss in these patients
so if you were to look at the back of my
eye the retina
this is what you’d see a circular pink
structure
of the optic nerve from which emanate
the major blood vessels of the retina
what might richard bright have seen if
he was able to examine his patients eyes
well probably something like this now on
first glance
these images might appear quite similar
but look closer
and you’ll notice red blots suggestive
of bleeding
fluffy yellow areas indicating swelling
or blocked nerves and severe cases
a lack of clarity of the border of the
optic nerve
suggestive of swelling of the brain fast
forward almost 200 years
and we know that our eyes show much more
than just the state of our blood
pressure
changes in the retina can reflect a
multitude of diseases
from common conditions like diabetes
to uncommon infections like tuberculosis
in fact you’d be hard-pressed to think
of a chronic disease
that doesn’t have a manifestation
somewhere within the eye
now it doesn’t take an expert to look at
these two images
and realize that they’re different but
not all
changes are as clearly discernible to us
what if i were to instead show you
another pair
of seemingly normal images but tell you
that one of these patients
will develop a stroke within the next
three years and that this prediction can
be made through the eye
it’s unlikely that any of us would be
much more accurate than tossing a coin
one option for identifying structures
that may not be obvious to us
is deep learning a subfield of
artificial intelligence
where patterns are discovered using
large datasets
with this tool we’ve realized that
images of the retina don’t just tell us
about disease
they can tell us about ourselves
in the last few years we’ve seen that
eyes can show
our age our sex whether we smoke
whether we’re anemic and give us an
indication of our risk of future events
like heart attack or stroke all from the
single picture
of the back of the eye now the focus on
heart attack and stroke is deliberate
collectively these so-called
cardiovascular diseases
are the leading cause of mortality
worldwide
but many of us will have personal
experience of a new villain
that has emerged as the number one cause
of death in the united kingdom
and that is dementia dementia is rising
at an alarming rate
in the context of the aging population
and even more concerning is that it’s
estimated
that around 50 percent of cases are
undiagnosed globally
so it’s important that we develop
effective strategies
for identifying those at risk modern
scanning technology
has not only redefined how we treat eye
diseases
but they’ve helped further our
understanding of the links
between the eye and the brain
the retina is derived from the same
tissue as the brain
and the circuitry connecting the two
means that changes in one
are often reflected in the other for
example
one landmark study from the netherlands
showed that thinner nerves
were found in the retinas of people with
dementia
and also several years before developing
any symptoms of it they were able to
show this with less than 100 patients
but applying deep learning to this
problem requires much larger data sets
and that’s why we spent the last couple
years at moorefields
the largest eye hospital in europe and
north america
linking our retinal scans with national
hospital admissions data our outside
cohort comprises more than
5 million retinal scans and
15 000 patients in our cohort have
developed dementia
the prospect of eye scans for dementia
screening is attractive
given the challenge of diagnosis this
typically relies on symptoms
which are a late manifestation of the
disease
all the concerns of a friend or family
member
and awareness is only the beginning
along this arduous path
individuals first need to consult their
general practitioner
complete a non-specific questionnaire
be referred to a specialist and have
blood tests to rule out
secondary causes of dementia finally
they need to undergo scans
which are often expensive time consuming
and potentially invasive all before
revisiting their specialist
to discuss the results all this
invariably leads to frustration
and anxiety but high resolution eye
scanning technology
can show us even subtler changes with
microscope-like resolution
in a non-invasive risk-free approach
that takes seconds to acquire
and much like the field of genetics
where sequencing a person’s genome
is a fraction of the cost it was 10
years ago
each season sees greater affordability
in retinal scanning technology to put
this into perspective
at more fields we did around 25 000 eye
scans
in the 12 months of 2008 we now do more
than that
each month and this technology isn’t
just limited
to the hospital or clinic it’s
increasingly available in the community
for example specsavers one of the
world’s largest optician businesses
now has high resolution scanning in
nearly 700 of its branches in the united
kingdom
but if eye scans are a potential
solution
how do we actively encourage the public
to consider having them
well vision is precious surveys
consistently show that we treasure our
sight
above any other sense some
are even willing to trade five years of
life
to remain with their sight intact and
this is not just an opinion
this powerful sentiment translates into
our health-seeking behavior
and here’s an example when you turn 40
chances are that you’ll be invited to a
general health check
where among other things your risk of
having a heart attack or stroke
will be estimated but how many of us
actually take that up
between 2009 and 2013
in the united kingdom it was around nine
percent
but what if we consider a similar age
group
similar time but instead rephrase the
question
how many do you think reports seeing
their optometrist at least
every four years a very telling
80 percent the current landscape of
community healthcare
and technological development has us at
an exciting crossroads
and not just in europe and north america
but low and middle-income countries
are also undergoing infrastructural
transformation
with the introduction of affordable eye
scanning technology
and regional eye health programs some of
these scans can even be taken
using your standard smartphone by
combining our understanding
of how the eyes change in systemic
diseases
with artificial intelligence the growing
availability of eye scanning technology
and our natural concern for our vision
we can democratize
access to a comprehensive health
evaluation
not through a visit to your primary care
doctor
blood tests or a long wait for that
hospital mri scan
but through a single picture taken in
the blink of an eye
you