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