April 4, 2024 • 27 mins
As excitement grows regarding the upcoming solar eclipse, anxiety is also increasing amongst patients. How should we be counseling concerned patients regarding the solar eclipse and what precautions they should be taking to protect their eyes? Dr. Tina Felfeli joins the podcast.
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Episode Transcript
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(00:11):
Hey everybody, I'm Zael Mednick andwelcome to a special combined episode of Preconceived
and blind Spot. So, forthose of you who don't know, and
there's no reason you would know,I've run two podcasts. I've run Preconceived
for the past five years, butmy day job is as an ophthalmologist,
and I figured last year I mightas well blend my two interests of podcasting
and ophthalmology, and I also startedan ophthalmology podcast. And for those who
(00:33):
don't know what an opthalmologist is,that's an eye doctor. So today's topic
is going to be on the solareclipse. So for those of you listeners
to blind Spot, I thought thiswould be a relevant topic because we've got
a lot of patients asking us what'sgoing on with this solar eclipse? What
do I need to be aware of, what exactly is a solar eclipse?
How can I damage my eye?What do I need to do to prevent
(00:54):
it? And then for my Preconceivedlisteners, I thought this would be an
area of interest too, because you'reall in theory the patients who might be
coming in with questions about what isthe solar eclipse? And it was a
chance to a rare chance to usemy ophthalmology knowledge on Preconceived. So thank
you to listeners of Preconceived and BlindSpot for tuning into this episode to chat
(01:15):
about the solar eclipse. I'm recordingthis episode on Wednesday night, April third,
and the solar eclipse is scheduled tohappen on April eighth, and I'm
going to be speaking with an ophthalmologisttoday who's going to walk us through what
exactly the solar eclipse is, whyit can cause retinal damage, eye damage,
what we need to watch out for, what we should be counseling people
(01:38):
as people, what you should beaware of. Have things gone a little
bit too far in terms of shuttingdown schools and people not going to work.
What is all of the truth behindsome of the noise that's out there.
So I am joined today by doctorTinflfelli. She is a resident physician
in the Department of Ophthalmology and VisionSciences at University of Toronto. She completed
her medical school training at University ofwhere she received the JP Bully Prize and
(02:01):
Optomology for the highest academic standing inher graduating class. She recently completed a
PhD degree in Clinical Epidemiology at theInstitute of Health Policy, Management and Evaluation
as part of the Integrated Physician Scientistprogram. Amongst her many achievements, she
is a Vanyard Scholar, which isawarded by the Government of Canada to world
class doctoral students. She has alsobeen awarded the Fighting Blindness Canada Clinician Scientist
(02:24):
Emerging Leaders Award. She's the authorof the Toronto Guide to Clinical Ophthalmology,
which is a textbook used in theophthalmology curriculum for medical students at University of
Toronto. She has an impressive researchand publication record with several first author journal
publications. She's presented her research atnumerous national and international conferences. Her research
interests include population based studies, economicevaluations and prediction models for outcomes of surgical
(02:49):
retinal disease and uveitis, the evaluationof healthcare delivery within the fields of ophthalmology.
Doctor Tina f f Elli, Welcometo the podcast. Thank you so
much for joining me. Thank youdoctor for organizing this wonderful podcast that's beneficial
to both ophimologists but also patients.And we're inviting me to speak about an
exciting event that's coming up that mostpeople are talking about these days. But
(03:15):
my pleasure, the pleasure is allmine. I'm laughing because you called me
doctor Mednick. And as I saidat the beginning, I've never recorded a
joint podcast for blind Spot and Preconceived, and I'm preconceived. I don't think
anybody's even called me that, evenin blind Spot. So we'll go with
zeal and Tina. So I'm I'mreally excited to record this because, like
I said, I haven't done anepisode for both podcasts because it's rare that
(03:35):
these two worlds would blend. Buton the one hand, the audience of
Preconceived, it's kind of like thepatients who are wondering what do I need
to know about the solar eclipse?And the audience for blind Spot is the
people who are telling the patients whatyou need to know about the solar eclipse.
I myself am more naive about thistopic than I should be. Perhaps
I don't know tons about it otherthan some basic stuff, I guess.
(03:59):
So we're going to dial it backfrom the beginning and we're just gonna start
off with Tina, what is asolar eclipse? Basically? Without getting too
much into the physics of it.Yeah, great, Yeah, So the
solar eclipse usually occurs when the Sun, the Moon, and the Earth and
the most kind of basic senses lineup, and this can be either fully
or partially and that's what refers tothe partial eclipse, or it's a total
(04:25):
solar eclipse. And so, dependinghow they align, these eclipses can provide
a very unique and exciting view ofeither the Sun and the Moon, and
in parts of the world, basedon your geographic location, as the Moon
passes between the Sun and the Earth, it can create a shadow on the
Earth that's either again fully or partiallyand can actually result in full blockage of
(04:50):
the sunlight. And in midday itcan appear as night because all of the
sun rays are fully blocked, andso it's quite extra ordinary experience. It
doesn't happen very often. The lasttotal eclipse that we had in Canada was
actually all the way back in nineteenseventy nine, and so and the next
(05:11):
one that's expected to take place isthe next partial eclipse in Toronto. It's
going to be in twenty twenty nine, and total solar eclipses in Toronto is
expected to be in twenty one fortyfour, and so we'll be very dead
by then. Hopefully the podcasts aregoing on by then. But you know,
(05:33):
a lot of people are super excitedabout this because it's a rare event,
and there's a lot of talk aboutit. Sools are being canceled,
things are being scheduled around this.There's a lot of tourism happening. Even
prices and nicer Falls hotels have goneup because it's one of the best places
to view this. So there's alot it's surrounding this kind of eight pri
eighth total solar eclipse that's coming up, and so of course with that,
(05:56):
there's a lot of questions about safetyand how do we protect our eyes during
this kind of extraordinary event that's aboutto take place. Wow, so I
didn't realize how rare that was.So this is pretty exciting, and as
you said, obviously a lot ofpeople are tuning into this because they're excited,
but they're also concerned about their eyes. My understanding, and please correct
me if I'm wrong, and I'msure I'm missing part of the picture here.
(06:19):
My understanding is that because the moonis going to be blocking the sun,
you look at it and you thinkWow, that's really cool. But
usually when you look at the sun, you have a reflex where you look
away because it's too bright for youto look at the sun. But if
the moon is blocking it, you'renot necessarily going to have that same reflex
to look away because your eyes aren'tin pain from looking at the sun.
(06:42):
Kind of like putting your hand ona stove but not realizing that it's hot,
and then if you were to takeyour hand off, your hand's burnt.
Same way that you could sustain retinaldamage retinas at the back of the
eye if you're looking at the sunfor too long when it's not painful.
Is that the gist of it.Yeah, And that's actually for the most
part, I would say it's correct. So, you know, some people
(07:04):
mistakenly believe that if you look ata total solar eclipse, which is going
to happen on April eighth, thatit's safe because the moon is completely blocking
the sunlight. And so most peopleunderstand that looking directly on the sun it's
not safe. You year round,we were youv blocking sunglasses to protect your
eyes from the damage from UV lightthat can cause retinal damage, and some
(07:29):
of that can be permanent and soon this kind of particular event. You
know, people believe that because thesun rays or completely blocked, that it's
safe to actually look at the solarclips. But that's not true. And
the reason for that is that ittotal solar eclips, meaning the light rays
from the Sun being completely blocked bythe moon. It's actually very very short
(07:53):
lived. It's only about ninety seconds, and it can be even shorter depending
on your geographic location. In certainareas they actually have get a total solar
eclipse. And so unless someone isone hundred percent certain that they're viewing the
sun and totality of a solar eclipse, and this totality of an eclipse is
a very short lived phenomenon, you'realways at risk of damaging your eyes.
(08:18):
And so the kind of safest thingto tell your patients that is that it's
never, never safe to look ata solar eclipse with a naked eye unless
you're wearing specialized eclipse glasses, whichare not your typical sunglasses. Sunglasses are
not protective looking at it indirectly throughyour phone or through a telescope or any
(08:41):
sort of other binoculars that do nothave proper filters will still cause damage to
your eyes. And that's really importantto reiterate to our patients because the complications
that we worry about are solar retinopathy, which can actually be permanent damage to
the retina, and patients can havelifelongs gitomas, blurred vision, distorted vision,
(09:01):
other altered color vision, et cetera, and light sensitivity as a result
of this damage. So basically,unless you are confident, which nobody would
be, that they're viewing it inthat ninety seconds of totality when the sun
is completely blocked, the odds arewhen you're viewing the eclipse, some of
that sunlight is going to be gettingthrough. You're not going to be feeling
(09:24):
it necessarily because it is blocked toan extent. So you'll be looking at
it, but it will be causingdamage and you won't have that same Is
that is that aspect I said about, You won't have the same reflex.
Is that an appropriate way of thinkingof it? Yeah? Absolutely so some
of the you know, we wehave a hard time looking at the sun
when it's in full kind of notfully blocked. Usually most people know to
(09:46):
not look at the sun because it'svery uncomfortable. But during those kind of
few seconds where it's partially blocked,it is easier for people to look at
it, but you're still getting lotsof sun rays. They are still damaging
to the eyes. And so asmoon is continuing to move across this on
as the total eclipse is ending,the bright sunlight suddenly appears, and so
(10:07):
by the time people react or kindof have that recognition, it's already the
damage has already been caused, andso it can only take a few seconds
for the retina to be damaged.And it's been well documented in the literature
that there's a thought that there's somesort of a photochemical toxicity and thermal injury
from the short wavelength visible lights fromnear infrared radiation that happens during sun gazing,
(10:31):
and that can permanently damage the photoreceptorsand the retina and in particular the
macula, which is the central partof your vision, responsible for your kind
of refined vision. And so youcan imagine as a patient if you have
a black spot and the central partof your vision, and this can be
permanent. That could be quite troublingfor some people to have to live with
(10:52):
that, especially because we don't haveany treatment for solar retinopathy. So you
mentioned that term solar retinopathy, andophthalmologists and optometrists listening to that know what
that is, but to the generallaperson who doesn't. As you just explained,
tina, the retina at the backof the eye, that's the tissue
that is really responsible for our vision. And when light connects with the retina,
that's what's responsible for our vision.But if the light damages it,
(11:16):
especially in the macula, which isthe part that's responsible for our central vision,
as you said, that can causesomething called solar retinopathy. So you
said that can happen after just severalseconds of directly looking of directly staring at
the sun. Would somebody know rightaway that that's happened or would it take
a little bit of time typically forthe solar retinopathy, for that damage that's
(11:39):
been done to the retina to presentsymptomatically for a patient. Yeah, and
that can be That's a great question, and that can be quite variable.
So some people may notice it afteronly a few minutes or to a few
hours. For some people it maytake a little bit longer. And again
the recovery of it is also verydifferent to the degree of the effect is
also very different. There's been somesuggestion that in particular children or younger people
(12:03):
are more susceptible to it, andthere's different hypotheses. So maybe they have
you know, they're more likely tobe on supervise and look at your sung
gaze without recognizing the effects of it. And also because they have clear optics,
so they have a very clear lens, they have a very clear cornea,
and so if you think of theeye as sort of like a telescope,
(12:24):
you know, in a telescope,you have a strong lens that focuses
the light, you know, rightwhere you wanted to, so you have
that Chris clear picture, and itcreates a lot of heat as well.
At the same time, sometimes youeven use you know, lenses and light
to create a sun to create fire, right, So same as that our
(12:45):
lens also creates and focuses the lightonto the back of the eye, which
is the macula, to give usthat sharp vision. And so with kids
and children younger people, it's hypothesizedthat because they have such a clear lens,
they have such clear optics, thatthey're actually more susceptible to having lots
of sun rays causing damage and beingfocused in that central part of the vision
and causing that damage to the photoreceptors. And that makes a lot of
(13:09):
sense if you compare that to anolder person where the lens is going to
be more yellow, which we calla cataract, and light can't necessarily get
to the back of the eye aswell. Once it does get to the
back of the eye, it's notgoing to be as potent and as damaging.
If somebody does get solar retinopathy,you explain scatoma, which for those
who aren't in the field, thatjust means kind of like a blind spot
in the center of your vision.In this case, what's the typical course
(13:31):
for solar retinopathy. It's typically prettypermanent, right, Yeah, so it
has been described in various different types, so some of the symptoms can be
permanent. And unfortunately, the badnews is that there's really no definitive treatment.
Some people have advocated for use ofsystemic steroids or steroids for the treatment
(13:52):
of solar retinopathy, but really there'sno definitive treatment. And in some cases
with observation, there has been someresolution and a complete resolution, but there's
also cases where there's permanent damage thatpatients experienced in some of these black spots
or schtomas do persist lifelong. Andthat's not to scare people. It's just
(14:13):
to be honest with people that thisis this is serious stuff. Photoreceptor damage
is very tough to fix. Sothat's why there is a lot of panic
on social media and in the news. But I want to unpack that panic
a little bit because for me,I guess this is where I get a
little bit confused. And I'm sureyou can help me out with this.
(14:35):
When I hear about schools closing,I hear about people not going outside for
work, my thought is, can'tpeople just go outside and just not look
at the sun? Not look atthe eclipse. Obviously better to have the
sunglasses on, But if you're justlooking straight ahead and you're not staring at
it, that's kind of the sameas you walking around on a regular day
not staring at the sun. Isthat accurate? Yeah, you're absolutely right.
(14:58):
You know, there's there's nothing inparticular about that day where the sun
is more bright or there is morelikelihood of damage to your eyes, So
you going about your day to dayactivity is perfectly normal. I think the
biggest concern is that people are soexcited about this event, this extraordinary event,
(15:18):
and so they're more likely to bestaring at the sun and causing damage
to their eyes by looking directly atthe total solar eclipse, because this is
what people are interested in wanting tosee. And of course, you know
you don't you don't have to fullystep away from this experience or not have
the opportunity to enjoy it. There'sdefinitely safe ways of doing this, and
(15:39):
there's a lot of information that's actuallyavailable on governmental Government of Canada websites and
other websites online that are trusted trusted, such as the American Academy of Ophthalmology.
But really the most important thing isthat you shouldn't look at the solar
eclips with a naked eye, butlooking through it. To add with binoculars
or telescopes unless they have a properfilter or through a phone camera, none
(16:03):
of these are going to protect youreyes, and even sunglasses and really the
only type of things that are safeor using an eclipse glass, and these
usually have a particular standard or anISO number, which is ISO one two
three one two dash two, whichsuggests that these are regulated, regulated glasses
that are meant for the solar eclipsand they meet the standards for eye protection,
(16:30):
and so you really want to makesure that those are the type of
glasses you're using. Any sort oftinted glass won't be properly able to protect
your eyes. And unfortunately there hasbeen some recent suggestion that there are companies
that are releasing these glasses with theISO number that is that I just listed,
but they're not actually the proper typeof glasses that meet the standards.
(16:52):
So you really want to make sureyou're getting your eclipse glasses from a reliable
source and also even taking them alland putting them on, you really want
to make sure you're always looking downwhen you put your glasses on, your
eclips glasses and even taking them off, you're looking down, so you always
are avoiding that direct contact and directsun gazing to avoid any accidental exposure to
(17:15):
sun. Reason making sure again supervisingchildren to make sure that they're also keeping
their glasses on at all times,that they're down always to put them on,
and always looking down to take themoff. Other options that are actually
very interesting, and this may behard to explain over a podcast. We
can maybe include a link to this, but there are some other cool ways
(17:37):
to do this where you can actuallypoke a small hole in a kind of
thick piece of cardboard or paper,and then with your back to the solar
eclips, you can actually raise thepaper so that it's actually directly facing the
sun, and then you hold anotherpiece of cardboard where you can through that
whole of the first one view theshade and the light coming through the hole,
and you can actually see in directlyof the moon and the sun and
(18:02):
the eclipse through dad. So that'sanother cool way, and it's a way
to actually try doing with your withyour kids. It's called a solar eclipse
pinhole projector method, So it maybe a fun way to even kind of
try doing with your kids to avoidhaving them look at the solar eclips directly.
Well, that sounds fun, andthat those are great recommendations and practical
(18:22):
recommendations, And what I'm hearing thereis as long as you're cautious and following
these guidelines so to speak, andusing the protective lenswear, then you're fine.
And I wasn't trying to diminish beforethis idea of all these, Well,
maybe I am to an extent allthe hysteria that's going on. But
it's important to understand that hysteria.Walking outside and looking down, you're not
(18:45):
doing any damage. Now, ifyou think you are somebody who is not
going to be able to contain yourselfand you are going to start looking up,
then don't do that. Stay indoorsand don't go outside if you don't
think you're going to be able toprevent yourself from doing it. But if
you wear the glasses outside you shouldbe fine. And if you are outside
and you are very certain for tenseconds you need to walk outside to pick
(19:07):
up the paper, you can dothat looking down, not at the sun,
and you're not going to cause damage. That's kind of correct. Absolutely,
that's absolutely correct. And of course, you know, if someone's anxious
or you have a child that youthink you know will be harder to supervise,
there's always you know, recordings ofthis that are going to be available
on TV and YouTube. That's anotherway of doing it as well. But
(19:30):
yeah, the best way is tojust make sure you're not directly sun gazing.
My last question is I imagine alot of people after the eclipse are
going to be like, oh myGod, my eyes, they feel a
bit off right now? Should Igo to the emerge? And if somebody
after the eclipse is concerned that something'sgoing on with their vision, is there
utility can go into the emergency roomor is there really nothing to be done
(19:52):
in the acute phase. That's notto say you shouldn't see a doctor,
but in terms of that fear youneed to see should people be rushing to
the emergency room if they are worriedthat they did do something improper and they're
noticing that something's off with their vision. Yeah, so I think I would
say unfortunately, because there's no treatmentfor solar retinopathy, that's the unfortunate part.
(20:17):
But if you're having symptoms in yourvision, you really do want to
make sure that that is due tosolar retinopathy or it could be due to
another cause and it's just a coincidence. And so anytime you have any symptoms
like development of new black spots,photosensitivity or sensitivity to lights, distortion in
your vision, difficulty or changes inyour color vision and your blurry vision,
(20:40):
you should always seek an eyecare provideroutside of this solar eclipse phenomenon, And
so if that does happen in thenext few days after the solar clips,
you really should see an eyecare providerto make sure that it's either due to
solar retinopathy or maybe due to anothercause. And it's really important to get
that diagnosed right away. And wecurrently have very good imaging techniques for our
(21:03):
ophthalmologists, listeners, but also ourpatients. You know, we do oct
imaging, but even oct imaging,the typical B scan OCT images that we
do may not be sensitive enough todetect solar retinopathy. But we have on
fast OCT images and we also havea new technology or technology that's been around
(21:23):
for a little while now called adaptiveoptics Scanning Light ophthalmoscopy or for short AOSLO,
and that's actually really sensitive imaging techniquefor detecting changes in the photoreceptors.
And what's really cool is that someof the patients that have kind of these
(21:45):
distortions in their vision and they've actuallydone drawings of the types of distortions they
see after solar retinopathy, we're actuallyable to exactly match up the distortion that
they're experiencing and the drawing of thepatient that has done and they're sketoma that
they're experiencing to correspond it directly withthe findings that we see on adaptive optics
(22:07):
where we see damage to the photoreceptor. So we're really at that stage where
even to the kind of microstructural changesthat happen in our photoreceptors in the rentina,
we're actually able to detect those andcorrespondos with the exact changes that the
patient is experiencing in their symptoms.So we're very accurate in terms of making
this diagnosis. It's really helpful forpatients to actually know whether this is caused
(22:30):
by solar anopathy or something else,and for other things there may actually be
a treatment option available for them.Wow. We take some of this technology
for granted sometimes in ophthalmology, butit's really really incredible when you talk about
being able to outline specifically where thatdamage has occurred and how you can map
that out to a patient's subjective drawingof a scatoma. I think what you
(22:52):
said there was really really smart,and that's probably one of the more important
pieces of what we've talked about.How well, probably the bigger risk on
this day if somebody is concerned andthey're saying, ah, my vision's probably
fine. Is not dismissing that somethingelse is going on with their eyes completely
unrelated, because I things happen allthe time, and I didn't think about
(23:14):
this before. But you might beinclined to say, oh, my eyes
are maybe a little bit off,but that's maybe a tad normal. Maybe
I'm just it's in my head.But there are other things other than the
solar eclipse, and there are peoplewho unfortunately are going to experience other eye
conditions on the day or the followingdays or the days following the eclipse.
So don't ignore your symptoms. Ifyou're saying, ah, everything's fine,
(23:34):
I'm just being hyper cautious because theremight be something else going on that is
treatable. Tina, do you haveany final thoughts you want to share with
people? I would say, youknow, always take measures to protect your
eyes. So on April eighth,of course, if you want to enjoy
this extraordinary event that's going to happens, extraordinary experience, just make sure you
(23:56):
use proper viewing of the eclipse.Make sure you have the protective or the
proper solar eclipse glasses or some ofthose other techniques that we talked about.
To make sure you protect your eyes. And again make sure all year around
you're also protecting your eyes from dangersof you belighte by wearing you be blocking
(24:18):
sunglasses. And again, anytime thatyou experience any blurred vision changes in your
central vision, blind spots alter colorvision and light sensitivity, it's always important
to see an I care provider.One last question for you that's just coming
to me now in terms of drivingon that day, because walking is an
easier example that I used before,where it's easier to kind of walk looking
(24:38):
down. But if you need todrive somewhere, should you not be driving
if you don't have those special sunglasses, or again, if you're not staring
directly into the sun, are youokay? Or is it kind of an
unknown where it might just be saferto not drive during that period. Yeah,
so that's an excellent question, andI'm sure many people will think about
that. So in theory, aslong as you're not directly having to stare
(25:03):
at the eclipse while driving, oryou're headed directly in that direction and have
to view it, your eyes shouldbe safe and it's safe for you to
drive. But if you're worried,and that's causing a level of concern for
you, then it's fairly okay toalso avoid driving that day of no So
there's actually been a recent study that'sbeen done where they have actually linked an
(25:29):
increase in the number of traffic fatalitiesand car accidents during total solar eclipses.
And this was a study that wasdone in the US around the previous time
of a total solar eclipse, andalso a study that's being conducted in Canada
as well, based at Sunnybrook.And so what they suggest actually is driving
(25:52):
a lot of the increased traffic andincreased fatalities from car crashes is due to
reasons such as distracted driving, speedingto arrive to destination on time, going
and traveling in unfamiliar routes. Andalso increase traffic from more people driving that
(26:14):
day or more tourists going a certaindirection, and so that's also something to
be very mindful of as well.So this is something that's been noted in
the past, and it's also somethingthat the Safety the National Highway Traffic Safety
Administration is actually warning people about isto be mindful of when driving that day,
to not be distracted, to notbe impaired, to always wear their
(26:37):
seatbelt and make sure that you knowthey're not taking unfamiliar routes and busy traffic
areas where there's lots of tourists lookingat the total solar eclips Well, really
interesting, Tina. You've taught mea lot, and I'm sure you've taught
the listeners a lot. I thinkthere's a healthy balance here where you need
to be concerned and you need tobe taking the appropriate precautions. There doesn't
(27:00):
need to be a mass hysteria either, as long as you take those precautions.
And I'm delighted that you shared withthe listeners all your knowledge about the
eclipse and but solo retinopathy and hopefullygive people a little bit of ease as
they enter this exciting day coming upnext week. Thank you so much for
joining me, Tina. Thank youso much for having me. It was
an absolute pleasure chatting with you.So for doctor Tina fel Felly, optimologist
(27:25):
from the University of Toronto, I'mZael Mednick. Have a great day.
Hey everybody, I'm Zael Mednick andwelcome to a special combined episode of Preconceived
and blind Spot. So, forthose of you who don't know, and
there's no reason you would know,I've run two podcasts. I've run Preconceived
for the past five years, butmy day job is as an ophthalmologist,
and I figured last year I mightas well blend my two interests of podcasting
and ophthalmology, and I also startedan ophthalmology podcast. And for those who
(00:33):
don't know what an opthalmologist is,that's an eye doctor. So today's topic
is going to be on the solareclipse. So for those of you listeners
to blind Spot, I thought thiswould be a relevant topic because we've got
a lot of patients asking us what'sgoing on with this solar eclipse? What
do I need to be aware of, what exactly is a solar eclipse?
How can I damage my eye?What do I need to do to prevent
(00:54):
it? And then for my Preconceivedlisteners, I thought this would be an
area of interest too, because you'reall in theory the patients who might be
coming in with questions about what isthe solar eclipse? And it was a
chance to a rare chance to usemy ophthalmology knowledge on Preconceived. So thank
you to listeners of Preconceived and BlindSpot for tuning into this episode to chat
(01:15):
about the solar eclipse. I'm recordingthis episode on Wednesday night, April third,
and the solar eclipse is scheduled tohappen on April eighth, and I'm
going to be speaking with an ophthalmologisttoday who's going to walk us through what
exactly the solar eclipse is, whyit can cause retinal damage, eye damage,
what we need to watch out for, what we should be counseling people
(01:38):
as people, what you should beaware of. Have things gone a little
bit too far in terms of shuttingdown schools and people not going to work.
What is all of the truth behindsome of the noise that's out there.
So I am joined today by doctorTinflfelli. She is a resident physician
in the Department of Ophthalmology and VisionSciences at University of Toronto. She completed
her medical school training at University ofwhere she received the JP Bully Prize and
(02:01):
Optomology for the highest academic standing inher graduating class. She recently completed a
PhD degree in Clinical Epidemiology at theInstitute of Health Policy, Management and Evaluation
as part of the Integrated Physician Scientistprogram. Amongst her many achievements, she
is a Vanyard Scholar, which isawarded by the Government of Canada to world
class doctoral students. She has alsobeen awarded the Fighting Blindness Canada Clinician Scientist
(02:24):
Emerging Leaders Award. She's the authorof the Toronto Guide to Clinical Ophthalmology,
which is a textbook used in theophthalmology curriculum for medical students at University of
Toronto. She has an impressive researchand publication record with several first author journal
publications. She's presented her research atnumerous national and international conferences. Her research
interests include population based studies, economicevaluations and prediction models for outcomes of surgical
(02:49):
retinal disease and uveitis, the evaluationof healthcare delivery within the fields of ophthalmology.
Doctor Tina f f Elli, Welcometo the podcast. Thank you so
much for joining me. Thank youdoctor for organizing this wonderful podcast that's beneficial
to both ophimologists but also patients.And we're inviting me to speak about an
exciting event that's coming up that mostpeople are talking about these days. But
(03:15):
my pleasure, the pleasure is allmine. I'm laughing because you called me
doctor Mednick. And as I saidat the beginning, I've never recorded a
joint podcast for blind Spot and Preconceived, and I'm preconceived. I don't think
anybody's even called me that, evenin blind Spot. So we'll go with
zeal and Tina. So I'm I'mreally excited to record this because, like
I said, I haven't done anepisode for both podcasts because it's rare that
(03:35):
these two worlds would blend. Buton the one hand, the audience of
Preconceived, it's kind of like thepatients who are wondering what do I need
to know about the solar eclipse?And the audience for blind Spot is the
people who are telling the patients whatyou need to know about the solar eclipse.
I myself am more naive about thistopic than I should be. Perhaps
I don't know tons about it otherthan some basic stuff, I guess.
(03:59):
So we're going to dial it backfrom the beginning and we're just gonna start
off with Tina, what is asolar eclipse? Basically? Without getting too
much into the physics of it.Yeah, great, Yeah, So the
solar eclipse usually occurs when the Sun, the Moon, and the Earth and
the most kind of basic senses lineup, and this can be either fully
or partially and that's what refers tothe partial eclipse, or it's a total
(04:25):
solar eclipse. And so, dependinghow they align, these eclipses can provide
a very unique and exciting view ofeither the Sun and the Moon, and
in parts of the world, basedon your geographic location, as the Moon
passes between the Sun and the Earth, it can create a shadow on the
Earth that's either again fully or partiallyand can actually result in full blockage of
(04:50):
the sunlight. And in midday itcan appear as night because all of the
sun rays are fully blocked, andso it's quite extra ordinary experience. It
doesn't happen very often. The lasttotal eclipse that we had in Canada was
actually all the way back in nineteenseventy nine, and so and the next
(05:11):
one that's expected to take place isthe next partial eclipse in Toronto. It's
going to be in twenty twenty nine, and total solar eclipses in Toronto is
expected to be in twenty one fortyfour, and so we'll be very dead
by then. Hopefully the podcasts aregoing on by then. But you know,
(05:33):
a lot of people are super excitedabout this because it's a rare event,
and there's a lot of talk aboutit. Sools are being canceled,
things are being scheduled around this.There's a lot of tourism happening. Even
prices and nicer Falls hotels have goneup because it's one of the best places
to view this. So there's alot it's surrounding this kind of eight pri
eighth total solar eclipse that's coming up, and so of course with that,
(05:56):
there's a lot of questions about safetyand how do we protect our eyes during
this kind of extraordinary event that's aboutto take place. Wow, so I
didn't realize how rare that was.So this is pretty exciting, and as
you said, obviously a lot ofpeople are tuning into this because they're excited,
but they're also concerned about their eyes. My understanding, and please correct
me if I'm wrong, and I'msure I'm missing part of the picture here.
(06:19):
My understanding is that because the moonis going to be blocking the sun,
you look at it and you thinkWow, that's really cool. But
usually when you look at the sun, you have a reflex where you look
away because it's too bright for youto look at the sun. But if
the moon is blocking it, you'renot necessarily going to have that same reflex
to look away because your eyes aren'tin pain from looking at the sun.
(06:42):
Kind of like putting your hand ona stove but not realizing that it's hot,
and then if you were to takeyour hand off, your hand's burnt.
Same way that you could sustain retinaldamage retinas at the back of the
eye if you're looking at the sunfor too long when it's not painful.
Is that the gist of it.Yeah, And that's actually for the most
part, I would say it's correct. So, you know, some people
(07:04):
mistakenly believe that if you look ata total solar eclipse, which is going
to happen on April eighth, thatit's safe because the moon is completely blocking
the sunlight. And so most peopleunderstand that looking directly on the sun it's
not safe. You year round,we were youv blocking sunglasses to protect your
eyes from the damage from UV lightthat can cause retinal damage, and some
(07:29):
of that can be permanent and soon this kind of particular event. You
know, people believe that because thesun rays or completely blocked, that it's
safe to actually look at the solarclips. But that's not true. And
the reason for that is that ittotal solar eclips, meaning the light rays
from the Sun being completely blocked bythe moon. It's actually very very short
(07:53):
lived. It's only about ninety seconds, and it can be even shorter depending
on your geographic location. In certainareas they actually have get a total solar
eclipse. And so unless someone isone hundred percent certain that they're viewing the
sun and totality of a solar eclipse, and this totality of an eclipse is
a very short lived phenomenon, you'realways at risk of damaging your eyes.
(08:18):
And so the kind of safest thingto tell your patients that is that it's
never, never safe to look ata solar eclipse with a naked eye unless
you're wearing specialized eclipse glasses, whichare not your typical sunglasses. Sunglasses are
not protective looking at it indirectly throughyour phone or through a telescope or any
(08:41):
sort of other binoculars that do nothave proper filters will still cause damage to
your eyes. And that's really importantto reiterate to our patients because the complications
that we worry about are solar retinopathy, which can actually be permanent damage to
the retina, and patients can havelifelongs gitomas, blurred vision, distorted vision,
(09:01):
other altered color vision, et cetera, and light sensitivity as a result
of this damage. So basically,unless you are confident, which nobody would
be, that they're viewing it inthat ninety seconds of totality when the sun
is completely blocked, the odds arewhen you're viewing the eclipse, some of
that sunlight is going to be gettingthrough. You're not going to be feeling
(09:24):
it necessarily because it is blocked toan extent. So you'll be looking at
it, but it will be causingdamage and you won't have that same Is
that is that aspect I said about, You won't have the same reflex.
Is that an appropriate way of thinkingof it? Yeah? Absolutely so some
of the you know, we wehave a hard time looking at the sun
when it's in full kind of notfully blocked. Usually most people know to
(09:46):
not look at the sun because it'svery uncomfortable. But during those kind of
few seconds where it's partially blocked,it is easier for people to look at
it, but you're still getting lotsof sun rays. They are still damaging
to the eyes. And so asmoon is continuing to move across this on
as the total eclipse is ending,the bright sunlight suddenly appears, and so
(10:07):
by the time people react or kindof have that recognition, it's already the
damage has already been caused, andso it can only take a few seconds
for the retina to be damaged.And it's been well documented in the literature
that there's a thought that there's somesort of a photochemical toxicity and thermal injury
from the short wavelength visible lights fromnear infrared radiation that happens during sun gazing,
(10:31):
and that can permanently damage the photoreceptorsand the retina and in particular the
macula, which is the central partof your vision, responsible for your kind
of refined vision. And so youcan imagine as a patient if you have
a black spot and the central partof your vision, and this can be
permanent. That could be quite troublingfor some people to have to live with
(10:52):
that, especially because we don't haveany treatment for solar retinopathy. So you
mentioned that term solar retinopathy, andophthalmologists and optometrists listening to that know what
that is, but to the generallaperson who doesn't. As you just explained,
tina, the retina at the backof the eye, that's the tissue
that is really responsible for our vision. And when light connects with the retina,
that's what's responsible for our vision.But if the light damages it,
(11:16):
especially in the macula, which isthe part that's responsible for our central vision,
as you said, that can causesomething called solar retinopathy. So you
said that can happen after just severalseconds of directly looking of directly staring at
the sun. Would somebody know rightaway that that's happened or would it take
a little bit of time typically forthe solar retinopathy, for that damage that's
(11:39):
been done to the retina to presentsymptomatically for a patient. Yeah, and
that can be That's a great question, and that can be quite variable.
So some people may notice it afteronly a few minutes or to a few
hours. For some people it maytake a little bit longer. And again
the recovery of it is also verydifferent to the degree of the effect is
also very different. There's been somesuggestion that in particular children or younger people
(12:03):
are more susceptible to it, andthere's different hypotheses. So maybe they have
you know, they're more likely tobe on supervise and look at your sung
gaze without recognizing the effects of it. And also because they have clear optics,
so they have a very clear lens, they have a very clear cornea,
and so if you think of theeye as sort of like a telescope,
(12:24):
you know, in a telescope,you have a strong lens that focuses
the light, you know, rightwhere you wanted to, so you have
that Chris clear picture, and itcreates a lot of heat as well.
At the same time, sometimes youeven use you know, lenses and light
to create a sun to create fire, right, So same as that our
(12:45):
lens also creates and focuses the lightonto the back of the eye, which
is the macula, to give usthat sharp vision. And so with kids
and children younger people, it's hypothesizedthat because they have such a clear lens,
they have such clear optics, thatthey're actually more susceptible to having lots
of sun rays causing damage and beingfocused in that central part of the vision
and causing that damage to the photoreceptors. And that makes a lot of
(13:09):
sense if you compare that to anolder person where the lens is going to
be more yellow, which we calla cataract, and light can't necessarily get
to the back of the eye aswell. Once it does get to the
back of the eye, it's notgoing to be as potent and as damaging.
If somebody does get solar retinopathy,you explain scatoma, which for those
who aren't in the field, thatjust means kind of like a blind spot
in the center of your vision.In this case, what's the typical course
(13:31):
for solar retinopathy. It's typically prettypermanent, right, Yeah, so it
has been described in various different types, so some of the symptoms can be
permanent. And unfortunately, the badnews is that there's really no definitive treatment.
Some people have advocated for use ofsystemic steroids or steroids for the treatment
(13:52):
of solar retinopathy, but really there'sno definitive treatment. And in some cases
with observation, there has been someresolution and a complete resolution, but there's
also cases where there's permanent damage thatpatients experienced in some of these black spots
or schtomas do persist lifelong. Andthat's not to scare people. It's just
(14:13):
to be honest with people that thisis this is serious stuff. Photoreceptor damage
is very tough to fix. Sothat's why there is a lot of panic
on social media and in the news. But I want to unpack that panic
a little bit because for me,I guess this is where I get a
little bit confused. And I'm sureyou can help me out with this.
(14:35):
When I hear about schools closing,I hear about people not going outside for
work, my thought is, can'tpeople just go outside and just not look
at the sun? Not look atthe eclipse. Obviously better to have the
sunglasses on, But if you're justlooking straight ahead and you're not staring at
it, that's kind of the sameas you walking around on a regular day
not staring at the sun. Isthat accurate? Yeah, you're absolutely right.
(14:58):
You know, there's there's nothing inparticular about that day where the sun
is more bright or there is morelikelihood of damage to your eyes, So
you going about your day to dayactivity is perfectly normal. I think the
biggest concern is that people are soexcited about this event, this extraordinary event,
(15:18):
and so they're more likely to bestaring at the sun and causing damage
to their eyes by looking directly atthe total solar eclipse, because this is
what people are interested in wanting tosee. And of course, you know
you don't you don't have to fullystep away from this experience or not have
the opportunity to enjoy it. There'sdefinitely safe ways of doing this, and
(15:39):
there's a lot of information that's actuallyavailable on governmental Government of Canada websites and
other websites online that are trusted trusted, such as the American Academy of Ophthalmology.
But really the most important thing isthat you shouldn't look at the solar
eclips with a naked eye, butlooking through it. To add with binoculars
or telescopes unless they have a properfilter or through a phone camera, none
(16:03):
of these are going to protect youreyes, and even sunglasses and really the
only type of things that are safeor using an eclipse glass, and these
usually have a particular standard or anISO number, which is ISO one two
three one two dash two, whichsuggests that these are regulated, regulated glasses
that are meant for the solar eclipsand they meet the standards for eye protection,
(16:30):
and so you really want to makesure that those are the type of
glasses you're using. Any sort oftinted glass won't be properly able to protect
your eyes. And unfortunately there hasbeen some recent suggestion that there are companies
that are releasing these glasses with theISO number that is that I just listed,
but they're not actually the proper typeof glasses that meet the standards.
(16:52):
So you really want to make sureyou're getting your eclipse glasses from a reliable
source and also even taking them alland putting them on, you really want
to make sure you're always looking downwhen you put your glasses on, your
eclips glasses and even taking them off, you're looking down, so you always
are avoiding that direct contact and directsun gazing to avoid any accidental exposure to
(17:15):
sun. Reason making sure again supervisingchildren to make sure that they're also keeping
their glasses on at all times,that they're down always to put them on,
and always looking down to take themoff. Other options that are actually
very interesting, and this may behard to explain over a podcast. We
can maybe include a link to this, but there are some other cool ways
(17:37):
to do this where you can actuallypoke a small hole in a kind of
thick piece of cardboard or paper,and then with your back to the solar
eclips, you can actually raise thepaper so that it's actually directly facing the
sun, and then you hold anotherpiece of cardboard where you can through that
whole of the first one view theshade and the light coming through the hole,
and you can actually see in directlyof the moon and the sun and
(18:02):
the eclipse through dad. So that'sanother cool way, and it's a way
to actually try doing with your withyour kids. It's called a solar eclipse
pinhole projector method, So it maybe a fun way to even kind of
try doing with your kids to avoidhaving them look at the solar eclips directly.
Well, that sounds fun, andthat those are great recommendations and practical
(18:22):
recommendations, And what I'm hearing thereis as long as you're cautious and following
these guidelines so to speak, andusing the protective lenswear, then you're fine.
And I wasn't trying to diminish beforethis idea of all these, Well,
maybe I am to an extent allthe hysteria that's going on. But
it's important to understand that hysteria.Walking outside and looking down, you're not
(18:45):
doing any damage. Now, ifyou think you are somebody who is not
going to be able to contain yourselfand you are going to start looking up,
then don't do that. Stay indoorsand don't go outside if you don't
think you're going to be able toprevent yourself from doing it. But if
you wear the glasses outside you shouldbe fine. And if you are outside
and you are very certain for tenseconds you need to walk outside to pick
(19:07):
up the paper, you can dothat looking down, not at the sun,
and you're not going to cause damage. That's kind of correct. Absolutely,
that's absolutely correct. And of course, you know, if someone's anxious
or you have a child that youthink you know will be harder to supervise,
there's always you know, recordings ofthis that are going to be available
on TV and YouTube. That's anotherway of doing it as well. But
(19:30):
yeah, the best way is tojust make sure you're not directly sun gazing.
My last question is I imagine alot of people after the eclipse are
going to be like, oh myGod, my eyes, they feel a
bit off right now? Should Igo to the emerge? And if somebody
after the eclipse is concerned that something'sgoing on with their vision, is there
utility can go into the emergency roomor is there really nothing to be done
(19:52):
in the acute phase. That's notto say you shouldn't see a doctor,
but in terms of that fear youneed to see should people be rushing to
the emergency room if they are worriedthat they did do something improper and they're
noticing that something's off with their vision. Yeah, so I think I would
say unfortunately, because there's no treatmentfor solar retinopathy, that's the unfortunate part.
(20:17):
But if you're having symptoms in yourvision, you really do want to
make sure that that is due tosolar retinopathy or it could be due to
another cause and it's just a coincidence. And so anytime you have any symptoms
like development of new black spots,photosensitivity or sensitivity to lights, distortion in
your vision, difficulty or changes inyour color vision and your blurry vision,
(20:40):
you should always seek an eyecare provideroutside of this solar eclipse phenomenon, And
so if that does happen in thenext few days after the solar clips,
you really should see an eyecare providerto make sure that it's either due to
solar retinopathy or maybe due to anothercause. And it's really important to get
that diagnosed right away. And wecurrently have very good imaging techniques for our
(21:03):
ophthalmologists, listeners, but also ourpatients. You know, we do oct
imaging, but even oct imaging,the typical B scan OCT images that we
do may not be sensitive enough todetect solar retinopathy. But we have on
fast OCT images and we also havea new technology or technology that's been around
(21:23):
for a little while now called adaptiveoptics Scanning Light ophthalmoscopy or for short AOSLO,
and that's actually really sensitive imaging techniquefor detecting changes in the photoreceptors.
And what's really cool is that someof the patients that have kind of these
(21:45):
distortions in their vision and they've actuallydone drawings of the types of distortions they
see after solar retinopathy, we're actuallyable to exactly match up the distortion that
they're experiencing and the drawing of thepatient that has done and they're sketoma that
they're experiencing to correspond it directly withthe findings that we see on adaptive optics
(22:07):
where we see damage to the photoreceptor. So we're really at that stage where
even to the kind of microstructural changesthat happen in our photoreceptors in the rentina,
we're actually able to detect those andcorrespondos with the exact changes that the
patient is experiencing in their symptoms.So we're very accurate in terms of making
this diagnosis. It's really helpful forpatients to actually know whether this is caused
(22:30):
by solar anopathy or something else,and for other things there may actually be
a treatment option available for them.Wow. We take some of this technology
for granted sometimes in ophthalmology, butit's really really incredible when you talk about
being able to outline specifically where thatdamage has occurred and how you can map
that out to a patient's subjective drawingof a scatoma. I think what you
(22:52):
said there was really really smart,and that's probably one of the more important
pieces of what we've talked about.How well, probably the bigger risk on
this day if somebody is concerned andthey're saying, ah, my vision's probably
fine. Is not dismissing that somethingelse is going on with their eyes completely
unrelated, because I things happen allthe time, and I didn't think about
(23:14):
this before. But you might beinclined to say, oh, my eyes
are maybe a little bit off,but that's maybe a tad normal. Maybe
I'm just it's in my head.But there are other things other than the
solar eclipse, and there are peoplewho unfortunately are going to experience other eye
conditions on the day or the followingdays or the days following the eclipse.
So don't ignore your symptoms. Ifyou're saying, ah, everything's fine,
(23:34):
I'm just being hyper cautious because theremight be something else going on that is
treatable. Tina, do you haveany final thoughts you want to share with
people? I would say, youknow, always take measures to protect your
eyes. So on April eighth,of course, if you want to enjoy
this extraordinary event that's going to happens, extraordinary experience, just make sure you
(23:56):
use proper viewing of the eclipse.Make sure you have the protective or the
proper solar eclipse glasses or some ofthose other techniques that we talked about.
To make sure you protect your eyes. And again make sure all year around
you're also protecting your eyes from dangersof you belighte by wearing you be blocking
(24:18):
sunglasses. And again, anytime thatyou experience any blurred vision changes in your
central vision, blind spots alter colorvision and light sensitivity, it's always important
to see an I care provider.One last question for you that's just coming
to me now in terms of drivingon that day, because walking is an
easier example that I used before,where it's easier to kind of walk looking
(24:38):
down. But if you need todrive somewhere, should you not be driving
if you don't have those special sunglasses, or again, if you're not staring
directly into the sun, are youokay? Or is it kind of an
unknown where it might just be saferto not drive during that period. Yeah,
so that's an excellent question, andI'm sure many people will think about
that. So in theory, aslong as you're not directly having to stare
(25:03):
at the eclipse while driving, oryou're headed directly in that direction and have
to view it, your eyes shouldbe safe and it's safe for you to
drive. But if you're worried,and that's causing a level of concern for
you, then it's fairly okay toalso avoid driving that day of no So
there's actually been a recent study that'sbeen done where they have actually linked an
(25:29):
increase in the number of traffic fatalitiesand car accidents during total solar eclipses.
And this was a study that wasdone in the US around the previous time
of a total solar eclipse, andalso a study that's being conducted in Canada
as well, based at Sunnybrook.And so what they suggest actually is driving
(25:52):
a lot of the increased traffic andincreased fatalities from car crashes is due to
reasons such as distracted driving, speedingto arrive to destination on time, going
and traveling in unfamiliar routes. Andalso increase traffic from more people driving that
(26:14):
day or more tourists going a certaindirection, and so that's also something to
be very mindful of as well.So this is something that's been noted in
the past, and it's also somethingthat the Safety the National Highway Traffic Safety
Administration is actually warning people about isto be mindful of when driving that day,
to not be distracted, to notbe impaired, to always wear their
(26:37):
seatbelt and make sure that you knowthey're not taking unfamiliar routes and busy traffic
areas where there's lots of tourists lookingat the total solar eclips Well, really
interesting, Tina. You've taught mea lot, and I'm sure you've taught
the listeners a lot. I thinkthere's a healthy balance here where you need
to be concerned and you need tobe taking the appropriate precautions. There doesn't
(27:00):
need to be a mass hysteria either, as long as you take those precautions.
And I'm delighted that you shared withthe listeners all your knowledge about the
eclipse and but solo retinopathy and hopefullygive people a little bit of ease as
they enter this exciting day coming upnext week. Thank you so much for
joining me, Tina. Thank youso much for having me. It was
an absolute pleasure chatting with you.So for doctor Tina fel Felly, optimologist
(27:25):
from the University of Toronto, I'mZael Mednick. Have a great day.
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