Having dry eye syndrome or dry eye disease is a lot more complicated than just not producing
enough tears. Dry eye is multifactorial, meaning your eyelids, medication, lifestyle, medical
diseases all of these play a role and for your doctor to find the best treatment for you you're
going to want to sit through a thorough dry eye examination. So in this video i'm going to walk
you through the dry eye examination that we offer at our clinic showing the different dry eye tests,
how they're done and what they mean to me as a doctor. That way you will know what to expect
at your dry examination and what those results mean in finding the best dry eye treatment for
you. So blink your eyes a few times, smash that like button, and let's take a look.
Hello and welcome this is Dr Joseph Allen here from the Dr Eye Health show and today i'm super
excited to be talking to you about the dry eye examination and all the dry eye tests that we
offer at the clinic that I work at called the Pinecone Vision Center in Sartell, Minnesota.
Now right away, I do want to mention that the examination that we're walking through and all
these tests are pretty comprehensive compared to a lot of other clinics that i've been to, so
depending on where you live and what different dry eye specialists in your area may offer
you may not see all of the tests that we're doing but my hope through this video is whether
you come to see us or you do see another dry eye specialist that you'll better understand
what all the tests are going to be doing and what they translate to like what they mean
to us as your doctor and how that helps us guide what treatment is going to be best for
you. So if you were to come into our clinic for a dry eye eval our technician would first greet
you bring you on back to the exam where they would check your eyesight, your vision. They
make sure that your eye pressures are doing okay and then they're going to take a thorough history
just to make sure that we know what is going on medically, your past medical history, surgeries,
any sort of medications that you've been on and if you have autoimmune disorders. All of those
things. You'd be amazed to learn how many medical diseases autoimmune disorders and different like
skin care medications all these things can affect potentially how our eyes are feeling,
inflammation and leading to dry eye. So again, a thorough history is really important and honestly
never ends throughout the entire exam. I'm usually asking my patients tons of questions throughout an
exam now one thing that we use at our clinic is a dry eye questionnaire. This is where a patient
will fill out some basic questions about how their eyes are feeling in terms of dryness, how often,
how severe they are and that all gets calculated out to a score. And we like to do this at
every evaluation so we can track that score over time to make sure that if we do start a treatment
that we are having a kind of relief for those symptoms. This is also good for us to document
because some patients their eye will not look like dry eye in fact it'll look pristine and perfect
but they're still having these symptoms and that tips us off that perhaps it's not dry eye. In fact
it could be a neuropathic pain issue. So again, just a good thing to document. Now one of the
first true dry eye tests that we do in our clinic is called tear film osmolarity. Which is really
just a fancy way of saying that we're measuring the salt content of the tear film. If you remember
the last time you ever did cry and you tasted your tears they taste salty right? And that's because
with dry eye syndrome there is an irregularity of the tear film which causes an increase in
this osmolarity or increase in salt content and that causes a disruption or loss of homeostasis
to the front surface of the eye. Now the device that we have is called the tear lab and it's very
simple it just goes up to the side of your eye and it takes a small sample of your tears and then it
reads this off a number in milliosmoles per liter. In general anybody with less than 300 on their
osmolarity is considered fairly normal but anybody that's above 300 does mean that there's a loss of
homeostasis or balance with the salt content and with increasing amounts the higher your osmolarity
if you're getting up to 320 330 and above you're getting into more severe cases of dry eye. And as
a doctor i'm not just looking at the pure number i'm also looking at the asymmetry between the eyes
as well as the fluctuation from exam to exam. But overall the osmolarity I believe is an important
test mainly because if i have a patient who is symptomatic for dry eyes but their osmolarity
is normal then I need to be thinking as a doctor, okay, this may not be dry eye,
this could in fact be blepharitis or maybe an allergy of some kind. Or perhaps maybe this is
the second or third time we've done this and we've started you on a treatment and that treatment is
starting to have an effect, we're seeing in normal levels again. That's why osmolarity testing can
be so helpful for dry eye. Now the next test that we do is something called Meibography. This is an
imaging or scanning technology that will scan your both your lower and hopefully your top eyelid,
sometimes the top eyelids are tough to image but the lower ones are the most important anyway.
But we scan your eyelids specifically to look for how many oil glands remain for a lot of people
these oil glands in your eyelids which we call the Meibomian Glands, can eventually get inflamed and
clogged up and potentially even atrophy or die off for some people. Now here in this channel we've
covered a lot about Meibomian Gland Dysfunction and this specific issue with the oil glands a lot
of other videos but in short, if you haven't seen that, Meibomian Gland Dysfunction or this problem
with the oil glands is very common and it happens to be that when their glands aren't functioning
or they're not producing either enough or the type of oils they are producing are very low,
your tear film evaporates very quickly and that causes a problem with too much salt content and
this unstable tear film, and hence, dry eye. The purpose of scanning the oil glands and getting
this my biography really serves two purposes; one is to show us how many glands are there and if
they're inflamed or if they're in trouble and two; the instrument also takes an active measurement of
the oil layers on the tear film itself. And I personally just love looking at the images of
the lipid layer itself because you can see kind of this cool rainbow color on the front surface
of the tears which honestly reminds me of seeing gasoline or some other type of fuel floating on
top of like a puddle on the road or something but being able to see those oil layers active on
the top of the tear film is very powerful. And then, furthermore, being able to quantify that
and being able to say "hey yes your glands are there" we know you have oil glands but they're
not producing well enough and so we know that the quantity is very low. And in a case like that then
we're definitely thinking about a treatment such as a thermal pulsation like Lipiflow for example
or perhaps an IPL or something to help with those Meibomian Glands. And same thing for after a
treatment we can always repeat this test and then being able to show hey are your warm compresses
even being effective. Now the instrument that we use also tracks how our patients are blinking
during that evaluation because a lot of people including myself are incomplete blinkers. We
don't blink all the way and so we can capture that and see that might be one of the reasons
why someone's having such bad dry eye. Now the next test in a dry eye exam is that of measuring
with Inflammadry. This is a test that kind of looks like a pregnancy test but it really just
helps sample the tears and then it after it's run will tell us the presence, positive or negative,
if a patient has a biomarker called mmp9. Which its whole name stands for matrix metalloproteinase
9. Try to say that one three times fast! Now this mmp9, is an inflammatory biomarker. Basically
shows us that there is presence of inflammation which is consistently found in patients with dry
eye. Inflammation also plays a major role in the cyclical nature of what dry eye is and is
one of the major reasons why conservative dry eye treatments often don't end up giving us any
results. Because if you not just have dry eye but then you have the inflammation present at the same
time the inflammation kind of just acts like adding gasoline to a fire, making it worse
and worse. So if a patient does have this signs of positive inflammation on the eye that's why
your doctor is going to think about prescribing either a topical steroid or a medication such as
Xiidra or Restasis to help get that inflammation under control. I personally find that topical
steroids are really good with patients who have bad flare-ups but again long-term there are some
safety concerns where other medications like Restasis and Xiidra they have a better safety
profile for people who need long-term treatment. Now from here the next part in Dry Eye Testing is
legitimately measuring the quantity of tears that somebody produces. Historically, there have been
two tests used primarily in research to measure the quantity of tears this is either through what
is called Schirmer's testing or another one which is called the phenol red thread test. However,
the phenol red thread test is no longer being manufactured so you may not see that anymore.
But in general Schirmer's testing is where your doctor will put a special piece of paper
on the lower eyelid and then that will absorb tears for a certain amount of time. In general,
if somebody produces more than 10 millimeters of tears in a five-minute period then they're
considered to have more normal tear production but if somebody has less than 10 then that is
significant for dry eye disease. And if somebody has something like five millimeters or less then
i'm seriously considering if somebody has an autoimmune component like something like sjogren's
syndrome, for example. But on the flip side if you can imagine somebody producing a lot of tears like
20 plus millimeters in that time frame then we're not so concerned about them not producing enough
tears we're more concerned about the quality of tears and perhaps the tears are evaporating too
quickly. All right so let's move on and talk about the slit lamp examination. This is where
your doctor is looking behind the microscope that we call a sit lamp so that they can see
what's going on on your eye at that moment. Now with the slit lip exam we do what's called
fluorescein sodium staining. Fluorescein sodium put onto the tear film will highlight any defects,
any surface damage, anything going on in the front surface. One of the major things your doctor is
going to look for during this test is something called spk or superficial punctate keratitis.
Which is basically a type of surface damage that's occurring where the front epithelium of the cornea
is starting to get little divots, almost little erosions due to the dryness that's occurring. But
depending on how that spk or these little surface damage are showing up that'll tell us more about
the potential cause of the dryness and all the symptoms. For example, if it's a very diffuse spk
then we may be concerned that perhaps somebody's medication that they're using, like antibiotics,
may be in fact causing a toxic reaction to the cornea or if somebody has just a very
defined like lower one-third of their cornea then we're thinking that perhaps there's an
exposure issue that maybe their eyelids aren't closing all the way while they're sleeping.
These are just a few examples but it's a really important thing for your doctor to be looking for.
In fact, just a pro tip for any students or other doctors who may be watching this
I highly encourage you try a yellow wratten filter you'll see a lot more subtle spk and other surface
damage that could be going on. Okay another thing that we use that fluorescein standing for is also
measuring for what is called TBUT or tear break up time which is really done easily. Your doctor is
just looking at the eye asking you to close your eyes and then open them up and hold them open
while they're observing for how the tear film on the front surface of the eye separates and
breaks up and while that's occurring your doctor is counting back in their head from zero one 2 3
and then once the tear film has broken up then they know you're to your breakup time.
But historically a decreased tbut measurement is associated with a poor tear film quality.
Mainly surrounding the meibomian glands and then not producing enough oil or the oil is
poor quality. Now other than fluorescein staining, we do use another stain which is called lissamine
green, which is just a kind of a stain that gets put on your tear film and yes as you can see here
it does look rather dark green and i know a lot of patients who do kind of freak out because of how
green their eyes will look during this part of the exam. but lissamine green is a dye that stains
devitalized cells or surface cells that have lost their glycocalyx or their mucin layer which i find
is very good for staining the conjunctiva the outer clear coating on the white part of the eye
because for some people the cornea may look great they're not having any surface damage there but in
fact the damage is all on their conjunctiva. And you can see they have no mucous layer
and they're just having extreme staining there so dry eye is really not just about the cornea
it's about the whole eye, your doctor has to be looking at everything. And with all the
staining your doctor is also observing for deformities of the cornea such as scarring
post surgeries as well as a corneal dystrophies for example any scenario where the front surface
of the eye is not normal or regular. Now outside of just looking at the front surface of the
eyeball itself a big part of this examination is also looking at the eyelids first expect that
your doctor is going to push on the margin of your eyelid just very gently to try and express
some of the oils trapped in those meibomian glands because they want to see the quality of those oils
first we want to see that oils are coming out and ideally the oil will come out like a smooth olive
oil or something like that but unfortunately for a lot of people when there's inflammation present
we can see those oils coming out as kind of a milky cloudy appearance or for some people it's
almost like popping a zit or watching wax slowly ooze out of those glands. Outside of expressing
these glands we're also noting any presence of spider veins on the eyelids which we call
telangelectasia, as this is more of a marker that there's been prolonged inflammation of the eyelids
and somebody may have potentially ocular rosacea. Your doctor is also going to take note of how the
eyelids are coming together are they actually coming together all the way when they're closing
or are they only again partially blinking. Also with how the eyelids are scraping on the eye,
I often have my patients look down and then I lift that upper eyelid looking for any signs of redness
or new inflammation there because that could be a sign of SLK or superior limbic conjunctivitis
which may be an early sign to me that a patient has thyroid problems. Okay, so from all of this
we now know the quantity of tears someone is producing and if that's playing a role the
quantity and quality of the oils that are being produced and if somebody's glands are present
on the eyelid, we know if blinking or exposure is potentially a problem, if inflammation and surface
damage is contributing, as well as a medical history and medications, as well as a survey
to base our future treatments off of. All of that gives us a good idea if a patient has aqueous
deficient dry eye, do they have evaporative dry eye, do they have a mix of the different types of
dry eye and at the very least it gives us a good baseline to base our treatments and to monitor our
treatments if they're successful down the road. Again that way as we begin treatment whether it's
an in-offers procedure or a medication i can have the patient back and i can see the data if things
are improving. That way hopefully the dry eye treatment is not just a random guessing game
now i do have one other test that i want to talk about and i know a lot of other clinics don't do
this test but first let me know in the comments section which part of this video really helped
you out the most or helped you at least learn the most about dry eye and dry eye testing i'd love
to hear your feedback. but the one of the tests that we do is that of corneal sensitivity testing
specifically using what is called a Cochet-Bonnet test. The Cochet-Bonnet kind of looks like a pen
but when you extend it it looks like fishing line kind of comes out to a certain length and when
this line is fully extended the tensile strength is very low but your doctor will literally come
toward you and just barely touch the front surface of your eye and you'd be surprised how many people
cannot feel that if somebody's corneal sensitivity is normal they should feel that even at just the
barely just a little bit coming close to them. But when people have severe dry eyes there could be
corneal sensitivity issues where the neurological connection between the nerves of the cornea and
the brain aren't communicating correctly and this miscommunication can result in decreased
tear production and poor healing of the corneal surface. Thankfully with the Cochet Bonnet we're
not just testing hey is it there or not we can legitimately quantify it and watch it improve with
proper treatment but again that's a very specific test and i don't know of many other clinics that
have that specific test. Now hey i really hope this video helps you out and better understanding
what to expect at your next dry eye exam but i know that a lot of clinics depending on where
you live may not be as comprehensive as what we've talked about here. But I do encourage
you to find a dry eye specialist in your area. For help on finding a dry eye specialist in your area
i did some research and trying to figure it out myself it turns out to be a little bit more
complicated but I built kind of a how-to guide and i encourage you to check out that video up
over here to learn a little bit more. Otherwise thank you so much for watching, if you enjoyed
the video hit the like button, subscribe to the channel if you're new, otherwise again
this is Dr. Allen here from the Dr Eye Health show, keep an eye on it and we'll see you soon