Southwest, FL | Case of the Day- New Dry Eye Testing | Cataract & Refractive Institute of Florida
Dr. Croley: Hello and welcome to the case of the day. I'm Dr. Croley and today we're shifting gears a little bit again, in that we're not going to be discussing a specific case or patient, but we're going to discuss a new instrument we have at our office called a Keratograph 5 that we use mostly to diagnose dry eye patients. It does have a lot of the capabilities that are used for measuring the curvature of the cornea. It has a lot of contact lens fitting parameters where you can look at a contact lens on the eye and make sure it fits well, especially like bifocal contacts where you could see a segment height, that you can line it up with this system. It also has pupil size that we'll measure, that sometimes we use that measurement for prior to LASIK surgery, but what we're going to discuss today is mostly about dry eyes.
Dr. Croley: We have lots of people come with dry eyes and we actually have a LipiFlow and a LipiView machine that we have sort of gone over in the past, but we'll maybe re go into more depth in the future, but we use this machine because it measures several different attributes of your tear film and so we're going to go over to show you what that is. Your tear film is made up of actually three layers. There's a bottom mucus layer, then a water layer and an oily layer. We try to find out what part of your tear film is not correct so then we can treat the underlying problem or cause of your dry eyes, because if all you're doing is putting tears in your eyes, which is a good thing to do, you're not really getting down to the reason why you have dry eyes. You're not treating the cause of your dry eyes, which longterm you need to do because if you don't do something, the dry out problem will slowly over time, months and years of time, get worse and worse and worse.
Dr. Croley: We actually now have young kids coming in with dry eyes because they're sitting there gaming all day long and they stare at what they're looking at and they stopped blinking and then their eye dries out and then it starts this inflammation that starts the whole dry eye problem. We now actually have young people coming in. The first thing that we're going to do is go over some of the tests that this allows us to do.
Dr. Croley: The first thing I'm going to show you is this is a keratograph, or topography, and it measures exactly the curvature of your cornea. We use these measurements typically for cataract surgery. We use this for fitting contact lenses. This shows us exactly the shape of your eye, the contour of your eye. This is a typical keratograph or topography of someone's eye.
Dr. Croley: We're going to go to the next test, which this is measuring the lipid layer of your tear film. Now we're looking at the amount of colors that are on the ring. When this shines a light onto the surface of your eye, then we're looking at how colorful is that pattern. If it's just dull gray, all these little rings are dull gray, then you don't have any lipid layer to your tear film. If it has a lot of color to it, then you have a lot of the lipid layer there. The LipiView machine actually measures that layer down to microns of detail. This tells us that this person has a moderate amount of oil or lipid layer, because there is some color but not as much as you would normally like to see.
Dr. Croley: Now we'll go to the next test. This is actually a movie. We're not going to think the movie is going to show very well, but this takes a movie and you can watch the tear film move around on the surface of the eye as the person blinks. If your tear film is very thick because there's not enough liquid layer, then the motion is very limited, whereas if you have lots of tears, the motion is a lot. This is another parameter that we use to evaluate your dry eyes.
Dr. Croley: Then the next thing we're going to go in and is looking at the tear meniscus height. This will measure tiny detail of how much tear film is present from here up to where the edge. This tear film lake we can measure down to tiny little parts of a millimeter. This is 0.26 millimeters in height, and that's sort of the limit of lower, lower limit of normal. Anything below that is dry. Anything above that is pretty normal. We can measure exactly how dry somebody's eye is and how much tear meniscus they have.
Dr. Croley: Then we'll go to the tear breakup time. The tear breakup time calculates how many seconds... We have someone blink a couple of times and then we have them not blink, and then we count, the machine counts, how long does it take before the tear film breaks apart? It calculates how long that is. This was 8.6 seconds, which also is at the shorter, lower limit of normal. It tells us exactly what part of the tear film, where it was and located where the tear film started to break apart. It's watching these mires, these rings, and wherever it starts to fall apart, that's when it stops the timer and it tells us where it happened, what part of the cornea.
Dr. Croley: The next one is a redness test. It calculates how red are the eyes. It gives us a reading and it gives 1.1. and it gives on the redness on the white part of the eye, the limbal redness is 0.7, and that is the temporal side is 0.7, 1.0 on the left. That tells us exactly how red someone's eye is, which that tells us how inflamed their eye is from dry eyes.
Dr. Croley: Then the next test, which is a really important test, is that actually we can measure and take a 3D image of their meibomian glands. What this shows us is if you see this, we'll try to zoom in, you can see these glands right here. These glands empty out in a tiny little opening on the edge of the lid. These glands secrete the oil or lipid into your tear film. You can see this, these glands right here have died. This gland is a little short. This gland is a little short. These glands are pretty normal over here. This person has mild to moderate dry eyes due to the meibomian glands not secreting the proper amount of oil into the tear film. We can actually photograph the quality of their glands.
Dr. Croley: The last thing is just a photo. If there was a lid lesion here, if someone had skin cancer or something like that, then we could take a picture of that so we could track the lesion and what it's doing. This is all the different things that this will do. It allows us to diagnose the type of dry eye someone has, and then we come up with a treatment protocol based on what type of dry eye they have. This person has some meibomian gland disease, so therefore we would treat the meibomian glands to try to make their dry eye better. If someone had a normal meibomian gland, but their liquid layer was thin, then we would treat them because that portion of their tear film is abnormal with different things. Now it's just not going to a doctor's office and saying, "My eyes are dry," or we find out, we examine you and we tell you that your eyes are dry and just use some tears, but now we can get specific about the treatment.
Dr. Croley: If you have any questions about how we examine someone for dry eyes and the different types of treatment, you can always contact us through the website. If not, may God bless you with healthy eyes and great vision.