Dr. Prager: Today I'm going to talk about a few clinical pearls, but mainly I want to talk about the new methodology using the ClearScan cover. The advantage of this is is that it's going to be a simpler exam. It's going to be faster, safer, and definitely more comfortable for the patient
Now, we're used to seeing images like this on ultrasound. And what this is showing then, in contrast to OCT or coherent light technology, is that we can see behind the iris. We have--we get a very good view of the sulcus and the ciliary body. And this can be accomplished with an immersion type of methodology.
But also, with the advent of this ClearScan cover, we're able to see pathology on the side of the eye. It can be an effusion in--it could be a retinal tear. It could be a cleft. Or, for instance if you want to see if a melanoma, in this instance, has invaded the ciliary body, it's easy to slide this bag cover to the side and get a full extension from 10 millimeters from the anterior chamber all the way back. You can even see muscle insertions.
Here's another example here of a large ciliary body detachment that you can see on the side of the eye. Now, in the traditional use of an eyecup full of Goniosol and saline, this would be impossible to do without causing a massive abrasion.
Here's an example of the subtleties that can be discerned with a 50-megahertz probe. This is a Quantel. You can see the edge of the lens. This patient presented with a lens iridodonesis. It was moving, and the question was are there broken zonules or are there zonules present at all
In the top picture, you can see just--there's a single solitary zonule that is stretched. If the zonule measures over one millimeter, we're going to assume that it's stretched. Here in the superior aspect, there are no zonules. So, this is what caused that lens to move so freely in the eye. We can see the cause and also know at which quadrant this was occurring.
This is not going to be the subject of today's talk, because we're interested in pathology that's going to be behind the iris. When--again, using coherent light technology, this is not permissible.
So, traditionally, and I think this is--as great of a tool as UBM is, there is reluctance to use it because of some drawbacks associated with the traditional shell and gel technique. You can worry about the probe tip or the end of the ultrasound itself coming in direct contact with the cornea, causing an abrasion.
The patient has to recline and they put a shell in the eye using a little Goniosol. And I'd say maybe 5 to 10 percent of all of the patients that receive this have a reaction to the Goniosol. And it's under the lids and it's uncomfortable.
And especially if you're doing an exam and you want to look on the side of the eye, even for a glaucoma exam at angles, that if you move the cornea to--slightly to the side, it's going to come in direct contact with the bottom of that shell and it's going to cause an abrasion. So, patients would object to this, and I think it definitely had an effect on UBM and keeping it from being as clinically applied as possible
So, the question is, why do you have to use a shell in the first place? You don't have to do it for B-scan, obviously. What's the--why is it necessary? What happens is, if you can open one of these probes, there's--it's motorized. The motor is taking that nub with emitting sound waves, and it's moving back and forth, back and forth. And as it's spewing out these sound waves, it creates a zone of interference.
And this zone of interference, which we call near-field artifact, any structures contained within that cannot be visualized. So, you have back off from this zone of interference, the near-field artifact, to see structures.
So, the concept of the ClearScan cover, which we suggest will replace the shell and gel technique, is there is a silicone collar with--and a clear bag that is invisible to sound waves. It's full of water. So, here it is.
It has a safety function. You know, instead of having to worry about that nub or the probe itself coming in contact with the cornea, here this bag is pressurized. When you put the probe into the bag of water, well, it's no longer a bag but, with this increased pressure, sort of like a balloon tire holding your--holding the car off the ground.
The more you push in here, the more pressure there is. And it's--gives you plenty of warning, and you don't have to worry about making accidental contact with the cornea. It's much safer
It's sterile for single use. Obviously you can't sterilize a probe every time if--without the probe dying after about 10 or 15 uses, if you could even sterilize it. So, here this is a disposable product and it--this allows use in situations where sterility is important, especially in the OR and for various different patients
We did a study. This was published just a few months ago in Cataract and Refractive Surgery. What we did is we looked at a cohort of 34 people. And we did the exam of both eyes, and then subsequently we swabbed the tip, sent it to the path lab, and saw what would grow out. In 80 percent of the samples, there were bugs associated with either endophthalmitis or keratitis. So, the take home lesson here is that the bag should be changed after each patient.
I think one of the main benefits of using this ClearScan are--is comfort. Here is a comparison study done a few years ago, random presentation of the shell and gel technique versus the ClearScan. A hundred percent of the cohort preferred the ClearScan. And you can see the average score here is in the comfort range, whereas with the open shell it was deemed very uncomfortable by almost all the patients. And if patient is uncomfortable, they're not going to come back for follow up exams.
So, the methodology to use this is actually pretty simple. It's very fast. I always use distilled water because tap water has minerals in it and they can deposit on the end of the probe, and it'd be a very expensive repair. Add the water slowly to minimize the formation of air bubbles.
And note here there are two sides. Here is the bottom side and here's the insertion side. There is a little raised nub right here to indicate that's the insertion side. Inserting in this end can possibly result in a leakage.
Basically just for the initial examination, the probe is going to be about one inch away from the bottom of the ClearScan bag. And the white line here should be peeking out just a little, about a quarter of an inch.
You can add a drop of BSS following some proparacaine. And I do a method called a faux speculum. I'm going to take my left hand, I’m going to take that lid and push it all the way up to the bony brow, because I don't want to cause any type of increased pressure in the eye. I'm going to cup my hand that's holding my probe and I'm going to pull down on the eyelid. I want the eye to be as open and as large as possible.
And my criteria is that I want to see--in all of my images, I want to see the pupil present. And I'm going to take this conical bullet in here and I'm going to aim it right into the center of the cornea. And if I need to make an adjustment, the skin--excuse me--is very pliable. I can move up or down, left or right just a few millimeters, and I can always capture that open pupil.
As Dr. Acea [sp] was pointing out that it's possible for the iris diaphragm to fall backwards in the supine position, I prefer examining the patient sitting up because that's the same way that you're going to see the patient at the slit lamp. Also, I can see around this collar. It makes it easier. And again, I'm going to aim the bullet tip right into the center of the eye, and then I'm going to move over to the side.
So, here's a typical scan where there is a smooth corneal surface here, which indicates that the pressure is appropriate. It's draping over from sulcus to sulcus. However, what happens if the eye is like slightly soft? Then you're not going to make the full contact here. And what this is going to suggest is that the intraocular pressure is lower than the bag pressure. It's going to result in a dent, as illustrated on the next slide
Important safety tip, you don't want to replicate this. But, in the soft eye, you have to be able to regulate the pressure or there are going to be--you're going to have a denting of the cornea. And the way that you do this--there are several easy ways to do it.
One way is that you can change the amount of fill into the bag. And when I first do the insertion, I'm going to have my basic exam. I want to have just several wrinkles appear. In a patient with a pressure of like three or four millimeters of mercury, I'm going to have wrinkles in almost every aspect of the bag and they're going to be very prominent.
Another way to adjust pressure, and you can do this instantly, is you push the probe in slightly. It's going to increase pressure. If you withdraw, it's going to lower pressure. Again, I would suggest having a few wrinkles appear, and that's going to be a good starting point.
The easiest way is to squeeze the green collar, because the collar itself is a valve and you can instantly change. And I have a little video here. Let's take a look.
Unidentified Man: Okay. This is a ClearScan cover. It consists of a clear bag and a silicone ring that has several functions.
I'm going to fill this full of water, as I do as I prepare for an immersion scan of the eye by ultrasound. This is a typical ultrasound probe. I'm going to insert it into the bag. At this point, you can see it's no longer a bag but it's pressurized, that the silicone ring has functioned as a seal.
You can see, as I push on the eye here, it conforms to the shape. One thing that's very important in an examination is that the internal pressure of the bag has to be less than the pressure of eye or it will dent.
So, the seal also functions as a valve. I can squeeze it and I can eliminate air or water and also reduce the internal bag pressure. There you just saw the water escape. You see the wrinkles here. Now I can examine an eye with lower intraocular pressure.
That's it. Okay, this is a--
Dr. Prager: --With the scleral spur, I just want to give a clinical tip here. A scleral spur is the gateway to the anterior chamber. It's an elevated circular ridge that's very subtle, often not visible when you're doing ultrasound. In other words, to find the scleral spur, the--its location has to be estimated.
Scleral tissue is different than uveal tissue. And in ultrasound, wherever there is a difference in tissue structure, you're going to see a line of differentiation here. Well, we know that the spur is somewhere on this line. So, I'm going to turn my gain down enough where I can see the difference between these two types of tissue.
And one method, since I know it's on that line somewhere, is to follow the curvature of the inside aspect of the cornea until it meets that line. That's one way to approximate the location of the spur.
And note here, when we do these exam in the glaucoma patient, the lights are off. It's very important. To cloud the angle, you want to have the worst-case situation possible.
Another method is, again recognizing that there is differentiation between these two tissues and the spur is on this line somewhere, as Chuck Pavlin, who is probably the father of UBM pointed out, that one millimeter from the limbus back and straight down is also the location of the scleral spur. I use both methodologies to make that determination.
There are a lot of YouTube videos on how to do this procedure if you're interested. And you can play these over and over again. Just search on YouTube for ClearScan cover.
Well, you know, it's nice to have an instrument like this, but it's even nicer if you can get the instrument paid for. So, I've been asked just to address a few of these billing and collection questions.
Now, the UBM reimburses per eye. And depending on the locale, in Houston we get about $85.00 per eye. And note that 76513 is an open code that's used for UBM. And I've had very few situations where I've been denied payment.
So, the question is, "Can an office visit and a UBM exam be billed at the same visit?" And the answer is yes, that both can be--will be paid. But, what's important is, is it medically necessary? And that can be deemed by the insurance company.
So, let's say during the global period after a surgical procedure, does that have a consequence on payment? Again, it's dependent on the insurer's determination if it is medically necessary. Let's say a patient comes in after cataract surgery. They're complaining of eye pain, iritis symptoms. Well, it could be that the haptic is touching the ciliary body. So, that would call for a UBM.
The diagnostic test will be paid, but note that the office visit will be denied during that global period. And the reason is that 20 percent of the global fee for surgery is dedicated to the postoperative management, and that's going to include the office visit.
Okay. Is there a clinical diagnosis, or can a UBM be performed as part of a screening exam routinely? It's--screening exams are not covered with the exception of a glaucoma screening. And if it's bilateral, if bilateral procedures are performed, can you bill for two procedures on the same day? And again, if it's medically necessary, Medicare will pay at 100 percent of the allowable. But, the supply code does not cover the cost of disposables, including the ClearScan cover.
So, UBM is--with this bag, balloon technology, I think it's like a hammer looking for a nail with all the pathologies, and can answer many of the clinical questions efficaciously, quickly, and safely