Canaloplasty Patient Outcomes at 250 Days Post-Op

Canaloplasty (pronounced Kah-NAL-oh-plas-tee) is a new glaucoma treatment that gives many people with this potentially blinding condition the hope of saving the vision they have. Canaloplasty can reduce pressure in the eye (IOP) by nearly 40%, and many glaucoma patients who have had Canaloplasty no longer need medications.

If you are not familiar with Canaloplasty, you might want to visit this post first: “What is Canaloplasty?

Dr. David Richardson, Ophthalmologist in Southern California, gives a talk about Canaloplasty to other ophthalmologists in the recently concluded American Society of Cataract and Refractive Surgery (ASCRS) 2012 Symposium on Cataract, IOL and Refractive Surgery.   Dr. David Richardson discusses the outcomes of 82 of his own Canaloplasty patients who are at least 250 days post-op

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FULL TRANSCRIPT:

Dr. David Richardson: I’m going to approach this talk from a different perspective than you’ve probably heard in terms of just experience. Most surgeons to start performing Canaloplasty have actually performed glaucoma surgery released since residency. I’ve made the choice not to perform glaucoma surgery after residency so for eleven years the only glaucoma surgery that I performed was ELT. So this perspective will be a little bit different but I think it’ll certainly have like everyone here.

First of all disclosure I am a consultant to iScience. Why didn’t I do glaucoma surgery? Well the reasons why we don’t like glaucoma surgery are the reasons why I didn’t do glaucoma surgery. The difference here is that whether I’m lazy or whether I just have really, really low tolerance for annoying things, I’d just found that with the risks in complications associated with Trabeculectomy and tubes, it’s just not something I wanted to deal with. The post-operative hassle for someone who has a busy general ophthalmology office, the idea of filling up my schedule and using up a valuable chair time with the post-operative trab patients, which is something that I wasn’t interested in doing. I couldn’t afford to disrupt my schedule with the unexpected, at least not if the unexpected was going to be something that was not only non-revenue generating but was actually going to take away revenue by removing a spot.

As Steve mentioned, I’m in southern California. Our overhead there is exceedingly high yet our revenue for Medicare, BlueCross, everyone else is actually lower than in most other areas of the country so we really do have to be ultra-efficient in our area.

And then I also benefitted from the fact that in Southern California, in the Los Angeles area that I was in, there are plenty of masochistic glaucomatologist; so if I had somebody who needed glaucoma surgery, it was a very simple thing for me to just say, “Well I don’t do glaucoma surgery”. So why did I change my mind? Well I didn’t really change my mind. My patients actually changed it for me. Anyone who’s been in practice for ten years or more discovers one day that your practice is glaucoma and there’s just no avoiding the fact that the vast majority of the office visits have to do with glaucoma. And I had more and more patients who simply wanted me to be the one who treated their glaucoma. They’d been with me for a long period of time. They didn’t want to go to somebody else. And although it’s nice to have academic centers in your area, we’re all familiar with what it’s like to be a patient in an academic center, perhaps it’s different at yours but in general there up for three to six hours each visit. And that’s just more than some of my elderly patients who were really willing to put up with.

So my glaucoma surgery volume, I’ve already mentioned that it was zero. Well that was zero glaucoma surgeries for me. The other reason why didn’t particularly want to get involved with Glaucoma surgery is that I knew I’d never give any good at it because before performing canaloplasty, I was sending out only one patient every month or two to the local academic glaucoma specialists. So how would it is possible for me to ever get any good at glaucoma surgery? Well as I said my patients convinced me to try something. I thought canaloplasty being a bleb-free procedure was something that I could do.  The post-operative hassle and frankly, the fear that I had of blebs and the tissues involved, are just weren’t going to be some things that I have to worry about.  So I thought well, I’ll give it a try. I’ll probably never be any good at it. And then my first year, sixty cases, now a hundred and ten. But then again I wasn’t doing glaucoma surgery beforehand (well sure was) and my practice isn’t quite as busy as yours I do believe. But that was surprising to me, because I really wasn’t pushing glaucoma surgery. Remember this is in my learning curve so I was still being uncomfortable with it. And even if I was to be pushy with surgery, my general practice in terms of cataract surgery is one where my conversion rate to premier miles is only about seven percent. So I’m not a very good salesperson. So this growth was essentially inorganic growth. This was truly a patient driven growth in volume.

So how have we done? Well I took a look at the charts by patients who were at least two hundred and fifty days out. And I had eighty two patients to look at. The first one thing that everybody asks about, as well as how frequently do you get the catheter all the way around? We’ll it turns out almost nine out of ten cases; the catheter was three hundred sixty degrees placed. And those patients who didn’t get the catheter placed still did very well.

Now of those initially eighty two patients, we took a look at those who, to get an idea of what was the pressure by the year out. We took a look at those patients who were two hundred and fifty to four hundred days out when the pressure was measured. What you see here is the individual pressure of those patients. Now those two, there are actually a positive change in pressure. Those were actually the two eyes of the same patient. Although it looks like this is a failure, this is actually a success. That’s only three points difference from pre-op. This patient was on three drops five times, well, three different drops five drops per day in actual placement in the eye. After surgery both eyes were zero drops so far. This is actually a positive effect. This is the actual Canaloplasty medications beforehand that the number of medications to patients were on, and then after and you can see that the vast majority of them have gone to no drops after surgery. And this is the actual number of drops used. And you can see that some of those patients were on quite a few drops per day.

This is the phacocanaloplasty. Now what you notice here is that the percent change, as well as the absolute change, is less than with canaloplasty. But my phacocanaloplasty patients on average started out at about sixteen millimeter of mercury as opposed to the big twenties for canaloplasty. So many of these patients were patients who needed to have cataract surgery but were on multiple drops. Their primary goal was not really to lower the pressure. These patients’ primary goal was to get off the drops. So what? did they get off the drops? Yes, they did. So you could see the drops there before surgery and after surgery. Only two out of twenty nine patients were still on any drops. Then we can see what they went from. In terms of the number of drops per day, it’s quite impressive.

So, what about the complications?  Wanted to see whether or not my complication rates were any higher than what we’ve heard? Well first of all, hyphema. My hyphema rate was much, much higher. If you look at the first eighty two cases, it was 59%, which seems like a lot. But again Steve mentioned, Hyphema is actually a positive prognostic indicator. Two independent European studies have looked at these and have shown that the presence of a hyphema after surgery means that you’re actually more likely to have a successful result. And it makes sense, you’re getting reflux. I actually tell my patients not only about what to expect in terms of their vision but I tell them that we want to see this hyphema. And I’m perhaps a little too convincing because of my patients come in the day after surgery, and their vision is identical to what it was before. Their word, “Doctor, did it work? My vision’s fine.” So this actually doesn’t bother me. And if you look at the time of resolution to hyphema, what you’ll see is in general a hyphema resolves in one to two weeks. I have had a couple of these were early on, and in general  what people find is that early on, your hyphema is high or larger. You know this is uncomfortable with procedure, it takes longer. My hyphema is now, are rarely more than one to two millimeters in size and almost always resolves by two weeks out. So again this is my early data.

How about a Seidel Test? When we talk about taking that flap watertight, the problem for me and my practice is that I have a lot of high myops. And getting that flap watertight sometimes result in a lot of induced astigmatism. So I’d try to get it down and opposed but it’s not always watertight. And so I do end up with some positive Seidel Test the first day after surgery because I’m not doing XXXXXX.  I’m just getting it down, re-opposing it. Well the thing with this positive Seidel test is I have had yet a single patient with the flat chamber. So even with some hypotony, not a single one with a flap chamber and again, they all resolved. By two weeks out they’ve all resolved.

How about a presence of a bleb? Now early on, I have about a quarter of my patients with the blebs. These blebs tend to be low-lying. They’re not a vascular. They’re just some fluid that’s getting through again because my plight probably isn’t watertight but what happen is they pretty much all resolved. I do have two patients still out of the eighty two who have a bleb. And these blebs are disappearing. They’re not keeping the patients from their normal activities. One of the patients actually has soft contact lens where she wanted to know whether or not she could wear contact lens so well I did threw mytomycin c on, go ahead and her bleb, the next time I give a talk, will probably be gone.

How about Descemet’s detachments? Early on I did get a few. I feel that injecting the viscoelastic every two clock hours can be aggressive in smaller eyes. I found that when I was doing that in the hyperopic eye, I was getting a detachment. Sight about a 7% rate. But if I look at my patients more recently, I don’t think that you would see even that higher the rate. So this is another one of those things that tends to become less common with time.

How about Goniopuncture? We hear about 10%. And in my experience, it’s about 11%. You’ll notice with my patients. It could be anywhere. People asked when will you do Goniopuncture. Well looking back I did Goniopuncture all the way from my three months out or two months out, actually to a couple years out? So there wasn’t really a pattern there.

Now this is a question I get asked a lot. Because we know that there’s induced astigmatism early on after canaloplasty and it can be significant. My first patient had six day after induces stigmatism. Then here’s the key, it goes away. We looked at induced astigmatism in my patients using pre-operative and post- operative case, and two hundred and fifty or more days out the mean change in astigmatism was just over a quarter diaptor with the rule. How about change in spherical equivalent? Another thing people ask about thinking well that suture in the canal is going to result in some sort of change in the dioptics strength of the cornea? It doesn’t.

So here I got, it’s just a brief summary of my early experience going from somebody who had no experience or skill on glaucoma surgery to someone who very quickly ramped up with Canaloplasty. If anyone was set up for failure in this procedure, it was me.

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