Canaloplasty Glaucoma Surgery
Intended for eye surgeons/ glaucoma specialists who want to master canaloplasty. Canaloplasty is a minimally invasive glaucoma treatment. Although technically challenging, Canaloplasty has several advantages over traditional glaucoma treatments/ surgeries, specially in its safety profile.
Canaloplasty Glaucoma Surgery
Using Mastel Instruments: Part 1 – Dissecting The Superficial Flap
The canaloplasty surgery has already been initiated here. I’ve essentially placed what is called a bridle suture, and pulled the eye into position, and created a mark so that I know where I need to make my initial superficial flap.
What I’m showing here is the actual Mastel diamond PhD II blade. And this is a multi use blade that is really a wonderful instrument for canaloplasty and can be used for all of the dissection, cutting, as I’m going to show in this video.
What I’m showing here is just the actual control end of the instrument. This is the end where you can choose just how many microns of diamond you want extending from the tip of the instrument.
So anyway, you can see the outline here of the superficial flap. And what I’m doing here is I’m actually showing the design of the instrument. But anyway, so this right here is what’s called the footplate, and the foot plate is what essentially delineates how much of the diamond is exposed beyond this footplate.
And what I’m going to show here is just how fine this diamond is. So what you see here is this diamond actually has a bevel… So this here is called the tri port. This instrument is a fixation instrument. And what you can see is that it’s got a tongue. it’s got a tongue that can be used to insert into a paracentesis.
And on the underside of this, which I think I have a better visualization of this, there are these little pyramids sticking out from the bottom of this that can be used to fixate the globe by placing them firmly down on the surface of the eye, so it’s a nice fixation instrument. And what you’re going to see to the right here now is my creation of the superficial flap using the diamond blade. And what’s really notable here is just how fine this incision is. There’s absolutely no fraying of the edges of the sclera. It’s just a very, very sharp, fine delineation.
And I’ve set this to 350 micrometers, and you can see that I actually angle the incision, so it’s not a perpendicular incision but rather an angle. So that gives me a little bit more visualization, and because I set it at 350 here, as you can see, it allows me to angle. And I end up at about 300 micrometers, which we’re aiming for 50 percent of the scleral thickness.
So you saw what I did there was I just placed the diamond on full extend, so it is now extended fully from the diamond blade or from the instrument. So here I’m going to take the diamond instrument and I’m going to freehand the flap, just the beginning of a flap. And I do this because I don’t want to actually have a titanium instrument anywhere near the tip of this blade. This is a very, very fine blade.
Now, the other nice thing about this blade is that… Oh here, these are .06 forceps, also Mastel forceps. It’s a prototype. And these forceps are just wonderful for grabbing onto these flaps. They’re very delicate. They are toothed. And here what you’re going to see is that I take a diamond instrument and use it to create the scleral plane.
And the key thing to recognize here is that this cutting is being done purely by sight. There is no tactile feedback with this blade at all. You can see how it just cuts through this sclera like butter and it’s so smooth. And the nice thing about it is that if you get off plane, it’s very easy to get back into the right plane because it’s so sharp. It’ll cut through tissue even when there is no traction.
Now, I’m actually moving pretty fast here in my dissection, which is not how I first used this blade because it just cuts through tissues so readily that you actually want to go pretty slow when you first start. And you’ll notice that I have this blade set so that the foot plate is actually down against the sclera, and that actually is allowing me to cut with the bevel down.
The bevel down approach essentially makes a natural tendency of the cut to come superficial. In general, it’s more concerning to go too deep than too superficial, and the bevel down results in protection from going too deep.
About the Author: David Richardson, MD
Medical Director, San Marino Eye
David Richardson, M.D. is widely recognized as one of the top cataract and glaucoma surgeons in the US and is among an elite group of glaucoma surgeons in the country performing the highly specialized canaloplasty procedure. Morever, Dr. Richardson is one of only a few surgeons in the greater Los Angeles area that performs Micropulse® "Cyclophotocoagulation" (MP3) glaucoma laser surgery. Dr. Richardson graduated Magna Cum Laude from University of Southern California and earned his Medical Degree from Harvard Medical School. He completed his ophthalmology residency at the LAC+USC Medical Center/ Doheny Institute. Dr. David Richardson is also an Adjunct Assistant Professor of Clinical Ophthalmology at Keck School of Medicine of USC. Twice weekly, he treats veterans at the VA Greater Los Angeles Veterans Healthcare System.