STENTS IN THE EYE: It’s like Blackberry vs iPhone (part 1)
Today we speak with Dr. Benjamin, not just about this surprising new product (although everyone may be immune to such excitement by now), but also about the rocky path to innovation.
Have there been any recent breakthroughs in glaucoma treatment? I use the word “treatment” hypothetically, because glaucoma is considered to be incurable.
The main breakthrough is a minimally invasive operation to reduce intraocular pressure. Usually, this is done with eye drops or a laser, but sometimes it turns out that neither of these is effective, so you have to seek a third option. Often, pressure in the eye rises due to so-called phacomorphic glaucoma, in which the lens starts to swell and presses against other structures. This narrows the drainage systems between the cornea and iris, causing pressure to rise even more.
And what if it’s accompanied by cataracts?
Excellent question! It turns out that after cataracts removal, intraocular pressure decreases. Recently, it’s been discovered that ultrasound, which is known to break down cataracts, somehow also affects either the drainage system or the ciliary body in such a way that leads to a decrease in pressure. But this decrease isn’t enough on its own, so auxiliary procedures are used that, if done at the same time as cataract removal, are approved by the FDA and covered through Medicare.
Why would we need ancillary operations? Is one not enough?
The advantage is that the auxiliary procedure is minimally invasive. The usual operation is very complicated, the affected areas are scarred for a long time, vision takes weeks to restore (sometimes months), pressure might be too low or too high, and the operation itself takes about an hour. For about 100 years, they’ve been searching for something minimally invasive and much more merciful. How bad would it be to just insert some kind of stent or perform a laser operation that is quick, effective, and had faster recovery times? First there was the iStent, a microscopic shunt made of titanium. A surgeon puts it in a special injector and shoots it into the so-called Schlemm’s Canal, where all the liquid drains from. The stent never closes, and this allows fluid to pass through the clogged sieve where it is normally filtered. And this procedure can be done simultaneously with cataract removal.
How long does it take?
If the surgeon is experienced, it takes 30 seconds to 2 minutes. If a patient is using eye drops and pressure is still around 20-24, then getting a cataract operation and inserting this stent will take pressure down to 16-18, and instead of taking two drops they’ll take only one.
And Medicare covers it?
Yes, but you could also ask the no-less-interesting question – is it possible to have two stents? Yes, but the results aren’t literally twice as good. If one stent lowers pressure by 3-4 units, two won’t take that down to 8, but rather 5. And insurance doesn’t pay for the second one, so this is a stumbling block for many, although two is better than one. The second costs $1500-2000, and furthermore its effectiveness decreases over time. A few years later, the sieve clogs again, pressure increases, and it’s again necessary to use eye drops or have a laser procedure.
What else is done?
Surgeons who master the iStent technique usually do endoscopic photo-coagulation, a laser treatment for the ciliary body. There’s a special probe with a microscopic chamber and this removes 2-3 units of pressure. So when removing cataracts, a stent plus photo-coagulation is used and has a good effect in the end. In Los Angeles, this technique is only used at two locations, and one of them is at our laser center with one of the only two surgeons capable of it.
But we, I feel, want to get to the main thing.
The results are good, but even they leave much to be desired. Now let’s talk about the main thing. Recently, a new type of stent appeared, called Cypass Micro-Stent Surgery, from Alcon. They’ve conducted many studies to prove its effectiveness and then began to teach surgeons how to use this technology.
It’s not easy, is it?
For the doctor, this is technically more difficult than iStent as it requires more skill, but the stent is simply amazing. It’s put exactly in the place where liquid is filtered, and as a result pressure drops significantly. Even for patients who take 3 to 4 different drops with little effect, you remove the cataracts and install Cypass – pressure drops to 10, sometimes even 8. In rare cases, it sometimes even gets too low.
Too low – how much is that?
Less than 7 is too low, because the eye needs a certain amount of pressure or it becomes soft, which causes complications. But in the hands of an experienced surgeon, Cypass is amazing. It’s only been around a year or two, and I’ve been using it for 6 months already. I’m an advocate and practitioner of this method. Moreover, I have patients with iStent in one eye and Cypass in the other, not to mention a larger number of patients that have only one or the other. The best results are achieved with a combination of Cypass and photocoagulation. iStent vs Cypass is like a Blackberry vs the iPhone!
(to be continued)