45 µ diameter as well as its 6mm length, outflow is predictable.
Clinical trials have shown it to reduce IOP by about 7 mmHg.
Significantly, the FDA approval for this stent does not require that it
be done in conjunction with cataract surgery. You can do it under top-
ical/intracameral lidocaine. I believe once this procedure starts to gain
traction, the number of trabeculectomies will decline precipitously.
Because all 3 stents have different mechanisms of action, I some-
times use more than one to get the amount of pressure lowering I
need. Occasionally that can cause a reimbursement issue, but if the
patient is willing to pay for the procedure privately it's not a problem.
We could see more stents soon: Glaukos's iStent Supra, which strong-
ly resembles the CyPass, and also the iStent Inject and Infinity. The first
employs 2 stents with cataract surgery and the second features 3 stents
as a standalone procedure.
Canaloplasty and
goniotomy/trabeculotomy
Since 2008, surgeons have also been able to use canaloplasty to clean
out and expand Schlemm's canal. This procedure might be akin to
using a roto-rooter to clean out a sluggish drainpipe underneath the
shower. A medical analogy would be angioplasty.
When this procedure started out, we used a tedious external
approach that was supremely difficult and time consuming. It was not
considered minimally invasive. Since then surgeons have discovered
that they can also do this procedure with an ab interno approach,
which is more efficient and can be classified as MIGS. To do the
newer technique, the surgeon makes an incision as one would for
cataract surgery, using a surgical gonioprism to visualize the angle
anatomy, dissects an opening into the canal and then feeds an ultra-
thin catheter all the way around the circumference of the canal back
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