This video demonstrates a goniotomy surgery using the Kahook Dual Blade (KDB). The patient had primary open angle glaucoma and the goal was to decrease the pressure as well as dependence on IOP lowering medication. Dr. Kahook explained the steps in detail and he also described the three common techniques used by Kahook Dual Blade.
Surgery Location: on-board the Orbis Flying Eye Hospital in Bridgetown, Barbados
Surgeon: Dr. Malik Y. Kahook, University of Colorado School of Medicine, Aurora, CO, USA
DR KAHOOK: This is Malik Kahook, Professor of Ophthalmology at the University of Colorado, and I’d like to share with you a case that I performed on the Orbis Flying Eye Hospital, involving goniotomy with the Kahook Dual Blade, also known as KDB. The patient had primary open-angle glaucoma, and the goal was to decrease pressure, as well as dependence on intraocular pressure-lowering medication. The patient also received peribulbar anesthetic, prior to entering into the operating room. We used a Swan-Jacob lens because an open-axis gonio prism was not available. We start off by placing the Swan-Jacob lens over the cornea, coupled with viscoelastic. It is key at this point to zoom in, so that the extent of your view is covered mostly by the gonio prism. You can see the excellent view that this provides to the trabecular meshwork. Once we’ve settled that the view is adequate for the procedure, we enter in with the KDB, and tilt the tip 10 degrees up toward the trabecular meshwork, to assist with entry through the TM and into Schlemm’s canal. This is followed by settling the heel against the anterior wall of the canal, and performing a one clock hour treatment at the area that we anticipate completing the second part of the maneuver. Here you see the second part, where we enter into the canal about three clock hours to the left of the initial treatment. And we perform parallel incisions in the trabecular meshwork, up until that initial treatment point. This allows us to produce a strip of trabecular meshwork that you can see here. The strip of trabecular meshwork is then removed with Utrata forceps, and you can see we move side to side to make sure that none of the tissue is tethered, and you can see the balled-up trabecular meshwork at the edge of the Utrata forceps. The tissue is then removed, and you can see that there’s some oozing from the collector channels, which is a wonderful sign signifying that the distal collector outflow system is patent. I’d like to go over three techniques that are commonly used with KDB. The first involves entering through the clear corneal incision across to the nasal trabecular meshwork, and performing what’s called the inside-out technique. Moving with a forehand to the left, and a backhand to the right, and it results in two balled-up areas of trabecular meshwork on either side that are left in place. Another technique, which we showed on the video, is called the mark and meet, where you place an initial treatment for one clock hour, at the site where you anticipate completing the treatment, and you move three to four clock hours to the other side, with another forehand maneuver, enter into the trabecular meshwork, and treat to the area of the initial pass that you completed. This results in a free trabecular meshwork strip that can be removed. The final technique is called the outside-in technique, where you enter into the anterior chamber, move two to three clock hours to one side, and treat to a point across from the clear corneal incision. You then reverse course two to three clock hours the other way, to result in a free trabecular meshwork strip. We then hydrate the wounds water tight, to a pressure of 20 to 25 millimeters of mercury, and that completes the case. Thank you.
June 14, 2018