What is trab 360?
Trab 360 is a newer glaucoma procedure belonging to a group of glaucoma surgical procedures known as microinvasive glaucoma surgery or MIGS. This procedure is similar to trabectome and another procedure called GATT (gonioscopy assisted transluminal trabeculotomy). Unlike trabeculectomy or tube shunt surgery, which bypass the internal drainage system to filter fluid outside the eye, these procedures are designed to improve eye pressure by enhancing drainage through the natural internal drainage pathway. Specifically, this procedure involves stripping the trabecular meshwork to expose the internal drainage canal called the canal of Schlemm which then has access to the remainder of the drainage system known as the collector channels. In effect, stripping the trabecular meshwork removes much of the resistance to flow of internal eye fluid allowing the internal eye fluid to drain faster and more efficiently resulting in lower eye pressure. However, in those patients who have poor outflow through the collector channels this procedure may only have limited effectiveness. Determining the status of the collector channels cannot be made prior to surgery but can be assessed indirectly during surgery. Scarring at the site where the tissue is removed may cause a block in the flow of internal eye fluid and limit the success of surgery.
How is the surgery performed?
A small incision is made in the clear part of the eye called the cornea and using a specialized viewing lens a device is inserted into the eye and the trabecular meshwork is pierced. Then the canal is threaded with a special stent for its entire length around the eye (that’s why it is called 360 because it is inserted 360 degrees around the eye) and then pulled to strip the meshwork. This maneuver will result in considerable reflux bleeding which sometimes requires an injection of gel like material to control the bleeding. Most of the time the blood clears and eye pressure decreases significantly.
Am I candidate for trab 360 or trabeculotomy?
Patients who have normal angle anatomy and mild-moderate stage of glaucoma are potential candidates. Certain subgroups of glaucoma patients such as those with pseudoexfoliation, childhood/developmental glaucoma, or juvenile open angle glaucoma seem to do better. The effectiveness of this procedure is reasonable for patients with earlier stages of disease but may not be effective enough for those who require very low eye pressures.
What are the risks of surgery?
Reflux bleeding is generally greater with more removal of tissue and can affect the success of procedure and require a repeat visit to the operating room to remove the blood. Blood clots can lead to scarring of the canal and adhesions resulting in surgical failure. Cataract may also develop in those eyes who are not undergoing simultaneous cataract surgery. Less commonly low eye pressure may occur due to development of a cleft. Trauma to the, cornea or iris with pupil distortion has also been reported. The risk of serious complications overall, was low.