GATT is gonioscopy-assisted transluminal trabeculotomy and it was described almost 10 years ago where the trabecular meshwork can be torn open and bypassed. This allows for better flow of aqueous into the collector channels and therefore a lower intra-ocular pressure. A 6-0 polypropylene suture is first slightly cauterized to blunt the end, the trabecular meshwork is accessed by incising it with a small gauge needle, and then the suture is passed circumferentially within Schlemm’s canal for a full 360 degrees until it re-emerges. Both ends are then pulled out of the eye which tears open the trabecular meshwork. Studies have shown good efficacy with a reduction of about 10 mmHg when combined with cataract surgery.
