Outcome of GATT Combined With Goniosynechiolysis in Glaucoma Patients With Secondary Synechial Angle Closure.

Glaucoma is a group of diseases that present with cupping of the optic nerve head and visual-field defects. It is the most common cause of irreversible blindness all over the world.Angle-closure glaucoma is a type of glaucoma characterized by narrowing or closure of the anterior chamber angle. Two major types of angle closure glaucoma are defined by the mechanism of angle closure: in appositional contact, the iris is pushed by a pressure difference between the posterior and anterior chambers due to relative pupillary block, while in synechial contact, the peripheral iris adheres to the trabecular meshwork by peripheral anterior synechiae (PAS). PAS can develop in various ocular conditions, including: ocular inflammation, a post-traumatic condition, after cataract surgery, or with an iris bombe in a pupillary block glaucoma. Grover et al. described a technique for ab-Interno circumferential trabeculotomy termed gonioscopy-assisted transluminal trabeculotomy (GATT). The procedure aims to create a 360° trabeculotomy from an ab-Interno approach. GATT procedure is a MIGS technique in which trabecular meshwork is circumferentially bypassed by incising it using a suture or microcatheter.In this technique, aqueous humor passes through the collector channels and episcleral veins through the cleaved open diseased trabecular meshwork. Elsayed et al previously demonstrated that combining phacoemulsification with GATT in PACG yielded more favorable outcomes in terms of IOP, glaucoma medications and surgical success compared to phacoemulsification alone.However, to date, no studies have looked at the outcomes of combining goniosynechialysis with GATT in secondary angle closure glaucoma. In fact, most studies looking at the outcomes of GATT in different types of glaucoma excluded eyes with synechial angle closure. Goniosynechialysis (GSL) is the process of physically separating PAS, which can develop in the trabecular meshwork due to various conditions including primary and secondary cases of angle closure. So, for those cases of synechial angle closure glaucoma combining GATT and GSL might aid in the IOP lowering effect required.