Prospective, noncomparative, nonrandomized case study of short-term outcomes of 360° suture trabeculotomy ab interno in patients with open-angle glaucoma

BACKGROUND In this paper, we describe 360° suture trabeculotomy (360°LOT) ab interno and the short-term course in patients who underwent this procedure. METHODS We prospectively studied 12 patients (12 eyes) with open-angle glaucoma who underwent 360°LOT ab interno at the Sato Eye Clinic between February and July 2014. The surgical procedure involved making a 1.7 mm temporal corneal incision, exposing an approximately 15° opening in the inner wall of Schlemm's canal (nasal side) using a Trabectome with a gonioscope, and inserting a 5-0 nylon suture rounded at the tip into Schlemm's canal opened via the anterior chamber. The suture was then threaded around Schlemm's canal, and the tip of the suture that emerged on the other side was then advanced through the opening to make a circumferential incision. Intraocular pressure (IOP), number of anti-glaucoma medications used, complications, and the surgery completion rate were prospectively studied. RESULTS Mean IOP, which was 19.4 mmHg at baseline, showed a significant decrease at each of the monthly observation points, reaching 13.8 mmHg at 6 months after surgery (P=0.0004, paired t-test). The mean number of anti-glaucoma medications decreased from 3.2 at baseline to 1.1 at 6 months after surgery. IOP spikes ≥30 mmHg were seen in 25% of patients, but there were no other serious complications and the surgery completion rate was 92%. CONCLUSION The 360°LOT ab interno procedure preserves the conjunctiva and sclera, and has a high surgery completion rate when using the anterior chamber approach, and could therefore be an effective short-term treatment of open-angle glaucoma.