Trabeculotome Tunneling Trabeculoplasty (3T): A Step-by-Step Surgical Protocol for Primary Open-angle Glaucoma

Summary

This protocol describes Trabeculotome Tunneling Trabeculoplasty (3T)—a minimally invasive glaucoma surgery that includes trabecular incision, Schlemm’s canal (SC) dilation, and tension suture implantation to restore physiological aqueous outflow—accompanied by a noncomparative case series.

Abstract

Primary open-angle glaucoma (POAG) requires sustained intraocular pressure (IOP) reduction to delay disease progression. Traditional filtering surgeries, while effective, are associated with significant tissue trauma, postoperative complications, and long-term scarring. Minimally invasive glaucoma surgery (MIGS) offers a safer alternative but may be limited by incomplete IOP reduction or long-term structural instability of Schlemm’s canal (SC).

Trabeculotome tunneling trabeculoplasty (3T) is a novel MIGS technique designed to restore physiological aqueous outflow while preserving trabecular meshwork (TM) structure. The procedure consists of three key steps: trabecular fenestration using a trabeculotome, viscoelastic-mediated dilation of SC, and placement of a tension suture to maintain long-term canal patency. This article provides a step-by-step surgical protocol and accompanying training video for the 3T procedure. Representative outcomes from a single-center, non-comparative case series demonstrate that 3T is associated with significant IOP reduction, decreased dependence on antiglaucoma medications, and a low complication rate. This protocol aims to facilitate standardized clinical implementation of 3T and provide a practical educational resource for surgeons performing minimally invasive glaucoma procedures.

Introduction

Glaucoma is the leading cause of irreversible blindness worldwide, with POAG being the most common subtype. The 3T procedure is based on the mechanobiological pump theory of the trabecular meshwork (TM), which describes the TM as a biomechanical structure responsive to its mechanical microenvironment¹. The structural and functional integrity of this system is maintained by the biological properties of TM cells and tissues². Preliminary findings from a single-center case series indicate that 3T is associated with significant IOP reduction, reduced medication dependence, and a low complication rate³....

Protocol

This protocol received approval from the Ethics Committee of Chengdu Integrated TCM & Western Medicine Hospital (2024.XJS.005). Clinical trial registration has been completed; the registration number is: ChiCTR2500099671. Prior to video production for educational purposes, informed consent was obtained from all patients.

1. Inclusion criteria

1. Use the following inclusion criteria: aged 18–75 years (inclusive) at informed consent signing, all sexes; POAG with IOP > 21 mmHg despite maximal tolerated medical therapy, indicating surgical indication; no prior glaucoma surgery or prior ocular surgery with....

Results

Study population and case distribution
Between December 2022 and September 2023, a single surgical team at Chengdu Integrated TCM & Western Medicine Hospital performed the 3T procedure on 42 patients (42 eyes) with POAG in this retrospective study. Consecutive patients meeting the inclusion criteria during the study period were enrolled without selection bias. All included cases underwent standalone 3T surgery; no combined cataract surgery cases were enrolled in this study. All surgeries were per.......

Discussion

The increased resistance to aqueous humor outflow in primary POAG arises primarily from microstructural alterations in the TM and SC, including excessive extracellular matrix deposition leading to tissue stiffness, SC collapse, and impaired biomechanical pumping function of the TM^14,15,16. In response to these pathomechanisms, the corresponding author developed the 3T procedure—a minimally invasive technique that reconstru.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Blunt hook threader	Suzhou Mingren Medical Instruments Co., Ltd.	MR-S600
Corneal scissors	Suzhou Mingren Medical Instruments Co., Ltd.	MR-V220
Double-mirror gonioprism	Volk Optical Inc.	G-2
Intraocular forceps	Suzhou Mingren Medical Instruments Co., Ltd.	MR-E315
Lens implantation forceps	Suzhou Mingren Medical Instruments Co., Ltd.	MR-I310
Lens manipulator hook	Suzhou Mingren Medical Instruments Co., Ltd.	MR-S520
Micro-capsulorhexis forceps (curved tip)	Suzhou Mingren Medical Instruments Co., Ltd.	MR-C140
Microcatheter	US New Sight Medical Co., Ltd. / Tianjin USIGHTS Ophthalmic Technology Co., Ltd.	iTRACK 250A / USIGHTS UC100
Micro-conjunctival scissors	Suzhou Mingren Medical Instruments Co., Ltd.	MR-V250
Micro-locking forceps	Suzhou Mingren Medical Instruments Co., Ltd.	MR-E161S
Micro-needle holder	Suzhou Mingren Medical Instruments Co., Ltd.	MR-N420
Micro-platform forceps	Suzhou Mingren Medical Instruments Co., Ltd.	MR-E160
Micro-toothed forceps	Suzhou Mingren Medical Instruments Co., Ltd.	MR-E140
Ophthalmic ruler	Suzhou Mingren Medical Instruments Co., Ltd.	MR-M100
Single-mirror gonioprism	Volk Optical Inc.	G-1 (VG1)
Thread fork	Suzhou Mingren Medical Instruments Co., Ltd.	MR-C810
Vannas scissors	Suzhou Mingren Medical Instruments Co., Ltd.	MR-V295
Zeng’s Trabeculotomy Knife	Bier Feng (now Bili Medical Group)	IF-8006D4