Long-Term Clinical Results of Ab-Interno Trabeculotomy in Glaucoma Management

Overview

Glaucoma is one of the leading causes of irreversible vision loss worldwide. Elevated intraocular pressure (IOP) is the most important risk factor for the development and progression of the disease. Ab-interno trabeculotomy (AIT) using the Trabectome system is a minimally invasive glaucoma surgery (MIGS) that reduces aqueous humor outflow resistance by ablating the trabecular meshwork and the inner wall of Schlemm's canal, thereby lowering intraocular pressure. Previous studies have demonstrated good short-term efficacy of this procedure. However, robust long-term data spanning several years remain scarce. The aim of this study is to evaluate the long-term outcomes of AIT in glaucoma patients who underwent surgery between 2019 and 2021 at the Department of Ophthalmology, University Hospital Würzburg. Patients are invited for a single study visit at which intraocular pressure, visual acuity, anterior chamber angle by gonioscopy, and optic nerve structure by optical coherence tomography (OCT) are assessed. The collected data are compared with pre-operative baseline values obtained from medical records. The results are intended to improve the assessment of long-term surgical success and to optimize patient selection for this procedure in the future.

Glaucoma is a progressive optic neuropathy in which elevated intraocular pressure (IOP) represents the primary modifiable risk factor. Ab-interno trabeculotomy (AIT) with the Trabectome is a minimally invasive glaucoma surgery (MIGS) that reduces IOP by ablating the trabecular meshwork and inner wall of Schlemm's canal, thereby improving aqueous humor outflow. Previous studies have demonstrated favorable short-term IOP reduction and a good safety profile. However, robust long-term data evaluating sustained surgical success, disease progression, and the need for additional interventions over multiple years are currently lacking. This single-center, observational study with a retrospective pre-operative baseline and a prospective cross-sectional follow-up visit addresses this knowledge gap. Patients who underwent AIT at the Department of Ophthalmology, University Hospital Würzburg, are contacted and invited for a single study visit of approximately 30 minutes. At this visit, the following assessments are performed: * Medical history review since the time of surgery * Visual acuity assessment * Goldmann applanation tonometry (IOP measurement) * Slit-lamp biomicroscopy including gonioscopy for the anterior chamber angle * Optical coherence tomography (OCT) of the optic nerve head and retinal nerve fiber layer (RNFL) All examinations are non-invasive, painless, and consistent with routine ophthalmic care. No additional follow-up visits are required beyond this single study contact. Pre-operative data, including baseline IOP, glaucoma diagnosis, medication use, and surgical details are obtained from existing medical records. These are compared with findings at the study visit to evaluate long-term treatment success. The study is initiated and funded by the Department of Ophthalmology, University Hospital Würzburg. No external funding or industry sponsorship is involved. The study has been approved by the responsible Ethics Committee with no objections raised. Approximately 180 participants are planned for enrollment. Data are pseudonymized and stored on password-protected servers. No data transfer to third parties or outside the European Union is performed. Data will be deleted no later than 10 years after study completion.