Advances in Excimer Laser Trabeculostomy within the Landscape of Minimally-Invasive Glaucoma Surgery

Abstract

Primary open-angle glaucoma (POAG) is currently treated with a variety of surgical and non-surgical approaches. Minimally invasive glaucoma surgery (MIGS) involves several devices and procedures that lower intraocular pressure (IOP) by increasing aqueous outflow. The first laser-based MIGS procedure, Excimer Laser Trabeculostomy (ELT), has emerged as a safe and effective treatment option. This article reviews ELT within the context of alternative MIGS procedures and focuses on the historical development of ELT, principles and techniques of the ELT procedure, safety and efficacy data, comparison to other outflow procedures, and future augmentations to expand the use of ELT. Performed alone or as an adjunct to cataract surgery, ELT has minimal complications and has shown long-term effectiveness in lowering intraocular pressure in thousands of patients. The non-thermal laser-tissue interactions of excimer lasers minimize peripheral tissue damage and ensure outflow channel patency without requiring foreign body implants or creating blebs. The development of 2D optical and 3D optical coherence tomography (OCT) guidance systems will eliminate the need for a goniolens to visualize angle structures and enable thousands more surgeons to perform ELT in the future.

Keywords: ELT; MIGS; excimer laser trabeculostomy; glaucoma; guidance; intraocular pressure; laser; micro-invasive glaucoma surgery; minimally invasive; treatment.

Figure 1

From Berlin et al. (2019): Comparison of various outflow procedures over time based on published results of exemplary studies. The y-axis represents the percentage decrease of IOP from Pre-Op IOP and the x-axis represents the number of years. Reprinted with permission from Ref. [35]. 2019, Kugler Publications.

Figure 2

Guided Excimer Laser Trabeculostomy (ELT) GEN 1 Schematic. Berlin, MS, inventor: Image Guidance Methods and Apparatus for Glaucoma Surgery. United States patent US 11,071,647 B2. 27 July 2021.

Figure 3

Guided ELT GEN 2 Schematic. Berlin, MS, inventor: Methods and Systems for OCT Guided Glaucoma Surgery United States patent US 10,517,760 B2. 31 December 2019.