Are All Microinvasive Glaucoma Surgeries (Migs) The Same? Comparing Microtrabecular Bypass (Istent), Microstent (Hydrus), Excimer Laser Trabeculostomy (Elios) And Gonioscopy-Assisted Transluminal Trabeculotomy (Gatt)

Glaucoma has benefited from a wide variety of new surgical techniques, namely MIGS, microinvasive glaucoma surgeries. Several MIGS have had promising studies; nevertheless, we need a real population study with direct comparisons among different techniques.

A retrospective monocentric study comparing different MIGS in glaucoma patients in our Ophthalmology service, performed by a glaucoma surgeon.

The different MIGS included iStent, iStent with goniotomy, Hydrus, ELIOS, and GATT; from 1^st January 2023 to 28^th February 2025. Less invasive surgeries (LIGS, including Preserflo, XEN, and MIMS) were excluded from this study, as classical filtering surgery (trabeculectomy, deep sclerectomy, Ahmed glaucoma valve, Baerveldt drainage device, and EyeWatch). We observed surgical success, defined as either 20% decrease in IOP without increasing medication, or decreasing at least one class without increasing IOP; without secondary glaucoma surgery We identified the number and severity of complications during and after surgery. We also assessed the need for secondary glaucoma surgery.

We included 425 eyes from 345 patients with surgeries from January 2023 to February 2025; the majority of these patients was submitted to iStent or iStent combined with goniotomy (284 eyes in 225 patients), followed by GATT (85 eyes), and by ELIOS (28 eyes) and Hydrus (28 eyes). ELIOS and Hydrus were incorporated into the service mid-2024, explaining its lower surgical numbers. The success of these techniques was similar, but slightly higher for the GATT surgery. The advantage of the iStent relied in its safety and speed, the ELIOS is implantless and fast, the Hydrus had less IOP spikes than the other techniques. ELIOS, GATT and iStent had IOP spikes, related probably to a steroid response, but without correlation to failure in our series.

All MIGS techniques (iStent, Hydrus, ELIOS, and GATT) were effective and safe for the surgical treatment of glaucoma. GATT was more powerful decreasing the IOP, at the cost of more intraoperative and postoperative complications, such as temporary bleeding, and need for closer follow-up. Each MIGS technique has its advantages and disadvantages, and respecting each technique’s indications, contra-indications, and improving one’s surgical approach are fundamental keys to increase success against glaucoma.