Outcomes of minimally invasive glaucoma surgery, trabeculectomy, and tube shunt surgery in secondary glaucoma: IRIS® Registry analysis.

Purpose

To evaluate the outcomes of minimally invasive glaucoma surgery (MIGS), trabeculectomy, and tube shunt surgery among young patients with secondary glaucoma.

Design

Retrospective clinical cohort study SUBJECTS: 2483 eyes with secondary glaucoma aged 18 to 40 years who underwent MIGS, trabeculectomy, or tube shunt surgery (2013-2024) in the IRIS® Registry (Intelligent Research in Sight).

Methods

The 2-year failure rates were calculated using the Kaplan-Meier estimator, with failure defined as having any of the following: (1) insufficient intraocular pressure (IOP) reduction, defined as either IOP > 21 mmHg or IOP reduction < 20% from preoperative IOP, (2) hypotony, defined as IOP < 5 mmHg, (3) any additional glaucoma procedures, or (4) development of no light perception.

Main outcome measures

The 2-year failure rates per surgery type per glaucoma subtype.

Results

A total of 454 MIGS, 337 trabeculectomies, and 1692 tube shunt surgeries were analyzed. The overall failure rates at 2 years were 50.6% for trabeculectomy, 52.1% for tube shunt surgery, 53.3% for goniotomy, and 49.0% for canaloplasty. The failure rates among traumatic glaucoma were 39.2% for trabeculectomy, 44.2% for tube shunt surgery, 55.6% for goniotomy, and 50.0% for canaloplasty. Glaucoma due to "other eye disorders," mostly following prior ocular procedures, had the highest failure rates following trabeculectomy and tube shunt surgery (58.5% and 62.2%, respectively). The failure rate for trabeculectomy was the lowest in steroid-induced glaucoma (37.6%), but hypotony was observed in 10.0% of cases. In uveitic glaucoma, the failure rates were 56.0% for trabeculectomy, 45.6% for tube shunt surgery, 55.1% for goniotomy, and 35.9% for canaloplasty.

Conclusions

MIGS accounted for nearly one in five of the glaucoma surgeries recorded in young patients with secondary glaucoma, with approximately half of cases remaining failure-free at 2 years. Surgical outcomes varied depending on the subtype of secondary glaucoma, with glaucoma due to other eye disorders being associated with higher failure rates. Trabeculectomy for steroid-induced glaucoma was successful in nearly two-thirds of the cases, but hypotony was more common in these individuals. The comparison between procedure types should be interpreted with caution as the results may be influenced by baseline disease severity.