When a Glaucoma Drainage Implant Stops Working: What a Review of 44 Studies Says About Next Steps

For glaucoma that is hard to control with drops, laser, or other surgery, many surgeons use a glaucoma drainage device, a small tube and plate that carry fluid out of the eye to lower pressure. These devices help many people, but they do not last forever in every eye. The authors of a new review note that up to 10% fail each year. So what comes next? A systematic review in the Journal of Glaucoma gathered the evidence.

What the researchers did

A team in Porto, Portugal, with a collaborator in Leuven, Belgium, searched PubMed, Web of Science, and Scopus in November 2025. They included 44 studies with 1,560 eyes of 1,518 patients who had surgery after a drainage device failed.

The main options studied

• A second drainage device. The most common approach. It lowered eye pressure by more than 30%, but success rates varied widely, from about 30% at three years to more than 90% at one year. Swelling and clouding of the cornea was a frequent complication.
• Cyclophotocoagulation. A laser treatment that reduces fluid production. It lowered pressure by 25% to 45%, with fewer device-related complications, but sometimes caused long-term pressure that was too low (hypotony).
• Trabeculectomy and other procedures. Trabeculectomy, angle-based surgeries, and revisions of the existing device showed mixed but encouraging results in selected patients.

One randomized trial found the laser and a second device worked about equally well, with fewer repeat operations in the laser group. Results in children were less favorable.

The authors’ cautions

Most studies were retrospective and defined success differently, which limits firm conclusions. There is no single best answer for every eye.

What patients should take from this

• A failed drainage device does not mean you have run out of options.
• The best next step depends on your cornea, your vision, your other eye, prior surgeries, and your overall health.
• Ask your glaucoma surgeon about the trade-offs: pressure control, risk of corneal problems, risk of low pressure, and the chance of needing another procedure.
• Keep every follow-up visit after any glaucoma surgery; early problems are easier to manage.

Complex glaucoma surgery is performed by glaucoma specialists. For more plain-language reading on eye health, see encinolasik.com.

Source: Surgical Options for Glaucoma Patients With Failed Glaucoma Drainage Devices: A Systematic Review (Journal of Glaucoma (PubMed), epub 07/10/2026). This article is an educational summary written by Khanna Vision Institute and is not a substitute for medical advice.