From the Research
Angle-based glaucoma surgery refers to procedures that target the eye's drainage system located at the angle where the cornea meets the iris, aiming to improve fluid outflow and reduce intraocular pressure (IOP). These surgeries are crucial in managing glaucoma, particularly open-angle glaucoma, where the drainage system is anatomically open but functionally impaired. The most common angle-based procedures include trabeculectomy, goniotomy, trabeculotomy, and newer minimally invasive glaucoma surgeries (MIGS) such as trabecular meshwork bypass stents (iStent, Hydrus) and trabeculotomy devices (Kahook Dual Blade, GATT) 1.
Key Procedures and Their Mechanisms
- Trabeculectomy: Involves creating a new drainage channel for fluid to leave the eye, thereby reducing IOP.
- Goniotomy: Targets the trabecular meshwork directly to improve outflow.
- Trabeculotomy: Involves creating a new opening in the trabecular meshwork to enhance fluid drainage.
- MIGS: Includes procedures like the implantation of trabecular meshwork bypass stents or the use of trabeculotomy devices, which are less invasive and offer quicker recovery times compared to traditional surgeries.
Post-Surgical Care and Recovery
Patients typically receive antibiotic and anti-inflammatory eye drops for 1-4 weeks after surgery to prevent infection and reduce inflammation. The recovery time varies by procedure, with MIGS generally offering faster recovery and fewer complications than traditional surgeries 2.
Effectiveness and Indications
Angle-based surgeries are particularly effective for open-angle glaucoma, addressing the fundamental problem of impaired aqueous humor outflow rather than just reducing fluid production as many medications do. A study comparing medical therapy versus trabeculectomy in patients with open-angle glaucoma found that trabeculectomy had greater efficacy in reducing IOP and preventing glaucomatous progression 2.
Considerations and Recommendations
Given the most recent and highest quality evidence, angle-based glaucoma surgery, particularly MIGS, is recommended for patients with open-angle glaucoma who have not responded adequately to medical therapy or have significant visual field loss. The choice of procedure should be individualized based on the patient's specific condition, including the severity of glaucoma, previous surgeries, and overall health status 1.