Is goniotomy (surgical procedure to treat glaucoma) a possible treatment option for angle closure glaucoma?

Goniotomy in Angle Closure Glaucoma

Yes, goniotomy is a possible and increasingly recognized treatment option for angle closure glaucoma, particularly when combined with other procedures such as cataract extraction, surgical peripheral iridectomy, and goniosynechialysis, after the pupillary block component has been addressed. 1

Clinical Context and Mechanism

Goniotomy can be considered in angle closure glaucoma specifically when:

• Pupillary block has been eliminated through laser peripheral iridotomy (LPI) or surgical iridectomy, but intraocular pressure (IOP) remains uncontrolled 1
• Trabecular meshwork dysfunction is contributing to persistent IOP elevation after the angle has been opened 2
• Peripheral anterior synechiae (PAS) are not extensive enough to preclude trabecular meshwork access 2

The American Academy of Ophthalmology guidelines explicitly list goniotomy as a surgical treatment option alongside cataract surgery or trabeculectomy for managing uncontrolled IOP following initial treatment of angle closure. 1

Evidence for Combined Procedures

The strongest evidence supports goniotomy when combined with other interventions rather than as a standalone procedure:

• Surgical peripheral iridectomy + goniosynechialysis + goniotomy achieved 59% complete success (IOP 6-18 mmHg without medications) and 91.8% qualified success (with medications) at 12 months in advanced primary angle closure glaucoma without cataract 3
• Phacoemulsification combined with goniosynechialysis effectively manages angle closure unresponsive to conventional therapy, reducing mean IOP by 62% and medications by 55% 4
• Cataract extraction with goniotomy provides additional IOP-lowering benefit beyond lens extraction alone 2

Treatment Algorithm for Persistent IOP Elevation After LPI

When IOP remains elevated after laser peripheral iridotomy in angle closure:

1. Confirm iridotomy patency by visualizing zonules, anterior lens capsule, or ciliary processes 1, 5
2. Perform dark-room gonioscopy with compression/indentation to assess extent of PAS and identify open trabecular meshwork 1, 5
3. Consider mechanism-specific interventions:
   • If trabecular meshwork dysfunction with accessible angle: goniotomy ± cataract extraction 1, 2
   • If recent synechial closure (<6-12 months): goniosynechialysis ± goniotomy 1, 6
   • If extensive PAS or optic nerve damage: trabeculectomy 1
   • If lens-related mechanism: cataract extraction ± goniosynechialysis ± goniotomy 1

Important Caveats

Goniotomy is NOT appropriate as initial treatment for acute angle closure crisis. The definitive first-line treatment remains laser peripheral iridotomy to relieve pupillary block. 1, 5

Goniotomy effectiveness depends on:

• Presence of accessible trabecular meshwork - extensive PAS reduces success 2, 3
• Mixed mechanisms reduce success rates - older age improves outcomes while mixed angle closure mechanisms (OR=0.17) significantly reduce success 3
• Timing of intervention - goniosynechialysis is most effective within 6-12 months of angle closure 1, 6

Safety Profile

Goniotomy is categorized as minimally invasive glaucoma surgery (MIGS) with a favorable safety profile compared to traditional filtration surgery. 2 Common complications when combined with other procedures include IOP spike (14.8%), hyphema (11.5%), and shallow anterior chamber (4.9%). 3