Ab interno glaucoma surgery encompasses minimally invasive procedures performed from inside the eye through small corneal incisions. They target the trabecular meshwork, Schlemm’s canal, or suprachoroidal and subconjunctival pathways to lower pressure.
Types of Ab Interno Procedures
Examples include trabecular microbypass stents, goniotomy or trabeculotomy with microblades or cannulas, excisional goniotomy, and ab interno canaloplasty. Many are classified as MIGS.
- Often combined with cataract surgery in the same sitting
- Visual recovery is usually rapid with fewer serious complications than traditional filtering surgery
- Most suitable for mild to moderate open‑angle glaucoma
- Pressure lowering is typically moderate rather than profound
Role in Treatment Pathway
Ab interno surgery offers a middle ground between medications/laser and more invasive trabeculectomy or tube shunt surgery. Choice depends on glaucoma severity, angle anatomy, and surgeon experience.
- Patients may still need drops but often at reduced levels
- Complications can include transient bleeding, inflammation, or device failure
- Regular follow-up checks pressure and optic nerve status
- Some procedures can be repeated or combined if further pressure reduction is needed
