Health Technology Brief

supporting sound, evidence-based decision making

iStent Inject Trabecular Micro-Bypass Stent (Glaukos Corp.) as a Standalone Treatment for Open-Angle Glaucoma

September 17, 2019

Health Problem: Glaucoma is a disease of the optic nerve characterized by loss of retinal ganglion cells, remodeling of the lamina cribrosa, structural changes to the nerve, elevated IOP, and progressive, irreversible loss of vision leading to blindness. Open-angle glaucoma (OAG) is associated with partial blockage of the flow of aqueous humor. 

Technology Description: The iStent inject consists of 2 heparin-coated titanium multidirectional stents. The single-piece stent is 230 micrometers (µm) in diameter and 360 µm in height. The iStent inject stent design allows for the rear flange to reside in the anterior chamber and the head to reside in Schlemm’s canal, with the thorax of the stent retained by the trabecular meshwork, allowing aqueous humor to drain directly from the anterior chamber of the eye and reducing intraocular pressure (IOP). 

Controversy: Many glaucoma surgical procedures are associated with pain, infection, hypotony, hemorrhage, corneal edema, and visual disturbances. For these reasons, minimally invasive approaches are sought. However, controversy surrounds the comparative effectiveness of minimally invasive glaucoma surgeries with trabecular bypass stents and whether the long-term effect of such procedures will result in the reduction of the use of glaucoma medications.

Key Questions:

  • Is the iStent inject trabecular micro-bypass stent as a standalone procedure effective in managing OAG? 
  • How does the iStent inject trabecular micro-bypass stent as a standalone procedure compare with clinical alternatives in the management of OAG? 
  • Is the iStent inject trabecular micro-bypass stent safe? 
  • Have definitive patient selection criteria been identified for the iStent inject trabecular micro-bypass stent?