Table 1.
Implants used during micro-invasive glaucoma surgery procedures – overview and status
| Device | iStent® | iStent® inject | Hydrus | CyPass® | iStent® supra | XEN |
|---|---|---|---|---|---|---|
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| Outflow pathway | Trabecular | Suprachoroidal | Subconjunctival | |||
| Manufacturer | Glaukos Inc., Laguna Hills, CA, USA | Glaukos Inc., Laguna Hills, CA, USA | Ivantis Inc., Irvine, CA, USA | Alcon Inc., Fort Worth, TX, USA | Glaukos Inc., Laguna Hills, CA, USA | Allergan plc, Dublin, Ireland |
| Mode of action | Penetration of the trabecular meshwork and insertion into Schlemm’s canal | Penetration of the trabecular meshwork and insertion into Schlemm’s canal | Intracanalicular scaffold is inserted into Schlemm’s canal to maintain patency and establish outflow | Creation of a controlled cyclodialysis with stented outflow to the suprachoroidal space | Transport of aqueous humor from the anterior chamber to the suprachoroidal space via stent | Outflow path from the anterior chamber to the subconjunctival space |
| Material | Heparin-coated non-ferromagnetic titanium | Heparin-coated non-ferromagnetic titanium | Nickel-titanium alloy (nitinol) | Polyamide | Polyethersulfone and titanium | Collagen-derived porcine gelatin cross-linked with glutaraldehyde |
| Size | Length: 0.3 mm in height and 1 mm in length | Length: 360 μm Diameter: 230 μm |
Length: 8 mm | Length: 6.35 mm Outer diameter: 510 μm |
Length: 4 mm Lumen: 0.16–0.17 mm |
Length: 6 mm; Lumen: 45 μm |
| Specifics | Pre-loaded injector | Pre-loaded injector with two devices | Shape memory function | Lumen: 0.3 mm Stent must be loaded on injector by surgeon | Pre-loaded injector | Pre-loaded injector; 45 μm lumen size commercially available |
| Status | CE-mark granted in 2004: FDA approved since 2012 | CE-mark granted in 2010 | FDA approval for Phase IV clinical trials; CE-mark in Europe | CE-mark granted in 2008; FDA approval 2016 |
CE-mark granted in 2010: under FDA review | CE-mark granted 2013; FDA approved for refractory glaucoma where previous surgical treatment has failed and patient is unresponsive to maximum tolerated medical therapy; in 2016 |
Abbreviation: FDA, US Food and Drug Administration.