Glaukos iStent (New Microinvasive Glaucoma Surgery)
The Stent Procedure is a microinvasive glaucoma surgery that Is approved by FDA for the treatment of Open Angle Glaucoma by creating a permanent channel between the anterior chamber of the eye to the Canal of Schlemm.
What is the Design of iStent Device
It is a small L-shaped device made of highly inert titanium. In order to improve the outflow of aqueous humor from the anterior chamber through the Stent to Schlemm canal. It is coated with Heparin in both the external and the internal surface of the lumen.
1- Length is 1 mm
2- Snorkel with Lumen of 120 μm. Snorkel is exposed to the aqueous humor in the anterior chamber
3- Weight: 60 μg
4- Three retention arches. Help to ensure secure placement within Schlemm canal.
How does it Work
Aqueous Humor is drained outside the eye from trabecular Meshwork to collector channel and Schlemm Canal. In patients with Open Angle Glaucoma there is a defect in trabecular meshwork of the eye and aqueous Humor can’t pass through it to Schlemm Canal.
Stent is used to create a permanent opening in trabecular meshwork in which aqueous humor can be drained through it outside the eye and reduce the intraocular pressure.
Indications of Glaukos iStent
Reduction of intraocular pressure in patients with mild to moderate Open Angle Glaucoma.
Contraindications
Patients with Primary or Secondary angle closure glaucoma. In these patients the trabecular meshwork is usually damaged and compromised.
Advantages over traditional Glaucoma Surgery
1- Low Risk surgery because it is minimally invasive and it is usually done during the cataract surgery and the recovery time from Stent procedure is the same as cataract surgery recovery time with no additional eye drops.
2- Fast surgery. The implantation of the device won’t take more than 1-2 minutes.
3- No damages to eye tissues such as sclera and conjunctiva which often damaged during traditional glaucoma surgeries.
4- Once it is in the correct location it will start to work immediately.
Adverse Effects of iStent
1- Corneal Edema. This is the most common complication. It is transient and most of the time it is self limited.
2- Posterior capsular opacification
3- Obstruction of the stent.
4- Mild anterior chamber reaction which is a transient condition and can be treated with mild corticosteroid eye drops.
