iStent & Drainage: MIGS & Implants

An iStent is a tiny trabecular micro‑bypass stent used in minimally invasive glaucoma surgery (MIGS). During cataract surgery or as a standalone procedure, this device is inserted into the trabecular meshwork to create a permanent drainage channel. By improving the outflow of aqueous humor, it helps lower intraocular pressure and may reduce the need for glaucoma eye drops.

For moderate to severe glaucoma, drainage implants—also called tube shunts—may be recommended. These flexible devices consist of a small tube attached to a plate that sits under the conjunctiva. The tube diverts fluid to the plate, where it is absorbed, providing an alternative drainage pathway when eye drops, lasers, or conventional surgery are insufficient. Both procedures aim to protect the optic nerve and preserve vision by reducing eye pressure.

The iStent creates a tiny bypass through the trabecular meshwork to restore the eye’s natural fluid outflow. By inserting the stent through a microincision, surgeons allow aqueous humor to flow more freely, which lowers intraocular pressure and may reduce or eliminate the need for glaucoma drops. 

Drainage implants (tube shunts) divert fluid from inside the eye to a small plate positioned under the conjunctiva. The fluid collects and is slowly absorbed by surrounding tissue, providing long‑term pressure control for moderate to severe or refractory glaucoma. 

Benefits of these minimally invasive procedures include steady pressure reduction, decreased reliance on medications, the option to combine them with cataract surgery, and a quicker recovery compared with traditional filtration surgery.

Although generally safe, iStent and drainage implant surgeries carry some risks. Potential complications of iStent include bleeding inside the eye, inflammation, high eye pressure if the stent becomes blocked, and, rarely, damage to nearby structures. Drainage implants can lead to low eye pressure (hypotony), double vision, corneal swelling, infection, or the need for additional surgery if the tube becomes obstructed.

Not every patient is a candidate for these procedures. Your ophthalmologist will evaluate your eye anatomy, glaucoma severity, and history of surgeries or inflammation before recommending treatment. Following postoperative instructions and attending regular follow‑up visits can help minimize risks and ensure the best outcome.

iStent and drainage implant procedures are performed through a small incision, often at the time of cataract surgery. For an iStent, the surgeon inserts the tiny stent into the trabecular meshwork under direct gonioscopic view. The procedure takes only a few minutes and is typically done under topical or local anesthesia. Patients may notice mild irritation or blurriness afterward. Recovery is quick—most people resume normal activities within a day or two while using prescribed eye drops and following postoperative instructions.

For drainage implants, the device is sutured to the sclera and the tube is positioned in the anterior chamber. This surgery is usually performed under local anesthesia with sedation and may take 45‑60 minutes. Healing takes longer than iStent, with follow‑up visits over several weeks to monitor pressure and adjust medications. Patients should avoid strenuous activity and protect the eye until their doctor advises that healing is complete.

At Mainland Eye, we take a personalized approach to glaucoma care. Before recommending an iStent or drainage implant, Dr. Pastore conducts a comprehensive evaluation that includes eye pressure measurements, visual field testing, and optic nerve imaging. We discuss all available treatment options and help you choose the procedure that best fits your condition and lifestyle.

Our team guides you through preparation, performs surgery in a safe and comfortable environment, and schedules follow‑up visits to monitor healing and eye pressure. With offices in Somers Point and Cape May Court House, we provide ongoing support and encourage patients to contact us with any questions or concerns.

Ready to explore micro‑invasive glaucoma surgery? Contact Mainland Eye to schedule a consultation. We’ll evaluate your glaucoma, discuss whether an iStent or drainage implant is appropriate, and answer all your questions.

Call our Somers Point office at (609) 653‑1800 or our Cape May Court House office at (609) 465‑0404 to request an appointment.