The iStent Trabecular Micro-Bypass Stent is a tiny medical device used at the time of cataract surgery to lower pressures in patients with glaucoma.
Glaucoma is a medical condition where the pressure inside the eye is too high, leading to progressive optic nerve damage. Open angle glaucoma, the most common form of glaucoma, is essentially a backing-up of fluid due to a drain that has become increasingly clogged. The main drain in the eye is call the trabecular meshwork.
The iStent is placed within the trabecular meshwork, creating an open passage though this clogged drain. The Retention Arches (see above image) keep the iStent buried in position within the trabecular meshwork, and only the Snorkel is exposed. The Lumen of the Snorkel allows the fluid in the eye to easily bypass the trabecular meshwork, and in turn, results in a lower intraocular pressure.
The FDA has approved the iStent to be inserted in patients with mild to moderate staged glaucoma, and only in conjunction with cataract surgery. The iStent is not FDA approved to be placed in patients who have already had cataract surgery, or do not need cataract surgery.
The advantages of the iStent are that it is so small that the patient cannot feel it or see it when looking in the mirror. It does not require a separate surgical incision and is well-tolerated. This Minimally Invasive Glaucoma Surgery (MIGS) is not an aggressive procedure, but with minimal risks, can make the difference if intraocular pressures are borderline controlled.
If you have glaucoma and need cataract surgery, it is definitely worth considering. Ask one of the doctors at the San Jose Eye Institute about MIGS, the iStent, or any other MIGS devices.