Technology has always played an important role in eye care. Today, almost every aspect of vision is connected to a product or procedure that wasn’t available even ten short years ago. The cataract surgery you are scheduled for is a good example of how innovations can make a difference. Every aspect of it utilizes recently developed technology that will help us improve your vision. Today, this includes managing your mild-to-moderate open-angle glaucoma: because now we are able to add another step to your cataract surgery that allows you to treat your open-angle glaucoma in a completely new way. This is important because once diagnosed, you and most patients like you will spend the rest of your lives putting one, two or even three different kinds of drops in every day. Unfortunately, all of these drops will not only be inconvenient, but potentially very expensive. The iStent Trabecular Micro-Bypass Stent is designed to reduce your eye pressure and you can have it done at the same time you have cataract surgery.
iStent: the world’s smallest medical implant delivers big results in mild-to-moderate open-angle glaucoma.
While mild-to-moderate open-angle glaucoma is very common, many people are unaware of their condition, especially in the early stages, when their vision may be unaffected. In many people, open-angle glaucoma is characterized by an increase in the intraocular pressure (IOP) of your eye. This pressure is caused by the buildup of fluid within the eye. Too much fluid raises pressure, which can cause the gradual loss of vision. And while glaucoma moves slowly, its damage is irreparable.
The world’s tiniest medical device—iStent—is 20,000 times smaller than the intraocular lenses (IOL) used in your cataract surgery. But the size of iStent is only part of its story. By increasing the eye’s ability to drain fluid, this technology is designed to reduce the pressure in your eye.
How does iStent work?
iStent works like the stents used to prevent heart attacks and strokes. When blood vessels get clogged, a stent creates access to the vessel flow. While a highly innovative technology, how iStent works is elegantly simple:
- If you have glaucoma, over time the eye’s natural drainage system becomes clogged
- iStent creates a permanent opening through the blockage to improve the eye’s natural outflow
- Restoring this mechanism lowers and controls pressure within the eye
iStent: managing glaucoma while treating your cataracts
iStent is implanted during your cataract surgery procedure. Once implanted, iStent will begin working to safely and effectively manage pressure. What’s more, patients who receive iStent may experience a reduction in glaucoma medications; but this will be at the discretion of your physician.
If you have glaucoma and medications and laser surgeries do not lower your eye pressure adequately, your eye doctor may recommend a procedure called a trabeculectomy. This procedure is often performed with use of an anti-scarring medication to reduce the risk of scarring.
During this procedure which is performed in an operating room on an outpatient basis, a tiny drainage opening is made underneath a flap or trap-door of the sclera (white of the eye). The new opening allows fluid from inside the eye to flow underneath the edges of the flap to raise a filtration site with in the conjunctiva (outer layer of the eye) called a “bleb”. The bleb is mostly hidden under the eyelid and is often quite low and spread over a large area. The aqueous humor diverted to the bleb then gets re-absorbed by surrounding blood vessels. When successful, the procedure will lower your intraocular pressure (IOP), minimizing the risk of vision loss from glaucoma.
Some of the risks and complications from trabeculectomy surgery include the following:
- bleeding in the eye
- swelling in the eye
- cataract (in cases where cataract has not already been removed) and
- decreased or lost vision
- failure to control intraocular pressure, with the need for another operation
- eye pressure that is too low
- irritation or discomfort in the eye
There is also an option to implant an ExPress mini-shunt under the flap which may reduce the short term complications of the surgery. There is some evidence suggesting that implanting a stainless steel shunt under the scleral flap through a small opening, avoiding cutting the internal aspect of the sclera or the iris, results in a more predictable early post-operative recovery period. The longterm success appears to be equal but this more stable first couple of months is sometimes worth the extra expense of the shunt in suitable patients.
While some people may experience side effects from medications or surgery, the risks associated with these side effects should be balanced against the greater risk of leaving glaucoma untreated and losing your vision.