What is an iStent?
An iStent is the smallest medical device that can be implanted in the human body and is used to enhance drainage of internal eye fluid in patients with glaucoma. The stent is implanted in the internal eye drain to enhance flow through the existing natural pathway.
Who can get an iStent?
The procedure is approved by the FDA and is implanted at the time of cataract surgery only. The implant is approved for patients with early to moderate stage glaucoma who are on medicines to treat high eye pressure.
How successful is the iStent in lowering eye pressure?
In a multicenter U. S. clinical trial comparing cataract surgery with an iStent versus cataract surgery alone, 72% of the patients who had an iStent at the time of cataract surgery were able to achieve an eye pressure of less than or equal to 21mmHg on no medications as compared to 50% after cataract surgery alone. At 1 year those who had an iStent after cataract surgery required fewer medications to achieve target pressure. Overall, iStent plus cataract surgery achieved modest benefits. One can expect, on average (some more and some less), an extra 2mmHg drop in pressure and greater likelihood of being able to come off 1 medication when an iStent is implanted at the time of cataract surgery.
Am I a candidate to have an iStent?
If you have mild to moderate stage glaucoma and your pressure is controlled on medications or is slightly higher than desired target and have a cataract then you are a candidate for the procedure. If you have advanced stage glaucoma or your eye pressure is too far from target pressure than the iStent would not be appropriate for you.
Does implantation of more than 1 iStent likely to achieve better control than 1 iStent?
Yes. Multiple studies have shown that implanting 2 or more iStents are more likely to achieve better results than 1 iStent. However, Medicare and insurance companies do not cover insertion of more than 1 iStent, leaving the financial responsibility for payment of the stent and insertion to the patient.
What are the risks of cataract surgery plus iStent?
The risks of serious complications are no worse that cataract surgery alone. Occasionally, there will be more bleeding than anticpated but usually resolves without any need for surgery. There have been reports of iris trauma but most were not significant and did not impact vision.