Glaucoma: what to expect from the iStent® implant

For patients who have mild to moderate glaucoma, the iStent® can be implanted to help lower eye pressure. Following surgery, many patients can reduce the number of eye drops they use to treat their glaucoma. Mr Shabbir Mohamed was one of the first ophthalmic surgeons to pioneer the procedure over a decade ago via his service in Birmingham. Here he explains what happens during the procedure, if there are any risks and how recently it has advanced even more.

What is the iStent®?

The iStent® is a tiny device (0.2mm x 0.3mm) that is implanted into your eye. Its job is to help control eye pressure and treat glaucoma thereby preserving vision. It tends to be implanted at the time of cataract surgery in patients who have glaucoma as a combined procedure but can also be used as a standalone device in certain selected cases. The role of the iStent® is to reduce the chances of the patient needing more invasive and risky procedures.
 

What is your experience with the iStent®?

In the West Midlands, I was one of the pioneers of iStent® back in 2009. I have been using it in cases here ever since for the last ten years. I have implanted it in numerous patients with different types and severity of glaucoma with good results. For some patients, it has been really helpful in saving their eyesight from being lost due to glaucoma.
 

How can I prepare for the procedure?

iStent® implantation is a procedure that is recommended by ophthalmologists in patients whose glaucoma is not adequately controlled on medication. It is a surgical procedure that is relatively minor for the person but is a significant intervention for the eye. It is less invasive than other types of glaucoma surgery. We call it a minimally invasive glaucoma surgical (MIGS) procedure. In terms of preparation, you don’t have to do anything specific.
 

What happens during the procedure?

Usually, the iStent® is implanted at the time of cataract surgery and often the patient would have a numbing injection (local anaesthetic) around the eye. The procedure is performed in the operating theatre in a sterile environment. The patient would lie on a surgical table and the painless procedure takes about ten minutes if it is a stand-alone procedure and if combined with cataract surgery, about 30 minutes.
 

Will I be able to see or feel the device once implanted?

The patient will not be able to feel or see the implanted iStent® as it is tiny measuring about 0.2mm x 0.3mm. It sits inside the eye and so you would not feel it at all.
 

What happens during recovery?

The risks of the procedure include risk of infection and bleeding and we obviously take steps to minimise these from happening. iStent® implantation doesn’t tend to affect vision. If the patient could drive before, they should be able to after within a couple of days. They would just need to use the eye drops that are prescribed. We like to review our patients on the first day, after one week and also one month after the procedure.
 

Are there any risks of the iStent®?

There are the standard risks of infection and bleeding and occasionally the iStent® can move. This can cause difficulty in implanting and it might need to be repositioned in a secondary procedure. The risk is less than 1 in 100 in my practice. Sometimes the stent does not work and in about 15-20 per cent of cases, the pressure doesn’t come down after implanting the iStent®. This means that the patient might need another procedure.
 

How do I know if I am a suitable candidate?

iStent® is ideally suited to patients who have mild to moderate glaucoma and whose eye pressure is not controlled on their current medical treatment (eye drops). It works very well when combined with cataract surgery, therefore, patients undergoing cataract surgery, who also have glaucoma, should have iStent® put in at the time of their surgery.
 

There is a newer version of the iStent®, which is known as the iStent inject ®. The latest version of the procedure has been around for about 18 months and you have two stents for the price of one. It is more straightforward, cost-effective and less risky than the original iStent®.

Read more on living with glaucoma

Book an appointment with Mr Mohamed now if you would like to discuss your glaucoma treatment options.