**As of 29 August 2018, the CyPass Micro-Stent has been withdrawn from use globally by Alcon due to concerns regarding its long term effect on the cornea. It is no longer available for implantation in Australia and worldwide until further notice. You can read the press statement by Alcon here.
More information regarding the risk of corneal endothelial cell loss is available from the Alcon presentation at the September 2018 ESCRS Meeting in Vienna.**
Video demonstrating successful removal of the CyPass micro-stent, two months after initial implantation. It is probably unsafe to remove the CyPass micro-stent beyond 3 to 6 months of implantation. Despite the increased rate of corneal endothelial cell loss, most patients with the stent are unlikely to develop corneal decompensation requiring treatment with corneal transplant surgery.
Why is implantation of the CyPass stent necessary?
The CyPass Micro-Stent is implanted at the same time as cataract surgery for patients who have both cataract and glaucoma. The aim of the iStent Inject is to decrease the eye pressure so that you can reduce the number of pressure-lowering eye drops you use. In some cases, it may be possible for you to stop your pressure-lowering eye drops completely.
The lens is the middle window inside the eye that focuses light entering the eye. As you age, your lens becomes gradually more cloudy – this is called a cataract. As the cataract progresses, you may experience worsening vision and increasing glare. During cataract surgery, the cloudy lens inside your eye is removed and replaced with an artificial clear lens implant. The lens implant remains in the eye permanently.
Fluid in the eye (aqueous) is produced by the ciliary body, and drains out through the trabecular meshwork (drainage pathway) in the drainage angle. Sometimes the trabecular meshwork no longer copes, preventing aqueous from draining out easily. This causes pressure to build up in the eyeball. When the pressure in the eye is too high, it can cause optic nerve damage and permanent vision loss – this is called glaucoma.
See Related:
Surgical treatments for glaucoma
Surgical treatments for cataract
What does the CyPass Micro-Stent do?
The CyPass Micro-Stent is one of the glaucoma surgery techniques called minimally invasive glaucoma surgery (MIGS). In contrast to traditional glaucoma surgery, MIGS is quicker and easier to perform and has less risk of complications, but has reduced overall pressure control.
The CyPass Micro-Stent is made of polyamide and measures 6.35 mm long. The stent is implanted in the suprachoroidal space (space between the wall and inner lining of the eye). This creates an opening in the suprachoroidal space, and allows aqueous to drain out in a controlled manner, thereby reducing eye pressure.
There is no change to the way the cataract surgery is performed. The stent is implanted into the eye after the lens implant has been inserted into the eye. This adds around 5 minutes to the overall cataract surgery time.
See Related:
iStent implantation for glaucoma
Hydrus microstent implantation for glaucoma
What are the potential risks?
The CyPass Micro-Stent is inert, well accepted by the eye, and safe for Magnetic Resonance Imaging (MRI). Apart from the usual risks associated with cataract surgery, additional risks specific to the CyPass Micro-Stent are usually self-limiting and not sight-threatening. These include:
● Bleeding into the eye. This is common and the amount of blood may initially
be alarming. However this generally settles over a few days without the
need for additional treatment.
● Initial low eye pressure. This is common and the pressure usually
increases gradually after a few weeks. Your vision may be slightly blurry
until the eye pressure stablizes.
● Stent implantation issues, such as implantation at a non-ideal location,
depth or angle. Rarely, the stent may become dislodged from its
implanted position. No harm or damage will be caused to the eye, so
usually no additional procedure is needed to reposition or remove the stent.
However, you may need to restart your glaucoma eye drops.
● Failure to work. It is possible that the CyPass Micro-Stent may not work
in your eye despite successful and uncomplicated implantation. Sometimes
the stent works well initially, but the pressure gradually increases over time.
If this occurs, you may need to restart your glaucoma eye drops.
● Problems with the cornea (the clear front window of the eye). Five-year data
has shown that the CyPass Micro-Stent can result in increased loss of
corneal endothelial cells (innermost layer of cells lining the cornea). This
may result in the cornea becoming cloudy, which may require treatment
with a corneal transplant if severe.
**As of 29 August 2018, the CyPass Micro-Stent has been withdrawn from use globally by Alcon due to concerns regarding its long term effect on the cornea. It is no longer available for implantation in Australia and worldwide until further notice.**
See Related: Risks and complications of glaucoma surgery
What should I expect?
CyPass Micro-Stent implantation (in combination with cataract surgery) is a hospital-based day case procedure performed under local anesthetic. The operation is usually performed one eye at a time.
Before and during surgery:
All the instructions before and after surgery are the same as for cataract surgery. All the precautions and surgical steps taken are the same as for cataract surgery. The following are the extra steps that will occur during CyPass Micro-Stent implantation:
● You will be asked to rotate your head to one side. Please remain still during
the procedure.
● A contact lens will be placed on your eye.
● The stent will be implanted. You should not feel any pain during stent
implantation.
After surgery:
After cataract surgery and CyPass Micro-Stent implantation, a pad and shield will be placed over your eye. The pad and shield can be removed the next day, and you can start your normal postoperative eye drops, usually a steroid (Prednisolone or Dexamethasone) and an antibiotic (Chloramphenicol) 4 times daily for 3 to 4 weeks.
You will usually be reviewed the day after surgery to check the positioning of the stent and your eye pressure. The reduction in the eye pressure with the CyPass Micro-Stent is usually immediate, so you should stop your usual pressure-lowering eye drops after surgery.
Over the next few days, you may experience blurriness, discomfort, sensitivity to light, and blood around the eye. This will gradually improve with the eye drops. As with routine cataract surgery, it can take a week or two before you notice any improvement in your vision.
Please contact the clinic immediately if you experience pain or a sharp drop in vision.
See Related:
 with the CyPass Micro-Stent to treat glaucoma.){kind=link}