iStent is the smallest medical implants known to be implanted in the human body. iStent measures just 0.36 mm long and is made of titanium (C).
It is designed to reduce intraocular pressure safely and effectively in patients diagnosed with primary open-angle glaucoma, pseudo-exfoliative glaucoma or pigmentary glaucoma.Studies have shown the device to be safe and effective when implanted in combination with cataract surgery, or as a stand-alone procedure, in those patients who require intraocular pressure reduction and/or would benefit from glaucoma medication reduction.
The device may also be implanted in patients who continue to have elevated intraocular pressure despite prior treatment with glaucoma medications and conventional glaucoma surgery.
How does iStent work?
Implanted at the time of cataract surgery, or in a separate procedure, iStent is designed to create a bypass between the front part of the eye and its natural drainage pathway to increase the flow of fluid.
By creating a permanent bypass through the primary blockage site (trabecular meshwork), iStent is designed to –
- improve the eye’s natural fluid outflow to safely lower intraocular pressure, and
- work continuously to improve the natural flow of fluid in the eye.
What does the iStent procedure involve?
The operation is usually performed under a local anaesthetic, meaning that you are awake but your eye is numb so you will not feel anything.
The iStent Trabecular Micro-Bypass System is implanted through a small, self-sealing incision in the clear part of the eye (cornea) using a small inserter, and can be performed at the same time as a cataract surgery or by itself. Once implanted, the iStent Trabecular Micro-Bypass System can work immediately.
At the end of the procedure, your operated eye will be covered with a pad and / or protective shield, which you might also be instructed to wear at night for a few days as a precautionary safety measure to protect your eye.
iStent Trabecular Micro-Bypass System surgery and cataract surgery is usually completed as a day case, meaning that you should be able to go home the same day, but you will not be able to drive so you are advised to have someone collect you from the hospital / clinic.
What are the benefits of implanting an iStent?
The iStent Trabecular Micro-Bypass System is designed to lower eye pressure and reduce the risk of vision loss from glaucoma. It may also reduce or remove the number of glaucoma eye drops you might be using now.
An international study has shown 72% of patients who were treated with iStent no longer needed to take glaucoma medication after 12 months.
How soon will I recover?
Immediately after the procedure your vision in the operated eye might be blurry for one to two weeks, and your eye might be slightly bloodshot for a few days.You will be prescribed antibiotic and anti-inflammatory eye drops to prevent infection and inflammation, which you should take as prescribed.
Your eye doctor will inform you if or when you can stop taking any glaucoma eye drops.
Do not stop taking your drops in either eye, unless specifically instructed to do so by your eye doctor.
What are the risks?
The iStent is indicated to reduce eye pressure in patients diagnosed with primary open-angle glaucoma, pseudoexfoliative glaucoma, or pigmentary glaucoma. It can be implanted as a standalone surgery or in combination with cataract surgery.The iStent can also be implanted in patients who would benefit from fewer eye drops or who have previously had glaucoma surgery. The iStent should not be used to treat those with closed-angle glaucoma, glaucoma due to new eye vessels, or in patients with thyroid eye disease, certain eye tumors or nerve conditions.
After iStent implantation, some patients have experienced inflammation and swelling of the eye, decreased vision sharpness and cloudiness, and stent obstruction.
Please refer to the iStent product labeling for additional safety information, or visit www.glaukos.com. iStent can only be sold by, or ordered by a physician.
Please consult your ophthalmologist to see if iStent is right for you.
Risk Factors –
Glaucoma is believed to be a genetic disease and may not appear until later in life. Besides hereditary factors, glaucoma can also be caused by a severe eye infection, a blunt eye injury or trauma, inflammatory eye conditions, or blockage of the eye’s blood vessels.
Other risk factors may include:
- Elevated eye pressure
- Having a relative with glaucoma
- Sudden considerable changes in eye pressure
- Decreased central corneal thickness
- Older age
- Blunt eye trauma
- African, Asian or Hispanic ethnicity
- Inflammatory eye Conditions
Authored by Sheraz Daya MD FACP FACS FRCS(Ed) FRCOphth, Consultant Ophthalmic Surgeon & Medical Director, June 2019.
Next review due June 2020.