Glaucoma surgery involves either laser treatment or conventional surgery in which a cut is made in the eye to reduce intraocular pressure (IOP) for preventing further vision loss or blindness.
Glaucoma is an eye disease that results in progressive vision loss due to the increased intraocular pressure and subsequent optic nerve damage. Optic nerve is a bundle of nerve fibres that carries visual images or signals from the eyes to the brain. In general, a clear fluid called aqueous humour circulates through the eye and then drains out through a mesh-like channel (trabecular meshwork). Whereas, in glaucoma this channel becomes blocked and flui does not drain properly thus increasing pressure inside the eye (intraocular pressure). This increased intraocular pressure causes damage to the ocular nerves and blood vessels resulting in loss of vision.
The different types of glaucoma include:
Open Angle Glaucoma: This is the most common form of glaucoma, also called primary or chronic glaucoma. This type of glaucoma occurs when the eye’s drainage system becomes clogged and gradually increases the pressure inside the eye. The angle between the iris and cornea is wide and open.
Closed Angle Glaucoma: This type of glaucoma is less common and can cause a sudden build-up of pressure in the eye. The angle between the iris and the cornea is narrow or closed.
Normal tension (pressure) glaucoma or low tension glaucoma: In this type of glaucoma the optic nerve is damaged despite normal intraocular pressure.
Congenital Glaucoma: This type of glaucoma is seen in babies and often runs in families. It is caused by improper development of eye’s drainage canals before birth.
Other types of Glaucoma are pigmentary, secondary glaucoma, pseudoexfoliative glaucoma, traumatic glaucoma, neovascular glaucoma and irido corneal endothelial syndrome (ICE).
The aim of the treatment is to reduce the pressure in your eyes, which involves using special eye drops or medications. In certain cases, laser treatment or surgery is performed to prevent further damage.
Laser treatment is usually recommended if the use of eye drops does not improve your symptoms. Laser treatment involves using powerful beams of light to improve the flow of fluid out of your eye and reduce the pressure inside the eye.
During the laser surgery, your eye is numbed with anaesthetic eye drops. Then, your doctor will place a special lens in front of your eye. Afterwards, a laser beam is aimed into your eye and you can see flashes of coloured light.
Laser trabeculoplasty: Laser trabeculoplasty is often used to treat open-angle glaucoma. The laser is aimed at trabecular meshwork, where fluid drains from the eye. This surgery opens the clogged areas and makes it easier for fluid to flow out of the eye.
There are two types of laser trabeculoplasty surgery:
Laser Iridotomy: Laser iridotomy is normally performed to treat people with closed angle glaucoma. During iridiotomy, the laser creates a small hole through the iris to improve the flow of fluid from the back of the eye to the trabecular meshwork. This opening drains out the fluid and helps lower eye pressure.
Cyclophotocoagulation or laser cyclo-ablation: Laser cyclo-ablation may be helpful in treating people with severe glaucoma, which has not been manageable with medications or surgeries. In cyclophotocoagulation a laser is used to destroy the parts of the ciliary body, a part of the eye that produces eye fluid. This therapy decreases the production of fluid thus reducing the eye pressure.
A trabeculectomy is the most common type of surgical procedure performed to relieve pressure caused by glaucoma. During the procedure, a new drainage channel is created to ease drainage of fluid from the eye. This new opening allows fluid to drain out of the eye forming a bleb covered by the white outer covering (the conjunctiva) of the eye. Over time the drainage site can scar and therefore close up. Scarring is the main reason for failure of trabeculectomy. Anitmetabolites can be used to reduce the risk of scarring. Mitomycin C (MMC) is most commonly used antimetabolite in trabeculectomy surgery. Mitomycin C inhibits the multiplication of cells which produce scar tissue, thus preventing the scar formation.
Trabeculectomy with antimetabolites is generally recommended for reducing intraocular pressure in patients with advanced glaucoma.
You may have a slight burning sensation in the eye during laser surgery. Your eyes may feel irritated and have slightly blurred vision. Rarely a short term increase or an excessive drop of intraocular pressure can also occur after laser surgery. Both of these complications can be manageable with medications. You may also have a slight risk of cataract formation after some type of laser surgeries for glaucoma.
What is the CyPass® Micro-Stent?
The CyPass® Micro-Stent is an advanced implantable device which reduces intraocular pressure without the risk of complications from invasive eye surgery.
How does the CyPass® Micro-Stent work?
Normal intraocular eye pressure is maintained by continuous drainage of aqueous fluid. In conditions such as glaucoma, the drainage of aqueous fluid is disrupted leading to increased intraocular pressure and vision problems. The CyPass® Micro-Stent allows physicians to restore continuous drainage of aqueous fluid with a minimally invasive conjunctiva sparing procedure.
How is the CyPass® Micro-Stent inserted?
After patient prepping, a standard paracentesis is made opposite the intended CyPass® device implantation site. Pupil constricting medications are delivered inside the anterior chamber to aide in angle visualisation and access. Gonioscopy is used prior to device insertion to ensure proper position and approach. The proprietary delivery system is introduced through the paracentesis with the CyPass® preloaded on the guidewire employing magnified visualisation of the anterior chamber angle to confirm the intended implant location. With the guidewire positioned toward the angle, it is advanced to enter just posterior to the scleral spur at the iris root. The guidewire’s atraumatic bevel tip allows for ease of insertion and it is advanced into the supraciliary space until only the proximal collar of the device remains in the anterior chamber. The guidewire is then retracted, and the delivery device is removed from the anterior chamber.
What are the benefits of the CyPass® Micro-Stent?
Few of the benefits of CyPass® Micro-Stent include:
The iStent inject® is very tiny titanium implant placed inside the eye into the trabecular meshwork to improve outflow of eye fluid. It is the smallest implanted device that has been approved for use in the human body.
Can glaucoma be treated with iStent inject®?
Yes, if you have mild-to-moderate open-angle glaucoma and are currently on one to three anti-glaucoma medications, the iStent inject® device may help normalize your eye pressure.
How does the iStent inject® system work?
The iStent inject® system creates tiny channels which allow fluid to drain from the eye by bypassing the trabecular meshwork.
How is the iStent inject® procedure performed?
A topical anaesthetic drop is placed on the eye and a small opening is made to access the front portion of the eye. Next, a gel and a pupil-constricting medication is injected into the eye. The iStent inject® system is then inserted to access the angle of the eye. Under a magnified view, the iStent inject® device is inserted into the trabecular meshwork to create a tiny channel which allows fluid to drain from the eye. The hand piece of the iStent inject® system is rotated and an additional iStent inject® device is placed to create another channel for drainage. The iStent inject® system is then withdrawn.
What are the benefits of iStent inject®?
The benefits of iStent inject® system include: