Glaucoma

Reviewed by: Miss Humma Shahid

What is glaucoma?

Glaucoma is an eye disease affecting the optic nerve, which transmits information from the retina to the brain enabling you to see clearly. It can lead to loss of vision if it is not diagnosed early and treated. It affects 2% of the UK population over the age of 40 years, increasing to 10% of people over the age of 75 years. Sadly, this condition remains the most common cause of irreversible blindness in the world, but the number of people who lose vision is reducing every year due to the advances in treatment and the earlier detection of the disease.

What causes glaucoma?

Glaucoma can be caused by an increase in pressure in the eye when the fluid that is made in the eye does not drain properly. Sometimes the optic nerve can be damaged, even though the pressure in your eye is within the normal range. 

Is there a genetic risk of glaucoma?

Glaucoma does run in families and the risk could be eight times higher if someone in your family has glaucoma. Regular eye checks are important particularly if there is a family history of glaucoma.

What are the symptoms of glaucoma?

As there are often no symptoms, most people are affected without realising it. Glaucoma is often identified at a routine sight test. During the late stages of glaucoma, people can become aware of reduced vision, but by this time a significant amount of damage to sight has occurred. Regular monitoring is needed by an eye specialist after a diagnosis is made to ensure that the sight remains stable.

How is glaucoma diagnosed?

Increased eye pressure can often be the first sign of glaucoma. To make a diagnosis, a full eye examination should be carried out by an eye specialist, including measurement of eye pressure, examination of the optic nerve and a visual field test to check the function of your optic nerve.

Our consultants offer glaucoma screening, monitoring and treatment. They use specialist imaging equipment to diagnose and treat all forms of glaucoma, including OCT testing, which can detect the earliest onset of this eye disease. A screening appointment can help set your mind at rest if you have concerns that you may be at risk.

How is glaucoma treated?

There are different types of treatment, depending on the type and severity of glaucoma and how fast it is developing. All treatments will act to lower the eye pressure and can range from eye drops and laser treatment to surgery, including the latest minimally invasive glaucoma surgery (MIGS) devices.

The common types of surgery and laser treatments available to treat glaucoma are:

Trabeculectomy: also called ‘filtration surgery’.
During this procedure, your surgeon removes a piece of tissue from the eye’s trabecular meshwork to allow drainage of fluid from the eye.

YAG laser peripheral iridotomy
An iridotomy is a small hole created with the laser beam in the outer part of the iris (coloured part of the eye), that is used to treat or prevent a sudden rise in pressure inside the eye (acute glaucoma). The iridotomy allows fluid to circulate freely within the eye minimising the risk of a sight‐threatening pressure rise.

Selective laser trabeculoplasty (SLT)
During this outpatient procedure, your surgeon uses a slit lamp to examine your eye. This slit lamp also contains an SLT laser. This procedure aims to reduce pressure within the eye by using a focussed laser beam of light to selectively remove certain cells containing melanin to improve the drainage angle of the eye.

Tube-shunt surgery
This procedure is typically carried out if trabeculectomy has failed, and aims to reduce pressure within the eye by improving drainage. Tube surgery involves placing a flexible plastic tube with an attached silicone drainage pouch in the eye to help drain fluid from the eye.

Most importantly, with glaucoma conditions, early-stage diagnosis, treatment and repeated testing is effective in preventing glaucoma blindness.

What is the iStent procedure?
Glaucoma is the most common cause of irreversible blindness. Minimally invasive glaucoma surgery (MIGS) offers the opportunity to lower intraocular pressure, preserve vision and reduce the need for eye drops.

This safe procedure, which is often performed at the same time as cataract surgery, involves inserting a small titanium tube into the drainage channel of the eye. It offers the chance to lower intraocular pressure and reduce the need for glaucoma eye drops.

Is there a cure for glaucoma?

While there is no cure for glaucoma, it is often possible to keep it under control and stop or slow down the disease developing.