Glaucoma (mate pēhinga karu) is an eye disease in which progressive damage to your optic nerve can result in blindness if not treated in time. Often there are no symptoms, so get regular eye checks from the age of 45 years.
Key points
Glaucoma is one of the main preventable causes of blindness in New Zealand. More than 1 in 10 people over 80 years of age have glaucoma.
Because there are often no symptoms, damage can occur for many years before diagnosis.
If you are over 45 years of age, get your eyes checked every 5 years by an optometrist, or every year if you are over 60 years. These checks help identify glaucoma at an early stage before too much vision has been lost.
Seek urgent medical advice if you experience sudden changes in your vision or pain in your eye.
Treatments are available to help prevent further damage. With proper care, less than 2% of patients with glaucoma will go blind.
(Source: What is glaucoma? EyeSmart, Academy of Ophthalmology)
What are the causes of glaucoma?
Fluid is produced in the front of your eye and produces pressure within your eye. When the pressure is too high within your eye, the optic nerve becomes damaged, leading to loss of vision. In some people, damage can occur with pressure within the normal range and is largely thought of a problem in pressure sensitivity. The causes of glaucoma are largely unknown at present; however, there is strong evidence for a genetic cause.
How does glaucoma cause vision loss?
Vision is lost due to damage to the optic nerve, which is the ‘cable’ that connects your eye to your brain. This damage is irreversible, so glaucoma must be detected early to stop progressive damage leading to blindness.
Who is most at risk of glaucoma?
You are at an increased risk of glaucoma if you:
are older than 40 years
have a family history of glaucoma
are either short-sighted or long-sighted
have a history of migraine or Raynauds syndrome
use cortisone or steroids
have a previous eye injury.
If you fit into one of these risk groups, see an eye care professional (known as an optometrist or ophthalmologist) at least every 1 to 2 years for an eye check.
There are optometrists who have advanced training in glaucoma. Ophthalmologists are medical doctors who have completed training in managing eye conditions. Fellowship-trained glaucoma specialists are ophthalmologists who have conducted additional training in managing glaucoma and performing glaucoma surgery.
What are the symptoms of glaucoma?
Glaucoma mainly has no symptoms, except in advanced glaucoma or in people with acute angle closure glaucoma. Contrary to previous assumptions, you do not develop a darkening of vision in your peripheral vision. Instead, you usually experience a ‘jack in a box’ perception of the sudden presence of objects missed from your peripheral vision.
When to seek urgent medical help
In cases of acute angle closure glaucoma and some other causes of glaucoma, you may develop rapid onset of these symptoms:
blurred vision
seeing coloured halos around lights
redness of your eye
nausea or vomiting
pain in your eye.
These are all serious symptoms and you should see a doctor immediately.
What can I do to protect my eyes from glaucoma?
Early detection through regular check-ups is the key to protecting your vision from damage caused by glaucoma. Glaucoma is easy to treat when found early.
If you are in any of the higher risk groups above, have an eye check at least every 1 to 2 years.
For everyone else, have a regular eye check from the age of 45 (see the 45 + 5 recommendations below).
If you are over 60 years of age, get your eyes checked every year.
The 45 + 5 eye examination
Glaucoma NZ recommends the 45 + 5 glaucoma eye examination.
From the age of 45 years, have an eye check examination – even if you haven’t had any eye problems.
If the examination is normal you can repeat it every 5 years.
If the examination shows any signs of glaucoma, your eye specialist will advise you on a course of treatment.
How is glaucoma diagnosed?
A complete eye exam will include several tests to detect glaucoma. Common tests include taking measurements of:
your vision
your inner eye pressure (intraocular pressure)
the appearance of the optic nerve
your field of vision (this indicates the function of the optic nerve)
the drainage angle (where fluid drains out of your eye)
the thickness of your cornea
the structure of your optic nerve and retina (OCT).
What is the treatment for glaucoma?
Although glaucoma cannot be cured, it can usually be stopped from getting worse. Things you can do to slow the progression of glaucoma include to:
stop smoking
exercise regularly
eat a balanced diet
see an optometrist or eye specialist regularly for advice and monitoring
apply your eye drops everyday as directed.
Eye drops
Medicated eye drops are the most commonly used treatment. They reduce the pressure in your eye by helping the fluid drain from your eye or by reducing the amount of fluid produced. Read more about eye drops for glaucoma.
Laser treatment
Another treatment option is laser surgery to make it easier for fluid to drain from your eye. The lasers used for glaucoma are quite different from the refractive surgery used to correct vision and are usually clinic-based procedures. The types of laser surgery for glaucoma include the following:
Laser trabeculoplasty: This is a safe, easy treatment for most people with glaucoma. Read more about laser trabeculoplasty.
Laser iridotomy and laser iridoplasty: This treatment is most often used if you have narrow angle or angle closure glaucoma. Read more about laser iridotomy.
Complementary or alternative treatments are not usually recommended in the treatment of glaucoma due to a lack of quality evidence that they are effective. Examples of alternative therapies include vitamins, meditation and acupuncture. Read more about alternative glaucoma therapies and glaucoma and gingko biloba.
Surgery
If you have progressive glaucoma despite medical and laser therapy, or have significant side effects from medical therapy, surgery may be the only form of treatment for controlling the pressure in your eyes.
Most surgeries are day procedures, which means you don't need to stay in hospital after the procedure. The procedures can range between 10–90 minutes and may be done in conjunction with cataract surgery. Most procedures are done under local anaesthetic and you do not need to fast (not eat) for them. This is similar to having your teeth filled by your dentist.
Surgical options include the following:
filtration surgery (trabeculectomy and deep sclerectomy)
Dr Divya Perumal works at the Eye Institute and Auckland Public Hospital. She has expertise in performing eye surgery, including advanced glaucoma surgery and cataract surgery. She is a senior lecturer at the University of Auckland and is actively involved in teaching junior doctors and research, as well as conducting public lectures.
Credits: Health Navigator Editorial Team . Reviewed By: Dr Divya Perumal, Ophthalmologist, Auckland
Last reviewed: 11 Sep 2020
Eye drops for glaucoma
Although glaucoma cannot be cured, it can usually be stopped from getting worse. Common treatments include medicated eye drops which reduce the pressure in your eye, either by helping the fluid drain from the eye, or by reducing the amount of fluid produced.
What are the types of eye drops used for glaucoma?
There are many different types of eye drops used to treat glaucoma.
Some drops work better in some people than in others. The possible side effects vary between the different types of drops. So, if the first does not work so well, or does not suit, another may work better. For some people, multiple combination of eye drops may be needed to reduce the eye pressure.
Types of eye drops
Description
Prostaglandin analogues
These are the most commonly used eye drops for glaucoma and help increase drainage of fluid out of your eye. Examples include:
bimatoprost (Lumigan®, Bimatoprost Actavis®)
latanoprost (Hysite®)
travoprost (Travatan®, Travopt®).
Possible side effects include:
changes in eye colour
increased growth and thickness of eyelashes
sunken appearance to eyes
red eyes and irritation.
Beta-blockers
These eye drops reduce the production of fluid in the eye. Examples include:
betaxolol (Betoptic ®, Betoptic S®)
levobunolol (Betagan®)
timolol (Arrow-Timolol®, Timoptol-XE®)
dorzolamide + timolol (Arrow-Dortim®)
These eye drops are not suitable if you have breathing problems such as asthma or COPD.
Possible side effects include:
shortness of breath, reduced exercise tolerance
vivid dreams
impotence
irritated eyes.
Other eye drops
Examples of other eye drops include:
brimonidine (Alphagan P®, Arrow- Brimonidine®)
brinzolamide (Azopt®)
dorzolamide (Trusopt®)
pilocarpine (Pilopt®, Isopto Carpine®)
Possible side effects include:
dry mouth and dry eyes
red eye
stinging sensation to the eye
metallic taste
headache.
To reduce the effects of glaucoma, it’s important to use your eye drops every day, in the way your doctor has told you to. The effect of the medication wears off so if you do not use your eye drops on time, your eye pressure will rise even though you cannot feel it. If you miss using your drops, apply them as soon as you remember, but if it is closer to your next scheduled dose then just apply your dose as usual.
Speak to your doctor if you develop any of these side effects. They will be able to change your medications, or suggest alternative therapy such as laser or surgery. Do not stop your medication without checking with your doctor. Note: sometimes people react to preservatives present in the eye drops. Currently there is no funded preservative free eye drops available in NZ.
Tips when using eye drops
How to use eye drops
When using eye drops, press the inside corner of your eyelids immediately after putting in the drop, blot off any excess with a tissue and keep your eye closed for 2–3 minutes. This helps to stop the drops from going down the tear duct and being absorbed into the body. Read more about how to use eye drops.
If you are having trouble getting the drop into your eye, lie down flat, face up, with your eye closed. Place the drop outside of the lid in the corner of your eye near your nose. As you open your eye, the drop will roll in.
If you are not sure if the drop actually got into your eye, put in another. The eyelid can hold only about one drop, so any excess will run out of the eye.
If you are having trouble holding onto the bottle, try wrapping a paper towel around the bottle to make it wider or alternatively use an eye drop dispenser. This is a plastic device in which you place the eye drop bottle. It makes holding the eye drop bottle easier and helps you to guide the eye drop into your eye. Ask you pharmacist about an eye drop dispenser.
If you can’t put the drops in yourself, ask a family member or friend to help you. Let your doctor know if it is too difficult.
Using more than 2 types of eye drops
If using 2 or more types of drops at the same time, wait 5 minutes before putting the next drop in your eye to prevent dilution of the first medication.
Contact lenses
If you are using contact lenses, remove them before using the eye drops and do not replace them until 15 minutes after using the drops.
(Moorfields Eye Hospital NHS Foundation Trust, 2014)
Possible side effects
Eye drops are absorbed by the surface of your eye as well as going into your bloodstream. This means they can cause side effects in other parts of your body. Usually, side effects lessen after a few weeks. However, you should ask your doctor about any physical or emotional changes that occur when taking glaucoma medications. If the side effects are troublesome or last a while, your doctor can prescribe another medication.
Make sure that you tell all of your doctors, including your GP about any glaucoma medications you are taking and any side effects you are experiencing.
If you have progressive glaucoma despite medical and laser therapy, or have significant side effects from medical therapy, surgery may be the only form of treatment for controlling the pressure in your eyes.
Most surgeries are day procedures, which means you don't need to stay in hospital after the procedure. The procedures can range between 10–90 minutes and may be done in conjunction with cataract surgery. Most procedures are done under local anaesthetic and you do not need to fast (not eat) for them. This is similar to having your teeth filled by your dentist.
Surgical options include the following:
filtration surgery (trabeculectomy and deep sclerectomy)
drainage tube
cyclodiode laser
minimally invasive glaucoma surgery (MIGS)
XEN
iStent
Hydrus
micropulse laser.
Filtration surgery (trabeculectomy and deep sclerectomy)
This procedure is the traditional glaucoma operation that has been performed for 40+ years. It involves making a separate channel for the fluid to drain out of your eye and form a clear transparent ‘bleb’ on the outer wall of your eye.
Follow-up after glaucoma surgery is fairly frequent at first, and can include weekly reviews for the first 6 weeks. In these reviews, small manipulations are performed in clinic and may include injections. You may need to be off work for up to 2 weeks after your procedure, depending on your vision and how strenuous your work is. Potential risks of surgery include high or low eye pressure, damage to your cornea, inflammation, reduced vision and bleeding.
Drainage tube
This procedure involves placing a silicone tube into the front of your eye, which allows fluid to drain out onto a plastic plate that has been secured to the wall of the eye. This procedure is generally reserved for advanced glaucoma and refractory glaucoma (glaucoma that has failed with previous conventional surgery). The surgery is generally performed under general anaesthesia and typically takes up to 90 minutes to perform. Potential risks of surgery include damage to your cornea, cataract, exposure of the implant, high eye pressure, low eye pressure, double vision and reduced vision.
Cyclodiode laser
This procedure involves applying a special laser treatment though the coat of your eye, which targets reducing the production of aqueous. It is done typically with local anaesthetics, and takes approximately 15 minutes to perform. Potential risks include failure to sufficiently reduce eye pressure, inflammation and shrinking of your eye.
Minimally invasive glaucoma surgery (MIGS)
This refers to a group of glaucoma surgeries that are associated with smaller incisions and generally have a safer and quicker recovery. MIGS procedures don't provide any better treatment than standard treatment, but there are fewer side effects. Long-term results are not available for some MIGS procedures, as new devices are constantly being developed. MIGS procedures can be seen as operations that enhance existing glaucoma control or may allow a reduction in eye-drop treatment burden. The biggest disadvantage of MIGS procedures are the costs associated with these devices.
MIGS procedures may be particularly beneficial if you:
can't tolerate eye drops because of side effects or allergy
can't use eye drops for other health reasons
are having a cataract operation and have mild to moderate glaucoma, and would like to decrease the number of drops you are using.
XEN
This is a 6mm porcine gelatin implant inserted through the wall of your eye and drains fluid onto the surface of your eye. The procedure is usually performed under local anaesthesia and takes generally 15 minutes. Potential risks of surgery include high or low eye pressure, inflammation, reduced vision and bleeding.
iStent
This is a small titanium implant and is the smallest implant approved for use in the human body. The implant increases drainage of aqueous by bypassing the trabecular meshwork and is generally used in treating mild to moderate glaucoma.
The implant is generally inserted at the time of cataract surgery and adds about 10 minutes to the time taken for a standard cataract surgery. Potential risks include failure to sufficiently reduce eye pressure and implant migration.
Hydrus
This is a metallic implant made from titanium and nickel which can also be implanted at the time of cataract surgery, and works by dilating the drain that aqueous drains into. This is generally used in treating mild to moderate glaucoma.
The implant is generally inserted at the time of cataract surgery, and adds approximately 10 minutes to the time taken for a standard cataract surgery. Potential risks include failure to sufficiently reduce eye pressure, implant migration and scarring.
Micropulse laser
This procedure involves applying a special laser treatment though the coat of your eye that targets reducing the production of aqueous and increasing the outflow of aqueous.
It is done typically with local anaesthetics and takes about 15 minutes to perform. Potential risks include failure to sufficiently reduce eye pressure and inflammation.
Take this test to see if you have an increased risk of glaucoma
Are you older than 40?
Do you have a family history of glaucoma?
Do you have near-sightedness (myopia)?
Do you have diabetes?
Do you have high blood pressure?
Do you have a history of migraines?
Do you use cortisone or steroids?
Have you had a previous eye injury?
If you answered yes to any of these questions, visit an eye care professional (known as an optometrist) for an eye check. They can also assess your risk more carefully and advise how often you should have your eyes tested.
Access to the following regional pathways is localised for each region and access is limited to health providers. If you do not know the login details, contact your DHB or PHO for more information:
