If you are interested in seeing what having glaucoma looks like, here is a great link to the sight simulator on the Fred Hollows Foundation website, which offers you a sense of what it is like to have visual impairment.
What is Glaucoma?
The eye is a ball filled with clear fluid under pressure. The fluid is constantly made within the eye, circulates and then drains out through small holes in the internal angle of the eye, into the vascular system.
The pressure of the fluid is usually maintained quite constant, keeping the eye spherical, so that we can see clearly. As we age, the drain holes can become narrow and the fluid drains away less readily, leading to a rise in pressure (like when the sink blocks up).
If this pressure rise is very high, or if the high pressure is maintained for some time, it can damage the nerves as they enter and leave the back of the eye, leading to loss of peripheral vision in the early stages and ultimately, if left untreated, to complete loss of vision. This process is known as glaucoma.
Glaucoma may be acute or chronic.
Acute glaucoma comes on rapidly and causes symptoms of pain in the eye, haloes around lights, and blurred vision. Most people realise something is seriously wrong and seek help quickly. The condition is treatable with eye drops, tablets and laser. Sometimes surgery is required. If treated early, permanent damage can be prevented.
Chronic glaucoma is much more common and causes no symptoms at all until significant permanent damage has occurred. This is why it is so important to have regular eye health checks, for everyone over 40, and even earlier if there is a family history of glaucoma or if your eye has been injured, causing damage to the internal drainage angle.
The diagnosis is made by measuring eye pressures, examining the angle, examining and recording the appearance of the optic nerves and measuring the peripheral vision with a visual field test.
How can you treat glaucoma?
Treatment usually consists of eye drops used every day for the rest of your life. Some of these drops reduce the production of the fluid, such as Timolol. Others increase the drainage of the fluid, such as Xalatan.
All drops are drugs and may cause side effects, and Anne will discuss these with you. If you experience any problems from using eye drops, you must discuss these with your doctor, so the drops can be changed to something that suits you better, if need be.
Regular checks are required to ensure the drops are working, reducing the pressure to a safe level that is causing no further harm to your optic nerves, and to make sure the drops are causing you no harmful side effects. Once we find drops that work without causing you side effects, we need to keep checking you regularly, as the effectiveness of the drops can wear off over time, and the disease can progress.
Sometimes treatment with laser or surgery is required and Anne will discuss this with you in detail if necessary.
Laser treatment for glaucoma
Recent studies have shown that SLT laser treatment for glaucoma is at least effective as drops, if not more so. SLT is a gentle laser treatment that can be performed in the office with local anaesthetic drops. There are no significant side effects. As a first line treatment, it has about an 80% chance of reducing the pressures to the level where daily drops will not be required. Ongoing monitoring is still required as the effectiveness of the laser can wear off. If it is effective, the laser treatment can be repeated from time to time.
Surgery for glaucoma
In the past, major surgery to create a partial thickness hole in the eye was required if the eye drops and laser were no longer effective. This procedure is called trabeculectomy and is still used if all other treatments are no longer effective. This procedure has significant rates of complication and of failure.
In recent times, small stents have been developed that can be inserted into the eye at the time of cataract surgery if you already have glaucoma. This is called Minimally Invasive Glaucoma Surgery (MIGS). Several stents are available for use. This surgery is less risky than trabeculectomy surgery but at present is only funded in conjunction with cataract surgery.
Please Contact the Clinic if you would like to know more.