What is Glaucoma?
Glaucoma is a group of eye conditions that can damage the optic nerve, which carries information from the light sensitive retina to the brain where it is interpreted as an image.
While there are several forms of Glaucoma they all have similar key symptoms including increased pressure within the eye, a ‘cupping’ appearance of the optic disc and a reduction or loss of peripheral vision.
How is the pressure controlled?
The eye contains a water based fluid called the aqueous which being constantly refilled with fresh water based liquids. To maintain a stable internal pressure ‘drains’ are located at the front of the eye between the iris and cornea edge.
Increased pressure is the result of an increase in fluid production, a reduction in fluid drainage, or a combination of the two.
How common is Glaucoma?
Glaucoma is one of the most common causes of blindness in the Western World and there are several different forms: acute glaucoma; congenital glaucoma; chronic glaucoma (the most common form); and secondary glaucoma (resulting from another condition).
Who is at risk of chronic Glaucoma?
There are numerous risk factors associated with chronic glaucoma, including:
- Family History – If a close relative such as a parent or sibling has glaucoma, you should not worry, but ensure you have regular check-ups to detect any changes as early as possible, should they ever occur.
- Myopia – people with high myopic (minus) prescriptions.
- Age – Chronic glaucoma affects 1% of people over 40 and 5% of people over 65. It is very uncommon for it to develop in those below the age of 40.
- Race – People of Afro-Carribean origin have an increased risk of developing glaucoma.
Why is it so important to catch and treat chronic glaucoma?
Chronic glaucoma is one of the highest causes of sight loss as it usually has NO detectable symptoms. Your vision will appear normal and there won’t be any pain. It is the peripheral vision which Glaucoma damages first which is why it can go unnoticed for so long. Only once the peripheral vision has been extensively reduced might you by aware of the issue.
If there are no symptoms, how can chronic Glaucoma be detected?
There are several tests an Optometrist can perform to detect chronic glaucoma, such as:
- Examination of the optic nerve – as part of the examination our Optometrist will examine the health of the optic nerve and retina. They will also use the Fundus camera to take a photograph of the optic nerve. These are kept with your patient record and used to monitor any changes.
- Measuring the internal pressure of the eye – pressures are usually taken using a non contact ‘puff of air’ test. If there are other risk factors present or the pressures are higher than expected the Optometrist may repeat the test with a contact tonometer.
- Visual Field Test – this test is performed on our Zeiss Humphrey Visual Screener with both eyes testes separately for accuracy.
When it comes to Glaucoma tests there is nothing to worry about, all of these tests are routine, not painful and are performed by our Optometrists.
Can chronic Glaucoma be treated?
For the majority of patients the progression of glaucoma can be slowed with a simple prescription of daily eye drops. In some circumstances an operation called Trabeculectomy may be required.
What is acute Glaucoma?
When the internal pressure of the eye suddenly increases this is known as acute glaucoma. It usually occurs as the result of a blockage in the drain between the cornea edge and the iris. This area is known as the ‘angle’ and the condition called ‘Closed Angle Glaucoma’.
What are the symptoms of acute Glaucoma?
Symptoms of acute glaucoma include:
- Severe pain – usually manifesting in one eye, it can occur in both eyes but this is uncommon.
- Blurred Vision – some patients are aware of haloes around bright light source.
- Nausea and vomiting
- Red eyes
What treatment is there for acute glaucoma?
In an acute glaucoma attack the first priority is to reduce the intraocular pressure of the eye. The initial pressure reduction is achieved using powerful drugs, with secondary treatment consisting of drops, laser treatment or surgery depending on the nature of the attack.
Whilst an acute attack typically occurs only in the one eye, the other eye is often treated with laser only to prevent a future attack.