Everything you need to know about Glaucoma
Glaucoma is a group of blinding eye conditions characterised by damage to the optic nerve. In most cases of glaucoma, the nerve damage is gradual and often goes unnoticed until it is too late to treat - which is why it is important to have regular glaucoma checks. It is the number one cause of preventable blindness in New Zealanders and early detection is vital for maintaining sight.
At the back of the eyeball there is a nerve that connects from the eye to the brain called the optic nerve. Like a camera cable downloading images to a computer, this nerve ‘downloads’ the images the eye takes and sends them to the brain.
With glaucoma, irreversible damage is caused to this nerve - such as - if you were to remove a camera cord before the images finished downloading. Damage can be sudden or gradual and cannot be repaired once the nerve has been compromised.
Excessive pressure within the eye (intraocular pressure) is a risk factor for glaucoma and is generally always associated with optic nerve damage. While pressure within the eye is important, high pressure is dangerous and occurs when the eye’s drainage system fails. This can happen gradually in the case of chronic glaucoma, or it can happen suddenly, in the case of acute glaucoma.
There are many different types of glaucoma, and all have different signs and symptoms. The most common include:
Angle-closure glaucoma - caused by a bulging iris that blocks the drainage system, resulting in a build up of pressure.
Primary open-angle glaucoma - caused by a partial blockage in the drainage system, gradually increasing the intraocular pressure.
Pigmentary glaucoma - where the drainage channels are blocked by pigment granules.
Normal-tension glaucoma - When the intraocular pressure remains normal but the optic nerve is inexplicably damaged, possibly due to poor blood flow.
Developmental glaucoma - occurs in children and infants.
Signs and symptoms
Symptoms of glaucoma are wide ranging and can vary. The two most common types of glaucoma have different signs and it is important to know the difference:
Acute angle-closure glaucoma:
Severe eye pain
Sudden visual disturbance
Halos around lights
Primary open-angle glaucoma:
Peripheral vision is lost gradually (blind spots)
Tunnel vision (indicates advanced glaucoma)
Warning signs for primary open-angle glaucoma are few until permanent damage has occurred - which is why it is vital to have regular eye checks. If glaucoma is caught early, it can be successfully treated and progression can be prevented.
How is glaucoma treated?
Treatment for glaucoma aims to lower the intraocular pressure and prevent further damage to the optic nerve. This is done by either increasing the drainage of fluid in the eye, lowering the amount of fluid in the eye altogether. Treatment cannot restore vision, only prevent further loss - which is why it is important to have your eyes tested regularly. Everyone, regardless of how well they can see, needs an eye examination every two years. Treatment options can include medication, surgery and lifestyle remedies.
All our OCULA clinics have an Optical Coherence Tomography (OCT) machine which can pick up nerve damage years before symptoms occur and also our Queenstown and Wanaka based optometrist, Oliver, has a sub-specialty in glaucoma.
For more information or to have a chat about any concerns, book in for an appointment here.