Glaucoma is the ocular disease where vision is slowly lost due to gradual damage to the optic nerve. There are a few different types of glaucoma but the end result is the same – permanent loss of peripheral vision. Unfortunately, glaucoma can go undetected for a long time without any warning signs or symptoms until a significant amount of irreversible damage has occurred because it occurs in the periphery.
2 in 100 Australians will develop Glaucoma in their lifetime
1 in 8 Australians aged over 80 years will develop glaucoma
First degree relatives of people with glaucoma have an up to 10-fold increased risk of developing the disease
Currently, about 50% of people with glaucoma remain undetected.
The most common form of glaucoma is called Open Angle Glaucoma (OAG) where the liquid inside the eye, called the aqueous humor, fails to drain properly leading high intraocular pressure (IOP) which then damages the optic nerve at the back of the eye.
Angle Closure Glaucoma (ACG) is where the drainage channels are constricted due to a narrowing of the pathway by the iris. The blockage of the outflow can either be chronic or occur suddenly. The sudden type is referred to as acute angle closure. Acute angle closure causes a severe rise in the IOP which can result in pain, blurred vision, haloes around bright lights and headaches.
Normal Tension Glaucoma (NTG) is where damage to the optic nerve occurs resulting in the loss of peripheral vision, however, the eye pressure is measured to be within the normal range. So other factors such as family history, the appearance of the optic nerve, visual field tests and other factors play a role in determining the diagnosis.
Secondary Glaucoma is similar to OAG where there is an increase in IOP or damage to the optic nerve but the condition stems from another source such as the use of certain medications, cataracts, eye injuries or other ocular conditions. Therefore treatment can vary for this form of glaucoma depending on the cause of the increase in pressure.
In the early stages of glaucoma, typically there are no signs or symptoms. Once the disease has progressed to cause a significant amount of peripheral visual field loss, then you may know you have been affected. People often describe the effects of late-stage glaucoma as having tunnel vision.
Unfortunately, there are no treatments to reverse the damage that has been done due to glaucoma. However, treatment can slow down or stop additional vision loss if glaucoma is detected. The treatment options will vary depending on the form of glaucoma, lifestyle of the patient, and many other factors. The main options will be either eye drops, laser treatment, surgery or a combination of these treatments. Therefore prevention is the best treatment – regular checks with your optometrist can ensure glaucoma is detected and treated promptly.