Glaucoma is the name given to a group of eye diseases in which the optic nerve at the back of the eye is slowly destroyed. In most people this damage is due to an increased pressure inside the eye - a result of blockage of the circulation of fluid in the eye or blocked drainage. In other patients the damage may be caused by poor blood supply to the vital optic nerve fibres, a weakness in the structure of the nerve, or a problem in the health of the nerve fibres themselves.
Over 300,000 Australians have glaucoma. While it is more common as people age, it can occur at any age. As our population becomes older, the proportion of glaucoma patients is increasing.
Source: Tunnel Vision. The economic impact of Open Angle Glaucoma, Centre for Eye Research Australia, 2008
In the first instance, glaucoma is asymptomatic. The problem with this is that you can permanently lose part of your vision before the disease is diagnosed. This is why ophthalmologists and optometrists recommend regular testing – every two years once you turn 40.
Although anyone can get glaucoma, some people have a higher risk, those with a family history of glaucoma, diabetes, migraine, short and long sightedness, previous eye injuries and steroid eye drops used in the past or at present.
Glaucoma assessment will involve checking the vision, the intraocular pressures and looking at the optic disc. Other tests may be performed such as visual fields, OCT imaging of the optic disc and glaucoma parameters and fundus photography.
Eye drops are the usual first line management of glaucoma.
Laser surgery can be used to lower intraocular pressure in glaucoma. It is used when eye drop medications are not lowering the eye pressure enough or are causing significant side effects. It may sometimes be used as initial treatment in glaucoma.
A trabeculectomy is an operation to make the pressure lower inside the eye. It involves making a new channel in the sclera, through which fluid flows out into a space underneath the outer layer of the eye.
Glaucoma may get worse if the pressure inside the eye is not low enough. Trabeculectomy is recommended when eye drops are not controlling the pressure and there is a significant risk that glaucoma is going to cause further damage to your sight.