Glaucoma is the second leading cause of blindness worldwide and is characterized by raised pressure inside the eye which causes damage to the optic nerve leading to permanent loss of vision.
Cross section of the eye showing the development of glaucoma
What causes glaucoma?
What causes glaucoma?
- Occurs most frequently in people over 60 years but can happen at any age.
- Association with race – Asians are more prone to closed angle glaucoma whereas Afro-Caribbeans tend to get open angle glaucoma
- Diabetics are more prone to developing glaucoma
- People who are nearsighted are more prone to open angle glaucoma whereas those who are farsighted tend to get closed angle glaucoma
- Serious eye injury can sometimes lead to glaucoma
- Steroid medication can also cause glaucoma when it is used for a long time
- Glaucoma can sometimes be inherited in certain families
Types of glaucoma
Open angle glaucoma is the more common and occurs when there is gradual build up of pressure within the eye even when the drainage angle is not blocked. Visual loss occurs gradually and often goes unnoticed by the patient until it is quite advanced.
Closed angle glaucoma occurs when there is physical blockage of the drainage angle and there can sometimes be a sudden build up of pressure associated with pain, headache, nausea and vomiting.
How to diagnose glaucoma?
Measuring the pressure in the eye is only one of many tests required to confirm the diagnosis. Other tests include examining the drainage angle, measuring the corneal thickness, testing the visual field and scanning the optic nerve are also important. Some of these tests need to be repeated periodically to monitor the progression of the disease.
Measuring intraocular pressure
Visual field assessment
How to treat glaucoma?
When glaucoma is advanced, surgery may be required to lower the eye pressure and Minimally Invasive Glaucoma Surgery (MIGS) is the latest technology available whereby microstents (or tubes) are inserted into the eye to improve drainage of fluid and lower pressure.
Formation of a ‘bleb’ after trabeculectomy
Screening for glaucoma
Early detection of glaucoma is important to prevent permanent visual loss and blindness. Regular visits to the eye doctor for screening should be done as follows:-
Age 20-29 years
- at least once during this period
- people with family history of glaucoma, diabetes, previous serious eye injury or nearsightedness should be screened every 3-5 years
Age 30-39 years
- at least twice during this period
- those with risk factors (as above) should be seen every 2-4 years
Age 40-64 years
- every 2 years
Age 65 years or older
- every year