“Glaucoma is a term that actually refers to a group of diseases that damage the optic nerve. Whilst glaucoma cannot be completely cured, appropriate treatment can slow the disease down.”
Dr Horak explains all about glaucoma, while Dr Bhatt discusses the signs and symptoms
Click on images below to see glaucoma videos
The term refers to a group of diseases that cause damage to the optic nerve. Retinal nerve cells are lost, resulting in optic neuropathy. Peripheral vision is lost initially – with sparing of the central vision – but as the disease progresses, total blindness can result.
Across the globe, glaucoma is the main reason for blindness that cannot be reversed. It is sometimes called the ‘silent thief of sight’ because damage occurs slowly and painlessly over a long period of time and is often missed until the disease is quite advanced.
The optic nerve carries images from the retina to the brain for processing. It is made up of approximately one million delicate nerve fibres that can be permanently damaged due to a number of factors including increased pressure within the eye.
When a significant number of nerve fibres is damaged, blind spots begin to appear in the peripheral field of vision, and eventually all vision can be affected. Visual loss that occurs through glaucoma is permanent and cannot be reversed.
There is a small chamber called the anterior chamber, which sits forward. Liquid flows in and out of this chamber, but if outflow of the fluid is reduced, increased eye pressure is often the result. Left untreated, this causes irreversible damage to the optic nerve. Raised intraocular pressure (IOP) is a known risk factor for glaucoma, but not all glaucoma is associated with high IOP.
It is important to realise that a significant proportion of patients have IOP well within the normal range. This is called normal-tension glaucoma. There is also a group of patients who have IOP levels above normal, but who do not suffer from the disease. This is called ocular hyper-tension. Apart from heightened intraocular pressure, other risk factors for glaucoma include:
Unfortunately not all the causes of glaucoma are known.
There are two main forms of glaucoma: open and closed angle glaucoma.
While glaucoma cannot be completely cured, appropriate treatment can slow the disease down and halt progression. Treatment options vary depending on the severity of each case.
The aim of any form of treatment is to reduce the production of fluid and to help improve the flow of the fluid throughout the eye. In the first instance, your ophthalmologist may prescribe eye drops.
In addition, a laser procedure may also be performed. In some cases, surgery may be required.
Closed-angle (acute angle closure) glaucoma is treated as a medical emergency. If you experience any sudden onset of eye pain and vision loss, contact your ophthalmologist immediately.
Unfortunately, anything compromising the optic nerve that damages it will result in vision loss, and this cannot unfortunately be reversed. That’s why the earlier you are diagnosed with glaucoma, the better your outlook will be.
It is therefore important to schedule regular (2 yearly) eye check-ups with your optometrist or ophthalmologist from the age of 40 (even if you don’t think there is anything wrong). If someone in your family has suffered from the disorder, or if you are in another risk category, more frequent check-ups may be recommended.