Glaucoma

What is glaucoma?

Glaucoma is a group of diseases with characteristic optic nerve damage, resulting in irreversible loss of vision. Most, but not all of these diseases are characterised by raised pressure in the eye (intraocular pressure). The level of pressure that causes damage can vary in different individuals and the resistance level of the optic nerve.

Glaucoma is known as the ‘silent thief of sight’ as the initial vision loss is mainly peripheral and not readily noticeable. Central vision and reading vision are usually spared until later.

The patient may not experience any symptoms until late in the disease when most of the vision has already been irreversibly lost.

Normal Vision

Vision with glaucoma

What are the different types of glaucoma and their symptoms?

• Open-angle glaucoma
  Open-angle glaucoma accounts for the majority of glaucoma in most countries. It often has no symptoms and progresses slowly. The rise in intraocular pressure is slow and painless.
• Closed-angle glaucoma
  Angle-closure glaucoma can either be acute or chronic. Acute angle-closure glaucoma is characterised by a sudden, dramatic increase in intraocular pressure. This can cause severe eye pain, redness, blurred vision and the appearance of haloes around lights. Headaches, nausea and vomiting may follow. This emergency requires prompt treatment. The chronic form may show no symptoms, as in open-angle glaucoma.
• Congenital glaucoma
  Congenital glaucoma is rare and occurs at birth. Enlargement of the infant’s eyes, corneal haze, tearing and unusual light sensitivity are symptoms that warrant an eye examination.
• Secondary glaucoma
  Secondary glaucoma may be caused by conditions such as poorly controlled diabetes, inflammation of the eye, tumours, previous eye surgery, injuries or cataracts in their advanced stages, or the use of steroid medications on the eye.