What is glaucoma?

Glaucoma is the name given to a group of eye diseases that cause progressive damage to the optic nerve. When the pressure in the eye (intraocular pressure) rises, the optic nerve fibres gradually deteriorate. The optic nerve carries visual information to the brain, and without it, the vision is affected.

As one of the leading causes of blindness for people over the age of 60, glaucoma can occur at any age but is more common in older adults.

Many forms of glaucoma have no warning signs. The effect is so gradual that you may not notice a change in vision until the condition is at an advanced stage.

As you are unlikely to be aware of your intraocular pressure, screening is essential. Optometrists usually include a pressure test as part of your regular check-up. If they detect an irregularity, they will refer you to an ophthalmologist who will then do a full glaucoma screening, including a visual acuity test, intraocular pressure check and cup/disc ratio of the optic nerve. If any of these results are concerning, further tests include corneal thickness, an optic nerve OCT, and visual field checks.

Routine screening is recommended from the age of 40. Anyone with the following risk factors should be tested every year or two after the age of 35:

  • A higher than normal intraocular pressure reading
  • A biologically related family member who has or had glaucoma
  • Myopic eyes (your optometrist can advise you here)
  • Being of African ethnicity

Because vision loss due to glaucoma can’t be recovered, it’s important to have regular eye exams so a diagnosis can be made in its early stages and treated appropriately. If glaucoma is recognized early, vision loss can be slowed or prevented. If you have the condition, you’ll generally need monitoring and treatment for the rest of your life. The treatment may include eye drop medication, laser procedures or surgical procedures.

For more patient information and videos, visit the South African Glaucoma Society website: