What is primary open-angle glaucoma?

Primary open angle glaucoma (POAG) is an optic neuropathy (disease of the optic nerve). It is generally a bilateral, although not necessarily symmetrical disease. If two or more of the following is present it is diagnosed:

- Raised intra-ocular pressure > 21mmHg
- Glaucomatous visual field defects (a test done to assess the peripheral visual field).
- Glaucomatous optic nerve damage (the part of the nerve visible in the eye becomes “cupped”. This is where the centre depressed part increases in relation to the whole disc diameter).

From this it is clear that even normal pressure can cause damage to the nerve, the so called normal lension glaucoma.