Types of Glaucoma

Glaucoma is grouped by how the drainage system is affected and by when it appears.

Primary open-angle glaucoma (POAG)

The most common type. The drainage angle looks open, but fluid drains too slowly. It develops slowly and painlessly, and affects side vision first.

Primary angle-closure glaucoma

The drainage angle is narrow or closes. It can be sudden (acute, painful and urgent) or slow (chronic, silent). It is more common in people with long-sightedness and in some Asian populations, including India.

Normal-tension glaucoma

The optic nerve is damaged even though eye pressure is in the normal range.

Secondary glaucoma

Caused by another condition: injury, inflammation, steroid use, diabetes related blood vessel growth (neovascular glaucoma), cataract or lens problems, or tumours.

Congenital and childhood glaucoma

Present at birth or in early childhood because the drainage system did not develop properly. It needs urgent specialist care.

Other forms

Pigmentary glaucoma and pseudoexfoliation glaucoma are also seen, mostly in older adults.

Suspects

People with raised pressure or a suspicious nerve but no damage yet are called glaucoma suspects and are monitored.

Key point

The type decides the treatment, so only an eye doctor can tell which you have. Suspected angle-closure with sudden pain is an emergency.

Before your eye appointment

Carry your old reports, glasses and a list of all drops, tablets and supplements you use. Note any family history of glaucoma, diabetes or steroid use, and write down when symptoms occur. This helps your eye doctor choose the right tests and plan, and spot changes early.