Glaucoma is a disease that causes damage to your eye’s optic nerve. It usually occurs when fluid builds up in the front part of your eye. The extra fluid increases the pressure in your eye, which then damages the optic nerve.
Glaucoma is a leading cause of blindness but blindness from glaucoma can often be prevented with early treatment.
In a healthy eye, excess fluid leaves the eye through the drainage angle, keeping pressure stable.
Types of glaucoma
There are two major types of glaucoma:
1. Primary open-angle glaucoma
This glaucoma happens gradually, where the eye does not drain fluid as well as it should (like a clogged drain). As a result, eye pressure builds and starts to damage the optic nerve. This type of glaucoma is painless and causes no vision changes at first.
Some people can have optic nerves that are sensitive to normal eye pressure. This means their risk of getting glaucoma is higher than normal. Regular eye exams are important to find early signs of damage to their optic nerve.
2. Angle-closure glaucoma
This glaucoma happens when someone’s iris is very close to the drainage angle in their eye. The iris can end up blocking the drainage angle (think of it like a piece of paper sliding over a sink drain). When the drainage angle gets completely blocked, eye pressure rises very high, very quickly which is called an acute attack. This is an eye emergency, and you should call your ophthalmologist right away.
Here are the signs of an acute angle-closure glaucoma attack:
- Your vision is suddenly blurry
- You have severe eye pain
- You have a headache
- You feel nauseous
- You throw up (vomit)
- You see rainbow-colored rings or halos around lights
Many people with angle-closure glaucoma develop it slowly. This is called chronic angle-closure glaucoma. There are no symptoms at first, so they don’t know they have it until the damage is severe or they have an attack. Thus regular eye tests are of utmost importance.
Read more about glaucoma on the South African Glaucoma Society website here.