Glaucoma:The silent thief of sight
It’s no surprise that the eye conditions you can physically see never fail to grab our attention. For instance, cataracts is visible as a gradual clouding of the white of the eye. Strabismus is recognised by the eyes pointing in two different directions. Uveitis is noticeable by a lump of fluid that builds up inside the eye.
The thing is, there are also many eye conditions that operate in covert and often mysterious ways.
Glaucoma is one of these conditions. In fact, glaucoma is not just one condition but a group of eye conditions which describe a particular type of damage to the optic nerve, usually due to increased intraocular pressure.
Because it can have no symptoms and therefore fall under the radar, glaucoma is often called “the silent thief of sight”. The condition develops gradually over time, and often it isn’t until it is more advanced does it begin to make itself known.
This is a big concern as, when left untreated, glaucoma can lead to everything from a slight loss of vision to complete blindness. To shed some light on glaucoma and bring this silent thief to account, let’s take a closer look at the four main types:
1. Primary open-angle glaucoma (POAG)
The most common type of glaucoma is primary open-angle glaucoma (POAG). It is a chronic condition that happens gradually and increases in likelihood as you age. POAG occurs when intra-ocular fluid from the eye is unable to drain as well as it should—a bit like a clogged drain. The result is eye pressure builds and begins to damage the optic nerve.
In the initial stages, this type of glaucoma is painless and doesn’t affect your vision. I.e. there are zero warning signs that you could have it. As POAG progresses, you may notice blind spots develop in your peripheral (side) vision.
Having regular eye exams is the best course of action to help identify POAG and ensure it doesn’t cause irreparable damage to your vision.
2. Primary angle-closure glaucoma (PACG)
A variation of POAG, primary angle-closure glaucoma (PACG) is when intra-ocular fluid cannot drain properly due to a variation in the angle of the eye’s anterior chamber.
This happens when the iris is very close to the drainage angle in their eye. It’s a bit like a piece of paper sliding over a sink drain.
Unlike POAG, PACG can cause symptoms like pain and redness in the eye due to a sudden increase in pressure. This is often referred to as an acute attack, and in its event, you should call your ophthalmologist immediately.
However, the majority of people with PACG develop it slowly. Like POAG, there are no symptoms at first, and often you don’t know you have it until the damage is severe or you have an acute attack.
3. Congenital glaucoma
Congenital glaucoma, otherwise known as childhood or infantile glaucoma, is a rare but serious condition that develops in babies and young children.
Congenital glaucoma is often inherited and usually diagnosed within the first year of life. It occurs due to the presence of an abnormality of the eye’s drainage system during its development, leading to increased intraocular pressure, which in turn damages the optic nerve.
Unlike the above types, there are often clear signs of childhood glaucoma. They include cloudiness of the cornea, enlarged eyes, and sensitivity to light.
4. Secondary glaucoma
Secondary glaucoma refers to any form of glaucoma in which there is increased eye pressure that results in damage to the optic nerve and vision loss.
It’s called secondary as it can occur due to a myriad of other primary conditions or factors, such as surgery, trauma or physical injury, inflammation, certain medications, and syndromes such as pseudo-exfoliation and pigment dispersion.
As with primary glaucoma, secondary glaucoma can occur in one or both eyes and can be of the open-angle or angle-closure type.
There are several categories of secondary glaucomas, such as exfoliative glaucoma, neovascular glaucoma, and pigmentary glaucoma, and the type of treatment depends on the underlying cause.
Treatments for glaucoma
Unfortunately, the damage from glaucoma is permanent and therefore cannot be reversed. However, there are a number of treatments available that ophthalmologists can use either on their own or in combination to manage the condition and prevent further damage.
The objective of glaucoma treatment is typically to reduce the pressure in the eye that causes glaucoma and to preserve your vision.
One treatment that is typically used to control glaucoma is eye drops. Such medicines can help you keep your vision, but they may also produce side effects like stinging and redness.
Lasers are also commonly used to treat glaucoma. For open-angle glaucoma, it’s used to temporarily increase the drainage of fluid from the eye. For closed-angle glaucoma, it’s used to create a hole in the iris and prevent the condition from happening again.
Another treatment option is surgery. The surgeon aims to create a new drainage channel for the fluid to leave the eye. The surgery is very effective but may leave you with a small blister on the eye, albeit hidden under the upper eyelid. Glaucoma is a complicated eye condition, but managing it doesn’t have to be.