Glaucoma is a group of eye diseases in which the optic nerve, which connects your eye to the visual processing centre in your brain, is damaged by the pressure of the fluid inside your eye. This may be because the pressure in the eye is higher than normal, or because your nerve is more susceptible to damage from relatively normal pressure. This may affect one or both eyes.
There are two main types of glaucoma – chronic glaucoma, which happens slowly, and acute glaucoma, which happens very quickly. Chronic glaucoma is much more common than acute glaucoma. The most common form of chronic glaucoma is called primary open angle glaucoma (POAG).
Chronic Glaucoma – Anyone can develop chronic glaucoma. The risk of developing it increases if you are aged over 40, are short sighted, are of African/Caribbean origin, are closely related to someone with glaucoma, have raised eye pressure (ocular hypertension; OHT), are diabetic or have high blood pressure. If one of your parents, children or siblings has glaucoma, and you are over 40, the NHS will pay for your eye examination as you are at greater risk.
If left untreated glaucoma can lead to tunnel vision and blindness, but most people who go blind from glaucoma are those in whom it was detected at a late stage. As a result, it is important to detect it early.
The tests to detect glaucoma may include looking at the nerve at the back of your eye, measuring your eye pressure (usually with a puff-of-air test), and checking your visual fields to see how far out you can see and if there are any blind spots in your field of vision.
We now also have a machine, called an OCT, which can perform a special scan (now available at both the Darlington and Horden practices). This can take a detailed look at your optic nerve, and the nerve tissue in your eyes, to check for signs of glaucoma.
Acute Glaucoma – This is a type of glaucoma where the drainage channels inside your eye are blocked or damaged in some way. This causes the pressure inside your eye to increase rapidly. It may be called acute angle closure glaucoma. People who are more likely to get acute glaucoma if they are over 40, women, of East or South Asian origin, have a family history of closed-angle glaucoma, or are long-sighted.
Sometimes the increased pressure can come and go, and people get short bursts of pain or discomfort and blurred vision. This can happen when your pupils get bigger, so you may notice it at night or when in a dark area (like the cinema). Other symptoms are an ache in the eye which may come and go, nausea and vomiting, red eyes, or seeing coloured rings around white lights. It can be a bit like looking through a haze or mist.
If you get these symptoms it is important to act quickly, even if the symptoms appear to go away, as your vision may be damaged each time you notice the symptoms. You should see your optometrist as soon as possible if your symptoms are intermittent. If you have acute symptoms and they do not go away, you should see your optometrist as an emergency, or if you are away from home, attend the nearest Accident and Emergency department.
If you have any concerns about glaucoma, please do not hesitate to contact your nearest Cooper & Leatherbarrow practice.