Glaucoma

 



Q1. What are the causes of glaucoma?
Do people with glaucoma have green eyes? Not really.
 
Glaucoma is an eye condition caused by high eye pressure. So why is the high pressure? Aqueous humor is the fluid inside the eyes that is secreted and drained to maintain normal eye pressure. However, due to blockage of drainage channels, the fluid will build up inside the eyes and increase eye pressure, causing glaucoma.
 
High eye pressure can damage the optic nerves. Think of the optic nerves as electrical wires inside a monitor. The screen will go dim when the wires are damaged. Likewise, glaucoma can cause dim and narrow vision.
 
Q2. Does glaucoma only occur in the elderly?
Glaucoma is a generic term as there are over 30 types of glaucoma. It can occur in infants as well as old people. As mentioned, glaucoma is caused by the blockage of drainage channels of the eyes, which is usually due to degeneration. Just like the drain pipes in the toilet. Drainage slows down when the pipes are damaged over time. That explains its relatively high incidence in the elderly
 
Some types of glaucoma are congenital, where the patients are born without the drainage channels and the aqueous humor cannot be drained. Eye pressure increases as the humor accumulates inside the eyes. Glaucoma can happen in children with congenital conditions, and is not limited to seniors
 
Q3. What are the symptoms of glaucoma?
Do glaucoma patients see everything in green? Actually only a small number of patients see green light. Most patients show no symptoms at all. High eye pressure causes gradual damage to the optic nerves. It’s just like a silent thief who steals a tiny amount of money time and time again, but gets unnoticed as you walk around with a lot of money. Once you know you’ve been pickpocketed for a long time, it’s already too late.
 
Glaucoma can also cause the narrowing of visual field over time. As symptoms are not detectable in the early stage, patients diagnosed with glaucoma is usually in the middle or late stage. In short, the lack of symptoms is the most common symptom of glaucoma. Regular eye examination is therefore important for early detection.
 
To put it simply, glaucoma can be chronic or acute. Acute glaucoma is characterised by a sudden increase in eye pressure which causes eye pain and corneal edema. Patients may see halos with rainbow rings: it is not just a bit diffused when you look at the lights. You should beware if you see a rainbow-coloured circle around the lights.
 
Besides halos, high eye pressure can also lead to blurred vision as it deprives the optic nerves of blood supply. When you start seeing halos with rainbow rings all of a sudden, have eye pain, nausea and headache, you must seek medical attention immediately. These are the symptoms of acute glaucoma.
 
Chronic glaucoma can be asymptomatic in the early stage. The visual field will get narrower in the late stage. Patients may have difficulty retrieving dropped objects and even bump into others from time to time. They may often bump into a glass door or get bumped by others, sometimes even unaware of it until they come by close enough. Please seek medical attention as soon as possible if you encounter any of these situations.  
 
Q4. Does acute glaucoma occur while watching a movie in cinema?
Some studies suggest that darkness may induce acute glaucoma. The drainage channels will narrow a bit in a dim environment, and it can get worse if the patients already have narrow channels. When the channels are blocked, the aqueous humor cannot be drained and builds up inside the eyes. It increases eye pressure and gives rise to glaucoma.
 
We usually watch movies in dark places. Some studies suggest that it is safe to do so, such that movie-going is fine for those who worry about glaucoma or for patients with glaucoma. What is important is that, in a dim environment, the drainage angle is more likely to narrow. It is better to watch movies in a lighted place. If you are going to watch a movie at home, please do not switch off all the lights. Try to use some soft light in the background as it helps widen the drainage angle and to reduce the risk of acute glaucoma and sharp increase in eye pressure.
 
Q5. What should I do if I have glaucoma?
It is very important for glaucoma patients to use eye drops regularly as the medication can help reduce eye pressure.
 
As far as lifestyle is concerned, first of all, avoid sleeping with your eyes against a pillow. Let say glaucoma occurs in the left eye. Studies show that sleeping with the glaucomatous eye pressed on a pillow will cause the rise of eye pressure by more than 10 mmHg. As normal eye pressure is below 21 mmHg, even eye drops cannot relieve the additional increase in eye pressure caused by sleep position. Please sleep on the other side or sleep on the back to mininise eye’s compression and reduce the risk of elevation in eye pressure.
 
Second, try not to drink too quickly. If you gulp down a litre of water or drink up a bottle of beer in in some drinking contests, the water is absorbed by the blood vessels quickly and released into the eyes, causing a sudden increase in eye pressure. Studies show that a “water-drinking challenge” can increase eye pressure by 10 to 20 mmHg. Therefore, try to drink small amounts of water throughout the day. Take sips of water at a time and a few glasses a day. Only drink another glass about an hour later. By drinking at different times and at a slow pace, it ensures slow water absorption into the eyes and avoids sudden water build-up. If too much water accumulates in the eyes and is not released in time, the extra water build-up can further increase eye pressure.

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