What is glaucoma?
Glaucoma is a relatively common eye condition; it affects about 1 in 60 people over the age of 40. This increases steadily with age such that by the time you are 80 years old you will have a 5% (1 in 20) chance of having the condition.
Generally it is a disease of very few or no symptoms until it has reached a very advanced stage. For this reason it is very important to attend an optometrist on a regular basis, particularly once you have reached the age of 40.
If a close member of your family is affected then this increases the chances of you developing the condition substantially. Possibly by as much as a factor of ten.
Your optometrist will check three things during an eyetest to rule out glaucoma. Firstly the pressure within the eye will be measured. This will often be done with the 'puffer' test but other methods may also be used. A visual field examination may be performed. This assesses the peripheral visual field which may be damaged once glaucoma is established. Finally the optic nerve head at the back of the eye will be examined. Characteristic changes known as 'cupping' are often seen in glaucoma. This represents a form of cellular erosion as the nerves at the back of the eye die off from the excessively high pressure within the eye.
If your optometrist is at all concerned about the possibility of glaucoma they will refer you on to see an eye doctor.
Further detailed assessment of the eyes will then be carried out. Pressure will be carefully checked, a very detailed field assessment will be carried out and the optic nerve will often be scanned to pick up the very subtle changes that usually occur well before the visual fields are affected. Further tests that your optometrist will not have performed include precise measurement of the thickness of the cornea (this can significantly alter the accuracy of eye pressure measurements) and an assessment of the 'angle' of the eye using a special contact lens to determine whether the type of glaucoma is open angle or narrow angle.
The good news is that the vast majority of patients respond very well to the use of daily eyedrops to lower the pressure within the eye. However, the treatment is nearly always lifelong and it is vitally important that you use your drops as instructed and get into the habit of using them every day. Glaucoma treatment should be viewed very much as a 'marathon' and not a 'sprint'. Taking your drops diligently now might make a huge difference to your eyesight in 10, 20 or 40 years into the future.
There are a variety of drops available nowadays. Often a single drop may not be sufficient to achieve a pressure that is low enough. In that case a second agent may be added but often this can still involve a single bottle as many of the preparations are now made as combination drops containing two separate treatments in one bottle.
If the pressure is not deemed low enough then further options may be required such as lasers and surgery to lower the pressure in the eye.
Glaucoma is a diagnosis with lifelong implications. However, the vast majority of patients with the condition do not go blind. In fact, most patients may be totally unaware of any visual problems and can continue all daily activities perfectly normally including driving. Whenever glaucoma is diagnosed you are obliged to inform the DVLA who will get a local optometrist to assess your visual fields with regard to meeting the driving visual standards. Most patients will be seen every six to nine months. If the situation is very stable then an annual visit may be sufficient.
What does this involve?
The operation usually takes between 45 minutes and an hour and involves draining out some of the fluid in your eye to lower the pressure. Your surgeon will make a small draining hole in the lining of the white of your eye to allow this to happen.
Once the operation is complete your eye will be stitched and normally covered by a clear plastic shield and you can rest for a while before your departure.
When will I recover?
You should be able to go home a few hours after the operation and you should ensure you have someone to drive you home after the operation.
Glaucoma surgery recovery involves your surgeon checking your eye the day after the operation and several times during the first few weeks after your operation. You should be able to return to work a few weeks after the operation.
What risks should I know about?
Glaucoma surgery is a regularly performed operation and is considered to be quite safe. Most patients do not suffer any complications or side effects but we should mention those complications that can occur:
- Severe bleeding inside the eye during surgery which may cause permanent loss of vision
- Bleeding at the front of the eye, which makes vision worse and usually settles after a week
- Drainage of too much fluid which usually settles on its own with aticht pad or contact lens being used.
- Developing a cataract, which is relatively common around 10%
- Reduced vision over time - risk 10%