Glaucoma is a word that many people tell us they’ve heard, but have no idea what glaucoma is! Read on to learn more about why you should have an eye examination to check for glaucoma.
What is Glaucoma?
Glaucoma is an eye disease that causes blindness if left untreated. The optic nerve of the eye is damaged by a pressure that is too great for the eye to cope with. The pressure comes from too much fluid in the front chamber of the eye. Glaucoma is divided into categories that refer to if the chamber angle is open or closed. Due to the anatomy of the nerve fibres that make up the retina and then form the optic nerve glaucoma damage will generally affect side vision and creep in leaving an island of central vision.
Find out more by clicking this link to Glaucoma NZ
Who gets Glaucoma?
Anyone can get glaucoma and it’s prevalence increases with age. About 10% of the population over 70 years of age have glaucoma. People of South Asian descent or long-sighted are more likely to get angle closure glaucoma and white short sighted females are more likely to get open angle glaucoma. Having a family history of glaucoma increases your risk too. Having a sibling gives you a 7x chance of developing glaucoma and a parent is a 4x chance. The more relatives the higher the risk.
How do I know I have Glaucoma?
Unfortunately you won’t know you have glaucoma until quite late on and have lost a substantial amount of vision. There is no pain and no symptoms. This disease is a good reason to keep up to date with your regular eye examinations even if you feel your vision is great! Don’t let the silent thief of sight steal yours.
What can I do not to get Glaucoma?
There is no cure for glaucoma and no vaccination against glaucoma. Regular eye examinations to detect for glaucoma are recommended. In people with narrow anterior chamber angles a laser may be used to make a tiny hole that acts as an extra drainage hole may be indicated. In some cases having a thick lens or cataract removed can be enough to make space in the chamber that the angle deepens. Ginkgo as a supplement has been shown to have some neuro-protective properties and some glaucoma specialists recommend it for their patients with glaucoma. Activities like blowing the bag pipes, standing on your head, downward facing poses in yoga will all increase the pressure in your eye. Eating lots of liquorice will also increase eye pressure. These activities are best avoided if you do have glaucoma.
How is Glaucoma Treated?
Glaucoma treatment is done to lower the pressure in the eyes. Often in primary open angle glaucoma there will be a one month trial of eye drops in the worse eye. A target pressure is set where this is low enough the eye will not progress to blindness. In angle closure glaucoma the treatment is more intervention to increase the angle depth with a lasered drainage hole or lens extraction. As glaucoma is for the rest of your life and not everyone is compliant with drops a laser technique SLT (selective laser trabeculoplasty) is used to improve drainage and this may give years of drop free treatment.
How we look for glaucoma in your eyes in your eye examination
During an eye examination when we are looking at the front of your eye we will assess how deep or narrow your anterior chamber is. If the ratio of angle is narrow we may use a gonioscopy lens (a large contact lens) to view the angle. When we look through your pupil at the back of your eye we look at the optic nerve. The nerve has a paler area referred to as cupping, this cupping will enlarge and even notch with glaucoma. Sometimes we will spot a haemorrhage on the optic nerve rim and this can be indicative of glaucoma. We will measure the pressure in your eyes (the stingy eye drops and the test with blue light). We compare your previous readings and our findings to the normal range which has an average of 15.
Why we would recommend further testing to exclude glaucoma in your eyes?
If we take an unusual pressure reading we ask you to return to repeat this. Often we like to do this in the morning when we know pressure is highest. For everyone over 50 years of age or optic nerves that aren’t a matching pair we will recommend returning for a visual field test. The test specifically checks where glaucoma first causes loss of vision and we are wanting to prove this area of your sight is unaffected. If you have a family history of glaucoma or unusual nerves we will recommend you have an OCT done. OCT (Ocular Coherence Topography) is a very fancy laser that scans all the nerves that make up the optic nerve head and compare your optic nerve with a normal population. Over time it can detect progression more accurately and earlier than any clinician. We will discuss what we find and sometimes as detecting glaucoma is so hard in its early stages we may recommend a referral to a glaucoma specialist of which there is about 6 in Auckland.