What is glaucoma?
Glaucoma is a group of diseases which affect the optic nerve at the back of the eye and over time can cause vision loss and blindness if left untreated. Glaucoma is often referred to as ‘the silent stealer of sight’ as you do not notice any vision problems until the disease is advanced and by then it is much too late.
The damage caused by glaucoma is irreversible. Therefore it is important to have regular eye examinations with us so we can monitor the health of the eye and detect any disease as soon as possible. If glaucoma is detected and treated early you can often protect your eyes against any serious vision loss!
How is the optic nerve damaged in Chronic Open-Angle Glaucoma (COAG)?
The pressure inside the eye is a major risk factor for optic nerve damage. In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of the chamber providing nourishment for nearby tissues.
In open-angle glaucoma although the fluid is drained from the eye it is not drained fast enough, leading to a steady rise in pressure inside the eye. The increased pressure in the eye can then damage the optic nerve at the back of the eye causing vision loss. Therefore it is very important to control the pressure inside the eye!
Optic nerve damage can also be affected by blood pressure so it is important to make sure your blood pressure is at a normal level for your body by working with your GP.
Can I develop glaucoma if I have increased eye pressure?
Not everyone with high intraocular pressure will go on to develop glaucoma: some people can tolerate higher pressure in the eyes than others. What may be high pressure for one person maybe low for another.
Whether you develop glaucoma depends on the level of pressure your optic nerve can tolerate without developing any damage. As it is very individual a comprehensive eye examination is required to assess whether glaucoma is a possibility – you cannot determine whether you have glaucoma by the pressure alone.
Can I develop glaucoma without high pressure inside the eye?
It is possible to develop low-level or normal-tension glaucoma (NTG), where the pressure inside the eye is well within what are considered normal limits. Risk factors for normal-tension glaucoma include low blood pressure and Raynaud’s syndrome.
Despite the pressure already considered ‘low’, lowering the pressure by about 30% has been proven to still slow the disease in some people with normal-tension glaucoma. Glaucoma may worsen in others despite the pressure being lowered.
Risk factors for Glaucoma:
At first there are NO SYMPTOMS! There is no pain and vision is normal. As glaucoma progresses you will gradually lose your peripheral vision until only your central vision remains, giving the impression of looking through a tunnel. If the glaucoma remains untreated still eventually you will be left completely blind. As the disease progresses so slowly most people adapt and therefore don’t realise they have lost vision until the damage is very advanced, preventing them from driving or navigating somewhere new.
Again we emphasise that it is very important to have regular check ups to prevent this happening to you! Don’t wait until you can’t see before you get the health of your eyes checked!
There is no cure for glaucoma: once the optic nerve has been damaged there is no way to repair any vision loss caused. However, if caught early enough there are many treatments to help prevent the progression of the disease so that vision is retained.
Eyedrops to lower the pressure inside the eye are the most common form of treatment for glaucoma. There are a number of drops that can be used: some lower the pressure by increasing the amount of fluid leaving the eye, others decrease the amount of fluid entering the eye.
Some eyedrops can have side effects such as stinging, burning and redness of the eyes. If you have any questions about the eyedrops you are on contact your ophthalmologist at the glaucoma clinic or email Claire firstname.lastname@example.org.
Before the surgery numbing drops are applied to your eye. A special lens is held to your eye. and a high-intensity beam of light is aimed through the lens and reflected onto the drainage meshwork inside your eye. You may see flashes of bright green or red light. The laser makes several evenly spaced burns that stretch the drainage holes in the meshwork, allowing the fluid to drain better. This can work very well in some patients but the effects can wear off over time. You are liekly to need to keep taking eyedrops even after this procedure.
Conventional surgery, called trabeculectomy, creates a new channel for the fluid to drain from the eye. The fluid is drained between the eye tissue layers causing a ‘filtration bleb’ which has a blister-like appearance on the eye. Eyedrops are needed after the surgery to help prevent infection and inflammation.
This type of surgery is about 60-80% successful at lowering the pressure of the eye but may need re-doing if the new drainage channel narrows. Sometimes your vision may not be as good as it was before conventional surgery. Conventional surgery can cause side effects such as cataract, inflammation, infection or low pressure problems. Therefore this method is normally a last resort when eyedrops and laser have failed to reduce the pressure.
Other types of glaucoma
Closed Angle Glaucoma
In Closed-Angle Glaucoma the drainage channel of the eye is blocked by part of the iris (the coloured part of your eye) causing the pressure in the eye to shoot up very suddenly. Symptoms include intense pain and nausea, as well as redness of the eye, blurred vision and seeing haloes around lights.
If you get these symptoms you must SEEK MEDICAL ASSISTANCE IMMEDIATELY. Closed-Angle Glaucoma is considered a medical emergency – you should go straight to hospital. If not treated as soon as possible the eye can go blind. Treatment usually involves intravenous medication and prompt laser surgery to reduce the pressure inside the eye.
In congenital glaucoma children are born with a defect of the drainage channel of the eye causing high intraocular pressure. The child normally has obvious symptoms such as excessive tearing, cloudy eyes and sensitivity to light. Conventional surgery is often the first course of treatment and is generally very safe and effective, giving them an excellent chance of good vision if treated promptly. Eyedrops are considered too risky in infants due the severe side effects they can cause in small children and are generally very difficult to administer properly.
Glaucoma can develop as a complication of other eye problems. Glaucoma can arise secondary to cataract, eye surgery, steroid use, some eye tumours or inflammation such as uveitis. One severe form of glaucoma called neovascular glaucoma is cause by very poorly contolled diabetes or high blood pressure.
Pigment Dispersion Glaucoma
This type of glaucoma is caused by pigment from the iris shedding and blocking the meshwork through which the fluid drains from the eye, causing the eye pressure to rise. It is more common in caucasians and those who are short-sighted.
Pseudoexofoliation glaucoma occurs when extra material is produced and shed from the internal eye structure, blocking the drainage meshwork and causing the pressure to rise.
Please call us on 01245 461 843 or send an email to email@example.com if you would like further advice.
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