About eye diseases What is Glaucoma? Glaucoma is a term that describes a group of eye conditions that affect vision. Glaucoma often affects both eyes, usually in varying degrees. One eye may develop glaucoma quicker than the other. Glaucoma is the most common cause of sight loss among those of working age. Pressure is raised in the eye which damages the optic nerve and increasingly causes sight loss. New treatments, including improved eye drops and surgical techniques to reduce this pressure in the eye are currently being researched. You can help to find new treatments and end sight loss forever. Please make a gift today. DONATE now How common is glaucoma? In England, about 480,000 people have chronic open-angle glaucoma. Among white Europeans, about 1 in 50 people over 40 years of age and 1 in 10 people over 75 years of age have chronic open-angle glaucoma. You are also at increased risk of developing open-angle glaucoma if you are of black-African or black-Caribbean origin. The other types of glaucoma, such as acute angle-closure glaucoma, are much less common. However, people of Asian origin are more at risk of getting this type of glaucoma compared with those from other ethnic groups. Types of glaucoma There are four main types of glaucoma: chronic open-angle glaucoma – this is the most common type of glaucoma and develops very slowly primary angle-closure glaucoma – this is rare and can occur slowly (chronic) or may develop rapidly (acute) with a sudden, painful build-up of pressure in the eye secondary glaucoma – this occurs as a result of an eye injury or another eye condition, such as uveitis (inflammation of the middle layer of the eye) developmental glaucoma (congenital glaucoma) – this is rare but can be serious. It is usually present at birth or develops shortly after birth. It is caused by an abnormality of the eye. Causes of glaucoma Glaucoma occurs when the drainage tubes (trabecular meshwork) within the eye become slightly blocked. This prevents eye fluid (aqueous humour) from draining properly. When the fluid cannot drain properly, pressure builds up. This is called intraocular pressure. This can damage the optic nerve (which connects the eye to the brain) and the nerve fibres from the retina (the light-sensitive nerve tissue that lines the back of the eye). Diagnosing glaucoma Glaucoma is usually picked up during a routine eye test, by measuring pressure in the eye. People often do not realise they have it, as vision is affected only gradually. Symptoms of glaucoma include blurred vision, rainbow-coloured circles around bright lights. Very occasionally symptoms can develop quickly causing intense eye pain, red eye, nausea and vomiting, headache, and tenderness around the eyes. It's important to have regular eye tests so problems such as glaucoma can be diagnosed and treated as early as possible. Preventing glaucoma Attending regular optician appointments will help to ensure any signs of glaucoma can be detected early and allow treatment to begin. You are entitled to a free NHS eye test if you are over 40 years old and have a first-degree relative (mother, father, sister or brother) with glaucoma. You may also be entitled to a free NHS eye test if: an ophthalmologist (eye specialist) thinks that you are at risk of developing glaucoma you are over 60 years old. Treating glaucoma Glaucoma can be treated with eye drops, laser treatment or surgery. However, early diagnosis is important because any damage to the eyes cannot be reversed. Treatment aims to control the condition and minimise future damage. If left untreated, glaucoma can cause visual impairment, but if it is diagnosed and treated early enough, further damage to vision can be prevented. Future treatments New treatments, including improved eye drops and surgical techniques to reduce this pressure in the eye are being researched. Dr Colin Chu and his team at the University of Bristol are investigating switching off a particular gene to reduce pressure in the eye. You can help to find new treatments and end sight loss forever. Please make a gift today. DONATE now For full medical information about glaucoma, please visit the NHS website.