Glaucoma refers to a group of conditions where the optic nerve at the back of the eye is damaged, usually by raised pressure inside the eyeball. It affects almost 10% of people over age 75. Glaucoma can lead to loss of peripheral vision (“tunnel vision”) and even to central vision loss if not detected and treated.
There are different causes but the type which is commonest in later life (“open-angle glaucoma”) develops gradually and there may be no symptoms in the early stages, meaning it is often picked up on a routine eye test. You are more at risk if you have a first-degree relative (parent/ sibling/child) with glaucoma, are of Afro-Caribbean ethnicity, are short-sighted, a diabetic or have taken steroids for a long period. Treatment will stop your vision from getting any worse and usually starts with daily eye drops to reduce the pressure. For most people, this is sufficient, but the drops have to be continued for life. Laser treatment or surgery is necessary in some cases.
In rare cases, there is a rapid-onset or acute form of glaucoma (“angle-closure glaucoma”) which is a medical emergency.
Acute glaucoma is a sudden rise in pressure in the eye when the drainage channels in the eye become blocked. Symptoms may include a red and intensely painful eye with blurred vision, a headache, nausea and vomiting. You may see rainbow-coloured rings around bright white lights. Some people feel generally unwell, have a hard, tender eyeball and the cornea may look hazy. Risk factors include smaller eyes, being long-sighted, female sex, Asian and Indian ethnicity and a family history of acute glaucoma.
Glaucoma UK has helpful information.