About Glaucoma

Glaucoma of some type is found in about 2 per cent of the population over the age of 40. It can also affect children and young adults, although much less frequently. It is estimated that more than 500,000 people suffer from glaucoma in England and Wales alone, with more than 70 million people affected across the world. The great majority of those with glaucoma have a chronic (slowly developing) form of the condition, primary open angle glaucoma (POAG), and studies have demonstrated that half of all cases remain undiagnosed. People of African-Caribbean origin have about four times the risk of POAG as whites.

Close blood relatives of patients with POAG have at least a four-fold increased risk of glaucoma compared with those without a family history of glaucoma. People from families in which a member has glaucoma should be tested for glaucoma from the age of 35 onwards. People with other glaucoma risk factors in addition to the family history (e.g. being of African-Caribbean origin or having diabetes) should be tested from an even earlier age.

The treatment of glaucoma has developed considerably over recent years and new, more potent drugs with fewer side effects than earlier medications are now available. Surgical techniques have also improved and it is estimated that around 95 per cent of those diagnosed early with glaucoma in the UK will retain useful sight for life.

POAG usually affects both eyes, but initially produces few symptoms. Eventually, if untreated, sufferers may become aware of a severe restriction of their field of vision or even loss of central vision in the worse eye. Although blindness from glaucoma is uncommon, it is responsible wholly or in part for 13 per cent of those on the blind register in England and Wales and is the leading cause of preventable blindness in the UK . A significant risk factor for glaucoma blindness is advanced loss of vision when the condition is first detected. Appropriate examinations during a routine eye test are, therefore, essential to detect glaucoma early and prevent significant sight loss.

What are the different types of glaucoma?

Adult glaucoma falls into two categories –open angle glaucoma and closed angle glaucoma. These categories are subdivided, according to whether the cause is unknown (primary glaucoma) or known i.e. the high eye pressure is caused by other conditions of the eye (secondary glaucoma).