Glaucoma set to reach 80 million by 2020

The global toll of the disabling eye disease glaucoma is set to reach 60 million by 2010, rising to almost 80 million by 2020, finds research in the British Journal of Ophthalmology.

Women and people living in Asia, Africa, and India will be worst affected, the research shows.

Glaucoma is characterised by damage to the nerve at the back of the eye, and is related to increased pressure within the eye. But many people have the disease despite normal eye pressure.

Glaucoma is the second leading cause of blindness in the world, and is estimated to be responsible for 12 per cent of global blindness

The authors reviewed all the data on glaucoma derived from studies based on populations. These figures were then used to calculate rates of the disease by age, sex, and ethnicity, in combination with United Nations projections for world population.

Based on these calculations, the authors estimate that 60.5 million people will have glaucoma by 2010, almost six out of 10 of whom will be women. By 2020, just under 80 million people will be affected.

Three out of four cases will be what is known as open angle glaucoma, which progresses more slowly than angle closure glaucoma.

People living in Asia will account for almost half of those with glaucoma and most of those with the open angle form.

Around 8.5 million people will be blind in both eyes as a result by 2010, a figure which will rise to more than 11 million people by 2020.

And the authors calculate that between 2010 and 2020 the disease is likely to increase most rapidly in India.

The authors note that there are treatments available in the developed world, which would help to reduce the amount of disability the disease causes.

An accompanying editorial points out that efforts to tackle the disease have been hampered by a lack of consensus on the definition and the absence of a simple and accurate screening test

The disease also suffers from an image problem, writes Dr Rupert Bourne a glaucoma specialist at Hinchingbrooke Hospital in Cambridgeshire and senior lecturer at the International Centre for Eye Health, London School of Hygiene and Tropical Medicine.

"The fact that it is irreversible, difficult to detect, and difficult to treat means that it is often viewed as less of an urgent issue, particularly in developing nations where other more remediable diseases are more prevalent," he says.