Glaucoma is becoming an increasingly important cause of blindness, as the world’s population ages. New statistics gathered by WHO in 2002, and published in this edition of the Bulletin (Resnikoff et al., p. 844–851), show that glaucoma is now the second leading cause of blindness globally, after cataracts.
Glaucoma, however, presents perhaps an even greater public health challenge than cataracts: because the blindness it causes is irreversible. WHO officials are looking into ways to address the problems caused by glaucoma which was until now estimated to be the third leading cause of blindness.
“It is a major problem, we’ve been concerned about this for some time and we are now working hard to address this important cause of blindness,” said Dr Robert Beaglehole, WHO’s Director of Chronic Diseases and Health Promotion in Geneva.
“It highlights the growing problem created by chronic eye diseases, including diabetic retinopathy and age-related macular degeneration,” Beaglehole said.
Glaucoma is a collective term for a group of eye conditions in which the main nerve to the eye (the optic nerve) is damaged where it leaves the eye. This nerve carries information about what is being seen from the eye to the brain and as it becomes damaged, vision is lost. This results in misty and patchy vision, with eventual loss of central vision, although this is rare.
In its early stages, glaucoma usually has no symptoms, which is what makes it so dangerous — by the time you notice problems with your sight, the disease has progressed to the point that irreversible vision loss has already occurred and additional loss may be difficult to stop.
In most cases, glaucoma is associated with higher-than-normal pressure inside the eye — a condition called ocular hypertension. But it also can occur when intraocular pressure (IOP) is normal. If untreated or uncontrolled, glaucoma first causes peripheral vision loss and eventually can lead to blindness.
Although any vision which has been lost to glaucoma cannot be recovered, with early diagnosis, careful monitoring and regular use of treatments, the vast majority of people retain useful sight for life. The only way to know if you have glaucoma is to have your eyes checked at your local optometrist (optician). Because most cases of glaucoma have few or no early symptoms, about half of all glaucoma patients don't know they have it.
Watch the video below for an in-depth review of the different types of Glaucoma.