The Canadian Glaucoma Strategy [PDF; 4.5 MB] Canadian perspectives in glaucoma management: setting target intraocular pressure range [PDF; 450 KB] COS patient information: Glaucoma: It can take your sight away [PDF] Le glaucome : Il peut vous rendre aveugle [PDF]

One often hears the term "glaucoma" but few know that it is actually a family of eye diseases all having in common damage to the optic nerve head at the back of the eye (see pictures below). The 2 main groups are called open angle and closed angle glaucoma. Although both (and each has a number of subtypes) are found in all societies, the most common one in Western people is open angle while that in Oriental people is closed angle glaucoma.

Unfortunately, most glaucomas don't signal to the individual that the disease is present. In other words, there are no symptoms to indicate its presence. The main exception is the acute form of angle closure glaucoma which often has dramatic symptoms such as nausea, vomiting, dull pain around the eye, and decreased vision relative to before the attack in the affected eye. All chronic forms have no symptoms until vision is noticeably decreased. As this is permanent, the person affected has no ability to recover this vision. Most people recognize a loss of vision only when it affects the central part of their vision such as in macular degeneration. But this is not the case here where vision is gradually destroyed from the periphery toward the centre and does not appear as a black spot to the victim. Recognition at this point has a chance of retaining only the small amount of vision in the centre. Chronic glaucomas are truly "the silent blinding diseases."

In general, these diseases are detected by a qualified eye professional who is able to recognize subtle changes in the optic nerve head, or who randomly performs a test of side vision (visual fields, see below). There is a common understanding of glaucoma as being a problem totally to do with intraocular pressure (pressure in the eye). This is not correct, although treatment for the glaucomas is mostly aimed at lowering this pressure.

Treatment for these diseases is mainly medical but can also involve laser and standard surgical procedures. All are aimed at lowering the eye pressure although newer drugs may affect other risk factors in the future. This is a serious disease which, left untreated, can lead to non-reversible blindness. The need for continuing care and continuous treatment is obvious as vision lost is gone forever. It is a chronic disease and commonly requires self-medication for the remainder of one’s life. Treatment often controls the pressure and stops or slows the progression successfully.

Understanding the glaucomas has become very complicated over the last few years as our knowledge has increased. There have been exciting new developments in the field as far as diagnosis and treatment and these will continue in the future. 

The visual fields of glaucoma patients are shown above. The right hand image shows a mildly damaged visual field. The dark area to the lower left represents the area of damage. The left hand image is from a patient with severe glaucoma. The entire area tested is markedly affected.