Glaucoma is defined as "an increase in pressure in the eye with a loss of vision". The disease is quite painful in most cases, especially when the eye pressure is very elevated.

The signs of glaucoma include: redness, cloudy eye, tearing, loss of vision, an enlarged eyeball, unusual aggressiveness, lethargy, and loss of appetite.

The normal physiology of the fluid in the eye calls for the fluid to be made in one structure behind the pupil (ciliary body), travel through the pupil, and exit out the space between the cornea and the iris. When the fluid cannot properly drain from the eye, the pressure in the eye is increased. An analogy would be a kitchen sink -- if the drain is open and the water is running, there is no problem. However, if a plug is placed in the drain and the water keeps coming, then the sink fills up with water and overflows! Some patients have primary glaucoma where there is no concurrent disease but some secondary causes of glaucoma include: inflammation, trauma, and tumours. All of these factors can obstruct the drainage of fluid from the eye.

Glaucoma is an ophthalmic emergency and must be treated immediately. If the pressure remains elevated for even a few hours, permanent vision loss occurs. The disease is difficult to treat but several options are available depending on whether the patient still has vision, the specifics of the patient, financial considerations, etc. Some of the options include: medical management with oral drugs and eye drops, laser treatment to reduce the fluid production, cryosurgery to freeze the structure producing fluid, surgically placed drainage tubes, removal of an end stage blind painful eye or replacement with a cosmetic prosthesis. There are pros and cons to each of these treatments, and the options will be discussed with the client after initial examination, consideration of the possible duration and severity of the glaucoma and the chances of getting vision back again.