Background:
Just as in humans, pets can develop glaucoma as they age. Glaucoma
is a disease of one or both eyes, causing permanent loss of vision
in a very short time. The eye is a fluid-filled structure in which
the pressure of the fluid within the eye is controlled by both a
filling mechanism and a drainage mechanism. Glaucoma is most
commonly the result of a dysfunction of the drainage mechanism,
causing increased fluid pressure in the eye. The increased pressure
can cause damage to tissues within the eye such as the retina and
optic nerve, eventually leading to blindness.
Drainage of the fluid within the eye
may be impaired due to primary or secondary causes. Primary causes
are generally hereditary, and are most often seen in Beagles, Cocker
Spaniels, Basset Hounds, Chow Chows, Sharpeis and Samoyeds. Dogs
suffering glaucoma due to hereditary causes are more likely to have
both eyes affected.
Secondary causes of glaucoma
include trauma to the eye, infection of the fluid within the eye,
cancers of the iris or ciliary body or corneal ulcers.
Clinical
Signs:
The clinical signs of glaucoma depend on the cause as well as
whether the condition appeared acutely or over time. Acute glaucoma,
which presents very suddenly, is generally very painful. It is
accompanied by tearing and squinting, and the fluid within the eye
may appear hazy. The pupil may be enlarged, and the eye may appear
larger than normal or feel very hard. In chronic cases of glaucoma,
the signs may include a change in the color of the iris, watering of
the eye, a large eye and blindness.
Diagnosis:
The diagnosis of glaucoma can only be made by your veterinarian.
Using a special device called a tonometer, your veterinarian can
measure the fluid pressure of the eye. Your veterinarian can also
use an opthalomoscope to determine whether there are any changes to
the retina and optic nerve and possibly find the cause of the
drainage problem.
Treatment:
For acute cases of glaucoma, your veterinarian may advise that your
pet be hospitalized to receive medications intravenously. These
medications quickly reduce the intraocular pressure and may prevent
vision loss. In more chronic cases of glaucoma, the fluid pressure
may be controlled with topical eye medications or oral medications.
Depending on the cause of fluid build-up, surgical methods to reduce
fluid production may also be considered or recommended. For those
pets which have already lost vision in the eye, surgery may be
considered to implant a prosthesis or remove the eye altogether.
|
