Glaucoma and Your Eyes
Glaucoma, another common
visual problem in older adults, is a progressive
loss of mid-peripheral vision caused by pressure
inside the eyes. Glaucoma has no symptoms, so it's
important to get regular eye exams to look for it.
You should have a glaucoma check every two years
after age 40. If you have glaucoma, it's very
treatable in its early stages.
Fluid is constantly flowing through the inside of
your eye. The front segment of the eye is filled
with a fluid called aqueous humour. This fluid helps
maintain normal intra-ocular pressure, preventing
the eyeball from collapsing. It also nourishes the
lens, the iris and the inside of the cornea.
When the fluid doesn't flow normally, the pressure
inside your eye rises and damages your sight. This
is a medical condition known as glaucoma. If this
pressure in the eye remains high and is left
untreated, it may lead to blindness.
Symptoms of glaucoma include loss of vision to each
side (peripheral vision), halos around lights, pain
in the eye, blurred vision, and gradual loss of
Types of glaucoma
glaucoma is the most common kind of
glaucoma. Pressure inside the eye rises slowly and
destroys vision gradually, starting with side
vision. This "sneak thief of sight" usually causes
no pain or other warning signs. In some cases,
vision may be lost, even though pressure stays
within a normal range (low-tension glaucoma).
is less common. Pressure inside the eye rises
suddenly and must be lowered right away to prevent
blindness. Severe pain and blurred vision can occur
with an acute attack. A chronic form of closed-angle
glaucoma occurs more slowly and often without any
Other kinds of glaucoma can be linked to an injury
or inflammation of the eye, a cataract (clouding or
the eye's lens), an eye tumour, or advanced diabetes
(high blood sugar).
are the risk factors?
The major risk factor for glaucoma is age.
Glaucoma most often strikes people over 50, but
everyone over 35 should be tested at least every two
Asians are somewhat more likely to develop
Family history of
You are at higher risk of developing glaucoma if a
close family member has had the disease.
High blood pressure and high blood sugar are
conditions that may predispose you to glaucoma.
Most people learn that they have glaucoma during an
eye exam by an ophthalmologist. A number of simple
tests can reveal changes in your eye pressure,
drainage angle, optic disc and visual field. This
can alert your eye doctor to a problem.
Consult your local ophthalmologist for more
A typical eye exam may
Medical history -
Glaucoma tends to be hereditary, so identify other
members of family who have glaucoma.
Tonometry - A test to
measure eye pressure.
Gonioscopy - Performed
with a special type of contact lens to evaluate the
aqueous fluid drainage angle.
Optic disc assessment -
Performed using special lenses with the slit lamp to
assess any enlargement of the optic cup.
Visual field analysis -
A test performed with a computer or short
wave-length light to evaluate your side vision. Each
eye is tested separately.