| Glaucoma
is considered an illness of the nerve conveying images
from the eye to the brain. This is often, but not always
associated with an increase in eye fluid pressure. The
eyeball is “pumped” to a certain normal
pressure by fluid production within the eye. In normal
eyes, this pressure is often between 10-21 mm of mercury
(mmHg).
Pressure in the eye that is above
this range may damage the nerve by affecting the blood
flow to the nerve, or may directly damage the nerve
itself. Sometimes, the nerve itself is unusually susceptible
to damage even at a normal level of eye pressure. Most
treatments for glaucoma therefore aim to reduce the
eye pressure to slow down or stop damage to the optic
nerve. People who have a family history of glaucoma
are at higher risk for glaucoma, and should be screened
by the eye specialist for a raised eye pressure or other
signs of glaucoma.
The initial treatment for glaucoma
is usually with eyedrops to reduce the eye pressure.
Many of these eyedrops now come with convenient once
or twice a day dosing, and work for a large number of
patients. Sometimes, 2 or 3 eyedrops may need to be
combined to achieve a low enough eye pressure.
Unfortunately, some patients will
need laser or glaucoma surgery to control their eye
pressure when even multiple eyedrops provide unsatisfactory
control. Laser treatment for glaucoma usually involves
enhancing the drainage of fluid from the eye, or reducing
the production of fluid, resulting in a drop in eye
pressure. This can be done in the doctor’s office.
Glaucoma surgery is usually quick
and effective, and is done as day-case surgery. With
adequate anesthesia, surgery is painless. Certain chemicals
may be used at the time of glaucoma surgery to reduce
the amount of scarring at the surgical site, and improve
the success rates of surgery. Following surgery or laser
treatment, eyedrops are prescribed to reduce inflammation
and infection and will need to be instilled usually
for a few weeks to months.
During the assessment and follow-up
of the glaucoma, the eye specialist will need to assess
several parameters to determine whether the glaucoma
is progressing. These include a visual field assessment,
the eye pressure, and the size of the optic nerve hollowing
(or cup-disc ratio).
A visual field assessment is a common
investigation used to determine glaucoma progression.
An automated machine projects a light in the patient’s
field of vision, and the patient responds by pressing
a button if the light is seen. The machine then goes
on to map the area of functional vision by assessing
which parts can and cannot see the light. This process
takes about 5-10 minutes each eye, and gives the doctor
an idea of the function of the eye and its optic nerve,
and how much vision has been damaged by glaucoma. At
EyeWise Vision Clinic, we use the Humphrey Visual Field
system, which is the gold standard in glaucoma assessment.
If you have a family history of glaucoma
or blindness in the family, especially in immediate
family members then it is best for a thorough eye screening
to rule out glaucoma. During its early stages, glaucoma
has NO symptoms and no pain. Because of this, it has
often been labeled “the silent thief of sight”.
Please call us to book an appointment.
Contact
Dr. Christopher Khng | Make an
Appointment
|
