GLEASON’ S SCORE
G
L
Acute closed-angle glaucoma
This type of glaucoma is caused by an unduly
narrow angle between the iris and the back
of the peripheral cornea. Dilation of the pupil
may therefore lead to a sudden complete blockage
of the outflow, which, in turn, causes a rapid
increase in pressure in the eyeball.
the same damage to the retina and optic
nerve as excessively high fluid pressure.
This condition is not well understood;
and it seems that the pressure, although
not considered to be excessive, is too
high for the tissues to withstand, and
thus causes damage.
DIAGNOSIS AND TREATMENT
Tonometry
is used to check for glaucoma
by measuring the pressure within the
eye.
Ophthalmoscopy
may show depres-
sion of the head of the optic nerve due
to the increase in pressure. Tests of the
visual field
w ill be needed to assess
whether vision has already been dam-
aged, because longstanding or severe
glaucoma can result in loss of peripher-
al vision
(see
tunnel vision
) .
Prompt
treatment is essential to prevent perma-
nent loss of vision.
Chronic simple glaucoma can usually
be controlled with eye-drops, such as
timolol
,
or tablets that reduce pressure in
the eye. Treatment needs to be contin-
ued for life. If drugs are ineffective,
surgery or
laser treatment
can unblock
the drainage channel at the edge of the
iris or create an artificial channel.
Acute glaucoma requires emergency
drug treatment, often in hospital. Sur-
gery or laser treatment may be needed
in order to prevent a further attack. The
usual procedure is
iridectomy
,
in w hich a
small opening is made at the edge of
the iris so that aqueous humour can
drain more easily,
Treatment for normal-pressure glau-
coma is the same as for open-angle
glaucoma, but is aimed at reducing the
intraocular pressure to an even lower
level than normal.
Gleason’s score
A system of grading prostate cancer
cells (see
prostate, cancer of
)
to deter-
mine the most appropriate treatment
and the patient’s outlook.
Several tissue samples are taken and
are assigned a score between
1
and 5.
The lowest and highest scores are added
together to give the Gleason’s score,
w hich is a number between 1 and 10. A
low Gleason’s score indicates that the
cancer cells are very similar to normal
prostate cells; a high score means that
the cancer cells are very different. In
general, the more the cancerous cells
diverge from the normal prostate cells,
the more serious the cancer.
The Gleason’s score is often used in
conjunction with a measure called the
TNM classification, w hich defines the
extent to w hich a cancer has spread.
glenoid
A term meaning “resembling a pit or
socket” . For example, the glenoid fossa
(depression) is the cavity at the top of
the scapula (shoulderblade) into w hich
the head of the humerus (the bone of
the upper arm) fits.
glibenclamide
An oral hypoglycaemic drug (see
hypo-
glycaemics, oral
)
used to treat type
2
(non-insulin dependent)
diabetes melli-
tus
.
In this form of diabetes, body cells
are resistant to the action of the hor-
mone
insulin
,
and absorb insufficient
glucose. The drug causes the pancreas to
increase insulin secretion thereby com-
pensating for the resistance.
gliclazide
An oral hypoglycaemic drug (see
hypo-
glycaemics, oral
)
used to treat type
2
diabetes mellitus
along with dieting. The
drug causes the pancreas to increase
insulin secretion. Side effects are mild.
glimepiride
An oral hypoglycaemic drug (see
hypo-
glycaemics, oral
)
used to treat type
2
diabetes mellitus
.
The drug causes the
pancreas to increase insulin secretion.
Side
effects
are
infrequent
but
may
include m ild nausea and diarrhoea. Low
blood sugar
(see
hypoglycaemia
)
may
occur if the drug is not taken with suffi-
cient food.
glioblastoma multiforme
A fast-growing and highly cancerous
type of primary
brain tumour
.
Glioblas-
toma multiforme is a type of
glioma
that
often develops in the
cerebrum
(the
main mass of the brain). The cause is
unknown. Treatment
of glioblastoma
multiforme may include surgery,
radio-
therapy
,
and/or
chemotherapy
.
glioma
A type of
brain tumour
arising from con-
nective tissue (glial cells) in the brain.
Types of glioma include
astrocytoma
,
glioblastoma
multiforme
,
ependymoma,
medulloblastoma,
and
oligodendroglioma
.
Symptoms, diagnosis, and treatment are
as for other types of brain tumour.
brain tumour) is visible as a dark area in the right
hemisphere (on the left of the image).
glipizide
An oral hypoglycaemic drug (see
hypo-
glycaemics, oral)
used to treat type
2
diabetes mellitus
.
Glipizide acts by stim-
ulating the pancreas into increasing its
production of
insulin
.
Side effects are
usually m ild and infrequent, but dizzi-
ness and drowsiness may occur. Rarely,
glipizide can cause an abnormal reac-
tion of the skin to sunlight and can
reduce blood sodium levels. Low blood
sugar (see
hypoglycaemia
)
may occur if
the drug is not taken with sufficient food.
342
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