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MR E MARK TALBOT
INFORMATION SHEET
LOW TENSION GLAUCOMA
This diagnosis is sometimes made when there are signs of glaucoma but the eye
pressure is not found to be abnormally high despite making pressure checks on
different days and at different times of the day.
It is thought that the nourishment of the nerve fibres within the eye depend
upon the blood flow to them and this in turn depends upon the balance between
eye pressure preventing blood flow into the eye, and blood pressure forcing the
blood into the eye and finally on the calibre of the blood vessels and the flow ability
of the blood.
TREATMENT
Conditions such as high blood pressure, diabetes, inflammation of the
arteries and blockage of major arteries in the neck can impair the blood flow.
Some Eye Units measure total blood flow entering the eye.
A brain scan is often carried out to check that there is no other cause for
the visual field damage such as external pressure on a nerve.
Some eyes can tolerate high pressures without damage whilst other eyes cannot
tolerate normal pressures. When an eye does not appear to be able to tolerate
normal pressures without developing visual field loss, then measures to improve
the nerve fibre nourishment by; reducing eye pressure or trying to increase
blood flow and treating underlying conditions, may be recommended.
Occasionally a surgical procedure is necessary to adequately lower the
pressure. (Trabeculectomy).
As with chronic glaucoma, patients usually don’t realise that they have a
problem until an Optometrist checks pressures, fields and disc appearance. In
this way patients with low tension glaucoma are detected and referred to the
hospital eye service. Although the visual field defect cannot normally be
improved, deterioration can be slowed or prevented by observation and treatment.
The eye doctor looking after your eye condition can advise you whether you
are fit to drive based on your distance vision with glasses and the height and
width of field with both eyes open.
Any driver who has any form of glaucoma should inform the DVLA.
LOWTEN.JAN2000
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