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Cataracts
The incidence of cataracts increases steadily after 50 years
of age, and is nearly 50% among people 75 years of age.
Maryann Hopkins, Pharmacist, Grace Hospital, Ottawa
Seeing is one of our most useful ways of learning about the
world around us. When we have clear vision, our eyes can sense
millions of different aspects of light and colour. They collect
millions of pieces of information and send them to the brain.
The various parts of our eyes contribute to how we see. The
lens, located behind the pupil, focuses light that passes through
the pupil on to the back of they eye (retina) and protects the
retina from harmful ultraviolet light. It works very much like
a camera lens. Normally, the lens consists of a clear gel held
in pouch or capsule. It is flexible and can vary in thickness.
Because of this, it can focus light from objects, whether they
are near or far, to one point on the retina. the retina collects
the information and sends it to the brain to complete the process
of "seeing".
As a lens ages, it becomes less flexible. the lens may also
become cloudy and gradually take on a yellowish-brown colour.
This cloudy, defective lens is called a cataract. With cataracts,
vision becomes distorted. Blindness can eventually develop.
there are several causes of cataracts, including injury, chemicals,
radiation, some eye conditions, diabetes, and the effects of
some drugs, but the most common cause is aging. Age-related cataracts
often result from a lifetime of exposure to sunlight. The incidence
of cataracts increases steadily after 50 years of age, and is
nearly 50% among people 75 years of age. Protective eyewear is
recommended to decrease exposure to solar radiation, especially
when participating in outdoor activities in bright sunlight.
Nothing can clear a cataract once it has developed. However,
modern micro-surgery allows doctors to remove the cataract and
dramatically improve vision. In the past, it was fairly common
to remove the lens and use thick glasses to correct vision. Now,
the foggy lens can be removed and a clear artificial one (intraocular
lens) implanted exactly where the old one used to be or at the
front in the anterior chamber of the eye. This type of surgery
is almost always successful (up to 99% of the cases) in greatly
improving vision. This is one of the most common and successful
types of eye surgery. It is usually done as a short-stay procedure
(home from hospital or clinic within a few hours of being admitted).
The individual will have to use eye drops at home for a few weeks
and take precautions not to damage the newly operated eye, a
small price to pay for improved sight!
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The information in this newsletter was prepared and reviewed
by pharmacists for the Canadian Pharmaceutical Journal.
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Ask Your Pharmacist newsletter is produced through
an unconditional educational grant from APOTEX/PACE. |
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