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Acquired
Immunodeficiency Syndrome (AIDS), a disease which affects the
body's ability to fight illness, is caused by the Human
Immunodeficiency Virus (HIV). The HIV attacks lymphocytes-white
blood cells. T-cells are a kind of lymphocyte, and when the number
of T-cells in the body drops below 200 per millilitre, a person is
considered to have AIDS. A person can be infected with HIV but not
get the disease until many years later.
Anyone
can contract HIV. It is normally transmitted by exchanging bodily
fluids when having unprotected sex with an infected person,
sharing hypodermic needles, receiving transfusions with infected
blood or being born to a mother with HIV.
The
incidence of AIDS is changing. More people are contracting the
disease. It is becoming more mainstream. New strains are
appearing. As the incidence of AIDS increases, so does the
incidence of AIDS-related blindness and eye diseases.
AIDS and the eye
The HIV
virus is found in the tears of people infected with AIDS. However,
no AIDS cases have ever been reported from tear contact. As a
precaution, ophthalmologists are particularly careful when
cleaning lenses and instruments which come in contact with tears.
Because
HIV attacks the body's immune system, eye infections are common in
people with the virus. Incidence of eye infection is high in
people with T-cell counts of less than 250. The following outlines
a few of the more common conditions:
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Cotton
wool spots is the most common eye problems resulting from AIDS.
This condition does not affect vision, but does affect the
retina-the inner layer of the eye that sends signals to the
brain. AIDS can cause small amounts of bleeding and white spots
on the retina.
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Cytomegalovirus (CMV)-found in 20 - 30% of people with
AIDS-causes a serious infection of the retina. Most CMV
infections occur in people whose T-cell counts is dangerously
low, usually under 40. CMV can harm vision permanently and as
yet, there is no cure, just treatment with medication. An
ophthalmologist should be contacted immediately if a person
notices: floating spots, flashing lights, blind spots or blurred
vision. CMV can also cause the retina to separate from the back
of the eye. A detached retina will cause serious vision loss.
The only method of attachment is surgery.
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Karposi's
sarcoma is a kind of tumour that normally appears as purple-red
spots. On the eye, it looks like a spot on the white part of the
eye or a bump on the eyelid. The tumour grows slowly, does not
harm the eye and can be treated with radiation, laser surgery,
freezing or operative surgery.
Other eye
infections may occur whose symptoms are similar to those of CMV-floaters,
flashes or blind spots. Only an ophthalmologist can make a
diagnosis and prescribe treatment.
The HIV
virus increases the incidence of eye infections. Therefore,
regular eye examinations by an ophthalmologist are important.
Early diagnosis of these conditions can prevent serious vision
loss.
New
approaches to the treatment of AIDS-related eye diseases are being
developed. For example, implants for treating CMV retinitis can
now be placed in the eye that allow medication to be released
slowly. Patients will no longer have to make frequent visits to
the ophthalmologist for treatment. |
