What is AIDS/HIV?
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:
- 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.
- 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.
- 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.
© Copyright by the Canadian Ophthalmological Society