Herpes Simplex Eye Disease
Herpes is a
very common virus to which the vast majority of us become
exposed in our early years. This virus infects the skin, mucous
membranes and nerves. Type I herpes generally causes disease
above the belt; Type II herpes is below the belt. By age 15
over 90% of Americans have circulating antibodies to Type I
herpes, which is the one we are concerned with in ophthalmology.
Following
primary infection, the herpes virus remains dormant in our
systems within nerve clusters behind the eyes and elsewhere.
From these reservoirs, the virus can make several trips to the
surface of the skin, as evidenced by recurrent infections on the
lips in the form of cold sores and in the eyes as recurrent
corneal ulcers and intraocular inflammation.
The most
common symptoms of the primary disease are fever, enlarged lymph
nodes, conjunctivits (pink eye or inflammation of the mucous
membrane that covers the white part of the eye.), keratitis
(infection of the cornea), and a general sense of “feeling
awful”. Often confused with the common cold or flu, primary
herpes infections usually occur in childhood and go undiagnosed.
Recurrent
ocular herpes is the form of the disease with which we are most
concerned. It is a recurrent eye infection of the cornea (the
clear front window of the eye) which can potentially threaten
sight. This causes true corneal ulceration, lid blisters, and
intraocular inflammation, almost always involving only one eye.
Once a patient experiences ocular herpes, the chances of
recurrence are about 40%, despite appropriate therapy. Some
patients can identify “trigger mechanisms” that tend to precede
such recurrences. These included fever, fatigue, becoming “run
down”, emotional upsets and exposure to ultraviolet light (when
in high altitudes, for instance).
The disease
usually begins on the surface of the cornea. The eye turns red,
is uncomfortable, teary, light sensitive and may have a scratchy
sensation, as if something were in the eye. Pain may also be a
prominent complaint. The process may go deeper into the cornea
and cause permanent scarring or inflammation inside the eye.
Chronic ulcers which are sometimes very difficult to heal, may
also develop on the cornea. After several bouts, patients learn
to detect the earliest signs and symptoms of the disease.
Spreading the infection to another person is unlikely.
Treatment
has improved greatly over the past 10 years. We now have
excellent drugs that will destroy the virus ability to multiply
itself, thereby, buring the infection. It is most important to
treat early in the course of the recurrence. If left untreated,
scars may form and significantly impair vision. Eye drops are
very effective. Sometimes we will literally scrape the herpes
virus and ulcer from the eye and allow it to heal with the
assistance of drops or ointments.
Our immune
system makes antibodies to the herpes virus, and sometimes these
antibodies create a “battlefield” on the surface of the eye,
leaving scars and reducing vision. This problem can and should
be treated vigorously, yet cautiously. It is very important to
consult an ophthalmologist before beginning any treatment since
some medications may actually make the disease worse.
Rarely is
corneal transplantation needed to eliminate the scars of ocular
herpes, but it remains an alternative in severe cases. |
