Hypertensive RetinopathyIntroduction High
blood pressure( which is discussed in more detail here) leads to
a chronic spasm of the smaller arteries, called arterioles. This leads to accelerated
hardening of these arteries (arteriosclerosis), which in turn leads to leakage
of some diseased arterial vessels (ween as flame-shaped hemorrhages by fundoscopy)
and to a lack of blood supply in other areas of the retina (ischemic changes and
infarcts). With leakage of exudate (containing blood proteins and lipids)
swelling and scarring occurs in the area of sharpest vision (fovea) with a resulting
loss of vision. There are 4
categories of severity that have been identified. This has significance
as untreated there would be an enormous difference
of survival as detailed in this link. Signs, Symptoms
and Diagnostic Tests: Painless
and gradual loss of vision in both eyes is what eventually occurs when blood pressure
is undetected and not controlled. The physician who looks through the ophthalmoscope
or uses the slit lamp, depending on the grade of severity of hypertensive retinopathy,
would see the kind of images
depicted here. These images have over the years received strangely
sounding names like "cotton wool spots" (looks like that, due to mini-infarcts
of the retina) and "macular star" (this is a ring of exudate from the
optic disc to the fovea or macula, the area normally of sharpest vision). Such
changes severely affect the vision of the person who has this finding. The most
dreaded of all hypertensive retinopathy cases is grade IV retinopathy where the
optic disc is included in the edematous process leading to "papilledema".
The reason this is so dangerous is that with this condition the central artery
and vein are both compressed effectively shutting down the circulation to the
retina. This is a medical emergency that needs to be treated in an Intensive Care
Unit setting. Treatment: The treatment is directed
at controlling the blood pressure.
In
the case of "malignant hypertension", which corresponds with papilledema
and grade IV retinopathy, intravenous titration of the blood pressure in an Intensive
Care Unit setting might have to be done in an attempt to rescue the patient's
vision. Otherwise the patient will be permanently blind. All other forms of hypertensive
retinopathy are treated in the office setting, but close blood pressure control
and self blood pressure monitoring at home are an important part of any therapy.
Longterm follow-up eye examinations and longterm blood pressure monitoring are
important. |
