Download Hyphema

Hyphema
Rhea V. Morgan, DVM, DACVIM (Small Animal), DACVO
BASIC INFORMATION
Description
Hyphema is blood in the front chamber of the eye. The blood may
be clotted, or it may move freely. Free blood often settles when the
animal is quiet, then disperses and becomes more noticeable when
the animal is active.
Causes
Numerous causes of hyphema exist, including the following:
• Trauma—blunt or penetrating
• Abnormalities of blood clotting
• Hypertension (high blood pressure)
• Excessively high circulating protein levels (hyperviscosity) or
number of red blood cells (polycythemia)
• Inflammation of the eye (uveitis), especially uveitis associated
with certain tick-borne infections (ehrlichiosis, Lyme disease,
and others)
• Movement of the lens within the eye and following retinal
detachment
• Tumors of the eye
• Congenital birth defects of the eye, such as persistence of certain blood vessels and structures that should disappear soon
after birth or the collie eye anomaly
• As a complication of eye procedures or surgery
Clinical Signs
Hyphema is usually diagnosed by a thorough eye examination.
The eye examination often involves tear testing, fluorescein staining of the cornea, glaucoma testing, and evaluation of the deeper
structures of the eye.
Diagnostic Tests
Once the presence of hyphema is confirmed, a search is instituted for the cause. A complete physical examination is conducted to look for other evidence of bleeding or an underlying
cause. Routine laboratory tests, blood pressure measurement,
blood clotting tests, and assays for tick-borne diseases may be
recommended.
If there is too much blood in the eye to allow examination of
the deeper structures, an ocular ultrasound may be helpful. X-rays
of the skull may be done to look for metallic foreign bodies and
evidence of trauma. Further testing may be needed if a systemic
cause is found, to better define its effects on other organs of the
body.
TREATMENT AND FOLLOW-UP
Treatment Options
Therapy for hyphema involves treating both the eye and the underlying cause. Appropriate treatment of the cause often helps prevent further hyphema. Affected animals are kept quiet to decrease
the chance of further bleeding.
If the cornea is not ulcerated, topical steroids are started, because
the hyphema commonly causes inflammation within the eye. Topical
atropine is often used to dilate the pupil, unless secondary glaucoma
is present. If glaucoma is detected, then anti-glaucoma drugs are
started. Injection into the eye of drugs that dissolve clots may be
tried when hyphema occurs after surgery on the eye.
Follow-up Care
Close monitoring of the eye is needed until the hyphema resolves,
which can range from days to months. Repeated staining of the
cornea and glaucoma testing are performed. Laboratory tests
and blood pressure measurements may be repeated periodically,
depending on the underlying cause.
Prognosis
Prognosis is highly variable. If the hyphema is mild and associated
with trauma or a disease that can be effectively treated, the prognosis is good. Mild hyphema may resolve within days and may
have no effect on vision.
If hyphema is severe, or if it is accompanied by bleeding into
the back of the eye or by a retinal detachment, then the eye will
be permanently blind. Severe hyphema may also lead to either
shrinkage of the eye (over several weeks to months) or secondary
glaucoma. If severe, unresponsive secondary glaucoma develops,
then removal of the eye may be considered.
Hyphema that does not respond to topical therapy or is caused
by diseases that are difficult to treat has a poor to guarded (uncertain) prognosis. In these cases, the hyphema can persist for long
periods of time and can recur. Long-standing hyphema can disrupt
the nutrition of the lens, which leads to cataract formation.
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Copyright © 2011 by Saunders, an imprint of Elsevier Inc. All rights reserved.