Hyphaema is a term used to describe bleeding in the anterior chamber (the space between the cornea and the iris) of the eye. It occurs when blood vessels in the iris bleed and leak into the clear aqueous fluid. Hyphaemas are usually characterized by pooling of blood in the anterior chamber that may be visible to the naked eye. The red blood cells of very small hyphaemas are visible only with magnification. Even the slightest amount of blood in the anterior chamber will cause decreased vision when mixed in the clear aqueous fluid.
Bleeding in the anterior chamber is most often caused by blunt trauma to the eye. It may also be associated with surgical procedures. Other causes include abnormal vessel growth in the eye and certain ocular tumors.
It is very important for the eye care practitioner to determine the cause of the hyphaema. If the hyphaema is related to an ocular injury, any detail regarding the nature of the trauma is helpful. The eye care practitioner will assess visual acuity, measure intraocular pressure, and examine the eye with a slit lamp microscope and ophthalmoscope.
The treatment is dependent on the cause and severity of the hyphaema. Frequently, the blood is reabsorbed over a period of days to weeks. During this time, the eye care practitioner will carefully monitor the intraocular pressure for signs of the blood preventing normal flow of the aqueous through the eye's angle structures. If the eye pressure becomes elevated, eye drops may be prescribed to control it.The pupils are also evaluated to rule out damage to the iris.
In some cases, a procedure is performed to irrigate the blood from the anterior chamber to prevent secondary complications such as glaucoma and blood stains on the cornea.
Patients with significant hyphaemas must rest and avoid strenuous activity to allow the blood to reabsorb.
Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.