Toxoplasmosis is a rare cause of iritis.  It is, however, a common cause of posterior uveitis in the Western world.


Pain, read dye (due to iritis)
Loss of vision in one eye (due to retinitis)
Flu-like illness
Enlargement of lymph glands (can be confused with glandular fever)

Features visible to an ophthalmologist

Scarring of retina
Focal retinitis
Inflammation of the retinal veins (periphlebitis)
Inflammation of the optic disc (papillitis)


A protazoal parasite which lives only within host cells, Toxoplasma gondii.


Poorly cooked meat, especially pork
Raw unpasteurised milk
From mother to unborn child
Blood transfusion
Organ transplantation


Tests are often inconclusive.  Blood tests may show previous exposure to toxoplasma, but in some areas this is so common as to be useless in indicating whether the eye problem is due to toxoplasmosis or not.


Treatment is controversial. Some ophthalmologists do not treat active retinal lesions unless they are near one of the vital structures inside the eye (optic disc, fovea). This is because the disease normally goes away by itself without causing further symptoms. Other ophthalmologists argue that all active retinal lesions should be treated because of the (small) risk of macular traction and secondary retinal detachment.

Where performed, treatment may include

Laser photocoagulation of the retinal lesions
Oral steroids, since most of the damage is thought to be due to the body's immune reaction rather than to the disease itself.
Antibiotics (eg. pyramethamine, clindamycin, spiramycin, atavoquone)

Maternal transmitted toxoplasmosis

Toxoplasmosis transmitted from mother to child is a much more serious infection. The earlier the infection occurs, the worse the outcome. Transmission is most common in the third trimester.

Possible problems are:

Cerebal calcification
Small eye (microphthalmos)
Optic disc involvement (optic atrophy)
Iritis, uveitis

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