Toxoplasmic chorioretinitis

An eye disease caused by the parasite Toxoplasma gondii''

Toxoplasmic chorioretinitis is an inflammation of the choroid and retina of the eye caused by the protozoan parasite Toxoplasma gondii. It is the most common cause of posterior uveitis in many parts of the world.

Signs and symptoms

The condition is characterized by a range of symptoms, including blurred vision, floaters, eye pain, and redness. In severe cases, it can lead to vision loss. The inflammation can cause a distinctive "headlight in the fog" appearance on examination, where a bright white lesion is surrounded by a hazy area of inflammation.

Causes

Toxoplasmic chorioretinitis is caused by infection with Toxoplasma gondii. This parasite can be acquired congenitally or postnatally. Congenital infection occurs when a mother is infected during pregnancy and transmits the parasite to the fetus. Postnatal infection can occur through ingestion of undercooked meat containing tissue cysts or exposure to oocysts from cat feces.

Diagnosis

Diagnosis is typically made based on clinical examination and history. Serological tests can support the diagnosis by detecting antibodies to Toxoplasma gondii. Imaging studies, such as optical coherence tomography, can help assess the extent of retinal damage.

Treatment

Treatment usually involves a combination of anti-parasitic and anti-inflammatory medications. Commonly used drugs include pyrimethamine, sulfadiazine, and corticosteroids. The choice of treatment depends on the severity of the disease and the patient's immune status.

Prognosis

The prognosis for toxoplasmic chorioretinitis varies. While many patients respond well to treatment, some may experience recurrent episodes of inflammation, leading to progressive vision loss. Early diagnosis and treatment are crucial for preserving vision.

Epidemiology

Toxoplasmic chorioretinitis is a global health issue, with higher prevalence in regions where Toxoplasma gondii infection is common. The risk of developing the condition is higher in individuals with weakened immune systems, such as those with HIV/AIDS or those undergoing immunosuppressive therapy.

Prevention

Preventive measures include proper food handling, cooking meat thoroughly, and practicing good hygiene, especially when handling cat litter. Pregnant women are advised to avoid exposure to cat feces and to consume only well-cooked meat.

Related pages

• Toxoplasmosis
• Uveitis
• Retinitis

References

• Jones, J. L., & Holland, G. N. (2010). Annual burden of ocular toxoplasmosis in the United States. American Journal of Tropical Medicine and Hygiene, 82(3), 464-469.
• Montoya, J. G., & Liesenfeld, O. (2004). Toxoplasmosis. The Lancet, 363(9425), 1965-1976.

Images

Chorioretinal scar in congenital toxoplasmosis

"Headlight in the fog" appearance in toxoplasmic chorioretinitis

Graph showing the relationship between precipitation and reactivation of retinochoroiditis

Toxoplasmic_chorioretinitis

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  Congenital toxoplasmosis - chorioretinal scar

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  Congenital toxoplasmosis - headlight in fog

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  Toxoplasmic chorioretinitis