Chorioretinitis, fundus photograph. View of scarring (centre) on the interior surface of a human eye as a result of chorioretinitis caused by toxoplasmosis. Chorioretinitis is an inflammation of the choroid (the thin pigmented coating in the eye) and retina of the eye. It is most commonly caused by toxoplasmosis and viral and bacterial infections. Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii.