Chorioretinitis, fundus photograph. View of the interior surface of a human eye affected by acute chorioretinitis caused by cytomegalovirus infection. 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 congenital toxoplasmosis (a parasitic disease) and viral and bacterial infections, including cytomegalovirus.