Chorioretinitis of the eye. Ophthalmoscope view of the retina (the light-sensitive membrane that lines the back wall of the eye) of an AIDS patient with chorioretinitis, an inflammatory and exudative (yellow fatty deposits) condition of the choroid and the retina. It is often congenital and mostly affects young children. Causes include congenital toxoplasmosis (a parasitic disease), viral infections, such as the West Nile virus, bacterial infections, such as syphilis and tuberculosis, and various fungal infections. AIDS (acquired immune deficiency syndrome) is a disease caused by the human immunodeficiency virus (HIV). It attacks white blood cells, weakening the immune system and making the patient prone to opportunistic infections such as these.