**Abstract**

Infections are a major cause for retinitis. Whereas Varicella-Zoster and Herpes Simplex viruses are the major reason for acute retinal necrosis, cytomegalovirus retinitis typically occurs in immunocompromised patients. Toxoplasmosis and toxocariasis are the major parasitic pathogens affecting the retina and adjacent tissues. Among the bacterial causes, tuberculosis, syphilis, and bartonellosis are discussed as retinal diseases. The emphasis is laid on the epidemiological and clinical peculiarities, the respective diagnostic procedures, and the therapeutic approaches. Moreover, global disease aspects of infectious retinitis are included.

**Keywords:** acute retinal necrosis, bartonellosis, chorioretinitis, cytomegalovirus, toxocariasis, toxoplasmosis, tuberculosis, retinis, syphilis, varicella zoster virus

## **1. Introduction**

Retinitis can present in various different forms. Some of them are rather specific for individual pathogens, whereas other phenotypes are rather overlapping (**Table 1**). In this manuscript, the major viral, parasitic, and bacterial pathogens are presented and discussed together with the different clinical manifestations.


**Table 1.**

*Classification of retinitis and related disease forms.*
