The Standardization of Uveitis Nomenclature (SUN) Working Group reported criteria for the diagnosis of cytomegalovirus (CMV) retinitis.
Criteria for CMV retinitis - all of the following:
(1) necrotizing retinitis with indistinct borders and numerous small satellites (diameter < 50 µm)
(2) immune compromise (systemic or intra-ocular)
(3) one or both of the following:
(3a) one or more of the following:
(3a1) wedge-shaped area of retinitis AND absent to mild vitritis
(3a2) hemorrhagic appearance of the retinitisAND absent to mild vitritis
(3a3) granular appearance of the retinitisAND absent to mild vitritis
(3b) objective evidence of intraocular CMV
(4) absence of syphilis
(5) absence of HSV, VZV and toxoplasmosis (unless immunocompromised with strong evidence of CMV)
where:
• Intraocular immunocompromising conditions include intraocular corticosteroids or chemotherapy.
• Since being immunocompromised is required for CMV retinitis criterion 5 becomes somewhat weak.