Cytomegalovirus Retinitis (CMV Retinitis) What Is Cytomegalovirus Retinitis (CMV Retinitis)? Cytomegalovirus (CMV) Retinitis is a virus that may infect the retina and potentially cause irreversible vision loss due to retinal detachment or destruction. It is most often diagnosed in patients with a severely compromised immune system, including those with AIDS or those on chronic immunosuppressive therapy following organ transplantation.