<prompt> A HIV patient complains of visual disturbances. Fundal examination shows bilateral retinal exudates and perivascular haemorrhages. Which of the following viruses are most likely to be responsible for this retinitis -Herpes simplex virusHuman herpes virus 8CytomegalovirusEpstein-Barr EB virus  <response>: CMV retinitis is the most common ocular infection in AIDS patient.CMV retinitisPresentation :Presents as a painless progressive loss of vision.Patients may also complain of blurred vision, Floaters and scintillations.Opthalmoscopic findings : BilateralCharacteristic retinal appearance ofperivascular haemorrhages and retinal exudates - HarrisonCotton wool spots appearing as a result of focal ischaemia of nerve fibre layer are characteristicRisk factors :The majority of cases of CMV retinitis occur in patients with CD4 count 50 1.Patients with CD4 count 100 1 should undergo an ophthalmic examination every 3-6 months.Treatment:Therapy for CMV retinitis consists of intravenous ganciclovirForscarnet cidofovir is an alternative. 