Final answer:
Valganciclovir and ganciclovir are the top medications for treating CMV retinitis, working by hindering viral DNA synthesis. Ganciclovir is used intravenously or as an intraocular implant, whereas valganciclovir is an oral medication offering similar treatment efficacy.
Step-by-step explanation:
Valganciclovir and ganciclovir are the primary choices for the treatment of CMV retinitis. These antiviral medications function as nucleoside analogs that inhibit viral DNA replication by incorporating into the growing viral DNA chain. CMV retinitis often necessitates aggressive treatment due to its potential for causing significant vision loss, particularly in immunocompromised individuals such as those with AIDS.
Diagnosis can be achieved through microscopic evaluation and specific stains, immunohistochemical methods, or molecular techniques like PCR for more severe cases. For the antiviral treatment of CMV retinitis, ganciclovir is administered either intravenously or as an intraocular implant while valganciclovir, an oral prodrug of ganciclovir, offers similar efficacy with the convenience of oral dosing. Both have a mechanism of action that mimics DNA nucleosides, once activated they are incorporated into the viral DNA and result in chain termination, effectively stopping viral replication.