Intravitreal ganciclovir effective for immunocompetent patients with cytomegalovirus anterior uveitis

This prospective study demonstrates the safety and efficacy of intravitreal ganciclovir injection as a loading dose with or without oral valganciclovir for the control of cytomegalovirus (CMV) anterior uveitis in immunocompetent patients. 

CMV is a recently recognized cause of unilateral anterior uveitis in immunocompetent patients. The condition is characterized by chronic and or recurrent uveitis with keratic precipitates and elevated IOP. The diagnosis can be confirmed by analysis of the aqueous humor with polymerase chain reaction. It is not clear why CMV causes necrotizing uveitis in immunocompromised patients and anterior uveitis in immunocompetent patients. Certain patients with CMV anterior uveitis are misdiagnosed as Posner-Schlossman syndrome, Fuchs' heterochromic[HHT1]  uveitis or herpetic uveitis. 

The systemic treatment of CMV uveitis with ganciclovir is difficult because of the potential renal and bone marrow toxicity. Previous studies have shown that intravitreal ganciclovir followed by a maintenance dose of valganciclovir was safe and effective in the management of CMV retinitis in immunocompromised patients. One should also keep in mind that the vitreal concentration of ganciclovir after the intravitreal injection can be around 100 times higher[HHT2]  than it is following intravenous injection. 

In this study, six consecutive patients with active CMV anterior uveitis received intravitreal injection of ganciclovir 2 mg/0.05 ml as a loading dose. Two patients received no additional treatment, while four others with persistent intraocular inflammation due to CMV were placed on a twice-daily, 900 mg maintenance dose of oral valganciclovir. At a follow-up of 12 to 22 months, the best corrected visual acuity of all patients improved or stabilized, and the IOP and inflammation of the anterior chamber of all patients were well controlled. 

While the small number of patients and lack of control group limit the study, this therapeutic strategy does appears effective in decreasing the potential renal and bone marrow toxicity of systemic ganciclovir in patients with CMV anterior uveitis.