CMV retinitis is the most frequently seen opportunistic infection of the eye in AIDS patients, and left untreated can lead to severe visual loss and blindness. While systemic administration of DHPG has been shown to be an effective treatment for CMV retinitis, the chronic administration required may be complicated by decreased blood cell counts (granulocytopenia) which may require discontinuation of treatment. While withholding treatment may allow recovery from the granulocytopenia, interruption of therapy may result in reactivation of the retinitis. Injection of DHPG into the vitreous cavity of the eye may be of benefit to severely neutropenic patients with CMV retinitis.