While cidofovir is effective in suppressing retinitis and prolonging time to progression, no studies have compared cidofovir to other therapies and its place in the treatment of CMV retinitis remains unexplored. By combining the ganciclovir intraocular device (slows retinitis progression) with oral ganciclovir (has the potential to treat both the ocular disease and to suppress dissemination to the contralateral eye and the viscera), without the use of a central venous catheter, this combination has become increasingly common. For these reasons, a comparative trial of cidofovir to other therapies is appropriate.