Dendritic epithelial keratitis is most commonly caused by infections of herpes simplex virus (HSV) type 1 (HSV-1), and less frequently by HSV type 2 (HSV-2). Ganciclovir, a guanosine nucleoside analogue, is a well established broad-spectrum antiviral agent that inhibits replication of viral DNA and is active against both HSV-1 and -2 and several other viruses. Ganciclovir ophthalmic gel 0.15% is a five-times-daily topical preparation that is indicated for the treatment of acute herpetic keratitis (dendritic ulcers). A randomized, open-label, phase III trial in immunocompetent patients with acute herpetic keratitis showed that ganciclovir ophthalmic gel 0.15% applied five times daily provided effective clinical resolution of dendritic ulcers following 7 days of treatment (primary endpoint). Moreover, a retrospective analysis of noninferiority showed that ganciclovir ophthalmic gel 0.15% was no less effective than aciclovir (acyclovir) ointment 3%. A pooled analysis of three randomized, single-masked, phase II multinational trials also showed high rates of dendritic ulcer healing at day 7 for eyes treated with ganciclovir ophthalmic gel 0.15% and aciclovir ointment 3%. Furthermore, in the individual phase II trials, most patients showed evidence of healed dendritic and geographic ulcers at day 14 in either treatment arm. Median healing times with either treatment ranged from 6 to 10 days. Ganciclovir ophthalmic gel 0.15% was generally well tolerated and was associated with a significantly lower incidence of visual disturbances than aciclovir ointment 3% in the phase III trial.