Acute Herpetic Keratitis: What is the Role for Ganciclovir Ophthalmic Gel?

Herpes simplex keratitis (HSK) is a major cause of corneal blindness in the world. Following the primary infection, the virus enters into a latent phase. Recurrent infectious or immune keratitis cause structural damage to the cornea, scarring, and may lead to blindness. Several commercially available topical and oral antiviral drugs for HSK are currently available. However, toxicity and low patient compliance hamper their use in HSK. Further, oral antiviral drugs alone are not always effective in HSK. Thus, there had been a need for safe and effective topical antiviral agents against HSK. Systemic ganciclovir has been in use for the treatment of cytomegalovirus infections. Recently, topical ganciclovir has become available for use in patients with HSK. Ganciclovir 0.15% ophthalmic gel has been shown to be both safe and effective against viruses of the herpes family. Topical ganciclovir ophthalmic gel is well tolerated and does not cause significant toxic effects on the ocular surface. Several multicenter studies have revealed the potential role of ganciclovir ophthalmic gel in the treatment and prophylaxis of epithelial HSK. In this paper, we have reviewed the pharmacology, efficacy, side effects, and the role of ganciclovir ophthalmic gel 0.15% in the treatment of acute herpetic keratitis.

Ganciclovir ophthalmic gel 0.15%: in acute herpetic keratitis (dendritic ulcers)

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.