Treatment of HSV-1 stromal keratitis with topical cyclosporin A: a pilot study

Background: In stromal keratitis induced by herpes simplex virus (HSV) the host's immune response contributes to corneal scarring and neovascularization. The purpose of this study was to analyze the efficacy of topically applied cyclosporin A (CsA) in patients with HSV keratitis. Methods: The authors performed a prospective pilot study in patients with HSV stromal keratitis (n=18). Eyes were treated with CsA eyedrops and acyclovir ointment. The drugs were tapered off gradually. Visual acuity, slit-lamp appearance, intraocular pressure and corneal sensitivity were evaluated monthly (follow-up 5.2+/-0.28 months, mean+/-SEM. Results: Keratitis resolved with CsA treatment in 10 of 14 patients with non-necrotizing keratitis and in 2 of 4 with necrotizing keratitis. As CsA was used topically, the corticosteroids could be withdrawn in all patients with non-necrotizing keratitis and in 1 of 3 with necrotizing keratitis. Under CsA therapy, persistent or progressive inflammation was noted in 6 of the 18 patients. These 6 patients with keratitis improved only with combined CsA/corticosteroids. Corneal ulcers healed in 4 patients with topical CsA, and corneal neovascularization improved in a further 8. Except for toxic epitheliopathy, no further CsA complications were noted. Conclusions: The findings in this pilot study suggest that HSV stromal keratitis can be treated successfully with CsA eyedrops, especially in non-necrotizing disease. CsA may be particularly helpful in the presence of steroid glaucoma, herpetic corneal ulcers, and to taper off topical corticosteroids. Additional use of acyclovir may aid in suppressing the recurrence of epithelial HSV keratitis. A randomized study should be performed to evaluate the role of topical CsA in more detail.