Latanoprost increases the severity and recurrence of herpetic keratitis in the rabbit.

PURPOSE: To determine whether topically applied latanoprost increases the severity of acute herpes simplex keratitis, the rate of recurrence of herpes keratitis, or both, in the rabbit.
METHODS: To determine the effect on severity of acute herpetic keratitis, the corneas of New Zealand white rabbits were infected with either the less-corticosteroid-sensitive McKrae strain or the corticosteroid-sensitive F(MP)E strain of herpes simplex virus type 1. Rabbits were randomly assigned to twice-a-day treatment with latanoprost 0.005%, dexamethasone sodium phosphate 0.1%, or balanced saline solution within 3 days of infection and evaluated daily for up to 13 days after infection. The severity of keratitis was graded in a masked manner. To determine the effect on recurrences of herpetic keratitis, animals infected with McKrae strain herpes simplex virus type 1 that survived to day 32 after infection were randomized to treatment with latanoprost 0.005% or balanced saline solution and evaluated for the presence of corneal lesions from postinfection day 32 to day 47.
RESULTS: In the severity studies, treatment of F(MP)E-infected corneas with latanoprost or dexamethasone significantly worsened herpetic keratitis; by postinfection day 5, F(MP)E-infected eyes treated with dexamethasone or latanoprost demonstrated significantly higher severity scores than the eyes treated with balanced saline solution (P = .0001 and .008, respectively). Scores of McKrae-infected corneas treated with latanoprost or dexamethasone were not significantly different from scores of balanced saline solution-treated corneas. In the recurrence study, treatment with latanoprost significantly increased the appearance of clinical recurrences in McKrae-infected eyes, compared with balanced saline solution treatment (P = .0064).
CONCLUSION: Latanoprost may worsen acute herpetic keratitis in the rabbit eye and increase the risk of recurrences in latently infected animals.