Therapeutic response of herpes simplex virus-induced corneal edema to trifluridine in combination with immunosuppressive agents

Herpetic stromal disease often is treated with combinations of antiviral agents and corticosteroids. The addition of steroids to the antiviral treatment regimen frequently increases the efficacy of therapy in patients; however, many complications may arise as a result of corticosteroid therapy. Using a rabbit model, the effects of trifluridine (F3TdR) on corneal edema and stromal disease were examined when combined with each of three immunosuppressive agents. The therapeutic response was evaluated by classifying eyes as either responsive or unresponsive based on the maximum corneal thickness attained during therapy. The data indicate that about 56% of the eyes responded to therapy with 1% F3TdR alone even when therapy was initiated after signs of stromal inflammation had begun to appear and epithelial disease was resolving. Combination of F3TdR with 0.125% prednisolone acetate significantly increased the proportion of responsive eyes to about 78%. Therapy with F3TdR combined with topical 5% cyclosporine A was no better than F3TdR alone, and combination with 0.2% deoxycoformycin and 0.4% 2'-deoxyadenosine significantly decreased the proportion of responsive eyes. These data further document that the responses of stromal disease to therapy must be evaluated on an eye-by-eye basis because the distribution of the data may not be Gaussian in nature. Eyes with corneal edema and stromal disease induced by herpes simplex viral (HSV) infection may respond to therapy with antiviral agents alone, but others require steroid. Still others do not respond to combined therapy. Combining the responses of all eyes in a given treatment group to obtain a "population mean" may be misleading.(ABSTRACT TRUNCATED AT 250 WORDS)