Intentional reactivation of latent ocular herpes infection during BVDU therapy

Abstract

Sixteen adult New Zealand white rabbits with previously confirmed herpes simplex virus type 1 (HSV-1) infections were stimulated by iontophoresis of 6-hydroxydopamine into the cornea and were followed-up by topical epinephrine treatment to confirm latency. A total of 224 ocular cultures were obtained, of which 73 were positive for HSV during the seven day cycle. Twenty-seven of the 32 eyes (84%) had at least one positive culture. Animals were randomly divided into two treatment groups. Upon repeat stimulation (Cycle 2), concurrent with oral and topical bromovinyl-deoxyuridine (BVDU) therapy, only 3/104 ocular cultures were HSV positive, while 24/112 ocular cultures from placebo-treated animals were positive. Anti-HSV serum titers were comparable before and after BVDU therapy and the HSV isolates from BVDU treated animals did not develop drug resistance (i.e., ED-50 values were approximately 0.1-0.2 ug/ml both before and after therapy). It was concluded that BVDU had a demonstrable therapeutic effect on the recovery of HSV-1 from ocular cultures during intentional reactivation, but the latent ganglionic infection was not eliminated.