EFFICIENT REACTIVATION OF LATENT HERPES-SIMPLEX VIRUS TYPE-1 INFECTION BY EXCIMER-LASER KERATECTOMY IN THE EXPERIMENTAL RABBIT OCULAR MODEL

PURPOSE: To investigate the role of excimer laser keratectomy as a tri gger for the reactivation of latent HSV type 1 (HSV-1) in the New Zeal and rabbit ocular model. There are conflicting reports in the current literature about reactivation of HSV-1 after excimer laser photoablati on. METHODS: New Zealand rabbits were inoculated topically with HSV-1 McKrae or W strain in each eye, and culture-positive dendritic keratit is was documented on day 7. After the establishment of latency (21+ da ys), animals were divided into three groups: group I animals underwent excimer laser photoablation in each eye; group IZ animals received in trastromal injections of sterile water to act as positive controls (a standard method); and group III animals received no treatment and repr esented spontaneous shedders. All eyes were swabbed daily from days 1 through 10 and plated on A549 cells. Recovery of HSV-1 on days 1 throu gh 10 postinduction was analyzed to compare the efficiency of the diff erent methods of viral reactivation. RESULTS: Reactivation of latent H SV-1 after excimer treatment was observed in nine (45%) of 20 eyes and was equivalent to the rate of reactivation seen in the positive contr ol animals (eight [44.4%] of 18 eyes) (P = .99). Both of these rates w ere significantly greater than those of the untreated animals (one [5. 6%] of 18 eyes) (P = .018). CONCLUSION: Excimer laser keratectomy appe ars to be an efficient trigger for the reactivation of latent HSV-1 in the New Zealand rabbit ocular model. (C) 1998 by Elsevier Science Inc . All rights reserved.