Exposure of herpes simplex virus-infected cells to excimer laser photocoagulation

Recent concerns over the safety of operator exposure to excimer laser plume prompted this study We sought to determine if live Herpes simplex type I (HSV-1 i could survive exposure to a routine excimer laser pulse sequence MRC-.5 cell monolayers were infected with wild-type HSV-1 in culture tubes to a concenlration of HI7 TCID (tissue culture infective doses). Cells were scraped to dislodge them and cenlrifuged to a pellel. The pellets were resuspended and subjected to a pulse sequence equal to a -VOO diopter correction (150 pulses with a 6.5mrn optical /one. Summit Technologies SVS Apex Excimer Laser System]. The laser plume from 10 samples and a negative control was collected via vacuum into a small vial containing tissue culture medium Fresh cell monolayers were immediately inoculated with the collecling medium. No virus grew from any of the 10 samples inoculated wiih HSV-1 or from the negative conlrol. A pooled collection medium was sent to a reference lab for PCR detection of viral DNA. Viral DNA was found by PCR in Ihe pooled sample but not from the negative control. In conclusion, viable HSV-1 could not be recovered from excimer laser plume under these conditions, but viral DNA fragments were detected by PCR. Studies are underway to further characterize the PCR products.