Tissue of origin of herpes simplex virus type 1 reactivated in tear film

In the present study, we tried to detect the tissue of origin of herpes simplex virus type 1 (HSV-1) reactivated in tear film after artificial reactivation. The combined treatment consisted of iontophoresis on postinoculation day 35, followed by topical epinephrine on 2 days, after which the rabbits were killed. The ocular tissues and trigeminal ganglia were immediately dissected. Their cell-free supernatants were inoculated on CV-1 (African green monkey kidney cell) monolayers for infectious HSV-1 detection. The percentage of recovery from the cell-free supernatants was 50% (5 out of 10 samples) from the cornea, 0% from conjunctiva or lacrimal glands, and 20% (2 out of 10 samples) from trigeminal ganglia. The percentage of HSV-1 reactivation in the tear film was 50%. No infectious virus was detected from tissues or tear film in the control group. Four eyes showed HSV-1 reactivation simultaneously from the cornea and tear film, but only one eye from the trigeminal ganglion and tear film. These results demonstrate that the cornea might be the tissue of origin of HSV-1 reactivated in tear film.