A 32-year-old woman presents with a 5-day history of right eye pain, photophobia, and blurred vision. She reports a vesicular rash on the forehead and upper eyelid 3 days prior to ocular symptoms. On examination, visual acuity is 6/12, and slit-lamp biomicroscopy reveals multiple branching, dendritic ulcers with terminal bulbs on the cornea. Fluorescein staining is positive. What is the most appropriate next step in management?