A 35-year-old man with a 3-month history of chronic follicular conjunctivitis, mild mucoid discharge, and intermittent foreign body sensation presents to the clinic. Examination reveals tarsal conjunctival follicles, no preauricular lymphadenopathy, and normal cornea. Gram stain of discharge is negative. Giemsa stain shows intracytoplasmic inclusion bodies in epithelial cells. What is the most appropriate next step in management?