A 28-year-old woman from rural Rajasthan presents with chronic bilateral eye irritation, photophobia, and recurrent purulent discharge for the past 3 years. On examination, she has upper tarsal conjunctival scarring, Arlt's line, and trichiasis. Conjunctival scrapings show intracytoplasmic inclusion bodies. She has already completed two courses of oral azithromycin (12 mg/kg/day for 3 days, monthly for 6 months) in the past 2 years. What is the most appropriate next step in management?