Pterygium are abnormal lesions on the sclera (the white surface of the eye). Pterygium are caused by chronic infection, and the lesion can spread to the cornea. Surgery to remove pterygium may make the pterygium worse, because surgery on infection creates a high risk the infection will spread to new tissue or reoccur. Antibiotics used during and after pterygium surgery can treat the infection but can also cause the pathogen to become more antibiotic resistant.

Patients with pterygium should be tested for immortal pathogens (chlamydia species and H-pylori), and treated with antibiotic eye drops, ointment, and medications, as needed. If not sufficient, and surgery is required, appropriate antibiotic drops and medications are needed, before and after pterygium surgery, to control the spread or reoccurrence of infection.