Intrastromal Moxifloxacin as an Adjunctive Therapy in Recalcitrant Bacterial Keratitis

Bacterial keratitis is a potentially sight-threatening corneal infection that is commonly treated with intensive topical antibiotics. Despite appropriate therapy, some cases show inadequate clinical response, particularly when the infection involves the deep corneal stroma. Limited penetration of topical antibiotics into deeper corneal layers may contribute to treatment failure in these recalcitrant cases. Intrastromal antibiotic injection is a targeted drug-delivery approach that allows high local antimicrobial concentrations directly at the site of infection. Moxifloxacin is a broad-spectrum fluoroquinolone with proven efficacy in bacterial keratitis and favorable corneal tissue penetration. However, evidence regarding the clinical benefit and safety of intrastromal moxifloxacin as an adjunctive treatment remains limited. This randomized controlled trial aims to evaluate the efficacy and safety of intrastromal moxifloxacin injection as an adjunct to standard topical moxifloxacin therapy compared with topical therapy alone in patients with recalcitrant bacterial keratitis. The primary outcome is time to complete clinical resolution of infection. Secondary outcomes include visual acuity improvement, ulcer healing rate, need for additional interventions, and treatment-related complications.