Evaluation of Rose-Bengal Photodynamic Antimicrobial Therapy for Refractory Infectious Keratitis in Dogs and Cats (22...

To report the clinical outcomes of Rose Bengal Photodynamic Antimicrobial Therapy (RB-PDAT) as adjunctive therapy for progressive infectious keratitis (IK) in companion animals.

A retrospective descriptive review was performed on 22 eyes (14 dogs, 8 cats from private owners) treated with RB-PDAT after failure of initial medical therapy between December 2024 and September 2025.

A freshly prepared 0.1% Rose Bengal solution was applied using iontophoresis, followed by green-laser irradiation for two cycles of 2 min (520-525 nm; 10.8 J/cm²). The frequency of topical antibiotic treatment was tapered following RB-PDAT. Examinations were conducted until complete corneal epithelialization was confirmed. Success was defined as infection signs resolution (ulceration, stromal infiltration) without surgical intervention.

All eyes achieved full epithelialization within 30 days (Dogs: median healing time 9 days-Cats: mean healing time 14 days). Sixteen cases yielded positive cultures, identifying 30 organisms, including multidrug-resistant isolates. Clinical improvement was documented in all patients. No significant adverse effects occurred. None of the eyes required additional surgery.

RB-PDAT appears to be safe, well-tolerated, and associated with rapid epithelial closure in refractory IK. The treatment may reduce reliance on aggressive antibiotic protocols and lower the likelihood of surgical intervention. Larger prospective studies are needed to further define indications, safety, and comparative efficacy of RB-PDAT in veterinary patients.