Bacteriophage Therapy for Staphylococcus aureus Induced Postoperative Acute Endophthalmitis In Vivo

Background: Postoperative acute endophthalmitis is a rare but severe complication following cataract surgery, with bacterial pathogens such as Staphylococcus aureus being the leading cause. Despite declining incidence rates globally, visual outcomes remain poor in many cases. Recent studies have explored the potential of bacteriophage therapy to treat bacterial infections, particularly for antimicrobial-resistant strains. This study aimed to assess the therapeutic effectiveness of bacteriophage treatment in a rabbit model of S. aureus-induced acute postoperative endophthalmitis. Methods: The study employed a randomized, controlled, posttest-only design using New Zealand white rabbits. Following extracapsular lens extraction surgery, rabbits were injected with S. aureus intracamerally to induce endophthalmitis. The treatment group received additional bacteriophage therapy. Ocular inflammation was assessed by measuring two biomarkers, myeloperoxidase (MPO) and intercellular adhesion molecule-1 (ICAM-1), using enzyme-linked immunosorbent assay (ELISA) from vitreous fluid samples. Histopathological analysis of retinal and scleral structures was performed post-enucleation. Statistical analyses were conducted using independent t-tests. Results: The treatment group showed significantly lower ICAM-1 levels (p < 0.001), indicating reduced leukocyte infiltration and inflammation compared to the control group. MPO levels were slightly elevated in the treatment group but were not statistically significant (p = 0.261). Histopathological examination revealed that retinal structures in the treatment group were preserved with reduced inflammatory cell infiltration, whereas the control group displayed extensive retinal damage, including neovascularization and retinal detachment. Conclusion: Bacteriophage therapy significantly reduced ocular inflammation and tissue damage in S. aureus-induced endophthalmitis, as evidenced by lower ICAM-1 levels and better-preserved retinal structures in the treatment group. These findings suggest that bacteriophage therapy may be an effective alternative to conventional treatments for postoperative acute endophthalmitis, particularly in cases involving antibiotic-resistant bacteria. Further studies are warranted to explore its broader clinical applicability.