Endogenous Endophthalmitis (EE) Associated with Methicillin-Sensitive Staphylococcus Aureus (MSSA)-Related Septic Arthritis: Case Report and Literature Review

Background: Endogenous endophthalmitis (EE) is a rare but serious intraocular infection caused by hematogenous dissemination of pathogens from a distant infectious focus. It represents approximately 2–6% of all cases of endophthalmitis and primarily affects immunocompromised individuals. Staphylococcus aureus, particularly methicillin-sensitive Staphylococcus aureus (MSSA), is a recognized but uncommon cause of EE. While EE is often associated with endocarditis, urinary tract infections, or gastrointestinal infections, its association with septic arthritis is exceedingly rare. Case Presentation: We report the first documented case in Morocco of an endogenous endophthalmitis secondary to septic arthritis in a 70-year-old diabetic male. The patient presented with a painful red eye and profound vision loss in the right eye evolving over two weeks, along with progressive swelling and pain in the left knee. Ophthalmologic examination revealed corneal ulceration, significant anterior chamber inflammation, and vitreous opacities suggestive of EE. Joint aspiration confirmed MSSA septic arthritis. Despite systemic and intravitreal antibiotic therapy, the patient’s visual prognosis remained poor, with persistent vitreous opacities and loss of light perception. Discussion: Endogenous endophthalmitis due to MSSA is a rare but severe manifestation of hematogenous spread, particularly in diabetic patients. Our review of the literature identified only six previously reported cases of MSSA-associated EE, with septic arthritis being an exceptionally rare primary infection site. The outcomes of MSSA-EE remain poor despite aggressive antibiotic treatment, and early recognition is crucial for preserving vision. Conclusion: MSSA-associated endogenous endophthalmitis secondary to septic arthritis is an extremely rare but serious clinical entity.