An Updated Retrospective Study on Clinical and Microbiological Profile, Management and Predictors of Poor Outcomes in Infectious Endophthalmitis

Abstract

INTRODUCTION: Infectious endophthalmitis is a rare but vision-threatening intraocular infection, with a global incidence ranging from 0.021%0.021% to 0.32%0.32%. The most frequent exogenous causes are intravitreal injections and cataract surgery, while endogenous cases account for 5%5% - 20%20%. Despite major advances in diagnosis and management, visual prognosis remains poor for many patients. This study updates a previous series from the same hospital, expanding the cohort and aiming to identify predictors of poor prognosis while evaluating the impact of protocol modifications introduced in recent years.

METHODS: A retrospective review was conducted of all patients diagnosed with infectious endophthalmitis between 2013 and 2025 at Pedro Hispano Hospital. Collected data included demographics, comorbidities, etiology, timing of presentation and treatment, microbiological isolates, and therapeutic approaches. Visual acuity (VA) was converted to the logarithm of the minimum angle of resolution (LogMAR) for statistical analysis.

RESULTS: Thirty-one patients were included (87.1%(87.1% exogenous, 12.9%12.9% endogenous endophthalmitis). The main causes were intravitreal injections (29%)(29%) and cataract surgery (19.4%)(19.4%). Mean symptom-to-admission time was 1.94±1.51.94±1.5 days. Most patients (90.3%)(90.3%) had ≥1≥1systemic comorbidity, most commonly hypertension (51.6%)(51.6%), dyslipidemia (45.2%)(45.2%), and diabetes (41.9%)(41.9%), and more comorbidities correlated with poorer final VA (q=0.418;p=0.033)(q=0.418;p=0.033). Median initial VA was 2.4 LogMAR (hand motion). Cultures were positive in 29%29%, with Staphylococcus epidermidis as the most frequent. Gram-negative infections were uncommon but led to severe outcomes. Vitrectomy (PPV) was performed in 80.6%80.6% of cases, significantly reducing complication rates (16.0%vs83.3%(16.0%vs83.3% p=0.001)p=0.001). Early PPV (≤48h)(≤48h) was associated with greater visual improvement compared with late PPV (>48h)(>48h) (ΔVA−1.58vs−0.55;p=0.002)(ΔVA−1.58vs−0.55;p=0.002)

CONCLUSION: This updated series confirms the predominance of exogenous endophthalmitis, particularly post-injection, and underscores the importance of early surgical intervention. Higher comorbidity burden and treatment delays were predictors of poor outcome, while early PPV significantly improved recovery and reduced complications. These findings support continuous refinement of preventive and therapeutic strategies to optimize prognosis in infectious endophthalmitis.