Pathogen-associated visual outcomes following post-procedure endophthalmitis

Abstract

Objective: To report the anatomic and functional outcomes of a large, multicenter series of post procedure acute endophthalmitis, stratified by pathogen virulence.

Design: Retrospective, interventional case series PARTICIPANTS: Two hundred forty adult patients diagnosed with post-procedural acute endophthalmitis from 2012-2022 at four tertiary, university-based care centers. Of these, two hundred and eight patients had adequate follow-up data for comparative analyses.

Methods: Medical records were reviewed for demographics, microbiology, treatment, and visual outcomes of patients that developed endophthalmitis following any intraocular procedure. Organisms were categorized into surface commensals (coagulase-negative Staphylococcus sp.) and non-surface commensals (e.g., Streptococcus, Enterococcus sp.) as a proxy for virulence. Visual acuity outcomes and complication rates were compared across groups using Fisher's exact test and regression models adjusting for age, sex, comorbidities, and treatment modality for post injection endophthalmitis.

Main outcome measures: Final visual acuity, number of interventions, and rates of vision-threatening complications including phthisis, retinal detachment, enucleation/ evisceration.

Results: Among culture-positive cases, patients infected with non-surface commensal organisms had significantly worse final visual acuity than those with coagulase-negative Staphylococcus (mean logMAR 2.14 vs. 0.77, p < 0.0001), as well as higher rates of third interventions (27.5% vs. 10.1%, p = 0.017), phthisis (15.4% vs. 1.1%, p = 0.0032), and enucleation/evisceration (12.8% vs. 0%, p = 0.0022). In multivariable regression of post-injection endophthalmitis, virulent, non-surface commensal organisms remained independently associated with poorer visual outcomes (p = 0.0005). Complication patterns were consistent whether culture-negative cases were included or not in the non-virulent group. Most patients were initially treated with intravitreal injections (92.1%). An initial vitrectomy was uncommon and not significantly associated with better outcomes, when performed.

Conclusions: Infections with virulent, non-surface commensal organisms such as Streptococcus and Enterococcus are associated with significantly worse outcomes in post-procedure endophthalmitis, independent of presenting vision or treatment delay. These findings support a shift toward pathogen-informed management and underscore the need for timely identification of virulent organisms in post procedural acute endophthalmitis.

Keywords: endophthalmitis; infection; pathogen; visual outcomes.