Endogenous Endophthalmitis: A Review of Case Series Published between 2011 and 2020

This is a literature review of 31 case series of endogenous endophthalmitis (EE) published in the last ten years, identified from a literature search of several databases (PubMed, EMBASE, and the Cochrane Library). While diabetes mellitus and malignancies remain the most frequently associated medical conditions, intravenous drug use is a significant risk factor (especially in the last years, in studies from Western countries). Ophthalmologic screening is recommended for candidaemia, but not in patients with sepsis of other aetiologies (however, the physician treating patients with sepsis must be well aware of EE). The most frequent Gram-positive microorganisms that cause EE are Staphylococcus and Streptococcus; the most frequent Gram-negative organism is Pseudomonas, and yeasts, probably Candida, usually cause fungal infections. In all-cause EE, prognostic factors of better visual outcomes are initial VA better than counting fingers, performing a pars plana vitrectomy (PPV), performing an intravitreal injection within the first 24 hours after clinical diagnosis, and the presence of a focal type of EE. In endogenous fungal endophthalmitis, more than 1/4 of patients have bilateral involvement. Blood samples have a low rate of positivity. Yeasts remain the most prevalent cause. Many authors report using azoles and echinocandins for systemic therapy (and voriconazole for intravitreal injections). Although PPV was performed in small proportions of eyes, the anatomical success rate is quite high. Klebsiella pneumoniae is an important cause of EE in Southeast Asia (and probably an emergent etiology in other regions), which is frequently associated with diabetes. There is a robust association with pyogenic liver abscess (PLA) (but in up to half of the cases, the diagnosis of EE precedes that of PLA). Blood cultures have a high diagnostic yield, while vitreous samples have a low yield. K. pneumoniae may carry antibiotic resistance. Anatomical and functional success rates are small, but they may be improved with PPV.