A retrospective study from Bascom Palmer Eye Institute highlights the diagnostic challenges of endogenous endophthalmitis, finding that most patients present with ocular complaints alone despite harboring potentially life-threatening systemic infections.
Reporting in the Journal of Ophthalmic Inflammation and Infection, the investigators reviewed 50 eyes from 41 patients with culture-proven endogenous endophthalmitis treated between 2013 and 2024. The study examined clinical presentation, microbiological findings, systemic associations, management strategies, and visual outcomes.
The researchers found that 73 percent of patients initially presented in an outpatient setting rather than during hospitalization, while only 39 percent reported systemic symptoms at diagnosis. Blurred vision was by far the most common presenting complaint, occurring in 88 percent of patients, followed by ocular pain (42 percent) and redness (27 percent). The average delay between symptom onset and diagnosis was 11 days.
“Endogenous endophthalmitis often manifests first as an eye issue,” the study authors noted, emphasizing that many patients lacked obvious signs of systemic illness despite active infection elsewhere in the body.
Candida species remained the leading causative organism, accounting for half of all positive vitreous cultures and 46 percent of affected patients. Among bacterial pathogens, Staphylococcus aureus was the most frequently isolated organism, followed by Klebsiella pneumoniae. These findings reinforce previous observations that fungal infections, particularly candidemia-related disease, remain a major driver of endogenous endophthalmitis in Western populations.
Systemic evaluation identified an infectious source in 56 percent of patients. Indwelling medical devices – including catheters, ports, and long-term intravenous lines – were the most common source, accounting for nearly one-third of identified foci. Other sources included osteomyelitis, urinary tract infections, endocarditis, liver abscesses, and pulmonary infections. Blood cultures were positive in 56 percent of cases.
The study also underscores the potential for misdiagnosis. Twelve percent of patients were initially diagnosed with alternative inflammatory conditions, including panuveitis, anterior uveitis, retinal vasculitis, and viral retinitis, before the infectious nature of the disease became apparent. According to the authors, the indolent presentation of Candida endophthalmitis in particular – frequently mistaken for non-infectious uveitis – can complicate timely recognition and treatment.
Initial management included intravitreal antimicrobial therapy in all eyes, with half eventually undergoing pars plana vitrectomy. Most patients also required hospitalization and systemic antimicrobial treatment directed at the underlying source of infection.
Despite aggressive management, visual outcomes remained guarded. Mean presenting visual acuity was approximately equivalent to 20/2000, improving to around 20/400 at final follow-up. Just over half of eyes achieved a final visual acuity of 20/400 or better, while one in five ended with light perception or no light perception vision. Two eyes required evisceration, and two developed phthisis.
Notably, systemic survival outcomes appeared better than those reported historically. Only three patients (7 percent) died from infection-related causes, substantially lower than mortality rates described in earlier studies. The study authors suggest that advances in critical care, systemic antimicrobial therapy, and multidisciplinary management may be contributing to improved survival.
The Bascom Palmer investigators conclude that endogenous endophthalmitis remains both a diagnostic and therapeutic challenge. Given that most patients lack overt systemic symptoms at presentation, the authors state that “it is imperative that physicians maintain a high clinical suspicion for this condition in patients with known risk factors who develop atypical intraocular inflammation.”
