Clinical review of endogenous endophthalmitis in Korea: a 14-year review of culture positive cases of two large hospitals

Endogenous Endophthalmitis - A Major Review

Endogenous endophthalmitis (EE) is an uncommon but potentially devastating ocular infection involving the inner layers of the eye. The global incidence of EE is on the rise. Common ocular signs and symptoms associated with EE include conjunctival injection, ocular pain, and reduced visual acuity. On clinical examination, a history of prior or coexisting systemic infections, symptoms (e.g., fever, malaise), and localizing features may be noted. Clinical diagnosis is often challenging, resulting in critical delays that contribute to a poor prognosis. Blood cultures and ocular fluid samples can aid in conforming causative pathogen(s), after which empirical antibiotic therapy, both systemic and intravitreal, should be instated. The use of steroids to suppress inflammation remains controversial. Surgical options include pars plana vitrectomy. Overall prognosis varies depending on host and pathogen factors, and early diagnosis and initiation of appropriate treatment are crucial.

Klebsiella Endogenous Endophthalmitis During the COVID-19 Pandemic

Purpose: To describe the characteristics of Klebsiella pneumoniae endogenous endophthalmitis (KEE) encountered during the COVID-19 pandemic. Methods: This retrospective consecutive case series evaluated eyes that presented with KEE between March 2020 and July 2022. Results: Seven eyes of 5 patients developed KEE. Between January 2020 and July 2022, KEE was observed in 42% of consecutive EE cases compared with 7.8% during the preceding 13 years. COVID-19 was positive in 4 of 5 patients before they developed KEE. Only 1 patient presented with a VA better than hand motions (20/400). All eyes were treated with urgent vitrectomy and intravitreal and systemic antibiotics. No improvement in vision occurred in any patient; VA remained light perception to no light perception in 60% of eyes. Conclusions: The visual prognosis in KEE is extremely poor. The presence of a preceding COVID-19 infection in 80% of patients may signal a new risk factor for KEE. Patients with a hypervirulent Klebsiella syndrome should be routinely screened for EE.

Gram-Negative Endogenous Endophthalmitis: A Systematic Review

Background: Gram-negative bacteria are causative agents of endogenous endophthalmitis (EBE). We aim to systematically review the current literature to assess the aetiologies, risk factors, and early ocular lesions in cases of Gram-negative EBE. Methods: All peer-reviewed articles between January 2002 and August 2022 regarding Gram-negative EBE were included. We conducted a literature search on PubMed and Cochrane Controlled Trials. Results: A total of 115 studies and 591 patients were included, prevalently Asian (98; 81.7%) and male (302; 62.9%). The most common comorbidity was diabetes (231; 55%). The main aetiologies were Klebsiella pneumoniae (510; 66.1%), Pseudomonas aeruginosa (111; 14.4%), and Escherichia coli (60; 7.8%). Liver abscesses (266; 54.5%) were the predominant source of infection. The most frequent ocular lesions were vitreal opacity (134; 49.6%) and hypopyon (95; 35.2%). Ceftriaxone (76; 30.9%), fluoroquinolones (14; 14.4%), and ceftazidime (213; 78.0%) were the most widely used as systemic, topical, and intravitreal anti-Gram-negative agents, respectively. The most reported surgical approaches were vitrectomy (130; 24.1%) and evisceration/exenteration (60; 11.1%). Frequently, visual acuity at discharge was no light perception (301; 55.2%). Conclusions: Gram-negative EBEs are associated with poor outcomes. Our systematic review is mainly based on case reports and case series with significant heterogeneity. The main strength is the large sample spanning over 20 years. Our findings underscore the importance of considering ocular involvement in Gram-negative infections.

Characteristics of Computed Tomography for Identifying Patients at High Risk of Endogenous Endophthalmitis Due to Klebsiella pneumoniae-Related Pyogenic Liver Abscess

Endogenous endophthalmitis (EE) associated with Klebsiella pneumoniae (K. pneumoniae)-related pyogenic liver abscess (PLA) is one of the fatal complications of PLA and leads to loss of vision. Early diagnosis and treatment are important to save the patient’s vision. We investigated the characteristics of computed tomography (CT) in EE associated with K. pneumoniae-related PLA for the identification of the predictors of EE, in order to facilitate early diagnosis. A total of 274 patients diagnosed with K. pneumoniae-related PLA, including 15 patients with EE, were identified between January 2005 and December 2019. The clinical (age, gender, and underlying disease) and radiologic (the location, size, and number of abscesses) features were reviewed. In addition, the involvement of the adjacent vessels, such as the hepatic vein and portal vein, was carefully reviewed. A comparative analysis was performed between the EE and non-EE groups. Uni- and multivariate logistic regression analyses were used to identify the predictors of EE. Diabetes mellitus (DM), the involvement of the left or both hepatic lobes, and the adjacent vessels on the CT were significantly more frequent than those in the non-EE group (p < 0.05 in all), and they were the significant predictors of EE in the logistic regression analyses. In patients with K. pneumoniae-related PLA, the CT findings, such as the locations of the abscess (i.e., left or both lobes) and the involvement of the adjacent vessels, should be considered in addition to the ocular symptoms for an early diagnosis of EE.

Endogenous Endophthalmitis-The Clinical Significance of the Primary Source of Infection

Endophthalmitis is a severe form of ocular inflammation. The source of pathogens in endogenous endophthalmitis is located inside the body, and infection spreads hematogenously. Although rare, endogenous endophthalmitis is a very serious condition, as this type of inflammation is very devastating for ocular tissues. Prognosis is very poor, and the patients are often in a serious general condition, so they require special care and an individual approach in the treatment process. Thanks to the knowledge of the risks associated with infections of individual tissues and organs as well as potential pathogens and the clinical picture, it is possible to make a correct diagnosis faster and implement the correct treatment. In the case of endogenous endophthalmitis, reaction time is absolutely crucial for prognosis. In this review, we focus primarily on the importance of the primary source of infection for the course of the disease and prognosis.

ENDOGENOUS ENDOPHTHALMITIS IN WESTERN AUSTRALIA: A Sixteen-Year Retrospective Study

PURPOSE

To review the clinical features, microbiology spectrum, management, and outcomes of patients with endogenous endophthalmitis in Western Australia over a 16-year period.

METHODS

This is a retrospective chart review of all patients with endogenous endophthalmitis who presented to all tertiary ophthalmology departments between 2000 and 2015 in Western Australia.

RESULTS

Sixty-six eyes of 57 patients with endogenous endophthalmitis were identified, and follow-up data were available for a mean of 554 days. The average frequency was 1.6 per 1,000,000 population per year. Diabetes mellitus (33%) and intravenous drug use (30%) were the most common risk factors. Concurrent systemic infections included urinary tract infection (28%), pneumonia (23%), and endocarditis (21%). Among culture-positive cases (93%), 57% were bacterial and 43% were fungal. Visual acuity improved in 33 (50%) and declined in 15 eyes (22.7%). Baseline visual acuity and the presence of Gram-negative or filamentous fungi were the only predictors of final visual acuity (P = 0.023 and P = 0.001).

CONCLUSION

The population frequency of endogenous endophthalmitis has not changed over 16 years despite the changing profile of pathogen and risk factors. Similar to previous studies in Asian and Western countries, visual and anatomical prognosis depends on initial visual acuity and isolated pathogen. Gram-negative and filamentous fungi culture predicted a worse visual outcome.

Endogenous Endophthalmitis in an Urban University Setting: Characteristics, Treatment, and Outcomes

Purpose:

This work describes the characteristics, treatment, and outcomes of endogenous endophthalmitis (EE) cases over 13 years at a tertiary care hospital.

Methods:

This retrospective case series included EE cases from 2006 to 2018. Eyes were categorized by cultured organism and initial treatment status.

Results:

Forty-five eyes of 38 patients were identified with EE. Mean age was 48 ± 12 years and approximately three-fourths were male. Mean visual acuity (VA) at presentation was logMAR 1.86 ± 0.83. More than 50% of patients had a history of intravenous drug use. In a quarter of patients, no systemic source of infection was identified; 90% of these patients had a history of intravenous drug use. Bilateral infections occurred in 18% of participants. Of positive cultures, 29%, 56%, and 13% were fungal, gram-positive, and gram-negative in etiology, respectively. Eyes with fungal infections had a better presenting VA and were more likely to have better than 20/100 final VA vs those with bacterial infections. All patients received IV antibiotics; additionally 29% of eyes underwent initial combined pars plana vitrectomy with intravitreal antibiotic injection while 51% of eyes initially received bedside intravitreal antibiotic injection. There was no significant difference in final VA with respect to initial mode of treatment.

Conclusions:

Initial treatment of intravitreal antibiotics with or without pars plana vitrectomy did not show any difference in the average final VA in eyes with EE. Eyes with fungal infections had more favorable visual outcomes than those with bacterial infections. Almost 1 in 5 EE eyes were enucleated.

Clinical and visual outcomes following endogenous endophthalmitis: 175 consecutive cases from a tertiary referral center in Taiwan

BACKGROUND

To elucidate the linkage between organisms and visual outcome in cases of endogenous endophthalmitis.

METHODS

Patients who presented with signs of endogenous endophthalmitis between January 2008 and December 2015 and underwent a vitreous tapping were enrolled. The patients' demographics and clinical findings were recorded. The outcomes include visual acuity and enucleation.

RESULTS

A total of 175 consecutive patients with endogenous endophthalmitis were enrolled. Forty-four percent of the patients had a known distal focus of infection. The most common focus was liver abscess (24.6%), and the major intravitreal isolate was Klebsiella pneumoniae (34.4%). In this series, 51.4% of the intravitreal cultures were positive. The visual acuity of fungal ophthalmitis were better than in bacterial ophthalmitis. Multivariate logistic regression showed that Gram negative vitreous isolates, compared with the negative vitreous culture, were associated with higher risk of enucleation (Odds ratio [OR]: 10.424, 95% confidence interval [95% CI]: 3.019-35.995). The use of intravitreal antibiotics, compared non-users, was associated with a reduced risk of enucleation (OR:0.084, 95% CI: 0.026-0.268). Trans pars plana vitrectomy was not associated with risk of enucleation (OR: 0.307, 95% CI: 0.035-2.693). The post-treatment VA was positively correlated with the presenting VA (r = 0.718, p = 0.0001).

CONCLUSION

Our study demonstrated that liver abscess is the most common source of endogenous endophthalmitis in Taiwan. The visual outcome is good when the presenting visual acuity is relatively well preserved and when the infecting organism is fungus. The use of intra-vitreal antibiotics reduces the risk of enucleation.

A 14-Year Retrospective Analysis of Endogenous Endophthalmitis in a Tertiary Referral Center of Southern Thailand

Purpose

To investigate patient characteristics, clinical features, common causative organisms, and visual acuity outcomes in endogenous endophthalmitis.

Methods

This was a retrospective chart analysis of patients with endogenous endophthalmitis between January 2006 and December 2019. Collected data included basic patient characteristics, presenting symptoms, causative organisms, treatments, and 3-month and 1-year visual outcomes.

Results

Twenty-nine eyes of 27 patients were included in the study. The mean age of the patients was 45.4 ± 19.9 years, and 63% were female. Visual acuity at presentation ranged from counting fingers to no light perception. Systemic comorbidities presented in 66.7% of the patients, the majority of which were related to diabetes mellitus (48.1%). The most common primary infection was a urinary tract infection. Positive blood cultures were identified in 48.1% of patients, and positive cultures from vitreous and aqueous samples were identified in 59.3% and 31.6% of eyes, respectively. Among all the specimens, Gram-positive bacteria were identified in 55.5%, Gram-negative bacteria in 22.2%, fungi in 14.8%, and mixed organisms in 7.4%. Among ocular specimens, 61.1% contained Gram-positive organisms, 16.7% contained Gram-negative organisms, and 22.2% contained fungi. Streptococcus spp. was the most common causative organism. From 29 eyes, 18 (62.1%) underwent vitrectomy, and 12 (42.9%) underwent either evisceration or enucleation. Positive vitreous culture was significantly associated with unfavorable final visual outcome. Final visual acuity ranged from 20/125 to no light perception. Although visual improvement at 3 months was significantly better in younger patients, this had no impact on final visual outcome at 1 year.

Conclusion

Eyes with positive vitreous cultures had significantly poorer visual outcomes. Despite full treatment coverage, visual prognosis was extremely poor and the rates of blindness and evisceration/enucleation were still high.

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.

Clinical profile and outcome of endogenous endophthalmitis at a quaternary referral centre in south India

Purpose:

The purpose of this study is to evaluate the clinical profile, visual, anatomical and survival outcome of patients with endogenous endophthalmitis.

Methods:

Retrospective chart review of consecutive cases with endogenous endophthalmitis presenting from 2009-2016.

Results:

In our study, 41 eyes of 34 patients were included. Most common co-morbidity associated with endogenous endophthalmitis was Diabetes Mellitus (70.7%) and most common infective foci was UTI (73.2%). Among the culture positive cases, fungi and bacteria were evenly distributed, 76.93% were Gram positive bacteria and 23.07% were Gram negative. Fungal endogenous endophthalmitis was more commonly seen in immunosuppressed state (72.7%) and bilateral cases (66.7%). The mean presenting vision (log MAR) of patients who died during the study were poor compared to those who survived (P = 0.014) Poor mean visual acuity at presentation was associated with more death (P = 0.014). Eyes with poor presenting vision, fungal isolates, culture positivity and immune suppression had poor visual and survival outcome. Poor visual outcome was observed more frequently in eyes with Aspergillus infection (85.7%) compared to Candida (75%) and bacteria (58.3%). Evisceration was done for 5 out of 41 eyes (12.2%). Vitrectomy rate was 53.7% in our study, with 40% of them showing overall improvement in vision.

Conclusion:

Endogenous endophthalmitis is a sight threatening condition associated with high mortality particularly when caused by Aspergillus spp. in immunocompromised patients. Contrary to the prior published reports of endogenous endophthalmitis outside India, we found an equal distribution of fungal and bacterial organisms among our cases, with predominance of Aspergillus among fungal isolates and Gram-positive organism among bacteria. Fungal infections, especially with Aspergillus spp., resulted in poor visual and survival outcome.

Endogenous Endophthalmitis: yield of the diagnostic evaluation

Background

Endogenous endophthalmitis is an infection of the eye secondary to sepsis, occurring in 0.04–0.5% of bacteremia or fungemia. Risk factors include intravenous drug abuse (IVDA), diabetes, indwelling catheters, and immune suppression. Many patients have known or suspected bacteremia or fungemia; however, culture yield is reported to be low (approximately 50%). The purpose of this study is to elucidate the yield of diagnostic evaluation including microbial cultures over a 6.5 year period at an academic center in the United States.

Methods

Retrospective chart review of patients with endogenous endophthalmitis at the University of Florida from June 2011 to February 2018.

Results

Included are 40 eyes of 35 patients. Endophthalmitis was secondary to an endogenous source in 23.5% of all endophthalmitis cases observed. Intraocular culture positivity was 28.6% overall but was 0% after initiation of systemic antibiotics. Most commonly identified organisms from the eye were coagulase-negative Staphylococcus and Candida. Blood culture positivity was 48.6%, most commonly Staphylococcus. IVDA was noted with increasing frequency as a risk factor. Diagnosis of endophthalmitis upon hospital admission was associated with a higher intraocular culture positivity (P = 0.040) and a shorter hospital stay (P = 0.035). Computed tomography (CT) and magnetic resonance imaging (MRI) were the highest yield imaging modalities; X-ray and non-ocular ultrasound were less diagnostically useful. Echocardiogram was positive by transesophageal route (TEE) in 22% and in 9% by transthoracic (TTE) testing. Following discharge from the hospital, 48.4% of patients failed to follow up with outpatient ophthalmology.

Conclusions

Based on the results of this study, the interdisciplinary team should consider directed imaging, eye cultures prior to antimicrobial administration, thorough history for IVDA, and caution with premature discharge from the hospital.

Infectious Sources, Prognostic Factors, and Visual Outcomes of Endogenous Klebsiella pneumoniae Endophthalmitis

PURPOSE

To investigate the infectious sources and prognostic factors for poor visual outcome, including subjective symptoms, presenting clinical features, laboratory data, and treatments, in patients diagnosed with endogenous Klebsiella pneumoniae endophthalmitis (EKE) at a tertiary referral center in Northern Taiwan.

DESIGN

Retrospective, single-institution, consecutive case series.

PARTICIPANTS

One hundred ten consecutive patients (124 eyes) diagnosed with EKE.

METHODS

One hundred ten patients (124 eyes) were reviewed retrospectively between January 1996 and April 2013.

MAIN OUTCOME MEASURES

Visual acuity (VA), subjective symptoms, presenting clinical features, laboratory data, treatments, and requirement of evisceration or enucleation.

RESULTS

Of the 110 patients with EKE, 74 (67.3%) were men. Diabetes was the most commonly associated systemic disease (75/110 [68.2%]), and liver abscess was the major infection source (85/110 [77.3%]). In addition, 91 of 124 eyes (73.4%) had final VA worse than counting fingers (CF; poor visual outcome), and 20 eyes required evisceration or enucleation. The binary multivariate logistic regression (forward-Wald) model revealed that poor initial VA worse than CF (odds ratio [OR], 8.8; 95% confidence interval [CI], 2.2-36; P = 0.002), positive vitreous culture results (OR, 9.8; 95% CI, 1.7-56.1; P = 0.010), posterior focal EKE (OR, 0.15; 95% CI, 0.03-0.8; P = 0.027), and the presence of intravitreal dexamethasone administration (OR, 0.19; 95% CI, 0.04-0.9; P = 0.030) were the significant independent factors for visual outcomes.

CONCLUSIONS

Liver abscess was the major infection source, and EKE typically has poor visual prognosis. Early diagnosis and prompt treatment may salvage useful vision in some eyes. Early diagnosis with fair initial VA and intravitreal antibiotic and dexamethasone combination therapy may have beneficial effects on visual outcomes.

Endogenous Endophthalmitis after Severe Burn: A Case Report

Purpose:

This report describes a rare ocular complication in a burned patient.

Case Report:

A 12-year-old girl was admitted to our burn center because of full thickness burn of 46% of her total body surface area. On the 23^rd day of her stay, she complained of pain and decreased visual acuity in the right eye. Examination of this eye revealed panuveitis, dense vitritis, and a large chorioretinal abscess in the macular area; her best corrected visual acuity (BCVA) in this eye was hand motion. The left eye was completely normal. A smear and culture of the vitreous biopsy revealed the presence of Candida albicans. With a diagnosis of endogenous endophthalmitis due to fungal infection, the patient was treated with systemic fluconazole, intravitreal injection of Amphotericin B, and pars plana deep vitrectomy. After 6 months, the patient's final ocular examination revealed BCVA of counting fingers at two meters, a large macular scar, and quiescence of the intraocular infection.

Conclusion:

Burn patients treated with broad-spectrum antibiotics are at risk of candidemia and its complications, including endogenous endophthalmitis. Early diagnosis of endogenous endophthalmitis in high risk patients could prevent visual loss.

Current Perspectives of Prophylaxis and Management of Acute Infective Endophthalmitis

Endophthalmitis is an intraocular inflammatory condition which may or may not be caused by infective agents. Noninfectious (sterile) endophthalmitis may be attributable to various causes including postoperative retained soft lens matter or toxicity following introduction of other agents into the eye. Infectious endophthalmitis is further subdivided into endogenous and exogenous. In endogenous endophthalmitis there is hematogenous spread of organisms from a distant source of infection whereas in exogenous endophthalmitis direct microbial inoculation may occur usually following ocular surgery or penetrating eye injury with or without intraocular foreign bodies. Acute infective endophthalmitis is usually exogenous induced by inoculation of pathogens following ocular surgery, open-globe injury and intravitreal injections. More infrequently the infective source is internal and septicemia spreads to the eye resulting in endogenous endophthalmitis. Several risk factors have been implicated including immunosuppression, ocular surface abnormalities, poor surgical wound construction, complicated cataract surgery with vitreous loss and certain types of intraocular lens. Comprehensive guidelines and recommendations on prophylaxis and monitoring of surgical cases have been proposed to minimize the risk of acute endophthalmitis. Early diagnosis and prompt management of infective endophthalmitis employing appropriately selected intravitreal antibiotics are essential to optimize visual outcome.

[Endogenous bacterial and fungal endophthalmitis at Nice University Medical Center: A 15-year case review]

PURPOSE

To evaluate epidemiology, diagnostic and therapeutic management strategies and visual outcomes of cases of bacterial and fungal endogenous endophthalmitis managed in the Nice University Medical Center between January 2000 and June 2015.

METHODS

Three hundred twenty-three charts of patients with endophthalmitis treated at the Nice University Medical Center over this period were retrospectively reviewed to select the ones with endogenous endophthalmitis. Demographic characteristics, medical history, clinical presentation, diagnostic and therapeutic management, microbiology, and final outcomes were analyzed.

RESULTS

Twenty-two eyes of 20 patients were selected, constituting 6.20% of all cases of endophthalmitis. The mean age was 69years, and 75% of patients were male. The most common risk factors were diabetes, malignancies and cardiac diseases. Bacterial isolates were found in 16 cases (80%), fungal isolates in 3 (15%) and co-infection in 1 case. Gram-positive organisms accounted for 70.6% of cases (mostly Staphylococcus aureus [25%], Streptococcus agalactiae [25%] and Streptococcus pneumoniae [16.7%]). Candida albicans was the most common fungal organism. There was one bacterial and fungal co-infection. Two patients died, 4 eyes were enucleated or eviscerated (20%), and 4 patients (20%) attained a final visual acuity of 1/10 or better.

CONCLUSION

Endogenous endophthalmitis is a rare and serious condition with a poor prognosis. Gram-positive microorganisms, mostly S. aureus, were the main causative pathogens found.

An eleven-year retrospective study of endogenous bacterial endophthalmitis

Purpose. To determine the clinical features, microbial profiles, treatment outcomes, and prognostic factors for endogenous bacterial endophthalmitis (EBE). Methods. The medical records of 27 eyes of 21 patients diagnosed with EBE for 11 years were reviewed. Collected data included age, site of infection, visual acuities (VAs), microbial profiles, and treatment regimen. Results. The mean age was 68.5 years. Gram-positive organisms accounted for 76.2%, while gram-negative ones accounted for 19.0%. Staphylococcus aureus was the most common causative organism (52.3%) of which 72.7% was methicillin-resistant S. aureus. A final VA of ≥20/40 was achieved in 44% and 20/200 or better was in 64%. Eyes with initial VA of ≥20/200 (P = 0.003) and focal involvements (P = 0.011) had significantly better final VA. Initial VA (P = 0.001) and the interval between onset of ocular symptoms and intravitreal antibiotic injection (P = 0.097) were associated with final VA in eyes receiving intravitreal antibiotics. Conclusions. EBE is generally associated with poor visual outcome; however the prognosis may depend on initial VA, extent of ocular involvement, and an interval between onset of ocular symptoms and intravitreal antibiotic injection. Early diagnosis and early intravitreal injection supplement to systemic antibiotics might lead to a relatively good visual outcome.

Endophthalmitis: state of the art

Endophthalmitis is an uncommon diagnosis but can have devastating visual outcomes. Endophthalmitis may be endogenous or exogenous. Exogenous endophthalmitis is caused by introduction of pathogens through mechanisms such as ocular surgery, open-globe trauma, and intravitreal injections. Endogenous endophthalmitis occurs as a result of hematogenous spread of bacteria or fungi into the eye. These categories of endophthalmitis have different risk factors and causative pathogens, and thus require different diagnostic, prevention, and treatment strategies. Novel diagnostic techniques such as real-time polymerase chain reaction (RT-PCR) have been reported to provide improved diagnostic results over traditional culture techniques and may have a more expanded role in the future. While the role of povidone-iodine in prophylaxis of postoperative endophthalmitis is established, there remains controversy with regard to the effectiveness of other measures, including prophylactic antibiotics. The Endophthalmitis Vitrectomy Study (EVS) has provided us with valuable treatment guidelines. However, these guidelines cannot be directly applied to all categories of endophthalmitis, highlighting the need for continued research into attaining improved treatment outcomes.

Klebsiella pneumoniae induces an inflammatory response in an in vitro model of blood-retinal barrier

Klebsiella pneumoniae has become an important pathogen in recent years. Although most cases of K. pneumoniae endogenous endophthalmitis occur via hematogenous spread, it is not yet clear which microbial and host factors are responsible for the ability of K. pneumoniae to cross the blood-retinal barrier (BRB). In the present study, we show that in an in vitro model of BRB based on coculturing primary bovine retinal endothelial cells (BREC) and primary bovine retinal pericytes (BRPC), K. pneumoniae infection determines changes of transendothelial electrical resistance (TEER) and permeability to sodium fluorescein. In the coculture model, bacteria are able to stimulate the enzyme activities of endothelial cytosolic and Ca(2+)-independent phospholipase A2s (cPLA2 and iPLA2). These results were confirmed by the incremental expression of cPLA2, iPLA2, cyclo-oxygenase-1 (COX1), and COX2 in BREC, as well as by cPLA2 phosphorylation. In supernatants of K. pneumoniae-stimulated cocultures, increases in prostaglandin E2 (PGE2), interleukin-6 (IL-6), IL-8, and vascular endothelial growth factor (VEGF) production were found. Incubation with K. pneumoniae in the presence of arachidonoyl trifluoromethyl ketone (AACOCF3) or bromoenol lactone (BEL) caused decreased PGE2 and VEGF release. Scanning electron microscopy and transmission electron microscopy images of BREC and BRPC showed adhesion of K. pneumoniae to the cells, but no invasion occurred. K. pneumoniae infection also produced reductions in pericyte numbers; transfection of BREC cocultured with BRPC and of human retinal endothelial cells (HREC) cocultured with human retinal pericytes (HRPC) with small interfering RNAs (siRNAs) targeted to cPLA2 and iPLA2 restored the pericyte numbers and the TEER and permeability values. Our results show the proinflammatory effect of K. pneumoniae on BREC, suggest a possible mechanism by which BREC and BRPC react to the K. pneumoniae infection, and may provide physicians and patients with new ways of fighting blinding diseases.

The emergence of Klebsiella pneumoniae endogenous endophthalmitis in the USA: basic and clinical advances

Endogenous endophthalmitis (EE) is a rare but devastating infection that occurs secondary to seeding of the intraocular cavity from an extraocular focus. Recent reports suggest the increasing prevalence and incidence of Klebsiella pneumoniae as a causative organism in Asian countries. Analysis of the largest cohorts published to date suggests that K. pneumoniae endogenous endophthalmitis (KPEE) is 10 to 15 times more prevalent than other causes of EE. The incidence of KPEE among patients with systemic Klebsiella infection appears to be >100-fold more common than other causes of EE. The exact reason for these observations is not clear, but a number of studies now suggest that Klebsiella serotypes K1 and K2 have virulence factors that enhance their survival in diabetic patients and increase their pathogenicity. Here, we report two cases of KPEE in the USA. We also review the recent clinical and basic science literature on the prevalence, incidence, and pathophysiology of this emerging and devastating infection.

Uncommon ophthalmologic disorders in intensive care unit patients

Ophthalmologic complications are frequently encountered in intensive care unit (ICU) patients (Grixti et al. Ocul Surf 2012;10(1):26-42). However, eye care is often overlooked in the critical care setting or just limited to the ocular surface because treatment is focussed on the management of organ failures. Lack of awareness about other less common intraocular sight-threatening conditions may have a devastating effect on the patient's vision. To identify specific, frequently missed uncommon ocular disorders in ICU, a literature review using the keywords "Intensive Care," "Eye care," "ITU," "ICU," "Ophthalmological disorders," "Eye disorders" was performed. The databases of CINAHL, PuBMed, EMBASE, and Cochrane library were searched. The higher quality studies are summarized in the table with statements of methodology to clarify the level of evidence. The most prevalent ophthalmologic disorders identified in critically ill subjects include exposure keratopathy, chemosis, and microbial keratitis. In addition, uncommon eye disorders reported in ICU include metastatic endogenous endophthalmitis, acute primary angle closure, ischemic optic neuropathy, pupil abnormalities, vascular occlusions, and rhino-orbital cerebral mucormycosis. Early diagnosis and effective treatment will help to prevent visual loss.

Endophthalmitis: A review of recent trends

Endophthalmitis is a feared complication of trauma, surgical procedures and septicemia. Although uncommon, its potential for significant visual loss is well recognized. Especially over the past decade, complicated surgeries and medical techniques have increased and seriously ill patients are being sustained in ever increasing numbers. New pathogens are being recognized and known ones reclassified thanks to advances in molecular analysis. Continuously evolving PCR methodologies also add a new dimension to the diagnosis of infectious endophthalmitis. As well, medical literature is now truly international, encompassing studies from around the world that expand our understanding of ocular infectious disease. This report reviews some of these changes as they relate to endophthalmitis and particularly to the spectrum of organisms involved.

Review of Clinical Features, Microbiological Spectrum, and Treatment Outcomes of Endogenous Endophthalmitis over an 8-Year Period

Purpose. To evaluate the clinical features, microbiological spectrum, and treatment outcomes of endogenous endophthalmitis. Methods. Retrospective review of consecutive cases with infective endogenous endophthalmitis presenting from 2000 to 2007. The main outcome measure was the visual outcome at the latest follow-up visit. Other outcome measures included microbiological investigations, anatomical and clinical outcomes. Results. 22 eyes of 21 patients were included, and the mean follow-up duration was 2.7 years. Eyes with fungal endogenous endophthalmitis were more likely to have visual acuity of finger counting or better at presentation compared with those with bacterial endogenous endophthalmitis (odds ratio = 15.0, P = 0.013). Gram-negative microorganisms accounted for 50% of infections, while fungal and gram-positive organisms accounted for 27.3% and 22.7%, respectively. Despite treatment, the visual outcome was poor in general as 10 (45.5%) eyes had no light perception at the latest follow-up visit and 6 (27.3%) eyes required enucleation or evisceration. Contrary to previous studies, fungal endogenous endophthalmitis did not appear to have better visual outcome compared with bacterial endogenous endophthalmitis. Conclusion. Gram-negative microorganisms were the main causative pathogens of endogenous endophthalmitis in Hong Kong. The visual prognosis of endogenous endophthalmitis is generally poor as almost 50% of eyes were blind despite treatment.