The clinical challenge of endogenous endophthalmitis

CLINICAL UTILITY OF BETA-D-GLUCAN TESTING FOR ENDOGENOUS FUNGAL CHORIORETINITIS OR ENDOPHTHALMITIS

PURPOSE

To evaluate serum beta-D-glucan (BDG) as a biomarker for endogenous fungal eye infection.

METHODS

Retrospective case-control study of 88 patients with a BDG test and eye examination at UPenn (2013-2018). Cases had endogenous fungal chorioretinitis or endophthalmitis diagnosed by eye examination and confirmed with positive culture; controls were without these fungal eye findings. Charts were reviewed for BDG values, blood/vitreous cultures, and eye examinations. Outcomes were BDG sensitivity, specificity, positive predictive value, and negative predictive value for fungal chorioretinitis or endophthalmitis, using prespecified BDG cut-off points of ≥80, ≥250, and ≥500 pg/mL as test positive.

RESULTS

Cases included six chorioretinitis and four endophthalmitis patients. Controls included 78 patients without chorioretinitis or endophthalmitis. Defining BDG ≥80 pg/mL as test positive, the BDG sensitivity (95% confidence interval) was 66.7% (22.3%-95.7%) for chorioretinitis and 100% (39.8%-100%) for endophthalmitis. The specificity was 74.4% (63.2%-83.6%) when BDG values ≥80 pg/mL were test positive, and 85.9% (76.2%-92.7%) when values ≥250 pg/mL were test positive. For a 1% endophthalmitis prevalence and BDG cut-off value of ≥80 pg/mL, the positive predictive value was 3.8% (2.4%-5.2%) and negative predictive value was 100% (99.1%-100%).

CONCLUSION

For endogenous fungal endophthalmitis, BDG's sensitivity and specificity seem good and the negative predictive value is high; a larger ophthalmic study is indicated.

The Role of Systemic Antimicrobials in the Treatment of Endophthalmitis: A Review and an International Perspective

Background

The optimal management of patients with endophthalmitis is challenging and includes both intravitreal and, in some cases, systemic antimicrobials. Systemic antimicrobials may be administered either intravenously or orally. In this article we review systemic antimicrobial options currently available for the treatment of types of endophthalmitis and the role of systemic antimicrobials (antibiotics and antifungals) in these treatments.

Review

While systemic antimicrobials are not universally utilized in the management of endophthalmitis, they may be helpful in some circumstances. The blood–retinal barrier affects the penetration of systemic medications into the posterior segment of the eye differently; for example, moxifloxacin and imipenem cross the blood–retinal barrier relatively easily while vancomycin and amikacin do not. However, inflammation, including endophthalmitis, may disrupt the blood–retinal barrier, enhancing the penetration of systemic agents into the eye.

Conclusion

Systemic antimicrobials may be particularly beneficial in patients with certain types of endophthalmitis; as such, they are standard treatment in the management of endogenous endophthalmitis (fungal and bacterial) and also widely used for prophylaxis and treatment of open-globe injuries. Although systemic antimicrobials are used in some patients with acute-onset postoperative endophthalmitis following cataract surgery, the literature generally does not support this practice. It is noted that there are currently no randomized clinical trials demonstrating a benefit of systemic antibiotics for any category of endophthalmitis.

Endogenous Endophthalmitis: Has the Opioid Crisis Impacted the Rates and Severity of Intravenous Drug-Related Cases?

Purpose:

Endogenous endophthalmitis is an intraocular infection associated with systemic illness and/or intravenous drug use (IVDU). Rising national rates of IVDU may have impacted rates and outcomes of endogenous endophthalmitis. The purpose of the current study is to compare rates and treatment outcomes in endogenous endophthalmitis with and without a history of IVDU.

Methods:

This is a single-center retrospective consecutive case series of 21 eyes of 17 patients with a diagnosis of endogenous endophthalmitis from May 2014 to December 2016. Clinical characteristics and treatment outcomes were compared between IVDU and non-IVDU groups.

Results:

A history of IVDU was present in 3 of 17 patients (18%), whereas the other 82% had systemic comorbidities. There was no statistically significant difference in presenting visual acuity (VA) between the IVDU and non-IVDU groups (20/630 vs 20/500, P = .75). Pars plana vitrectomy was performed at some point in the clinical course of 80% of eyes (4/5) in the IVDU group and 56% of eyes (9/16) in the non-IVDU group. Staphylococcus or Candida were the predominant causative organisms isolated in the IVDU and non-IVDU groups. Statistical analyses revealed trends towards worse last VA in the non-IVDU group compared with the IVDU group (20/1000 vs 20/110, P = .10).

Conclusions:

Compared with historical data from the same institution, there has not been an increase in the rates of IVDU-associated endogenous endophthalmitis at this tertiary referral center. VA outcomes are often poor in both groups, but there may be a better prognosis for IVDU-associated endogenous endophthalmitis.

BETA-D-GLUCAN TESTING IN PATIENTS WITH FUNGAL ENDOPHTHALMITIS

PURPOSE

To review the literature on beta-D-glucan (BDG) testing in fungal endophthalmitis.

METHODS

Review of primary literature using PubMed through April 2017 and presentation of an illustrative case report. A total of 231 articles were identified and 43 were ultimately chosen for review based on relevance and presence of ophthalmologic examination and objective data.

RESULTS

Beta-D-glucan is a major component of fungal cell walls. It is quantified using a calorimetry-based Fungitell assay based on modification of the limulus amebocyte lysate. Serum BDG levels are commonly used clinically in conjunction with other tests for early surveillance and diagnosis of invasive fungal infections. In the ophthalmic literature, elevated levels of BDG have been detected in vitreous fluid of patients undergoing vitrectomy for fungal endophthalmitis, tear fluid of patients with mycotic keratitis, and serum of a patient with bilateral endogenous subretinal abscesses. Elevated serum BDG levels appear to be highly associated with fungal endophthalmitis. Potential uses and considerations with regards to test limitations are discussed.

CONCLUSION

Beta-D-glucan testing may be used as an adjunct to support a diagnosis, initiate pharmacologic therapy or surgical intervention, and optimize overall clinical management in patients diagnosed with or under clinical suspicion for invasive fungal infections, including endophthalmitis. Additional clinical studies are necessary to fully characterize the utility of BDG testing in patients with fungal endophthalmitis.

Etiological agents of fungal endophthalmitis: diagnosis and management

Endophthalmitis caused by fungi is commonly diagnosed around the world in apparently healthy and immunocompromised individuals. An accurate clinical diagnosis for endophthalmitis confirmed by laboratory techniques is essential for early treatment with antifungal drugs, such as amphotericin B, imidazoles, and other antifungals. Here, we review endophthalmitis caused by fungi according to its classification into endogenous fungal endophthalmitis (EFE) and exogenous fungal endophthalmitis (EXFE). EFE is caused by endogenously acquired fungi, whereas the traumatic implantation of opportunistic fungal pathogens is the main feature of EXFE. We highlight the most important etiologies causing endophthalmitis and the steps required for a rapid diagnosis and management.

Incidence and outcome of endophthalmitis over a 13-year period

OBJECTIVE

The aim of the study was to assess the functional results and long-term visual prognosis in patients treated for acute endophthalmitis (AE).

DESIGN

Observational clinical series.

PARTICIPANTS

Evaluation of 120 eyes of 114 patients with AE treated between 1991 and 2004.

METHODS

This retrospective institutional analysis included 120 eyes of 114 patients (52 male, 68 female) with AE and a minimum follow-up of half a year. The patients had a mean follow-up of 23 months (6-135 months) and a mean age of 61 years (8 months-94 years) at the time of treatment. Treatment included intraocular injection of antibiotics alone (n = 18, 15%) and vitrectomy combined with intraocular and topical postoperative antibiotics (n = 85, 70%).

RESULTS

The most frequent complications were vitreous or retinal hemorrhages (n = 17, 14%), retinal detachment (n = 17, 14%), choroidal detachment (n = 3, 3%), secondary glaucoma (n = 7, 6%), and recurrent endophthalmitis (n = 3, 3%). Four eyes had to be enucleated because of recurrent and uncontrollable infection. Positive microbiological results were achieved in 67 of 88 specimens (76%). The most common isolate was Staphylococcus. At the end of follow-up, visual acuity was reduced (more than 2 lines) in 18 eyes (15%), stable in 22 (18%), and improved (more than 2 lines) in 72 eyes (60%).

CONCLUSIONS

AE is a rare but severe disease with a potentially deleterious outcome in affected eyes. In our series, 78% of all eyes had stable or improved postoperative visual acuity following various treatment regimens, depending on the severity of each case.

TREATMENT OUTCOMES AFTER PARS PLANA VITRECTOMY FOR ENDOGENOUS ENDOPHTHALMITIS

PURPOSE

To evaluate the causative organisms of and predisposing medical conditions in endogenous endophthalmitis and review visual acuity after pars plana vitrectomy.

METHODS

Records of 23 patients (32 eyes) who were diagnosed with endogenous endophthalmitis and treated at Shanghai Eye, Ear, Nose & Throat Hospital from January 2000 to December 2003 were retrospectively reviewed. Final visual acuity was followed up.

RESULTS

Of these 23 patients, 19 (86%) had endogenous endophthalmitis confirmed with a positive smear or culture; 12 cases (63%) were due to fungi, 6 (32%) were due to bacteria, and 1 (5%) was a mixed infection (fungus and bacteria). Culture specimens from four patients, which were obtained by vitrectomy, were all positive, while their initial vitreous needle biopsy specimens were negative. Of the 20 eyes that underwent pars plana vitrectomy, 17 (85%) had anatomical success, and 16 (80%) gained visual acuity of counting fingers or better; of these eyes, 8 (40%) had visual acuity of 20/200 or better.

CONCLUSION

Fungi, especially Candida albicans, were the most common causative organisms. The most common predisposing medical conditions were recent tumor surgery and intravenous administration in rural settings. Most patients with endogenous endophthalmitis who undergo pars plana vitrectomy will have useful vision (counting fingers). Vitreous specimens for culture that were obtained by vitrectomy were more sensitive in detecting the causative organism.

A 10-year comparison of endogenous endophthalmitis outcomes: an east Asian experience with Klebsiella pneumoniae infection

PURPOSE

To evaluate the infection sources and causative organisms in cases of endogenous endophthalmitis and review the outcomes for patients with Klebsiella pneumoniae infection during a 10-year period.

METHODS

All cases of endogenous endophthalmitis treated at one Taiwanese hospital from July 1992 to June 2002 were retrospectively reviewed (n = 74; 86 eyes). The study was divided into two 5-year periods, with patients stratified into Group F or Group L according to onset date within the first or last of these periods, respectively. The outcomes of cases of K. pneumoniae infection in Group L (21 eyes) and Group F (32 eyes) were compared.

RESULTS

The major source of infection (liver abscess) and the causative organism (K. pneumoniae) did not change throughout the 10-year review period; however, outcomes for Group L appeared superior. The interval from onset of ocular symptoms to ophthalmic consultation was shorter for Group L; however, a statistically significant difference was not demonstrated by between-group comparison. Patients with good final vision typically had good initial vision in cases of K. pneumoniae infection.

CONCLUSION

The authors' experience with endogenous endophthalmitis has confirmed the findings of analogous East Asian studies, with liver abscess as the major source of infection and K. pneumoniae as the causative organism. Superior outcome may be achieved with more comprehensive and collaborative management, ideally through the combined efforts of multiple medical subspecialties.