Diagnosis and management of fungal endophthalmitis: India perspective

Clinical characteristics and management outcome of acute infectious endophthalmitis

PURPOSE

This study aimed to investigate the demographics, clinical characteristics, and management outcomes of patients with acute infectious endophthalmitis (AIE).

METHODS

This retrospective chart review was conducted on all patients admitted with the clinical diagnosis of infectious endophthalmitis from 2017 to 2022. Demographic data, patients' clinical characteristics, the type of acute infectious endophthalmitis (post-operative, post-traumatic, bleb-associated, and endogenous endophthalmitis), the type of surgical procedure in the post-operative cases, the microbiologic analysis results of vitreous samples, therapeutic measures, and visual outcomes of patients were recorded.

RESULTS

In this study, 182 participants, including 122 male (67%) and 60 (33%) female, were involved. The mean age of patients was 54.56 ± 21 years, with a range of 1-88 years old. The most prevalent type of AIE was post-operative (59.9%), followed by endogenous (19.2%), post-traumatic (17%), and bleb-associated (3.8%). The most common type of intraocular surgery in the post-operative subgroups of AIE patients was phacoemulsification (57.8%). The median (interquartile range) of the primary and final BCVA of patients was 1.5 (1.35, 1.85) and 0.65 (0.35, 1.35), respectively. Vitreous haziness grade (OR, 2.89; 95% CI, 1.11-5.74; p = 0.009) and the primary VA (OR, 60.34; 95% CI, 2.87-126.8; p = 0.008) revealed statistical significance for final vision loss.

CONCLUSION

AIE is a devastating condition with poor visual outcomes, which presents with acute inflammatory signs and symptoms regardless of its type. However, prompt and appropriate treatment leads to visual recovery to a functional level in many patients.

Antibiotic susceptibility in Endophthalmitis Management Study and intravitreal antibiotic practice trend in India-EMS Report #5

AIM

Analyze antibiotic susceptibility in the Endophthalmitis Management Study (EMS) and compare it with the current intravitreal antibiotic practice trend of members of the Vitreoretinal Society of India (VRSI) practicing in India.

METHODS

The microbiology work-up of undiluted vitreous included microscopy, culture-susceptibility, polymerase chain reaction (PCR), and next-generation sequencing (NGS). VRSI members were invited to the survey. The EMS conventional culture-susceptibility (PCR and NGS excluded) results were compared vis-a-vis gram-positive cocci (GPC), gram-negative bacilli (GNB), and less commonly used antibiotics with the current recommended intravitreal antibiotics. p < 0.05 was considered significant.

RESULTS

Culture and positivity (culture + PCR/NGS) positivity was 28.8% and 56.1%, respectively. GPC was most susceptible to cefazolin, linezolid, and vancomycin; GNB was most susceptible to amikacin, ceftazidime, colistin, and imipenem. There was no susceptibility difference between cefazolin and vancomycin (p = 0.999) and between ceftazidime and imipenem (p = 1.0). Colistin was superior to ceftazidime (p = 0.047) against GNB. The GNB resistant to amikacin (n = 14) were equally susceptible to ceftazidime and colistin; resistant to ceftazidime (n = 16) were susceptible to colistin; and resistant to colistin (n = 7) were susceptible to ceftazidime. The preference of VRSI members (n = 231) practicing in India was a vancomycin-ceftazidime combination (82%), vancomycin for GPC (94%), ceftazidime for GNB (61%), and voriconazole for fungi (74%).

CONCLUSION

In EMS, GPC had good susceptibility to vancomycin; GNB had good susceptibility to ceftazidime and colistin. Given the lower resistance of colistin, a vancomycin-colistin combination could be an alternative empiric treatment in post-cataract endophthalmitis in India.

Evaluating the utility of inflammation score in post-cataract surgery endophthalmitis. Results from a prospective study in India. EMS Report #4

PURPOSE

To investigate if inflammation score (IS), calculated from the cornea, anterior chamber, iris, and vitreous, indicates endophthalmitis severity.

METHODS

In a prospective study, consecutive adults with a clinical diagnosis of post-cataract endophthalmitis within 6 weeks of surgery were recruited. Patients were allocated to IS-based primary treatment (IS < 10: intravitreal injection and IS ≥ 10: vitrectomy) and randomized to two intravitreal antibiotics combinations (vancomycin + ceftazidime and vancomycin + imipenem). Undiluted vitreous microbiology work-up included culture susceptibility, polymerase chain reaction, Sanger sequencing, and targeted next-generation sequencing.

RESULTS

The average age of 175 people was 63.4 ± 10.7 years and included 52.6% small incision cataract surgery and 47.4% phacoemulsification surgery. Severe endophthalmitis (IS ≥ 20), diagnosed in 27.4% of people, had a shorter time to symptoms (average 5.4 vs 8.7 days; P = 0.018), poorer presenting vision (all ≤ hand motion), higher culture positivity (50% vs 30.7%; P = 0.032), and higher Gram-negative bacterial infection (70.8% vs 46.2%; P = 0.042). For IS ≥ 20 discriminant and Gram-negative infection, Spearman's coefficient was 0.7 [P < 0.0001, 95% confidence interval (CI) 0.59-0.82], with an area under the receiver operating characteristic curve of 0.9 (95% CI 0.85-0.94, P < 0.0001), a Youden index J of 0.74, a sensitivity of 87.2%, and a specificity of 87.5%. The final vision of >20/400 and >20/100 was regained in 50.2% and 29.1% of people, respectively. The susceptibility of common Gram-positive cocci and Gram-negative bacilli was the highest for vancomycin (95.0%) and colistin (88.6%), respectively. NGS detected polymicrobial infection in 88.5% of culture-negative endophthalmitis.

CONCLUSIONS

Higher inflammation scores indicated severe disease and Gram-negative infection in post-cataract endophthalmitis.

Consensus and controversies in the science of endophthalmitis management: Basic research and clinical perspectives

Infectious endophthalmitis is a severe intraocular infection caused by bacteria, or less commonly by fungi. It can occur after penetrating eye procedures, trauma, or the spread of infection from contiguous structures or via emboli from distant organs. Because of the time-critical nature of the treatment, endophthalmitis is treated with the clinical diagnosis and modified by the microbiological report of the intraocular contents. The current strategy for managing endophthalmitis relies on pre-clinical literature, case series, and one large multi-center randomized clinical trial on post-cataract surgery endophthalmitis. Culture-susceptibility of the microorganisms from undiluted vitreous guides the definitive treatment in non-responsive cases. Strategies to reduce the incidence of endophthalmitis after penetrating eye procedures have been developed concurrently with refined means of treatment. Despite these advances, outcomes remain poor for many patients. Although consensus articles have been published on managing endophthalmitis, treatment patterns vary, and controversies remain. These include (1) the use of newer methods for early and precise microbiological diagnosis; (2) the choice of intravitreal antibiotics; (3) the need for systemic therapy; (4) early and complete vitrectomy. Here, we review the current consensus and address controversies in diagnosing and managing endophthalmitis. This review is intended to familiarize physicians and ophthalmologists with different aspects of endophthalmitis management to make informed decisions.

Endophthalmitis Management Study-A Prospective Randomized Clinical Trial on Postoperative Endophthalmitis Management in India: An Interim Analysis. Endophthalmitis Management Study Report #3

PURPOSE

An interim analysis of the Endophthalmitis Management Study to examine the outcome of inflammation score (IS)-based treatment and antibiotic susceptibility.

DESIGN

A prospective randomized study.

PATIENTS AND METHODS

IS was measured on a 0-4 scale from presenting signs in 4 cardinal ocular tissues. The eyes with IS <10 received vitreous tap and intravitreal antibiotics, whereas eyes with IS ≥10 received vitrectomy and intravitreal antibiotics. These eyes were randomized to 2 intravitreal antibiotic combinations: (1) vancomycin and ceftazidime and (2) vancomycin and imipenem. Microbiology workup of undiluted vitreous included microscopy, culture-susceptibility, Sanger, and targeted next-generation sequencing. The clinical and microbiology outcomes were analyzed for advanced (IS = ≥20) and less advanced (IS = <10) endophthalmitis.

RESULTS

Interim analysis was performed after the Endophthalmitis Management Study recruited 56.85% (248/436) of patients and completed 54.6% (238/436) of microbiology workup. A 90-day follow-up was completed in 90.8% (168/185) of eligible people. In eyes with IS ≥20, the time to symptoms was shorter (5.8 ± 6.7 vs 8.5 ± 9.1 d; P = 0.015), and the need for additional treatment was higher (95.8% vs 53.1%; P = 0.0267). Good final vision was associated with good presenting vision (r = 0.30) and IS-based treatment decisions (r = 0.170). Microbiology positivity was 55.9%. Eyes with IS <10 had a higher Gram-positive cocci (33.9% vs 4.8%; P = 0.013) infection. Gram-positive cocci were most susceptible to vancomycin (95.7%), and Gram-negative bacilli to colistin (95.7%).

CONCLUSIONS

Considering both IS and presenting vision, rather than only one of them, helps in making appropriate management decisions for acute postoperative endophthalmitis.

Proteomic profiling of aspergillus flavus endophthalmitis derived extracellular vesicles in an in-vivo murine model

Extracellular Vesicles (EVs) play pivotal roles in cell-to-cell communication, and are involved in potential pathological and physiological cellular processes. The aim of this study was to understand the proteomic cargo of these vesicles, in a murine model of Aspergillus flavus (AF) endophthalmitis. EVs were isolated from A. flavus infected C57BL/6 mice eyes by differential ultracentrifugation at 24 h post infection (p.i) and isolated EVs were characterized by Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), Exocet assay, and western blot. Proteomic profiling of EVs was then evaluated by mass spectrometry (LC-MS/MS) and compared it with control uninfected mice. The average size of the EVs were 180-280 nm by DLS and the number of EVs increased to 1.55 × 1010 in infected mice in comparison to EVs from uninfected eye (1.24 × 109). Western blot was positive for CD9, CD63, and CD81 confirming the presence of EVs. LC-MS/MS analysis, identified 81 differentially expressed proteins, of these 22 were up-regulated and 59 were down-regulated. Gene Ontology (GO) analysis revealed enrichment of lipid metabolism, protein complex binding, and transferase activity, and the proteins associated were Aquaporin-5, CD177 antigen, Solute carrier family-25, and Calcium/calmodulin-dependent protein kinase. Additionally, KEGG pathway analysis indicated that glucagon signalling, metabolic, and PPAR signalling pathway were significantly associated with EVs from A. flavus infected mice eyes. The protein cargo in EVs from A. flavus endophthalmitis provides new insights into the pathogenesis of fungal endophthalmitis and validation of these proteins can serve as diagnostic and/or prognostic biomarkers for patients with a clinical suspicion of fungal endophthalmitis.

LAY SUMMARY

EVs play an important role in cell communication. In our study proteomic profiling of EVs isolated from A. flavus infected mice provided new insights into the understanding of the pathobiology of A. flavus endophthalmitis and validation of these proteins can serve as biomarkers.

Proteomic profiling of exosomes in a mouse model of Candida albicans endophthalmitis

Exosomes play pivotal roles in intercellular communication, and pathophysiological functions. In this study, we aimed to understand the role of exosomal proteome derived from C. albicans infected mice (C57BL/6) eyeball. Exosomes were characterized by Dynamic Light Scattering and western blot, quantified and subjected to LC-MS/MS and cytokine quantification by ELISA. The average size of exosomes was 170-200 nm with number of exosomes amounted to 1.42 × 10¹⁰ in infected set compared to control (1.24 × 10⁹). Western blot was positive for CD9, CD63 and CD81 confirming the presence of exosomes. IL-6, IL1β, TNF-α, and IFN-γ levels were significantly elevated in infected eye at 72 h.p.i. Proteomic analysis identified 42 differentially expressed proteins, of these 37 were upregulated and 5 were downregulated. Gene Ontology (GO) revealed enrichment of cell adhesion, cytoskeleton organization, and cellular response proteins such as aquaporin-5, gasdermin-A, CD5 antigen-like, Catenin, V-ATPase, and vesicle associated protein. Additionally, KEGG pathway analysis indicated the association of metabolic and carbon signalling pathways with exosomes from C. albicans infected eye. The protein cargo in exosomes released during endophthalmitis with C. albicans seems to play a unique role in the pathogenesis of the disease and further validations with larger cohort of patients is required to confirm them as biomarkers. .

Evaluation of Vitreous Galactomannan and (1, 3) β-D-Glucan Levels in the Diagnosis of Fungal Endophthalmitis in Southern India

PURPOSE

To evaluate vitreous Galactomannan(GM) and 1,3 β-D-Glucan (BDG) levels in the diagnosis of fungal endophthalmitis, with emphasis on culture-negative cases.

METHODS

Vitreous from 31 clinically suspected fungal endophthalmitis patients and 11 controls were evaluated for GM and BDG using ELISA Kits. The Receiver Operating Characteristic (ROC) curves and diagnostic significance was calculated.

RESULTS

The median vitreous GM in culture-positive (60.83pg/ml) and culture-negative (59.9pg/ml) samples were higher than the (51.2pg/ml) control group. The median vitreous BDG in culture-positive (1.47pg/ml) and culture-negative (1.52pg/ml) samples were also similar, and higher than the control group (1.18pg/ml). ROC analysis showed that at a cut-off of 51.35pg/ml, the sensitivity and specificity for GM were 0.88 and 0.73.Similarly, for BDG at a cut-off of 1.18pg/ml, the sensitivity and specificity were 0.94 and 0.82 respectively.

CONCLUSION

Vitreous GM and BDG above the indicated threshold level could suggest a fungal infection, even when cultures are negative.

Fungi of the human eye: Culture to mycobiome

The focus of the current review is multi-fold and compares the diversity and abundance of fungi on the ocular surface by the conventional culture-based method with the more sensitive, high throughput, culture-independent NGS method. The aim is to highlight the existence of a core ocular mycobiome and explore the transition of the ocular fungal microbiota from the normal eye to the diseased eye. PubMed, Google Scholar and Medline were used to search for publications and reviews related to cultivable fungi and the mycobiome of the normal and diseased eye. The conventional cultivable approach and the NGS approach confirm that the eye has its own mycobiome and several confounding factors (age, gender, ethnicity etc.) influence the mycobiome. Further, dysbiosis in the mycobiome appears to be associated with ocular diseases and thus impacts the health of the human eye. Considering that the mycobiome of the eye is influenced by several confounding factors and also varies with respect to the disease status of the eye there is a need to extensively explore the mycobiome under different physiological conditions, different ethnicities, geographical regions etc. Such studies would unravel the diversity and abundance of the mycobiomes and contribute to our understanding of ocular health. Research focused on ocular mycobiomes may eventually help to build a targeted and individualized treatment.

Fungal endophthalmitis: Analysis of 730 consecutive eyes from seven tertiary eye care centers in India

PURPOSE

To evaluate the clinical and microbiological features of a large cohort of culture-confirmed fungal endophthalmitis across India.

DESIGN

Cross-sectional hospital-based retrospective medical records review.

PARTICIPANTS

Seven large tertiary eye care centers from different regions of India.

METHODS

The patient data were pooled from the electronic/physical medical records of each participating center. Fellowship-trained vitreoretinal specialists clinically managed all patients, and in-house microbiology laboratories performed all microbiology work-ups. The clinical and microbiology procedures were broadly uniform across all participating centers. The essential treatment consisted of vitreous surgery and intravitreal and systemic therapy with antifungal agents.

MAIN OUTCOME MEASURES

Clinical outcome by the causative event and causative fungus.

RESULTS

In the 2005-2020 period, seven centers treated 3830 cases of culture-proven endophthalmitis, and 19.1% (n=730) were culture-confirmed fungal endophthalmitis. It included 46.9% postoperative (87.4% post-cataract surgery), 35.6% traumatic and 17.5% endogenous endophthalmitis. The fungi included 39.0% Aspergillus (high in central, east and south zones), 15.1% Candida (high in west zone), 15.9% Fusarium (high in north and west zone). The time to symptoms was between 1w-4w in more than a third of patients except in traumatic endophthalmitis. Less than half of patients had hypopyon on presentation. Presenting visual acuity (PVA) in most patients was <20/400. Nearly all patients needed a vitrectomy and an average of two intravitreal injections of antifungal agents. At least 10% of eyes needed therapeutic keratoplasty, and up to 7% of eyes were eviscerated. Following treatment, the final (best corrected) visual acuity (FVA) was > 20/400 in 30.5% (n= 222) eyes; > 20/40 in 7.9% (n=58) eyes; and 12% (n=88) eyes lost light perception. Post-hoc analysis showed significantly more males in traumatic than post-operative (p<0.0001) and endogenous (p = 0.001) endophthalmitis; higher isolation of Candida species in endogenous than post-operative (p = 0.004) and traumatic (p<0.0001) endophthalmitis, better PVA in eyes with Candida species infection (p<0.0001) and poorer FVA in eyes with Aspergillus species infection.

CONCLUSIONS

Fungal endophthalmitis is not uncommon in India. The inclusion of antifungal agents with antibiotics as the first empirical intravitreal therapy before microbiological confirmation could be considered when fungal infection is suspected.