Aspergillus endophthalmitis: Potential role for vitreous galactomannan testing?

Postoperative Aspergillus Infection: A Case Series

PURPOSE

To report the clinical findings, therapy and outcomes of pauci-symptomatic Aspergillus infection in 11 eyes of 11 patients who had recently undergone uneventful cataract surgery and IOL implantation in a single operating room on the same day.

METHODS

Retrospective, observational study that looks at 11 patients who demonstrated Aspergillus infection after cataract surgery. All data were collected and intracameral samples sent for microscopic evaluation and culture. Additional swabs were sent from the operating room and operative consumables.

RESULTS

A total of 11 eyes of 11 patients were included in the analysis and were followed for at least 12 months. All patients responded completely to local and systemic voriconazole therapy. The source of infection was noted to be air-conditioning vents. Eyes with manual small incision cataract surgery (11/17) had a higher propensity for infection.

CONCLUSION

Pauci-symptomatic aspergillosis infection has been reported here following cataract surgery.

Recent Advances and Ongoing Challenges in the Diagnosis of Culture Negative Endophthalmitis

BACKGROUND

Culture negative (CN) but presumed infectious endophthalmitis poses a huge diagnostic challenge in terms of clinical management. This article outlines the current state of knowledge of infectious endophthalmitis with negative cultures and summarizes the recommendations for the work up of this condition along with providing a simple algorithm, by putting into context the recent concerns about over-diagnosing endophthalmitis.

METHODS

We searched the PubMed and Scopus databases for large hospital based studies on diagnosis of endophthalmitis, with emphasis on culture-negative infections in October 2021. Only clinical studies written in English were included. Basic science studies, letters to the editor and case reports on endophthalmitis were excluded.

RESULTS

Twenty studies were included in this study. The prevalence of CN endophthalmitis ranged from 40% to 70%. Recent advances in PCR along with high throughput sequencing have helped identify the etiological agent in most cases but these technologies are not easily available, requires advanced bioinformatic analysis and are not cost effective. Role of other inflammatory and relatively low-cost biomarkers in diagnosing a presumed infection is yet to be validated clinically but hold promise in helping ophthalmologists identify the causative agent.

CONCLUSIONS

CN endophthalmitis is a relatively frequent finding and should not be labelled as sterile endophthalmitis. Recent advances provide a new perspective for ophthalmologist in diagnosis of presumed infectious endophthalmitis and further studies are needed to confirm their utility in clinical settings.

Aspergillus Endophthalmitis: Epidemiology, Pathobiology, and Current Treatments

Fungal endophthalmitis is one of the leading causes of vision loss worldwide. Post-operative and traumatic injuries are major contributing factors resulting in ocular fungal infections in healthy and, more importantly, immunocompromised individuals. Among the fungal pathogens, the Aspergillus species, Aspergillus fumigatus, continues to be more prevalent in fungal endophthalmitis patients. However, due to overlapping clinical symptoms with other endophthalmitis etiology, fungal endophthalmitis pose a challenge in its diagnosis and treatment. Hence, it is critical to understand its pathobiology to develop and deploy proper therapeutic interventions for combating Aspergillus infections. This review highlights the different modes of Aspergillus transmission and the host immune response during endophthalmitis. Additionally, we discuss recent advancements in the diagnosis of fungal endophthalmitis. Finally, we comprehensively summarize various antifungal regimens and surgical options for the treatment of Aspergillus endophthalmitis.

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.

The facilitating effect of blue light on the antifungal agent susceptibilities of passaged conidia from the ocular-derived Fusarium solani species complex

The eye is a light-receiving organ and has anatomical advantages to accept phototherapy. Fungi colonizing on the eyes, which cause ocular mycoses, are affected by daily blue light and could easily accept additional light irritation. Ocular mycoses are recalcitrant and blindness-causing eye diseases, and antifungal agent treatments are insufficient. Our team previously found that blue light could inhibit Fusarium solani hyphal growth but promote conidiation. Here, we investigated the antifungal susceptibilities and biological characteristics of the passaged conidia. Twelve Fusarium solani strains (11 ocular-derived strains and 1 standard laboratory strain) were inoculated under blue light (0.5 mW/cm2) and darkness conditions, respectively, to obtain the passaged conidia of blue light group (n = 12) and darkness group (n = 12). Two groups were tested to determine the growth abilities and in vitro antifungal susceptibilities to five antifungal drugs (voriconazole (VRC), amphotericin B (AMB), terbinafine (TRB), caspofungin (CAS), and 5-flucytosine (5FC)), which were examined by microscopy for morphological observation and spectrophotometry for turbidity analysis. The results showed that blue light group passaged conidia were more sensitive to antifungal drugs (AMB, VRC, TRB, and CAS) compared to darkness group. The MIC50 of VRC significantly decreased after blue light treatment (P < 0.05). The fungal inhibition rate significantly increased for VRC, AMB, and TRB in the low concentration range (P < 0.05 or P < 0.01). Blue light did not affect germination or hyphal extension of passaged conidia. These results suggested that blue light could facilitate fungal inhibition effect of AMB, VRC, TRB, and CAS and may improve the therapeutic efficiency in VRC and AMB clinical applications. Blue light phototherapy may provide a new adjuvant approach for the treatment of ocular mycosis.

The Diagnosis and Treatment of Fungal Endophthalmitis: An Update

In recent, large case series of fungal endophthalmitis (FE) that were published by Asian authors, the most frequent etiologic agents for all types of FE are molds (usually Aspergillus species, while Fusarium is the prevalent etiology in keratitis-related FE). Candida was the organism found in most cases of endogenous FE. However, we must keep in mind that prevalence of fungal species varies with the geographical area. Lately, polymerase chain reaction (PCR) was increasingly used for the diagnosis of FE, allowing for very high diagnostic sensitivity, while the costs become more affordable with time. The most important shortcoming of PCR—the limited number of pathogens that can be simultaneously searched for—may be overcome by newer techniques, such as next-generation sequencing. There are even hopes of searching for genetic sequences that codify resistance to antifungals. We must not forget the potential of simpler tests (such as galactomannan and β-d-glucan) in orienting towards a diagnosis of FE. There are few reports about the use of newer antifungals in FE. Echinocandins have low penetration in the vitreous cavity, and may be of use in cases of fungal chorioretinitis (without vitritis), or injected intravitreally as an off-label, salvage therapy.

Bilateral endogenous Trichoderma endophthalmitis in an immunocompromised host

Purpose

To report a case of bilateral endogenous endophthalmitis, caused by the Trichoderma species, in a severely immunocompromised patient.

Observations

A 39-year-old man with acute myeloid leukemia, in a relapsed state on high-dose chemotherapy, experienced profound neutropenia and immunosuppression. The patient reported two weeks of severe bilateral vision loss. The diagnosis of bilateral endogenous endophthalmitis was initially established based on the patient's history, immune status, clinical findings, and confirmed positive vitreous culture.

The patient was initially managed with vitreous tap, pars plana vitrectomy with silicone oil injection in the left eye, and vitreous tap and antibiotic injection of the right eye. Eventually, the right eye underwent pars plana vitrectomy as well. Cultures of the vitreous sample grew a filamentous fungus, identified as the Trichoderma species. His blood and urine culture tested negative. The patient was kept on systemic amphotericin B over 52 weeks, and his condition improved dramatically. Three months post phacoemulsification and silicone oil removal, best-corrected visual acuity values were 20/50 in both eyes.

Conclusion and Importance

This is the first reported case of bilateral endogenous endophthalmitis, caused by the Trichoderma species, in an immunocompromised patient. Early recognition and intervention were associated with good functional and anatomical outcomes.