The Microbiome of the Nasolacrimal System and Its Role in Nasolacrimal Duct Obstruction

Computed Tomography Signs of Sinonasal Inflammation in Patients with Acute Dacryocystitis

BACKGROUND

Nasal and paranasal sinus abnormalities may be related to nasolacrimal duct obstructive disease but are strongly debated. Data of acute disease stage are lacking.

OBJECTIVE

The purpose of this study was to determine if there are correlations between radiologic signs of sinus inflammation and acute dacryocystitis (AD).

METHODS

This cross-sectional controlled study was conducted at Wenzhou, Zhejiang Province, China from February 2021 to November 2023. Forty-four consecutive patients with AD and 50 consecutive patients with orbital tumors (the control group), who completed preoperative computed tomography scans, were enrolled to evaluate the extent of their inflammatory sinonasal disease by the modified Lund-Mackay score system.

RESULTS

The inflammation signs of the paranasal sinuses (total mean sinus scores, 95% CI [0.00, 2.00]; P < 0.001), namely the anterior ethmoid sinus(95% CI [0.00, 1.00]; P < 0.001), the posterior ethmoid sinus(95% CI [0.00, 0.00]; P = 0.003), the frontal sinus (95% CI [0.00, 0.00]; P = 0.02), and the ostiomeatal complex (P < 0.001) were more extensive in patients with AD when compared with the controls. The disease course was negatively correlated with the anterior ethmoid (P = 0.03) and frontal scores (P = 0.01). The symptom of eyelid swelling was positively correlated with the anterior ethmoid (P = 0.03), ostiomeatal complex (P = 0.004), and total sinus scores (P = 0.005).

CONCLUSION

Inflammatory sinus disease was found to be more frequent in patients with AD, which was gradually alleviated with the prolongation of the disease course. The mutual spread of inflammation particularly in the acute course may play an important role in lacrimal duct obstructive disease.

Alterations of Lacrimal Sac Microbiota in Failed Dacryocystorhinostomy: The Lacriome Paper 6

PURPOSE

To study the metagenomics of the microbes isolated from the lacrimal sac in patients with failed dacryocystorhinostomy (DCR).

METHODS

A prospective study was performed on 10 consecutive patients with failed DCR. Lacrimal sac samples were obtained for metagenomic analysis during the revision endoscopic DCR. The samples were collected intraoperatively after a full-length lacrimal sac marsupialization and immediately transported on ice to the laboratory. A whole shotgun metagenome sequencing was performed on the IlluminaTM platform following DNA extraction and library preparation. The downstream analysis of the samples was performed using various software packaged in the Squeeze Metapipeline v1.3.0 and marker gene-based metagenomic phylogenetic analysis using MetaPhlAn4.

RESULTS

The five major phyla identified across the samples of failed DCR include Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Fusobacteria (Figure 1). The prevalent species include Stenotrophomonas maltophilia, Pseudomonas juntendi, Streptococcus pneumoniae, Acinetobacter ursingii, Citrobacter koseri, and Cutibacterium acnes (Figure 2). Among the other organisms identified, few were from genera candida and mezorhizobium. Among the viruses, the most abundant was the BeAn 58058 virus. It was interesting to note the occasional presence of plasmodium and toxoplasma species. The functional category distribution of KEGG (Kyoto encyclopedia of genes and genomes) data showed microbial metabolism to be the most involved function, followed by cellular processes.

CONCLUSION

This is the first whole metagenome sequencing of the lacrimal sac contents from failed DCR patients. The organisms identified varied significantly from those isolated from patients with primary acquired nasolacrimal duct obstruction (PANDO) using similar techniques and reflect altered lacrimal microbiota in surgically unsuccessful DCRs.

Metagenomics of the lacrimal sac in primary acquired nasolacrimal duct obstruction: the Lacriome paper 1

BACKGROUND

The purpose is to study the metagenomics of the microbes isolated from the lacrimal sac of patients with primary acquired nasolacrimal duct obstruction (PANDO).

METHODS

A prospective study was performed on ten consecutive lacrimal sac samples obtained for the metagenomic analysis from the patients with PANDO, who underwent endoscopic dacryocystorhinostomy at a tertiary care Dacryology service. The samples were collected intraoperatively soon after a full-length lacrimal sac marsupialisation and immediately transported on ice to the laboratory. Following DNA extraction and library preparation, a whole shotgun metagenome sequencing was performed on the Illumina platform. The downstream processing and bioinformatics of the samples were performed using multiple software packaged in the SqueezeMeta pipeline and MG-RAST pipeline.

RESULTS

The taxonomic hit distribution across the samples showed that bacteria were the most common isolates (mean-97.56%), followed by viruses (mean-0.29%), archaea (0.04%) and others. The five major phyla identified across the samples of PANDO were proteobacteria, Bacteroidetes, Fusobacteria, Actinobacteria and Firmicutes. The prevalent organisms include Acinetobacter johnsonii, Porphyromonas catoniae, Cutibacterium acnes, Pseudomonas alcaliphila, Escherichia coli, Haemophilus influenzae, Enhydrobacter aerosaccus, Fusobacterium nucleatum, Moraxella osloensis, Butyricimonas virosa and Variovorax paradoxus, among few others. The alpha diversity of the ten sample datasets ranged from 60 to 175 species.

CONCLUSION

This is the first whole metagenome sequencing of the lacrimal sac contents from PANDO patients. Lacrimal sacs harbour diverse microbial communities, including bacteria, viruses, and archaea. Further Lacriome studies may provide clues for a better understanding of the disease aetiopathogenesis.

Corneal ulcers with non-infectious appearance caused by nasolacrimal duct obstruction or canaliculitis

Purpose

To describe the clinical features of corneal ulcers with non-infectious appearance due to nasolacrimal disease in a retrospective case series.

Observations

Eight eyes of 8 patients (aged 74.4 ± 11.1 years) with corneal disease due to nasolacrimal duct obstruction or canaliculitis, who were treated between October 2013 and December 2020 at 3 hospitals were included. Patient background, anterior ocular findings, organisms in secretion, and time course during treatment were retrospectively analyzed. The corneal findings were peripheral ulcers (5 cases), phlyctenular keratitis (1 case), and paracentral perforation with slight cellular infiltration (2 cases). All cases were suspected as autoimmune disease-related-corneal ulcers because of the pathogenic region and clinical appearance and later diagnosed as corneal disorders derived from nasolacrimal duct obstruction or canaliculitis. The autoimmune disease-like appearance and purulent secretion connecting the punctum with/without swelling were characteristic. The most common microorganism detected in the purulent secretions was Streptococcus spp.. The resolution of corneal lesions needed steroid eye drops with antibiotic eye drops. Two patients required a superficial corneal transplantation. The extraction of nasolacrimal calculus, punctal tube insertion, or dacryocystorhinostomy was necessary for complete healing of ocular surface disease.

Conclusions and importance

Nasolacrimal duct diseases cause corneal disorders without bacterial colonization and growth. When corneal ulcers resemble autoimmune disease in shape and are not accompanied by systemic disease, attention should be paid to nasolacrimal duct obstruction or canaliculitis.

Metagenomics of infective canaliculitis: The Lacriome paper 3

PURPOSE

To study the metagenomics of the microbes isolated from the canaliculus of patients with infective canaliculitis.

METHODS

A prospective study was performed on five consecutive canalicular samples obtained for the metagenomic analysis from the patients with infective canaliculitis who underwent non-incisional canalicular curettage at a tertiary care Dacryology service. The canalicular concretions were collected intraoperatively soon after a canalicular curettage and immediately transported on ice to the laboratory. Following DNA extraction and library preparation, a whole shotgun metagenome sequencing was performed on the Illumina™ platform. The downstream processing and bioinformatics of the samples were performed using multiple software packaged in SqueezeMeta™ pipeline or MG-RAST™ pipeline.

RESULTS

The taxonomic hit distribution across the samples showed that bacteria were the most common isolates (mean-80.5%), followed by viruses (mean-0.74%), and archaea (0.01%). The five major phyla identified across the samples of infective canaliculitis were, Fusobacteria, Bacteroidetes, Proteobacteria, Actinobacteria, and Firmicutes. The prevalent organisms include Fusobacterium nucelatum, Fusobacterium periodonticum, Parvimonas micra, Prevotella oris, Selonomonas noxia, Pseudopropionobacterium propoinicum, Campylobacter showae, and Streptococcus anginosus, amongst few others. Actinomycetes israelii was noted in all the samples, though it was not the most abundant. The microbial gene mapping and protein prediction demonstrated proteins with known functions to range from 69.91% to 87.09% across the samples. The functional subsystem profiling demonstrated genes associated with carbohydrate, amino acid, and co-enzyme transport and metabolism, cell wall or cell membrane biogenesis, energy production and conversion, transcription, translation, and cellular communications.

CONCLUSION

This is the first whole metagenome sequencing of infective canaliculitis. Infected canaliculi harbor diverse microbial communities, including bacteria, viruses, and archaea. Functional analysis has provided newer insights into the ecosystem dynamics and strategies of microbial communities.

Acute Radiation Syndrome and the Microbiome: Impact and Review

Study of the human microbiota has been a centuries-long endeavor, but since the inception of the National Institutes of Health (NIH) Human Microbiome Project in 2007, research has greatly expanded, including the space involving radiation injury. As acute radiation syndrome (ARS) is multisystemic, the microbiome niches across all areas of the body may be affected. This review highlights advances in radiation research examining the effect of irradiation on the microbiome and its potential use as a target for medical countermeasures or biodosimetry approaches, or as a medical countermeasure itself. The authors also address animal model considerations for designing studies, and the potential to use the microbiome as a biomarker to assess radiation exposure and predict outcome. Recent research has shown that the microbiome holds enormous potential for mitigation of radiation injury, in the context of both radiotherapy and radiological/nuclear public health emergencies. Gaps still exist, but the field is moving forward with much promise.

Impact of Post-Surgical Therapies on Endoscopic and External Dacryocystorhinostomy: Systematic Review and Meta-Analysis

Background

Epiphora is a common ophthalmologic sign that is most commonly caused by distal acquired lacrimal obstruction. Recent data have demonstrated that external dacryocystorhinostomy (EXT-DCR) and endoscopic endonasal dacryocystorhinostomy (END-DCR) can be considered the treatments of choice. However, different post-surgical medical therapies are available and are currently used to improve surgical outcomes, although no direct comparison has been performed.

Objective

To analyse the influence of post-surgical medical treatments on END-DCR and EXT-DCR outcomes.

Methods

A structured search was conducted using the U.S. National Library of Medicine (PubMed), EMBASE, SCOPUS, and Cochrane databases with a final search performed in May 2020. The research identified papers published later than 2000 with at least 50 single clinician procedures performed in EXT-DCR and END-DCR. Articles that studied acute infections, revision cases, mixed cohort studies of acquired and congenital obstruction, and tumour were excluded. The influence of systemic antibiotic/steroids, local application of mitomycin C, nasal/ocular antibiotic, nasal/ocular steroids and nasal decongestants was analysed.

Results

In total, 11,445 papers were selected, 2,741 of which were reviewed after screening, and 18 included after full text review (0.6% of the initial articles reviewed) which involved 3,590 procedures. Considering the low number of publications on EXT-DCR, statistical analysis of post-surgical therapy was not feasible. In END-DCR, the analyses were performed only for nasal steroids (p = 0.58), oral antibiotics (p = 0.45) and nasal decongestant (p = 0.27), which demonstrated no meaningful influence. Given the variable association between adjunctive medical therapies, pharmacologic molecular heterogeneity and modality/concentration of application, these results should be considered critically. Additionally, no differences were seen for application of silicone stenting, whereas, no statistical analysis was performed for mitomycin C.

Conclusions

Given the high success rate of EXT-DCR and END-DCR and the heterogeneity of literature data, the effective influence of post-surgical medical therapy is difficult to identify. Future large prospective randomized studies could help in detecting the optimal adjunctive therapy for these surgeries.