Electron Microscopic Features of Canalicular Concretions

Lacrimal Canaliculitis: A Major Review

Lacrimal canaliculitis is an inflammation of the proximal lacrimal drainage system. It classically presents with symptoms of redness, mucopurulent discharge, medial canthal swelling, epiphora, and pouting punctum. Despite having classical clinical characteristics it is frequently misdiagnosed. The cause can be primarily due to various infectious agents or secondary mostly due to the use of punctal plugs. There are no universally accepted guidelines for the management of canaliculitis but different medical and surgical options have been employed with varying success rates and it is notorious for recurrences and failure to therapy. The present review summarizes the existing literature on lacrimal canaliculitis published over the past 15 years to provide an overview of this uncommon condition. A total of 100 articles published in the literature were anlaysed during this period. The mean age at diagnosis was 57.09 ± 16.91 years with a female preponderance. Misdiagnosis was common with many patients misdiagnosed as conjunctivitis and dacryocystitis. Primary canaliculitis was found to be more frequent than secondary with inferior canaliculus involved more commonly than the superior. Staphylococcus, Streptococcus, and Actinomyces were the most common microbes isolated. Surgical management was employed in 74.25% of cases while medical management was done in 20.82% of cases. The review presents an insight into the complexities of canaliculitis, its diagnosis, and management which will further help to improve the understanding of this uncommon infection of the lacrimal system.

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.