Metagenomic Shotgun Sequencing Analysis of Canalicular Concretions in Lacrimal Canaliculitis Cases

A lacrimal drainage pathway disease-associated keratopathy (LDAK) case with non-infectious endophthalmitis

Purpose

To report a case of lacrimal drainage pathway disease-associated keratopathy (LDAK) with endophthalmitis.

Observations

An 80-year-old man with diabetic retinopathy and nephropathy was referred to our hospital with endophthalmitis of the left eye. Slit-lamp examination revealed slight eye discharge, peripheral corneal ulcers, diffuse hyperemia of the conjunctiva, iris synechia, and a large amount of fibrin in the anterior chamber of the left eye. No puncta of the left eye were observed. The patient had undergone trabeculectomy for primary open-angle glaucoma 5 years previously. B-mode echo examination confirmed vitreous opacity in the left eye. We suspected endophthalmitis and performed a par-plana vitrectomy, bacterial culture, and polymerase chain reaction examination for eye discharge, aqueous humor, and vitreous humor. However, no bacteria or viruses were detected. The eye discharge and corneal peripheral ulcers did not improve following surgery. A lacrimal syringe test was performed two weeks after surgery, and bacterial concretion and discharge were observed. We detected Actinomyces in the bacterial concretions and performed dacryocystorhinostomy. After surgery, the corneal ulcer improved, and eye discharge disappeared.

Conclusions and importance

LDAK causes corneal perforation and endophthalmitis. In cases of intraocular inflammation with corneal ulcers, a lacrimal syringing test should be performed, even in the absence of lacrimal findings on slit-lamp examination.

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.

Microbiological isolates and associated complications of dacryocystitis and canaliculitis in a prominent tertiary ophthalmic teaching hospital in northern China

BACKGROUND

To report the microbiological isolates, aetiology, complications, antibiotic susceptibilities, and clinical remission of dacryocystitis and canaliculitis in a prominent tertiary ophthalmic teaching and referral hospital located in northern China and to offer appropriate recommendations for preventing and formulating drug treatment strategies.

METHODS

This prospective study recruited a total of 477 participants who had been diagnosed with either dacryocystitis or canaliculitis. The cohort comprised 307 patients with chronic dacryocystitis, 111 patients with acute dacryocystitis, and 59 patients with canaliculitis. Purulent discharge from the lacrimal duct was collected using a sterile swab and immediately subjected to microbial culture. Antimicrobial susceptibility testing was conducted following established protocols. All participants were scheduled for follow-up visits within 14 days after receiving antibiotic therapy.

RESULTS

The present findings indicated that women exhibited a higher susceptibility to the condition, as evidenced by the occurrence of 367 cases in comparison to 110 cases among men. Among the 477 patients, definitive causes were established in 59 individuals, accounting for 12.4% of the patients. Additionally, ocular complications were reported by 132 patients, representing 27.7% of the total. Monocular involvement was observed in the majority of cases, with 402 out of 477 patients (84.3%) affected, while binocular involvement was present in 75 patients (15.7%). In total, 506 microbiological strains were recovered from 552 eyes, with Staphylococcus epidermidis (16.4%) being the most prevalent microorganism. Other predominant isolates included Corynebacterium macginleyi (9.1%), Staphylococcus aureus (5.1%), Streptococcus pneumoniae (4.9%), Haemophilus (4.4%), Propionibacterium acnes (3.5%), and Eikenella corrodens (3.1%). Among the 12 isolated fungi, Candida parapsilosis accounted for 66.7%. The susceptibility to antimicrobial agents tested in gram-negative bacilli (79.5%) was observed to be higher than that of anaerobic bacteria (76.7%) and gram-positive cocci (55.4%). With pharmacological therapy, the remission rate of acute dacryocystitis (72.7%) was found to be higher than that of canaliculitis (53.3%) and chronic dacryocystitis (42.3%).

CONCLUSIONS

This study highlights the microbial spectrum of dacryocystitis and canaliculitis, particularly C.macginleyi, E.corrodens and C.parapsilosis, which are also more frequently isolated. Vancomycin and imipenem may be more effective treatment options. Most cases have an unknown aetiology, and essential preventive measures involve postoperative cleansing of the lacrimal passage following eye and nasal surgeries, as well as the proactive management of rhinitis.

Evaluation of the contribution of shotgun metagenomics in the microbiological diagnosis of liver abscesses

BACKGROUND

Shotgun metagenomics (SMg) sequencing has gained a considerable interest, as it enables the detection of any microorganisms through a single analysis. Due to the limitations of standard microbiological approaches, the microbial documentation of liver abscesses (LA), which is crucial for their medical management, can be difficult. Here we aimed to compare the performance of SMg with standard approaches for the microbiological documentation of LA.

METHODS

In this retrospective study conducted at two centers, we compared the results of standard microbiology with metagenomics analysis of consecutive LA samples. For samples tested positive for Klebsiella pneumoniae, we compared the analysis of virulence and resistance genes using metagenomics data to whole-genome sequencing of corresponding isolates obtained in culture.

RESULTS

Out of the 62 samples included, standard approaches and SMg yielded documentation in 80.6% and 96.8%, respectively. In 37.1% (23/62) of cases, both methods showed identical results, whereas in 43.5% (27/62) of cases, the samples were positive by both methods, but SMg found additional species in 88.9% (24/27), mostly anaerobes. When the standard approaches were negative, the SMg was able to detect microorganisms in 80.0% of cases (8/10). Overall, SMg identified significantly more microorganisms than culture (414 vs.105; p<0.05). K. pneumoniae genome analysis was able to detect resistance and virulence genes with a level of sensitivity depending on the depth of sequencing.

DISCUSSION

Overall, we showed that SMg had better performance in detecting and identifying microorganisms from LA samples and could help characterizing strain's resistome and virulome. Although still costly and requiring specific skills and expensive equipment, MGs methods are set to expand in the future.

Efficacy and safety of super pulse CO2 laser-assisted punctoplasty with canalicular curettage in primary canaliculitis

The objective of this study was to evaluate the efficacy and safety of super pulse CO2 laser-assisted punctoplasty with canalicular curettage in primary canaliculitis. In this retrospective serial case study, the clinical data of 26 patients who underwent super pulse CO2 laser-assisted punctoplasty for the treatment of canaliculitis were collected from January 2020 to May 2022. The clinical presentation, intraoperative and microbiologic findings, surgical pain severity, postoperative outcome, and complications were studied. Of the 26 patients, most were females (female:male 20:6), with a mean age of 60.1 ± 16.1 years (range, 19-93). Mucopurulent discharge (96.2%), eyelid redness and swelling (53.8%), and epiphora (38.5%) were the most common presentations. During the surgery, concretions were present in 73.1% (19/26) of the patients. The surgical pain severity scores ranged from 1 to 5, according to the visual analog scale, with a mean score of 3.2 ± 0.8. This procedure resulted in complete resolution in 22 (84.6%) patients and significant improvement in 2 (7.7%) patients, and 2 (7.7%) patients required additional lacrimal surgery with a mean follow-up time of 10.9 ± 3.7 months. The surgical procedure of super pulse CO2 laser-assisted punctoplasty followed by curettage appears to be a safe, effective, minimally invasive, and well-tolerated treatment for primary canaliculitis.

Bleeding From the Eye: An Unusual Presentation of Lacrimal Canaliculitis

Chronic canaliculitis is an uncommon condition secondary to an infection of the lacrimal canaliculus, frequently caused by Actinomyces israelii. It is often misdiagnosed due to its symptoms mimicking more common pathologies and regularly fails to respond to antibiotics alone. Surgical intervention is the definitive treatment. We present a case of chronic canaliculitis with an unusual presentation.