The role of CT-DCG in hardware - associated secondary acquired lacrimal duct obstruction: SALDO update study - (SUP) - Paper III.

Purpose: To study cases of hardware-associated secondary acquired lacrimal duct obstructions (SALDO) and the role of computed tomography dacryocystography (CT-DCG) scans in its diagnosis and management. Observations: Retrospective, interventional case review of four patients diagnosed as Hardware-associated SALDO, with primary maxillofacial repair performed elsewhere, were analyzed. The mean age was 36.5 years (range: 22-74 years), three of them being males. Left and right lacrimal systems were equally involved. Epiphora, swelling and discharge were the main presenting features. Three lacrimal sacs and nasolacrimal ducts on CT-DCG showed the screws of the orbital fracture plate directly piercing their walls, whereas a single case showed the sac displaced and pierced by the medial side of the orbital floor implant. Two cases underwent dacryocystorhinostomy with intubation, and the remaining two had to undergo dacryocystectomy due to extensive damage. Post-operatively all four cases were doing well at a mean follow-up of 2 months. Conclusions: The present series highlights the role of CT-DCG in delineating spatial relationship of lacrimal drainage system with the surrounding structures, facilitating planning as well as choice of surgery, and anticipating the intraoperative challenges. It also signifies importance of interdisciplinary coordination between oculoplastic and maxillofacial surgeons to avoid iatrogenic trauma to the lacrimal drainage system.

Aesthetic and Functional Outcomes of Upper Blepharoplasty Combined with Dacryoadenopexy in Lacrimal Gland Prolapse.

INTRODUCTION: Lacrimal gland prolapse (LGP) is a term used to describe a benign, anterior displacement of the lacrimal gland. If this condition is not properly addressed during upper blepharoplasty, the aesthetic and functional results are less than optimal. This study aimed to report the surgical outcomes of upper blepharoplasty combined with dacryoadenopexy in patients with LGP. METHODS: We reported an unusual case of severe LGP in a young patient. In addition, we performed a systematic review of the English literature on surgical cases of LGP published between 1973 and 2023. Eligible articles were analyzed for individual patient data (IPD) and aggregate patient data (APD). The primary predictor variable was the surgical technique used for lacrimal gland repositioning/suspension. The primary outcome variable was relapse rate. RESULTS: The bibliographic search retrieved 488 surgical cases of LGP: 12 in IPD, and 476 in APD datasets. The relapse rates in the IPD and APD cohorts were 8.3% (1/12) and 1.2% (6/476), respectively. Within the APD dataset, no significant difference in the relapse rates between dacryoadenopexy via suture suspension and Whitnall's ligament suspension (5/409 and 1/20, respectively; P > 0.05) was observed. Light cauterization of the lacrimal gland capsule and surrounding soft tissues was performed in mild LGP cases (< 4 mm prolapse), with a relapse rate of 0% (0/47). CONCLUSION: Upper blepharoplasty combined with dacryoadenopexy proved to be a safe surgical procedure with very satisfactory aesthetic outcome and minimal relapse rate. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

A transconjunctival surgical technique for dacryocystotomy in dogs with foreign body-induced dacryocystitis.

PURPOSE: The purpose of this study is to describe a simplified, less invasive dacryocystotomy technique that allows for complete inspection of the canine lacrimal sac and to retrospectively evaluate this surgical technique in a larger series of dogs. The anatomical background of the canine nasolacrimal system is described as a basis for the surgical technique. METHODS: Records of dogs from 2003 to 2023 which were diagnosed with dacryocystitis due to presumed foreign body and underwent surgical exploration and removal of foreign bodies within the lacrimal sac using this technique were reviewed. Postoperative treatment and outcome were evaluated. RESULTS: Records of 48 dogs were included. A foreign body was discovered during the surgery or upon retrieval of the catheter in 85% of cases (41/48). An indwelling catheter was placed in 83% of cases (40/48) for a median of 21 days. At the last recheck, the nasolacrimal duct was patent in 87% of the cases (41/47). The median follow-up time was 34 days (3-1255 days). The most commonly affected breeds were Golden retrievers (11) and dachshunds (8). The following complications occurred: two dogs removed or partly removed the catheter themselves (day 7, day 14), and one dog showed marked irritation at the catheter site which had to be removed by day 10. CONCLUSIONS: The transconjunctival dacryocystotomy technique is simple and less invasive than other described techniques with a successful long-term outcome in the majority of cases.

Tear Film Dynamics in Visual Display Terminal Users: A Review of Impact on Goblet Cells, Lacrimal and Meibomian Gland Function.

PURPOSE: The prevalence of dry eye disease (DED) is rising among visual display terminal (VDT) users, a trend that correlates with the growing use of digital devices. The prevalence of VDT-associated DED is reported based on dry eye questionnaires; however, VDT's impact on tear film parameters is less understood. METHODS: A review of published literature on both the alterations in tear film observed in VDT users and the impact of various interventions on their tear film. RESULTS: Most studies show reduction in tear stability as well as reduction in the blink rate. The role of lacrimal gland hypofunction in visual display terminal (VDT) users is a subject of ongoing debate. Schirmer test values typically exceed the 10 mm threshold, suggesting normal tear production, and tear osmolarity remains within normal ranges but VDT users consistently present with lower Schirmer values compared to non-VDT users. The effects on Meibomian glands and mucin levels need more research as the numbers studied are small. Very few studies have analysed mucin levels in VDT users with reports of normal or reduced values. Even asymptomatic users can have tear film instability; hence, the diagnostic criteria need to be formulated and validated. Different interventions such as neurostimulation, blink improving apps, eyelid warming devices, moist goggles, and lubricants have been explored in VDT users but without a control arm and in asymptomatic VDT users in most studies. CONCLUSION: The alterations have been observed on aqueous, lipid and mucin components of the tear film, although the extent of the impact is variable across studies. There is urgent need of well-designed studies for studying the tear film changes and management options for the upcoming lifestyle epidemic in VDT users.

A New Patient-reported Outcomes Measure for Surgically Treated Epiphora: Tearing Assessment and Rating Scale-12 (TEARS-12).

BACKGROUND: No widely accepted, validated instrument currently exists to measure clinical outcomes in patients who undergo dacryocystorhinostomy (DCR) for treatment of epiphora. OBJECTIVE: To develop a patient-reported outcome measure applicable to this population. METHODS: Psychometric evaluations, consultation with experts, and review of the literature informed item generation of a 12-question questionnaire to incorporate the most relevant symptoms experienced by patients with nasolacrimal duct obstruction. This questionnaire, known as the Tearing Assessment and Rating Scale-12 (TEARS-12), was administered to 32 patients before and after intervention, in the form of endoscopic DCR. Statistical analysis was performed to measure internal consistency, responsiveness, and test-retest reliability. RESULTS: Pre-operative and post-operative TEARS-12 scores (28.2 [standard error (SE) 3.19] vs 11.8 [SE 3.25], respectively, P = 0.001) demonstrated improved patient outcome within 6 weeks following endoscopic DCR. Cronbach's alpha for the questionnaire was 0.90, indicating high overall reliability. Additionally, each question demonstrated internal reliability, with a corrected item-total correlation greater than 0.30. The intraclass correlation between the two pre-operative scores was 0.858 (P < 0.001), indicating high test-retest reliability. CONCLUSION: TEARS-12 is a statistically valid, easy-to-administer instrument to measure clinical outcomes in patients who undergo endoscopic DCR.

Adenoid Cystic Cancer of the Lacrimal Gland: Management Aspects and Treatment Outcomes.

Adenoid cystic carcinoma (ACC) of the lacrimal gland is the most common malignant epithelial tumor of the lacrimal gland. The biological behavior of these tumors is characterized by a slow growth with frequent nerve invasion but rare invasion of the neck nodes. Local extension intracranially with bone erosions is seen in locally advanced tumors. Distant metastasis to lungs bone and liver are commonly reported. Treatments using surgery and radiotherapy are generally preferred for adequate tumor control. However there is still no consensus on the best treatment approach. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-023-04426-5.

The Use of Hand-Held Digital Otoscope as a Basic Nasal Endoscopy Tool for Lacrimal Evaluation and Pedagogy Instrument.

PURPOSE: To investigate the utility of a hand-held digital otoscope for nasal endoscopy and as a pedagogy tool for residents and fellows in patients undergoing external dacryocystorhinostomy (DCR) surgery. METHODS: A digital otoscope (MS450-NTE, Teslong Inc., USA) comprising a digital screen device and a connectible camera probe was used for performing nasal endoscopy. Inspection of nasal cavities was performed pre-, intra-, and post-operatively in sequential patients with nasolacrimal duct obstruction, who underwent DCR or lacrimal probing. Images (1920 × 1080 pixels) and videos (1280 × 720 pixels) were captured. The device was also used for training residents and fellows in performing nasal endoscopy, and to teach basic concepts. RESULTS: The digital otoscope could be used for routine outpatient nasal examination and for performing minor procedures. 53.8% (n = 13) of ophthalmology trainees had never observed nasal endoscopy and 84.6% could not identify more than one major structure correctly prior to the current training. Post-training, all trainees could independently perform nasal endoscopy with the device and 76.9% identified all structures correctly. CONCLUSION: A digital otoscope with a camera probe is a handy tool for nasal endoscopy and pedagogy. Low-cost gadgets such as this device can effectively be used for performing outpatient nasal endoscopy when expensive endoscopes are unavailable and in peripheral healthcare centers.

A New Immortalized Human Lacrimal Gland Cell Line.

The lacrimal gland is crucial for maintaining ocular health by producing the aqueous component of the tear film, which hydrates and nourishes the ocular surface. Decreased production of this component results in dry eye disease, a condition affecting over 250 million people worldwide. However, the scarcity of primary human material for studying its underlying mechanisms and the absence of a cell model for human lacrimal gland epithelial cells present significant challenges. Here, we describe the generation of immortalized human lacrimal gland cell lines through the introduction of an SV40 antigen. We successfully isolated and characterized three cell clones from a female lacrimal gland donor, confirming their epithelial identity through genomic and protein analyses, including PCR, RNAseq, immunofluorescence and cultivation in a 3D spheroid model. Our findings represent a significant advancement, providing improved accessibility to investigate the molecular pathogenesis mechanisms of dry eye disease and potential therapeutic interventions. We identified the expression of typical epithelial cell marker genes and demonstrated the cells' capability to form 2D cell sheets and 3D spheroids. This establishment of immortalized human lacrimal gland cells with epithelial characteristics holds promise for future comprehensive studies, contributing to a deeper understanding of dry eye disease and its cellular mechanisms.

Enterovirus A71 infection-induced dry eye-like symptoms by damaging the lacrimal glands.

Purpose: To determine the effects of EV-A71 (Enterovirus A71) infection on ocular surface and its mechanism. Methods: AG6 mice aged two to three weeks were randomly divided into control and EV-A71 infected groups. Slit-lamp observation, fluorescein staining, and phenol red thread test were used to assess symptoms of ocular surface at 4 dpi (days post infection). The pathological changes of cornea and lacrimal gland were observed by H&E staining, PAS staining, TUNEL assay, IHC staining and qRT-PCR. Corneas and lacrimal glands from mice were obtained and processed for RNA sequencing analysis. Newly diagnosed HFMD patients caused by EV-A71 were recruited and ensured they met the inclusion criteria. Ocular surface parameters (TMH and NIKBUT) were measured using the OCULUS Keratograph 5M. Tear samples were taken to examine Cxcl1 and IL-6 levels through the ELISA method. Results: Mice studies revealed that EV-A71 infection caused tear film instability, decreased tear secretions, decreased in lacrimal gland size, and distinct goblet cell loss. It also resulted in increased large vacuoles within acinar cells and structural damage in lacrimal gland. Apart from minor damage to the epidermis, there was no obvious inflammatory changes or apoptosis in the cornea. However, there were significant inflammatory injury and apoptosis in the lacrimal gland. RNA-seq analysis showed IL-17 and NF-κB signaling pathways were activated in the lacrimal glands of mice infected with EV-A71. In HFMD patients, the THM was in a low range and NITBUT was significantly shorter than the control group by Oculus Keratograph 5M. ELISA assay showed a higher tear Cxcl1 and IL-6 level in them. Conclusion: EV-A71 infection affected lacrimal gland structure and function and induced dry eye-like symptoms.

The Use of Venous Catheter and Irrigation with Povidone-Iodine 0.6% in Patients with Punctal and Proximal Canalicular Stenosis: Preliminary Report.

Background: This study aimed to evaluate the safety and efficacy of povidone-iodine 0.6% (PVI) irrigation for preventing recurrence of stenosis after punctoplasty in patients with punctal and proximal canalicular stenosis treated using a venous catheter as a stent. Methods: Twenty patients were enrolled and divided into two groups. Group 1 received irrigation of 1 mL 0.6% PVI, while Group 2 received 1 mL of balanced salt solution (BSS). The patients underwent baseline, 15-, 30-, and 90-day assessments using the Ocular Surface Disease Index (OSDI) questionnaire, Symptoms Assessment in Dry Eye (SANDE), Schirmer I test, tear meniscus height (TMH), bulbar redness, meibography, and non-invasive breakup time (NIKBUT) through Keratograph 5M (Oculus, Germany). Results: At three months, both groups demonstrated statistically significant improvements in symptoms and ocular surface parameters. However, Group 1 showed statistically significant improvements in OSDI, SANDE scores, bulbar redness, and NIKBUT compared to Group 2. Additionally, no patients in Group 1 presented a recurrence of stenosis, while three patients in Group 2 demonstrated stenosis relapse at the end of the follow-up period. Conclusions: The application of a venous catheter and PVI 0.6% irrigations proved to be effective in treating proximal lacrimal duct stenosis, reducing the risk of recurrence and improving tear film stability, ocular discomfort symptoms, and ocular surface parameters.

A Brief History of Lacrimal Bypass Techniques.

PURPOSE: Lacrimal bypass is the creation of a fistula connecting the conjunctiva with the lacrimal sac or nasal cavity. Bypass is indicated in canalicular obstruction or agenesis; sac absence, destruction or prior excision; lacrimal pump failure; or dacryocystorhinostomy failure. We aim to review the various techniques that have been developed over the last century for lacrimal bypass. METHODS: We conducted a comprehensive literature review of techniques which have focused on creating a conduit extending from the conjunctiva or canaliculi to the lacrimal sac, or extending that bypass to the nasal cavity bypass. RESULTS: The main techniques reviewed include canaliculodacryocystorhinostomy, conjunctivodacryocystostomy, conjunctivorhinostomy, conjunctivodacryocystorhinostomy, and conjunctivoductivodacryocystorhinostomy. CONCLUSION: Lacrimal bypass surgery has evolved due to innovation in microsurgical techniques, instruments and materials. Conjunctivodacryocystorhinostomy with Jones tube insertion is the predominant bypass technique, reflecting a culmination of historical developments. Understanding the variety of lacrimal bypass techniques is important for exploring alternative options when necessary.

Incidence of Pure Orbital Fractures with Concomitant Lacrimal Drainage System Injury in the Japanese Population: A Retrospective Study.

PURPOSE: This study aims to determine the incidence of pure orbital fractures with concomitant lacrimal drainage system injuries. METHODS: A retrospective observational study involving 956 sides from 940 pure orbital blowout fracture patients was conducted in our institution. Patients with concomitant orbital rim fracture and those with old orbital fractures were excluded. RESULTS: A total of 13 sides (1.4%) from 13 patients were included in the study. Canalicular laceration, bony nasolacrimal canal fracture, and lacrimal sac wall laceration were found in 9, 4, and 1 patients, respectively (one overlapping). Majority of the injuries resulted from either sports or falls. Inferomedial orbital strut fracture (23.1% vs. 7.6%; p = .075) and orbital floor fracture occurring lateral to the infraorbital groove (30.8% vs. 9.9%; p = .035) tended to be higher in patients with lacrimal drainage system injuries. CONCLUSION: There is a 1.4% incidence rate of pure orbital fractures with concomitant lacrimal drainage system injuries among the Japanese population included in this study. Inferomedial orbital strut fractures and orbital floor fracture lateral to the infraorbital groove were found to have higher association with lacrimal drainage system injuries.

Müller muscle-Conjunctival Resection (MMCR) Surgery: A Comprehensive Literature Review.

PURPOSE: This literature review aims to provide a comprehensive overview of the current understanding, indications, techniques, outcomes, and complications of Müller muscle-conjunctival resection (MMCR) surgery. It also addresses areas of debate with MMCR such as predictability concerning Phenylephrine response as well as the amount of muscle resection required. METHOD: This literature review was compiled based on the available evidence from PubMed from 1975 to August 2023. RESULTS: The success rate of MMCR ranges from 72% to 95%, with high patient satisfaction reported in most studies. The exact range of eyelid elevation after MMCR is variable, with a reported average of 2.1 mm MRD1 elevation. CONCLUSION: MMCR is a well-established surgical technique used to correct upper eyelid ptosis that results from dysfunction or attenuation of the levator aponeurosis. MMCR proved to be a safe and effective procedure with a high patient satisfaction rate and low risk of complications.

Dynamic viscosity of the wall of the lacrimal sac in disorders of the patency of the lacrimal ducts.

PURPOSE: To assess the dynamic viscosity of the lacrimal sac wall in patients with various origins of lacrimal duct obstruction. METHODS: The study was performed in 35 cases: 21 cases with primary nasolacrimal duct obstruction (PANDO) and 14 cases with secondary nasolacrimal duct obstruction after radioiodine therapy (SALDO). The study of biomechanical properties of the lacrimal sac was carried out using a test bench. The principle of the study was to indent the sample at a given speed and record the data obtained from the sensor of the force transmitted to the sample. The area under the curve (AUC) and the peak viscosity were calculated. A qualitative characteristic of the obtained curve was given. RESULTS: Median AUC in patients with PANDO was 17 × 106 [6 × 106; 19 × 106] N/m2 × s, in patients with SALDO 21 × 106 [13 × 106; 25 × 106] N/m2 × s. Intergroup differences were statistically significant (p = 0,048). The median peak viscosity in PANDO patients was 29 × 106 [25 × 106; 35 × 106] N/m2, in patients with SALDO 32 × 106 [21 × 106; 41 × 106] N/m2. The qualitative characteristics of the obtained curves differed. CONCLUSION: Biomechanical properties of the lacrimal sac may vary depending on the cause of obliteration of the lacrimal ducts. The integrated dynamic viscosity is significantly higher in SALDO patients due to exposure to radioiodine compared to that in PANDO patients.

Neoadjuvant Chemotherapy Alone or Combined with EGFR-Directed Targeted Therapy or Anti-PD-1 Immunotherapy for Locally Advanced Lacrimal Sac and Nasolacrimal Duct Carcinomas.

BACKGROUND/AIMS: We describe our findings in patients with locally advanced lacrimal sac and nasolacrimal duct (NLD) carcinoma who received neoadjuvant systemic therapy. METHODS: We identified patients with locally advanced primary lacrimal sac/NLD carcinoma treated with neoadjuvant systemic intravenous therapy at our institution during 2017-2019. RESULTS: The study included seven patients, four men and three women; the mean age was 60.4 years (range: 43-76). All patients had locally advanced disease with significant orbital soft tissue invasion with or without skull base invasion making eye-sparing surgery not feasible as an initial step. Three patients had poorly differentiated squamous cell carcinoma; two, invasive carcinoma with basaloid and squamous features; one, high-grade carcinoma with features suggestive of sebaceous differentiation; and one, undifferentiated carcinoma. The neoadjuvant regimens were cisplatin and docetaxel (n = 1); carboplatin and docetaxel (n = 1); paclitaxel and cetuximab (n = 1); carboplatin, paclitaxel, and cetuximab (EGFR inhibitor) (n = 2); cisplatin, docetaxel, and pembrolizumab (anti-PD-1 immunotherapy) (n = 1); and carboplatin, paclitaxel, and pembrolizumab (n = 1). All patients had radiologic disease regression, and one patient had radiologic near-complete response. After neoadjuvant therapy, all patients underwent wide local excision and adjuvant concurrent chemoradiation. Two patients had a complete pathologic response. At a median follow-up period of 13 months after chemoradiation (range, 8-54 months), all patients were alive without evidence of disease. One patient had nodal metastasis treated with lymph node dissection and adjuvant chemoradiation. CONCLUSIONS: Neoadjuvant systemic therapy can shrink tumors in patients with locally advanced primary lacrimal sac/NLD carcinoma with orbital or skull base invasion.

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.

Virtual Reality and Mixed Reality-Assisted Endoscopic DCR in Extremely Complex Lacrimal Obstructions.

OBJECTIVE: To report the techniques and outcomes of virtual reality (VR) and mixed reality (MR)-assisted powered endoscopic dacryocystorhinostomy (DCR) in extremely complex lacrimal drainage obstructions. METHODS: A prospective, non-randomized clinical study was performed in complex syndromic congenital nasolacrimal duct obstruction (CNLDO) and post-traumatic secondary acquired lacrimal duct obstruction (SALDO) in the setting of Le Fort fractures. All patients underwent preoperative planning in VR and intraoperative planning with a step ahead with MR assistance during the surgery. Surgery was supported by mixed reality intraoperative guidance with the use of the prearranged 3D models and real-time-rendered digital models. Parameters assessed include demographics, clinical presentation, complexities of the nasolacrimal duct obstruction, preoperative and intraoperative utility of VR and MR models, surgical techniques, complications, and outcomes. RESULTS: The technique is described as a proof of concept in challenging situations with Apert syndrome and traumatic SALDOs with gross malposition of the sac, and gross nasal and lacrimal anatomical deformities. The VR models helped the surgeon to assess the details of the altered anatomy preoperatively to plan an appropriate approach. Intraoperatively, MR models were present in the surgeon's view without disturbing the endoscopic procedure. Intermittently, the surgeon could pull any of the models virtually present in the operating room, slice them, rotate them, and intricately study the alterations in a stepwise manner, as the surgery proceeds. CONCLUSION: Virtual reality and mixed reality-assisted powered endoscopic DCR can be an alternate approach reserved for extremely challenging cases of complex syndromic CNLDOs and post-traumatic SALDOs. LEVEL OF EVIDENCE: Level 4 Laryngoscope, 2024.

The association of bacterial agents and flagellated protozoans in the etiopathogenesis of subspectacular abscesses in snakes.

OBJECTIVES: To describe the etiology, clinical pathology, and treatment of subspectacular abscesses (SAs) in 16 snakes. ANIMALS STUDIED: Sixteen snakes from private captive collections that were presented at a veterinary teaching hospital and diagnosed with SAs. PROCEDURES: Exudate was collected from SAs via percutaneous aspiration or by performing a partial spectaculectomy and submitted to direct light microscopic examination and/or microbiological examination. RESULTS: Bacterial isolates were cultured from exudate samples in 12 out of 16 snakes and comprised Pseudomonas aeruginosa isolates that showed identical antimicrobial susceptibility patterns in seven cases. Direct light microscopic examination demonstrated the presence of flagellated protozoa in the exudate in 10 out of 16 snakes and in all of these snakes, concurrent oropharyngeal flagellated protozoan infection could be demonstrated. Combined flagellated protozoan and bacterial SA infection was demonstrated in six snakes. Comparison of small subunit ribosomal RNA gene sequences of flagellated protozoans that were detected in the exudate of SAs from four snakes revealed they represented the parabasalians Monocercomonas colubrorum and Hypotrichomonas acosta in one and three cases, respectively. In all snakes, successful treatment of the SAs was achieved following surgical debridement of the subspectacular space combined with antimicrobial treatment. CONCLUSION: Bacteria as well as flagellates are considered to reach the subspectacular space through ascending infection from the oral cavity via the lacrimal duct. Although opportunistic bacterial infection presumably constitutes the predominant cause of SAs in snakes, the role of flagellate infection in the pathogenesis of this disorder should be further elucidated.

CT-Measured Angulation Between the Frontal Bone and Bony Nasolacrimal Duct: Variations in Obstructed and Healthy Lacrimal Ducts.

PURPOSE: The aim of this study was to analyze the characteristics of CT-measured intersection angle (FB-BNLD) between the frontal bone and bony nasolacrimal duct and to provide suggestions for treating primary acquired nasolacrimal duct obstruction (PANDO) patients in West China. METHODS: Three hundred and nine participants' CT were, respectively, evaluated with RadiAnt DICOM Viewer. We defined the FB-BNLD angle >0° as the anterior type and the FB-BNLD angle ≤0° as the posterior type. RESULTS: The mean FB-BNLD was -2.52° (95% CI, -3.16° to -1.88°) across all participants, of whom 37.2% were of the anterior type and 62.8% of the posterior type. Approximately 65.0% of the female patients had a posterior FB-BNLD type, and 54.2% of the male patients had an anterior FB-BNLD type (p = .002). Posterior FB-BNLD was the dominant type in the PANDO and control groups (p = .011), and the angle of FB-BNLD was statistically different in both groups (PANDO group, -2.54° to -0.71°; control group, -4.42° to -2.67°; p < .001). Among the male participants, the type of FB-BNLD differed between the two groups (p = .036), with differences in the angle of FB-BNLD (PANDO group, 0.59° to 5.13°; control group, -4.08° to 1.89°; p = .034). There was no difference in the type of FB-BNLD in female participants between the two groups (p = .051). CONCLUSION: The present study revealed individual differences in the type of FB-BNLD, with anterior-type majority in males and posterior-type dominance in females. Evaluating the FB-BNLD type on CT can provide a fast method for knowing the nasolacrimal duct condition during planning for lacrimal manipulation.