Comparison of bony nasolacrimal canal narrowing with or without primary acquired nasolacrimal duct obstruction in a Japanese population

Etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO)

Primary acquired nasolacrimal duct obstruction, or PANDO, is a common adult lacrimal drainage disorder. The current treatment modality of dacryocystorhinostomy to bypass the obstructed nasolacrimal duct has excellent outcomes. However, the understanding of the disease etiopathogenesis needs to be revisited. There are not many studies that specifically assessed any hypothesis or ones that convincingly put forth the presumed or confirmed interpretations regarding the PANDO pathogenesis or the mechanisms or pathways involved therein. Histopathological evidence points to recurrent inflammation of the nasolacrimal duct, subsequent fibrosis, and the resultant obstruction. The disease etiopathogenesis is considered multifactorial. Several implicated suspects include anatomical narrowing of the bony nasolacrimal duct, vascular factors, local hormonal imbalance, microbial influence, nasal abnormalities, autonomic dysregulation, surfactants, lysosomal dysfunction, gastroesophageal reflux, tear proteins, and deranged local host defenses. The present work reviewed the literature on the etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO) to gain insights into the present state of the understanding and the high-value translational implications of precisely decoding the disease etiology.

Computed Tomography Morphology of Affected versus Unaffected Sides in Patients with Unilateral Primary Acquired Nasolacrimal Duct Obstruction

BACKGROUND

This study aimed to describe the anatomical details of the bony nasolacrimal duct (BNLD) and adjacent nasal structures by analyzing computed tomography (CT) images, and to investigate their effects on the development of primary acquired nasolacrimal duct obstruction (PANDO).

METHODS

A total of 50 patients with unilateral PANDO who underwent dacryocystorhinostomy, with a mean age of 57.96 years, were included. The preoperative CT images were reviewed to measure the anteroposterior and transverse diameters of the BNLD at the entrance and exit levels, as well as the minimum transverse diameter along the tract. The sagittal CT images were analyzed to classify the shape of the bony canals into columnar, funnel, flare, and hourglass. The associated paranasal abnormalities, including nasal septum deviation (NSD), sinusitis, angle between the bony inferior turbinate and medial wall of the maxillary sinus, and mucosal thickness of the inferior turbinate, were investigated.

RESULTS

Fifty CT images were analyzed, and all parameters measured on both sides of the BNLD were not significantly different between the PANDO and non-PANDO sides, except for the minimum transverse diameter, which was significantly smaller on the PANDO side (p = 0.002). Columnar-shaped BNLD was the most common on both sides. No significant difference was observed in the incidence of paranasal abnormalities between sides; however, deviation of the septum toward the non-PANDO side was more common (67.9%).

CONCLUSIONS

A small minimum transverse diameter of the BNLD may be a risk factor for PANDO. The association between nasal abnormalities and PANDO was not remarkable.

Bony nasolacrimal duct size and outcomes of nasolacrimal silicone intubation for incomplete primary acquired nasolacrimal duct obstruction

Purpose

To investigate the association between the bony nasolacrimal duct (NLD) size and outcomes of nasolacrimal silicone intubation for incomplete primary acquired nasolacrimal duct obstruction (PANDO).

Methods

Patients who underwent silicone intubation for incomplete PANDO and had undergone facial computed tomography (CT) were included. Surgical success was judged by both epiphora improvement and normalized tear meniscus height (TMH; < 300 μm) on anterior segment optical coherence tomography at 3 months after tube removal. The area, major axis diameter, and minor axis diameter of the elliptic bony NLD sections were measured in 1.0 mm-thick axial CT images. These bony NLD sizes were analyzed for associations with surgical success and TMH normalization.

Results

Eighty-one eyes of 48 patients were investigated. The smallest area and the smallest minor axis diameter were significantly larger in the success group (49 eyes), compared with those in the failure group (median smallest minor axis diameter: 4.7 mm vs. 3.8 mm, P = 0.008, Mann–Whitney U test). There was also a tendency for the TMH normalization rate to significantly increase as the smallest area and the smallest minor axis diameter increased (P = 0.028 and 0.037, respectively, Fisher’s 2 × 4 tests). Under multivariable logistic regression analysis using generalized estimating equation, a larger smallest minor axis diameter was associated with success of the nasolacrimal silicone intubation (odds ratio: 2.481, 95% confidence interval: 1.143–5.384).

Conclusion

Surgical success of the nasolacrimal silicone intubation in incomplete PANDO is associated with a larger smallest minor axis diameter of the bony NLD. This finding will help understand the pathophysiology of surgical failure after nasolacrimal silicone intubation.

High-resolution computed tomography assessment of bony nasolacrimal parameters: variations due to age, sex, and facial features

PURPOSE

To compare nasolacrimal duct anatomy between gender, age, and facial features, and explore correlations between bony parameters.

METHODS

A retrospective case series of patients of four races who had high-resolution computed tomography (CT) between 2004 and 2019 covering the full length of their nasolacrimal ducts in two hospitals in Essex, England. Only normal ducts were included; patients with tearing or radiological abnormalities were excluded. Measurements were taken of the nasolacrimal duct and surrounding anatomy based on measurements found in the existing literature.

RESULTS

More females (n = 114) than males (n = 40) were included. Mean age was slightly older for females (45.7 years) compared to males (42.5). Males have taller noses and wider faces. Nasolacrimal duct calibre correlated positively with age, male gender, and facial width, and negatively with nasal height. There was a tendency for nasolacrimal ducts to be longer in males.

CONCLUSION

The bony nasolacrimal duct is smaller in younger female patients. Having a taller nose and narrower upper face is also correlated with a smaller calibre duct. Acquired nasolacrimal duct obstruction in patients without these demographics or facial features may be more likely due to secondary causes.

Morphometric differences in normal bony nasolacrimal anatomy: comparison between four ethnic groups

PURPOSE

To compare bony nasolacrimal duct anatomy between ethnic groups.

METHODS

A retrospective observational study of patients of four ethnic groups who had high-resolution CTs between 2004 and 2019 covering the full length of their nasolacrimal ducts in two hospitals in Essex, England. Only normal ducts were included; patients with tearing or radiological abnormalities were excluded. Measurements were taken of the nasolacrimal duct and surrounding anatomy based on measurements found in the existing literature.

RESULTS

More females (n = 114) than males (n = 40) were included. South Asian (Indian subcontinent), Afro-Caribbean and European groups were equivocal demographically (n = 25-29, mean age 40-45); however, the Oriental group was fewer in number (n = 13) and slightly older (mean age 51). South Asian and European ducts had no significant differences. Afro-Caribbean ducts were wider and shorter than European. Afro-Caribbean faces are wider and their noses flatter and wider than European. Oriental ducts were wider and longer than European, but Europeans have taller noses.

CONCLUSION

The results from our Oriental group fits with the published data in Orientals. The bony nasolacrimal duct is greater in calibre (inner diameter) if the patient is of Afro-Caribbean or Oriental origin compared to European or South Asian. Acquired nasolacrimal duct obstruction in Afro-Caribbean or Oriental patients may be more likely due to secondary causes.

3D morphological classification of the nasolacrimal duct: Anatomical study for planning treatment of tear drainage obstruction

BACKGROUND

The purpose of this study is to analyze and classify morphological features of the nasolacrimal duct (NLD) through 3D reconstruction to help understand the causes and treatment of NLD obstruction.

METHODS

In this study, we included 63 males and 55 females who underwent autopsy without NLD obstruction with ages ranging from 20 to 78 years. The NLD was defined from the lacrimal fossa to the opening of the BNLD to the inferior meatus, and all continuous CT images showing the NLD were selected. Segmentation was performed semi-automatically, and the reconstruction and measurement of NLD was performed using the Mimics program.

RESULTS

Overall NLD length, bony nasolacrimal duct (BNLD) length, anteroposterior and transverse diameters at the entrance to the BNLD, anteroposterior and transverse smallest diameters of the BNLD, BNLD volume, and lacrimal sac BNLD angle were significantly higher in males than females (p < .05). BNLD direction in the coronal plane was slightly more likely to be inward. The most common type in both sexes was cylinder type (42.0%), males were more likely to have lower-thicker types (34.1%), and females more likely to have upper-thicker types (22.7%).

CONCLUSION

There were sex differences in NLD measurements, and females had significantly smaller NLDs. These results may partially explain the increased prevalence of primary acquired NLD obstruction in females. The BNLD tends toward the midline, and inclines posteriorly.

Sinonasal Anatomical Variations and Primary Acquired Nasolacrimal Duct Obstruction: A Single Centre, Case-Control Investigation

Objective

Primary acquired nasolacrimal duct obstruction (PANDO) is an idiopathic narrowing of the nasolacrimal duct caused by chronic inflammation and consecutive stenosis of the nasal tissue. In the current investigation, we aimed to study the etiopathogenic role of sinonasal anatomical abnormalities and paranasal inflammatory pathologies in PANDO.

Materials and Methods

Computed tomography (CT) findings of 459 patients who were diagnosed with unilateral PANDO between April 2009 and March 2017 were compared with that of a control group, which comprised 200 subjects without nasolacrimal duct obstruction who had been referred to the ear nose throat (ENT) clinic with the complaint of vertigo and headache. A radiologist (R. S.) masked to the clinical situation of participants retrospectively examined their CT findings.

Results

The prevalence of deviated nasal septum was found to be strongly associated with PANDO incidence (55.3% on PANDO side of patients vs. 28.3% among controls; p<0.001). Significant increases, albeit of smaller magnitude, were also observed in the relative frequency of Agger nasi cells and maxillary sinusitis on the PANDO side of the subjects (14.6% and 27.0%, respectively) compared to controls (9.5% and 20.6%, respectively) (p=0.023 and p=0.038, respectively). Unilateral PANDO was also found to be robustly associated with an ipsilateral deviated nasal septum (p<0.001). The odds of septal deviation occurrence were 3.037 times (95% Confidence Interval (CI): 2.303-3.990; p<0.001) more on the PANDO than the non-PANDO side of the studied cases.

Conclusion

Ipsilaterally deviated nasal septum appears to have a role in the development of unilateral primary acquired obstructive disease of the lacrimal drainage system. The incidence of PANDO might also be affected by Agger nasi cells and maxillary sinusitis. Multicenter studies are essential to further elucidate the interaction between type, severity, extent, and dimensions of different pathologies with nasolacrimal duct obstruction.

Etiopathogenesis of Primary Acquired Nasolacrimal Duct Obstruction: What We Know and What We Need to Know

PURPOSE

To provide a systematic review of the literature on the etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO).

METHODS

The authors performed a PubMed search of all articles published in English with specific reference to etiopathogenesis of PANDO or associations of PANDO. Data captured include demographics, study techniques, hypothesis, presumed or confirmed interpretations with regards to pathogenesis, mechanisms, or pathways. Specific emphasis was laid on addressing the lacunae and potential directions for future research.

RESULTS

Numerous factors are believed to contribute to the etiopathogenesis of PANDO. The basic pathogenesis involves inflammation, vascular congestion, mucosal edema, fibrosis, obstruction, and stasis. Bony nasolacrimal duct diameter does not appear to play a significant role. There is no convincing data to substantiate nose as the site of disease origin and nasal factors appear to be comorbidities. Hormonal mechanisms are more evidence-based but can only partly explain the pathogenesis. Vascular theories are based on the behavior of perilacrimal cavernous bodies, their autonomic control, and additional structural changes in the helical patterns of connective tissue fiber arrangements. Repeated vascular malfunction leading to structural epithelial and subepithelial changes currently appears to be the most evidence-based and accepted theory. Tear proteomics holds a promise in decoding the etiopathogenesis of PANDO, at least in part.

CONCLUSIONS

The etiopathogenesis of PANDO appears to be multifactorial. Hormonal microenvironments, vascular factors, and tear proteomics are promising candidates for further work. There is a need for focused work by Clinician-Scientists and the answers can have far reaching clinical implications.

Complex Stenoses and CT Features of the Nasolacrimal Canal in Congenital Nasolacrimal Duct Obstruction

PURPOSE

To study the CT appearance of the nasolacrimal canal (NLC) in cases of congenital nasolacrimal duct obstruction (CNLDO) where there is a tactile sensation of a hard contact (HC) stop in the duct preventing stent intubation.

METHODS

The authors retrospectively reviewed all consecutive cases of chronic CNLDO observed between 2003 and 2018 in which an apparent HC obstruction prevented nasolacrimal intubation. CT scans were reviewed to determine the cause of probing failure: distal stenosis, loss of parallelism of the NLC walls, abnormal angulations or an adjacent obstacle blocking tear outflow.

RESULTS

Nine patients (12 sides) met the following criteria: CNLDO + HC + probing failure. The mean age at the time of the first HC was 3.9 years (range: 0.8-8.1 years) and at the time of a second confirmation of HC with subsequent dacryocystorhinostomy was 7.8 years (range: 4.1-9.2 years). Nasolacrimal duct opacification was noted in 33% of cases (4/12). Abnormalities of the NLC occurred in 8 of the 12 cases of CNLDO (8/12 = 66.6%) and on the asymptomatic side in 1 case (1/6 = 16.6%). A canine tooth bud situated in the same plane as the NLC was observed in 9 cases of CNLDO (9/12 = 75%) and on the asymptomatic side in 2 cases (2/6 = 33.3%).

CONCLUSIONS

HC noted during probing is a sensitive but relatively nonspecific sign which, nevertheless, does indicate either a complex obstruction or at least potential intubation difficulties. As confirmed by CT imaging, a significant anatomical variant is not necessarily predictive of epiphora, but nevertheless may complicate the intubation procedure.The authors describe hard contact palpation during probing for CLNDO and its relationship to anatomic location and etiologies of obstruction in the nasolacrimal canal by CT imaging.

Morphometric Measurements of Bony Nasolacrimal Canal in Children

OBJECTIVE

Morphology and dimensions of the bony nasolacrimal canal duct (BNLD) as a key factor in the development of primary acquired nasolacrimal duct obstruction. We aimed to obtain detailed morphometric analysis of BNLD in children without nasolacrimal duct pathology by using computed tomography and provide standard measurements by means of age which could be utilized in planning management or in invasive interventions.

METHODS

Picture Archiving Communication Systems database of our hospital's radiology department was searched for this retrospective study. Subjects were under 18 years of age who had undergone a paranasal, maxillofacial, or temporal bone high-resolution computed tomography scan in last 2 years with various indications. Those with fractures including facial bones and/or nasolacrimal canal or history of nasolacrimal duct pathology were excluded from the study. We measured the diameter, angle, and surface area of BNLD.

RESULTS

A total number of 136 subjects (86 boys, 50 girls) were included in the study. The average age was 7.3 ± 5.1 years. We documented statistically significantly positive correlation between all measured diameters and ages (P < 0.001), whereas there was a negative association between mean angle and age (P < 0.001). Mean angle is defined as the angle between BNLD and nasal floor. The surface area of BNLD was found to be significantly increasing depending on age (P < 0.001). However, we could not find any significant association between gender and measured parameters (P > 0.050).

CONCLUSION

Our study demonstrated that development of BNLD continues during childhood, regardless of gender.

Morphology and morphometry of lacrimal drainage system in relation to bony landmarks in Caucasian adults: a cadaveric study

PURPOSE

The objective of this study is to examine the morphometry of the lacrimal drainage system with reference to bony landmarks in the vicinity.

METHODS

Twenty midsaggitalized heads obtained from sixteen preserved cadavers were studied. Measurements involved detailed morphometry of anterior and posterior lacrimal crests, bony lacrimal sac fossa, entrance and length of the bony nasolacrimal duct (NLD), attachment of Horner's muscle, and characteristics of the inferior meatal opening of the NLD.

RESULTS

The mean lengths of anterior and posterior lacrimal crests were 16.3 and 12.5 mm, respectively. At the midpoint of the posterior lacrimal crest, Horner's muscle was found to be attached at a mean of 1.3 mm posterior to the crest. The mean dimensions of the bony lacrimal sac fossa at superior, mid and inferior levels were 6.5, 8.7, and 5.9 mm, respectively. The mean contribution of the lacrimal bone to the lacrimal sac fossa was 56.2%. The mean anteroposterior and transverse diameters of the entrance of the bony NLD were 5.7 and 4.7 mm, respectively. The most common type of NLD opening in the inferior meatus was that of "vertical sulcus" (70%, 14/20). The mean distance of the NLD opening from the anterior nasal spine and Limen nasi were 22.2 and 18.9 mm, respectively.

CONCLUSION

This study provides useful anatomical and positional relationship of bony lacrimal landmarks and nasolacrimal duct in Caucasian adults.

Endoscopic intranasal findings in unilateral primary acquired nasolacrimal duct obstruction

Purpose

To evaluate intranasal endoscopic findings in patients with unilateral primary acquired nasolacrimal duct obstruction and compare them with the normal cohort.

Methods

A prospective case-control study with 50 unilateral primary acquired nasolacrimal duct obstruction (PANDO) and 50 healthy controls. All patients were evaluated by endoscopic nasal examination for the presence of deviated nasal septum (DNS), type of deviation (bony or cartilaginous), side of deviation, septal spurs, caudal dislocation, any turbinate hypertrophy and endoscopic features suggestive of sinusitis.

Results

A significant increase in the incidence of nasal septal deviation was found in PANDO cases (60%, 30/50) compared to controls (36%; 18/50; P = 0.03). The laterality of septal deviation corresponded to the side of NLD obstruction in 90% (27/30) cases. Higher location of DNS (73% vs 22%; P = 0.0009) and bony deviation (77% vs 44%; P = 0.02) were observed among study group as compared to controls. The odds of having NLD obstruction are 2.7 times more among individuals having septal deviation versus no deviation (95% CI, 1.19–5.99).

Conclusion

Unilateral PANDO has a higher incidence of ipsilaterally deviated nasal septum. This association is significant. Routine nasal endoscopic examination should be performed in cases undergoing dacryocystorhinostomy to better plan a concomitant septoplasty if needed.

Morphometric Evaluation of Bony Nasolacrimal Canal in a Caucasian Population with Primary Acquired Nasolacrimal Duct Obstruction: A Multidetector Computed Tomography Study

Objective

The bony nasolacrimal duct (BNLD) morphology as a contributory factor in primary acquired nasolacrimal duct obstruction (PANDO) is still controversial. The objectives of this study were to evaluate the morphometric differences of BNLDs in unilateral PANDO patients between PANDO and non-PANDO sides, as compared with the control group using multidetector computed tomography (CT).

Materials and Methods

Bilateral BNLDs in 39 unilateral PANDO patients and 36 control subjects were retrospectively reviewed. CT images with 0.5-mm thickness were obtained with a 64-slice scanner. The length, volume, coronal orientation type, sagittal orientation angle of BNLD, and relative lacrimal sac-BNLD angle were assessed. The entrance, minimum and distal end transverse diameters (TD) of BNLD was investigated.

Results

The mean minimum and distal end BNLD TDs measurements were significantly narrower in PANDO patients, both in PANDO and non-PANDO sides, as compared with the control group (p < 0.001 and p = 0.040, respectively); however, there were no significant differences between PANDO and non-PANDO sides within PANDO patients. The length, entrance TD, volume, coronal orientation type, sagittal orientation angle of BNLD, and relative lacrimal sac-BNLD angle were not significantly different between PANDO patients and control subjects, as well as between PANDO and non-PANDO sides within PANDO patients.

Conclusion

The narrow mean minimum and distal end BNLD TD in PANDO patients, in both PANDO and non-PANDO sides, may be associated with PANDO development. The lack of difference between PANDO and non-PANDO sides within PANDO patients and some overlap between PANDO patients and control subjects suggest that narrow BNLD is not the sole factor.