Etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO)

Anatomical factors behind acquired primary nasolacrimal duct obstruction and acute dacryocystitis

PURPOSE

To compare the nasolacrimal and nasal anatomical parameters in cases of acquired primary nasolacrimal duct obstruction and acute dacryocystitis.

METHODS

The study included 62 eyes of 31 patients. The eyes were divided into three groups: Group A, comprising eyes presenting with acute dacryocystitis; Group B, comprising eyes with nasolacrimal duct obstruction but no previous episodes of dacryocystitis; and Group C, comprising eyes with an patent nasolacrimal duct. The coronal, axial, and sagittal computed tomography images of the cases were examined to assess parameters such as the canal's entry and exit, the narrowest transverse and anteroposterior diameters, the anatomical type of the canal, inferior turbinate thickness, the angle between the inferior turbinate and the medial maxillary wall, and the direction of septal deviation.

RESULTS

No significant difference was found in any parameter when comparing eyes with acquired primary nasolacrimal duct obstruction to the contralateral eyes without obstruction (p > 0.05). Among the three groups, eyes with acute dacryocystitis (Group A) had significantly wider exit transverse and narrowest anteroposterior diameters compared to the other two groups (p = 0.000, p = 0.001, and p = 0.006, p = 0.042), with the narrowest transverse diameter also being significantly wider compared to Group B (p = 0.007). The angle of the inferior turbinate was significantly lower in Group A compared to Group B (p = 0.038). There was no significant difference between the groups regarding the anatomical type of the canal (p = 0.981).

CONCLUSION

While anatomical parameters do not show significant differences between eyes with primary acquired nasolacrimal duct obstruction and those without obstruction in the same individual, the wider canal diameters in eyes with acute dacryocystitis suggest that secondary changes associated with dacryocystitis or a predisposition to dacryocystitis might be present in eyes with nasolacrimal duct obstruction.

Three-dimensional semi-autotamatic segmentation of nasolacrimal duct morphometry on computed tomography images

PURPOSE

Given the potential role of nasolacrimal duct (NLD) morphometry in the aetiology of primary acquired obstructions, it is imperative that clinicians have access to detailed anatomical information. The aim of this study was to determine normative data on nasolacrimal duct morphometry in the Turkish population sample and to provide guidelines for clinicians.

METHODS

The study included retrospectively computed tomography images of a healthy Turkish population sample of 151 individuals, 79 of whom were female and 72 of whom were male. Images were modeled and analyzed using 3D Slicer version 5.2.2.

RESULTS

The total volume and area of the NLD were smaller in females than in males. The right- and left-sided volume of the NLD were smaller in females than in males (In male, right side 219.28 ± 77.53 mm3 and left side 213.14 ± 73.82 mm3; in female, right side 193.82 ± 75.71 mm3, left side, 190.34 ± 82.54 mm3). Although the anteroposterior and transverse diameters of the right-sided NLD were not statistically different between the genders, the anteroposterior and transverse diameters of the left-sided NLD and distance between right and left NLD were smaller in female than in males. The volume and surface area of the right-sided NLD and the distance between the right and left NLD were larger with increasing age. The anteroposterior diameter was observed to be larger on the right side than on the left in both sexes, whereas the transverse diameter was larger on the right side than on the left side exclusively in females.

CONCLUSION

The results of this study may assist clinicians in the surgical approaches.

Endoscopic Dacryocystorhinostomy in Nasolacrimal Duct Obstruction With and Without Dacryocystitis: A Comparative Study

AIM

This research was designed to make a comparison of the treatment outcomes of endoscopic dacryocystorhinostomy (En-DCR) in nasolacrimal duct obstruction (NLDO) with and without chronic dacryocystitis.

METHODS

NLDO (obstruction group) and chronic dacryocystitis (dacryocystitis group) patients treated with En-DCR in the Eye Hospital of Wenzhou Medical University from March 2021 to February 2022 were retrospectively analyzed. According to CT dacryocystography, patients in each group were assigned into the high obstruction group (obstruction located in the lacrimal sac) and the low obstruction group (obstruction located at or below the junction of the nasolacrimal duct and dacryocystis). The surgery outcomes of patients in the 2 groups were compared 12 months postoperation.

RESULTS

One hundred four patients (104 eyes: obstruction group: 49 eyes; dacryocystitis group: 55 eyes) were recruited. Patients with high obstruction accounted for 61.2% in the obstruction group and 32.7% in the dacryocystitis group. There were significantly more high obstruction patients in the obstruction group versus the dacryocystitis group (P<0.05). At 12 months postoperative follow-up, the total anatomic and functional success rate was 83.7% and 80.8%, respectively. Higher anatomic success rate (90.9%) and functional success rate (89.1%) were noted in the dacryocystitis group versus the obstruction group (75.5% and 71.4%, respectively, P<0.05).

CONCLUSIONS

The obstruction site is higher in the obstruction group in comparison to that in the dacryocystitis group. En-DCR is effective in the treatment of NLDO and chronic dacryocystitis, and its efficacy on chronic dacryocystitis is better than that on NLDO.

Evaluation of primary acquired nasolacrimal duct obstruction: Comparison of CT-DCG and dacryoendoscopy in accurately localizing the lacrimal drainage obstructions

OBJECTIVE

To correlate and evaluate the power and limitations of CT-DCG in determining the level and type of lacrimal duct obstruction in comparison to dacryoendoscopy in patients clinically suspected to be having partial or complete primary acquired nasolacrimal duct obstruction (PANDO).

METHODS

A retrospective chart review was performed on 1232 lacrimal drainage systems of 957 patients who suffered from primary acquired nasolacrimal duct obstruction (PANDO) at Shanghai Ninth People's Hospital. Patients were examined with CT-DCG and correlated with dacryoendoscopy and the findings of clinical examination.

RESULTS

Of the studied patients, 173 were men and 784 were women with an age range of 18-93 years. Of the 1232 lacrimal pathways, good CT-DCG images could be obtained in 980 cases and dacryoendoscopy in 957 cases. Of these complete obstructions were noted in 81% (794/980), and partial obstructions were identified in 19% (186/980) with CT-DCG. CT-DCG and dacryoendoscopy showed 68.4% agreement for the type of the obstruction and 63% for the level of the obstruction. The majority of the obstructions occurred at the sac-duct junction (62.5%) followed by the upper half of the nasolacrimal duct (27.5%). There was a significant difference in the correlation of the obstruction type with age group and with the duration of symptoms. As the duration of symptoms increased, the proportion of complete lacrimal duct obstructions as shown on CT-DCG images increased and the proportion of incomplete obstruction decreased (p = 0.015).

CONCLUSIONS

The junction of lacrimal sac and nasolacrimal duct was the most common obstruction site. Age and the duration of symptoms influenced the type of obstruction noted. The degree and level of agreement between the investigations was moderate. A combination of CT-DCG and Dacryoendoscopy could together identify the location more accurately.

Dacryocystitis in a Patent Nasolacrimal Drainage System: A Literature Review

INTRODUCTION

Acute dacryocystitis is an acute infection and the lacrimal sac secondary to pathogenic microorganism growth within the stagnant fluid in the lacrimal sac secondary to nasolacrimal duct obstruction.

METHODS

A literature review was conducted on the PubMed database using the following search terms "dacryocystic retention" and "dacryocystitis" or "dacryolith" or "lacrimal duct" or "pseudo-dacryocystitis".

RESULTS

The literature review suggests that dacryocystitis in a patent nasolacrimal drainage system can stem from diverse causes including the mechanical impaction by dacryoliths, viral infections and anatomical variations. It is believed that these causes lead to transient obstruction to the nasolacrimal excretory system predisposing to secondary infections. Idiopathic temporary dacryocystic retention is also highlighted in this review.

CONCLUSIONS

This review broadens the understanding of dacryocystic retention and highlights the need for careful diagnosis and tailored treatment plans, particularly in cases deviating from the traditional etiological pathways.

Nasolacrimal duct rhinostomy for low-level nasolacrimal duct obstruction:long-term outcomes and surgical selection paradigm

PROPOSE

This study aims to present long-term outcomes in a specific patient population experiencing epiphora due to low-level nasolacrimal duct obstruction (NLDO) following endonasal endoscopic nasolacrimal duct rhinostomy, and to propose a surgical selection paradigm for varying locations of NLDO.

METHODS

Between September 1, 2017 and February 28, 2023, a retrospective analysis was conducted on 26 patients diagnosed with primary acquired nasolacrimal duct obstruction (PANDO) who underwent endonasal endoscopic nasolacrimal duct rhinostomy for low-level NLDO (defined as obstruction below the plane of the superior border of the inferior turbinate attachment). The study assessed surgical success through objective measures of anatomical patency and subjective measures of functional patency during a postoperative follow-up period of at least six months. Additionally, any complications that arose during this follow-up period were documented.

RESULTS

The study included a cohort of 26 patients, consisting of 24 women and 2 men, with a mean age of 47.58 ± 3.09 years (range: 8-75). All patients underwent endoscopic nasolacrimal duct rhinostomy, with 10 eyes having previously undergone tear duct recanalization procedures. Anatomical patency was achieved in 88.5% (23/26) of cases, while functional patency was achieved in 80.8% (21/26) after an average follow-up period of 41.9 ± 22.1 months. No significant complications were observed in any of the patients during the follow-up period.

CONCLUSION

Endonasal endoscopic nasolacrimal duct rhinostomy is effective in treating epiphora in over 80% of cases with low-level NLDO. Tailoring the surgery to the location of the obstruction can improve outcomes and minimize damage.

Clinical outcomes and prognostic factors in patients with nasolacrimal duct obstruction or stenosis using dacryoendoscopy

OBJECTIVE

To evaluate the effectiveness of dacryoendoscopic-assisted laser dacryoplasty with silicone intubation (DLDI) for the management of nasolacrimal duct obstruction (NLDO) or stenosis, and to identify the factors associated with DLDI failure.

METHODS AND ANALYSIS

This study was designed as a prospective, single-centre cohort study. Patients with NLDO or stenosis who underwent DLDI from December 2019 to December 2021 at Tianjin Eye Hospital were considered for enrolment. The Kaplan-Meier estimator was used to assess the anatomical and functional success rate of DLDI within 2 years follow-up after removal of the silicone stent. Cox proportional hazards regression models were used to identify risk factors for treatment failure.

RESULTS

170, 174 and 178 eyes were included in Groups A (proximal NLDO), B (distal NLDO) and C (nasolacrimal duct stenosis), respectively. The overall anatomical success rate was 84.8% for the entire cohort at the 2-year follow-up. The cumulative anatomical or functional success rate for Groups B and C was significantly higher than that for Group A. In the multivariable model, a higher risk of failed DLDI surgery was associated with a history of chronic dacryocystitis (HR=3.07; p<0.001) and a longer duration of epiphora than 1 year (HR=2.67; p<0.001). Of the 522 eyes, 37 patients (7.1%) had surgery-related complications.

CONCLUSIONS

DLDI is an effective minimally invasive technique for treatment in patients with distal NLDO or stenosis. Factors associated with a higher risk of reoperation include a longer duration of epiphora and a history of chronic dacryocystitis.

TRIAL REGISTRATION NUMBER

NCT05999058.

Management of adult focal nasolacrimal duct stenosis: long-term outcomes of 3D CT-DCG-assisted and endoscopically guided coronary catheter balloon dacryoplasty

The purpose was to evaluate the use of 3D CT-DCG-assisted and endoscopically guided coronary catheter balloon dacryoplasty (CC-BDCP) in adults with focal stenosis of the nasolacrimal duct (NLD) and report their long-term outcomes. A prospective, non-randomized, single-center clinical study was performed, and the patients underwent endoscopy-guided CC-BDCP using percutaneous transluminal coronary angioplasty (PTCA) balloon catheters. 25 patients were enrolled in the study. The CC-BDCP procedure was performed in 21 of 25 (84%) patients, and the remaining 4 (16%) patients had significant procedural difficulties due to unfavorable anatomical conditions. Of the 21 patients, 10 (47.6%) were procedurally assessed as "easy" (eCC-BDCP) and in 11 (52.4%) as procedurally "difficult" (dCC-BDCP). Values on Munk's epiphora intensity scale changed overall from 4.0 preoperatively to 1.4 ± 1.6 (p = 0.00001) postoperatively overall. FDDT changed overall from 2.9 ± 0.3 to 1.1 ± 1.2 after treatment (p = 0.00008) (from 2.8 ± 0.4 to 0.3 ± 0.6 in the eCC-BDCP group and from 2.9 ± 0.3 to 1.4 ± 1.2 in the dCC-BDCP group (p = 0.01352). The anatomical and functional success rate was 77% overall, 90% in the eCC-BDCP group, and 64% in the dCC-BDCP group. The CC-BDCP led to a statistically significant decrease in epiphora in a particular group of adult patients with demonstrable focal stenosis of the NLD.

Pre-Operative Planning of a DCR Surgery Using Virtual Reality

PURPOSE

To assess a novel Virtual Reality (VR) tool designed to enhance understanding of the nasal anatomy in patients eligible for DCR surgery.

METHODS

Preoperative Computed Tomography (CT) scans of the orbit were obtained and loaded as DICOM (Digital Imaging and Communications in Medicine) files onto the D2P software (3D Systems Inc. Littleton, CO) for tissue segmentation and 3D model preparation. Segmentation was performed on several anatomical structures, including the skull, lacrimal sac, nasal septum, inferior and middle turbinate. The resulting 3D model was visualized using a VR headset. After completing the segmentation procedure, ten cases were evaluated by a panel of six surgeons, including both senior and resident physicians from ENT and oculoplastic specialties.

RESULTS

The dataset under examination comprised images from 10 preoperative CT scans of the orbits of patients eligible for Endo-DCR. When evaluating the CT using the VR tool, in 73.3% of the cases ENT surgeons were right about the side of pathology, while only 43.3% ophthalmologists were right (chi-square, p = .018). In 72.8% of the cases ENT surgeons were evaluated right that there is a septum deviation, while only in 47.2% of the cases the ophthalmologists were right (chi-square, p = .094).When evaluating the CT using the VR tool, in 60% of the cases consultants were right about the pathology, while 57.7% of the residents were right (chi-square, p = .853). In 81.7% of the cases consultants were evaluated right that there is a septum deviation, while only in 58.3% of the cases the ophthalmologists were right (chi-square, p = .198).

DISCUSSION

ENT surgeons, as well as consultants, interpreted the CT better than the ophthalmologists and residents. Surprisingly, the VR system did not help them to interpret the CT better. Further, more extensive studies should be done to build a VR system that assists in the correct interpretation of the preoperative CT before DCR surgery as well as during DCR surgery.

Dry eye and decreased tear film stability in primary acquired nasolacrimal duct obstruction patients

PURPOSE

Exploring the prevalence of dry eye (DE) and the changes of tear film stability in patients with primary acquired obstruction of the nasolacrimal duct (PANDO).

METHODS

In this cross-sectional, observational study, 370 eyes in 223 patients with PANDO were assessed. The ocular surface disease index (OSDI) was used to evaluate ocular surface symptoms, and the Keratograph 5M non-invasive ocular surface analyser was used to assess ocular surface parameters. According to the TFOS DEWS II criteria, patients with OSDI ≥ 13 and NIKBUT < 10 s were diagnosed with DE.

RESULTS

Of the 223 PANDO patients, 65 (29.1%) met the diagnostic criteria for DE. Compared with patients without DE, PANDO patients with DE were significantly older (p < 0.001), had a longer duration of epiphora (p = 0.023), and more likely to have a positive regurgitation on pressure over the lacrimal sac (ROPLAS) sign (p = 0.003). Multifactorial analysis showed that older age, positive ROPLAS and hypertension were significant independent predictors of DE (p < 0.05). Among the 147 unilateral PANDO patients without DE, the TMH, NIKBUT-first, NIKBUT-average and bulbar erythema scores were significantly higher in the PANDO sides.

CONCLUSIONS

This study illustrated the prevalence of DE in PANDO patients was 29.1% and DE is more likely to occur in those who are older, have hypertension and are positive for ROPLAS. In addition, in patients with unilateral nasolacrimal duct obstruction, a decrease in tear film stability was observed in the healthy eye.

Update on lacrimal apparatus dysfunction associated with differentiated thyroid cancer after I-131 therapy

PURPOSE

The most prevalent lacrimal apparatus dysfunctions associated with differentiated thyroid cancer(DTC) after I-131 therapy are dry eye and nasolacrimal duct obstruction(NLDO), leading to ocular discomfort and lower quality of life for patients. It is crucial to diagnose and manage lacrimal apparatus dysfunction associated with I-131 therapy for DTC. Therefore, this review aims to comprehensively summarize and analyze the advances in mechanisms and therapeutic options underlying lacrimal apparatus dysfunction induced by I-131 therapy for DTC.

METHODS

A comprehensive search of CNKI, PubMed, and Wed of Science was performed from the database to December of 2023. Key search terms were "Thyroid cancer", "I-131", "Complications", "Dry eye", "Epiphora", "Tear", "Nasolacrimal duct" and "NLDO".

RESULTS

The research indicates that I-131 therapy for DTC causes damage to the lacrimal glands and nasolacrimal duct system, resulting in symptoms such as dry eye, epiphora, and mucoid secretions. Moreover, recent research has focused on exploring relevant risk factors of the condition and experimental and clinical treatments. However, there is some controversy regarding the mechanisms involved, whether it is due to the passive flow of I-131 in tears, active uptake of I-131 by the sodium-iodide symporter (NIS) in the lacrimal sac and nasolacrimal duct, or secondary metabolic and hormonal disturbances caused by I-131.

CONCLUSION

It is crucial for early detection and preventive measures by ophthalmologists and the need for further studies to elucidate the mechanisms underlying the disease.

Are inflammation-related diseases risk factors for primary acquired nasolacrimal duct obstruction? A large scale, national case-control study

PURPOSE

To evaluate the incidence and risk factors for inflammatory conditions among patients with primary acquired nasolacrimal duct obstruction (PANDO).

METHODS

A retrospective case-control study was conducted among patients of Clalit Health Services (CHS) in Israel from 2001 to 2022. For each case, three controls were matched among all CHS patients according to year of birth, sex, and ethnicity. Differences in demographic characteristics, ocular surface, eyelid, upper airway, and systemic diseases were assessed between the groups, and odds ratios (OR) were calculated.

RESULTS

A total of 60,726 patients diagnosed with PANDO were included. The average age of PANDO patients was 63 ± 18 years, 63% were female. Significant associations were found between PANDO and various ocular surface and eyelid conditions, including chronic conjunctivitis (OR 2.96, 95% CI [2.73-3.20]), vernal keratoconjunctivitis (OR 2.89, 95% CI [2.45-3.29]), and blepharitis (OR 2.75, 95% CI [2.68-2.83]). There was a significant association with various upper airway conditions, including rhinitis (OR 1.62, 95% CI [1.58-1.66]), chronic sinusitis (OR 1.71, 95% CI [1.62-1.80]), and deviated nasal septum (OR 1.76, 95% CI [1.69-1.84]). Association was also observed with systemic conditions, including asthma (OR 1.34, 95% CI [1.27-1.41]) and atopic dermatitis (OR 1.36, 95% CI [1.32-1.41]).

CONCLUSION

Ocular surface, eyelid, upper airway, and systemic inflammatory-related diseases were found to be associated with PANDO, supporting the theory that inflammation has a prominent role in the pathophysiology of PANDO.

Clinical characteristics and cytological changes in mucinous obstruction diagnosed by dacryoendoscopy

To analyze the clinical characteristics of mucinous obstruction diagnosed by dacryoendoscopy and compared the cytological changes with membranous obstruction using a modified liquid-based thin prep cytology method. A retrospective chart review was conducted on 53 eyes of 51 patients with mucus obstruction based on dacryoendoscopic findings from January 2022 to October 2022. Liquid-based thin-prep cytology was performed by irrigating the inside of the nasolacrimal drainage system with saline during dacryoendoscopy-guided silicone tube intubation. Pathological findings were analyzed through a comparison of mucinous obstruction with membranous obstruction as determined by dacryoendoscopic findings. The modified liquid-based thin prep cytology technique had a higher cytology detection rate across all cases. Mucinous obstruction exhibited a significantly higher number of successful canalicular irrigation test cases compared to membranous obstruction. In mucinous obstruction, epithelial squamous cells were more frequently detected in pre-sac obstruction, whereas columnar epithelial cells were predominant in post-sac obstruction. Inflammatory cells showed a stronger correlation with primary change and post-sac obstruction. Bacterial colonies were observed exclusively in cases of mucinous obstruction. The use of a modified liquid-based thin prep cytology method enables the examination of histopathological changes in the lacrimal passage in primary acquired nasolacrimal duct obstruction (PANDO), particularly in cases of mucinous obstruction, without the need for invasive biopsies. These findings enhance the understanding of the etiopathogenesis of mucinous obstruction, complementing knowledge of membranous obstruction in PANDO.

Outcomes of Endoscopic Endonasal Dacryocystorhinostomy in Glaucoma Patients

BACKGROUND

Anti-glaucoma eye drops have been investigated due to their production of fibrotic changes on the conjunctival surface, undermining the functioning of the upper lacrimal drainage system. We aimed to assess whether these effects may impair the effectiveness of endoscopic endonasal dacryocystorhinostomy (EE-DCR).

METHODS

This is a single-center observational retrospective study on EE-DCR via a posterior approach. Resolution of epiphora and dacryocystitis were analyzed after 1 (T1) and 6-months (T2) from surgery. Surgical success was defined as anatomical (patency at irrigation, no recurring dacryocystitis) or complete (zeroing of Munk score).

RESULTS

Twenty patients (32 sides) were enrolled. Preoperatively, 93.75% (n = 30/32) presented severe (Munk 3-4) epiphora and 68.75% (n = 22/32) recurrent dacryocystitis. At T1, 50.0% (n = 16/32) were referred with residual epiphora (Munk ≥ 1) and 18.75% (n = 6/32) dacryocystitis. At T2, 31.25% (n = 10/32) still complained of epiphora (Munk ≥ 1) and 6.25% (n = 2/32) dacryocystitis. Difference of outcomes at aggregate and paired timepoints (except for T1 versus T2) resulted in statistical significance (p < 0.05). At T2, 22 (68.75%) complete, 8 (25.0%) anatomical successes and 2 (6.25%) surgical failures were observed.

CONCLUSIONS

Despite the chronic uptake of anti-glaucoma eye drops, EE-DCR guaranteed high rates of clinical relief from epiphora and remarkable decreases in the rates of recurrent dacryocystitis.

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.

Comparing the diagnostic accuracy of MR dacryocystography (MRD) and dacryoscintigraphy (DSG) in NLDO-related acquired epiphora

PROPOSE

This study aimed to compare the diagnostic accuracy of MR dacryocystography (MRD) and dacryoscintigraphy (DSG) in the diagnosis of acquired epiphora related to NLDO. A total of 15 patients with acquired epiphora and suspected NLDO were included in this study.

METHODS

All patients underwent MRD and DSG examinations. MRD was performed using a 3-Tesla magnetic resonance imaging (MRI) scanner, while DSG involved injection of a radiotracer into the lacrimal drainage system followed by DSG. The results of both imaging methods were compared with the reference standard that was a combination of clinical examination findings and surgical exploration.

RESULTS

The results of this study showed that no abnormal findings were observed in MR-DCG in patients before the Valsalva maneuver. However, after the Valsalva maneuver, stenosis/obstruction at the canal surface was observed in all 15 patients diagnosed by DSG, giving a sensitivity of 100% for canal stenosis. Moreover, the results revealed that among these 15 patients, 9 showed stenosis or simultaneous obstruction at the level of the canal and lacrimal sac, but MR-DCG showed these lesions in only 9 patients, giving a sensitivity of 60%. The specificity of MRD and DSG were 85% and 76.7%, respectively. There was a statistically significant difference in the sensitivity of MRD and DSG (p < 0.05).

CONCLUSION

This study demonstrated that MRD has a higher diagnostic accuracy in the diagnosis of acquired epiphora associated with NLDO compared to DSG. MRD showed significantly higher sensitivity and specificity than DSG. Therefore, MRD can be considered as the preferred imaging modality in the diagnosis of acquired epiphora due to NLDO. By accurately identifying the underlying cause of NLDO, MRD can help determine the most appropriate treatment approach for patients and lead to better outcomes.