Assessment of the prelacrimal recess in different maxillary sinus pneumatizations in relation to endoscopic prelacrimal recess approaches: a computed tomography study.

PURPOSE: To assist in planning before the endoscopic prelacrimal recess (PLR) approach, we aimed to investigate the relationship between morphometry and variations of PLR in maxillary sinus (MS) pneumatizations. METHODS: Retrospective analysis of the paranasal sinus computed tomography images of 150 patients was conducted to determine the pneumatization patterns of the MS, PLR variations, and the applicability of the PLR approach. The results were compared based on lateralization, gender, and age groups. RESULTS: The PLRwidth, the anteroposterior diameter of the nasolacrimal duct (NLD), the vertical and horizontal diameters of the MS were the highest in hyperplasic MS, and decreased significantly with increasing age (p = 0.005, p = 0.017, p = 0.000), respectively. Most of the morphometric measurements were higher in hyperplasic MS, while the medial wall thickness of PLR was higher in hypoplasic MS. The PLRwidth for feasibility of the PLR approach were Type I (48%) in hypoplasic MS and Type III (80%) in hyperplasic MS (p < 0.001), respectively. The PLR medial wall thickness was higher in Type I, while the piriform aperture angle (PAA), MS volume, length, and slope of the NLD were higher in Type III PLRwidth (p = 0.000), respectively. The highest anterior and separation-type variations of the PLR were observed in hyperplasic MS, whereas 31.0% of hypoplasic MS had no PLR (p < 0.001). CONCLUSION: This study revealed that PLRwidth and PAA were the highest in hyperplasic MS, which allows the endoscopic PLR approach to be performed more easily. For safer and uncomplicated surgery, surgeon should be aware of the PLR anatomy in different MS pneumatization patterns.

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.

Computed tomographic assessment of the lacrimal sac fossa in the Japanese population.

PURPOSE: To analyze the morphology of the lacrimal sac fossa in the Japanese population using computed tomographic images. MATERIALS AND METHODS: One-hundred-fifty-five Japanese patients diagnosed with unilateral orbital fracture were retrospectively reviewed. Measurements of the dimensions of the lacrimal sac fossa were taken on three anatomical planes (upper, middle, and lower planes) using a digital caliper/protractor tool. RESULTS: The mean maximum thickness of the maxillary bone at the upper, middle, and lower planes of the lacrimal sac fossa were 4.60 mm, 5.07 mm, and 6.30 mm, respectively. The midpoint thickness of the maxillary bone at each plane were 3.04 mm, 3.00 mm, and 2.17 mm, respectively. The lacrimal bone thickness at each plane were 1.13 mm, 1.13 mm, and 1.08 mm, respectively. The proportion of the lacrimal sac fossa comprising of the lacrimal bone at each plane were 39.00%, 42.05%, 38.92%, respectively. On the middle plane, the mean angle between the lacrimal bone and sagittal plane was 131.92°. CONCLUSIONS: In Japanese patients, the proportion of the lacrimal bone on the lacrimal sac fossa tended to be of greater proportion compared to studies done on other races. The mean angle of the lacrimal sac fossa seemed to be comparatively high. These results indicate that performing an osteotomy during dacryocystorhinostomy could be relatively easier in the Japanese population compared to other races.

The value of lacrimal scintillography in the assessment of patients with epiphora.

PurposeTo assess the influence of dacryoscintillography (DSG) on the treatment decision for patients with epiphora and clinically patent non-functioning lacrimal systems.MethodsA retrospective 3-year review. Inclusion: patients having DSG for epiphora with delayed tear clearance, lacrimal system patency on syringing, and no visible external cause for watering. On the basis of regurgitation during syringing, tear ducts were divided into freely patent (FP≤20%) or stenosed. The DSG results were examined for correlation with symptoms and clinical examination, the influence on decision to proceed to dacryocystorhinostomy (DCR), and the ability to predict the surgical outcome.ResultsA total of 242 eyes were examined. The clinical diagnosis was FP in 45.5%, nasolacrimal duct stenosis (NLDS) in 26.4%, and other in 3.3%. The DSG was normal in 30.9% of FP and 18.7% of NLDS eyes. Of the asymptomatic eyes, 46.7% had an abnormal DSG. DSG sensitivity was 73.6% and specificity 53.3%. There was no significant difference in DSG results in those with FP or NLDS.DCR was recommended in 39.1% of the symptomatic eyes with abnormal DSG. DCR surgery was considered inappropriate in all 46 eyes with normal DSG. DCR was successful in 76.5%, however, the DSG result did not affect the success of surgery.ConclusionDSG has severe limitations due to lack of correlation with symptoms and clinical examination, inability to separate lacrimal duct narrowing from lacrimal pump function, and inability to predict the results of surgery. DSG can at best provide limited guidance on whether to proceed to DCR surgery.

Three-dimensional volumetric assessment of the nasolacrimal duct in patients with obstruction.

PURPOSE: The purpose of this study was to determine if a significant difference exists in the nasolacrimal duct volume of subjects with primary nasolacrimal duct obstruction compared with that of controls. METHODS: This was a retrospective, case-control study of 70 subjects with prior maxillofacial CT scans, including 35 subjects with obstruction and 35 controls. Volume measurements of the nasolacrimal duct were made on a GE Advantage Workstation using volume viewer software, and measurements were compared using an unpaired Student t test. Interrater and intrarater reliabilities were calculated. RESULTS: There was no significant difference in the nasolacrimal duct volume of patients (0.411 ± 0.18 cm) compared with that of controls (0.380 ± 0.13 cm(3)) (p = 0.23). Women had smaller volume ducts (0.356 ± 0.11 cm(3)) than that of men (0.482 ± 0.19 cm(3)) (p < 0.001). Male patients had smaller volume ducts (0.470 ± 0.23 cm(3)) than that of male controls (0.493 ± 0.14 cm(3)) (p = 0.70), while female patients (0.384 ± 0.13 cm(3)) had significantly larger volume ducts than that of female controls (0.328 ± 0.08 cm(3)) (p = 0.01). There was excellent interrater and intrarater reliabilities. CONCLUSIONS: CT 3-dimensional volumetric software can be used to accurately measure the nasolacrimal duct volume in patients with obstruction. Both the absence of a significant difference in patient's and control's nasolacrimal duct volumes and the overlap in range between the 2 groups imply that the volume of the tear duct is likely not related to the etiology of obstruction. The increase in volume seen in females with obstruction may be due to expansion of the bony canal during the postmenopausal years. The exact etiology of primary nasolacrimal duct obstruction requires further investigation.

Assessment of bony nasolacrimal parameters among Asians.

PURPOSE: A case series evaluating racial differences in the nasolacrimal region and quantifying the anterior lacrimal crest thickness and minimum nasolacrimal duct diameter in Asians. METHODS: Facial or orbital CT scans of 90 consecutive patients were retrospectively reviewed. Evidence of lacrimal fossa tumor or trauma excluded a patient. Using 3-dimensional image software, the thickness of the anterior lacrimal crest, narrowest diameter of the nasolacrimal duct, vertical diameter of the lacrimal sac fossa, frontonasal angle, and inter-frontozygomatic suture distance were measured in axial, sagittal, and coronal planes. RESULTS: Inter- and intraobserver correlation of a sample data proved reliability via intraclass correlation coefficient (0.706-0.917). Southeast Asians had a wider inter-frontozygomatic suture distance than South Asian and Occidental races (p = 0.025). Vertical lacrimal fossa diameter, anterior lacrimal crest thickness, and narrowest nasolacrimal duct diameter did not differ significantly between right and left sides or among ethnic groups. Narrower nasolacrimal duct diameter was significantly associated with decreased inter-frontozygomatic suture distance (p < 0.001), namely in patients with narrower faces. The anterior lacrimal crest thickness was significantly affected by the nasal configuration and thicker in patients with more acute frontonasal angle (p = 0.026). CONCLUSIONS: There is no significant difference in nasolacrimal duct diameter among ethnic groups, which may predispose one to nasolacrimal duct obstruction. But, this is significantly associated with inter-frontozygomatic suture distance, suggesting that a wider face is associated with wider nasolacrimal duct diameter. An acute frontonasal angle predicts a thicker anterior lacrimal crest for surgical preparation during dacryocystorhinostomy.

CT assessment of the nasolacrimal canal in a black African Population.

PURPOSE: Black Africans had been identified to have a lower prevalence of primary acquired nasolacrimal duct obstruction (PANDO). This has been attributed to the likely larger size of the nasolacrimal canal. However, there is paucity of studies that have quantitatively measured the dimension of the nasolacrimal canal in a homogeneous black population. The objective of this study was to determine the diameter of the bony nasolacrimal canal by CT in a normal adult Nigerian population. METHODS: The authors measured the minimum CT diameter of the bony nasolacrimal canal in 401 consecutive eligible adult patients using retrospective axial CT scans obtained between January 2006 and December 2010. The measurements were taken on axial images using a preset bone window algorithm on a standalone computer workstation with a ClearCanvas viewer (width: 2500, level: 480). The software calipers could measure up to a tenth of a millimeter. RESULTS: The CT images were made up of 378 cranial scans and 23 scans of paranasal sinuses. There were 286 male patients and 115 female patients aged 16 to 86 years with a mean age of 48.5 ± 18 years. The mean difference in nasolacrimal canal diameter of 3.52 mm in male patients and 3.36 mm in female patients was found to be statistically significant (t = 2.238, df = 400, p = 0.026). There was no significant difference in the canal diameter across age groups. In addition, there was no significant difference in the diameter between the right and left sides in the authors' study population (t = 1.551, df = 400, p = 0.122). CONCLUSIONS: The mean bony nasolacrimal canal diameter as measured by CT in Nigerians is smaller than those reported in African Americans, Asians, and Caucasians despite the reported lower prevalence of PANDO among blacks.

Assessment of the accuracy of lacrimal scintigraphy based on a prospective analysis of patients' symptomatology.

BACKGROUND: Dacryoscintigraphy is a noninvasive method frequently used for assessment of the lacrimal drainage system. Sometimes conflicting results with patients' complaints are obtained, which have no clear explanation. In our hypothesis, follow-up of patients evaluated with dacryoscintigraphy could be helpful in determining possible explanations for these conflicting results. METHOD: Thirty-eight consecutive patients (76 eyes) who had not previously undergone dacryocystorhinostomy or probing were entered in the study. Following instillation of 4 MBq (99m)Tc-pertechnetate, a routine procedure of dacryoscintigraphy was performed. After a mean follow-up time of 1.2 +/- 0.3 years (range 0.9-1.6 years), all patients were reassessed clinically. RESULTS: Using initial patients' symptoms as the gold standard, the sensitivity, specificity, NPV, and PPV of dacryoscintigraphy were calculated to be 82.1%, 75%, 60%, and 90.1%, respectively. The kappa value as a measure of agreement was 0.52. Considering the follow-up study as the gold standard, the sensitivity, specificity, NPV, and PPV were calculated as follows, respectively: 96.3%, 90.4%, 96.3%, and 90.4%. The kappa value was 0.86. There were three initially symptom-free eyes with obstructive pattern on the scans, which developed epiphora on the follow-up. In fact, these eyes were initially classified as false positive, but follow-up assessment showed that they were true-positive scans in a subclinical state. CONCLUSION: Despite certain drawbacks inherent to the technique, dacryoscintigraphy provides valuable independent information and allows more accurate management decisions. In some patients, data obtained from lacrimal scintigraphy could be predictive, and it makes possible determination of subclinical nasolacrimal duct obstructions.

Presurgical and postsurgical ultrasound assessment of lacrimal drainage dysfunction.

PURPOSE: In addition to the obligatory clinical tests, imaging of the lacrimal drainage system (LDS) is useful in its clinical evaluation. The purpose of this study was to examine the usability and reliability of ultrasonography in the evaluation of the lacrimal drainage system. DESIGN: Observational cohort study. METHODS: A prospective study was conducted at a single institution. We performed ultrasound examinations on 17 patients with epiphora before and after surgery, and on 17 asymptomatic volunteers, to visualize and evaluate the anatomic and functional condition or pathologic abnormalities of the LDS. RESULTS: Echographic evaluation of the LDS was possible in all individuals. Pathologic abnormalities (canaliculitis, diverticulitis, concretion, or dilation of the lacrimal sac, and reduced functionality of the orbicular muscle and/or lacrimal sac pump) could be well demonstrated. In the postsurgical course, functional patency of the dacryocystorhinostomy opening could be verified in all cases. CONCLUSIONS: Sonography of the LDS appears to represent a reliable diagnostic technique supplementary to clinical tests in the presurgical and postsurgical examination of patients with epiphora. Pathologic abnormalities that may not be apparent in routine x-ray dacryocystography can be demonstrated with ultrasound techniques. Patients also benefit from the avoidance of exposure to ionizing radiation. However, ultrasound is not suitable for imaging the lower part of the lacrimal sac and the lacrimal duct because of the presence of overlying bony structures.

Diameter of the bony lacrimal canal: normal values and values related to nasolacrimal duct obstruction: assessment with CT.

BACKGROUND AND PURPOSE: Epiphora, or tearing due to primary acquired nasolacrimal duct obstruction (PANDO), is increasingly being treated with balloon dilatation. The cause of PANDO is unknown, but a small diameter of the bony nasolacrimal canal might be one of the etiologic factors. The purpose of this study was to determine the normal distribution of diameters of the bony canal and to ascertain whether there is an association between the diameter of the bony canal and primary nasolacrimal duct obstruction. METHODS: Using axial CT, we measured the minimum diameter of the bony nasolacrimal canal in a control group of 50 men and 50 women and in 19 patients with PANDO. RESULTS: The mean minimum diameter in the control group was 3.5 mm, which was smaller than expected on the basis of published data. The difference between the mean minimum diameter in men (3.70 mm) and that in women (3.35 mm) was significant. The mean minimum diameter in the patient group was 3.0 mm, which was significantly smaller than that in the control group. There was, however, considerable overlap. CONCLUSION: A small diameter of the bony canal appears to be one of the etiologic factors in PANDO.

Ultrasonic assessment of rhinostomy size following external dacryocystorhinostomy.

AIM: To assess the dimensions and patency of the surgical epithelial fistula after external dacryocystorhinostomy, using B mode ultrasonography to define the postoperative soft tissue anastomosis. METHODS: 12 patients undergoing 16 external dacryocystorhinostomies, with the creation of large osteotomies, were included in a prospective study. The horizontal and vertical dimensions of the bone ostium was recorded during surgery and compared with the ultrasonographic dimensions of the soft tissue anastomosis at 1 day, 2 weeks, and 6 months after surgery. Functional patency was confirmed with dye testing and irrigation. RESULTS: Compared with an osteotomy of between 100 and 380 mm2 (mean 235 mm2), the soft tissue anastomosis on the day after surgery was, in all cases, markedly smaller (72-252 mm2; mean 144 mm2, or 61% of the bone window). The soft tissue anastomosis decreased to between 8 and 208 mm2 (mean 98 mm2; 68% of immediate postoperative value) at 2 weeks and 3-208 mm2 (mean 71 mm2; 49% of immediate postoperative value) at 6 months. 14 of the 16 (88%) dacryocystorhinostomies were functional at the end of the study, the two failures being associated with marked contracture of the soft tissue anastomosis; the outcome of surgery correlated significantly with the area of the anastomosis at 2 weeks (chi 2 = 16.3; p < 0.01) and at 6 months (chi 2 = 16.0, p = 0.01). CONCLUSIONS: B mode ultrasonography provides a simple and effective method for assessing the size of the soft tissue anastomosis after external dacryocystorhinostomy and there is a significant reduction in size after surgery, to which the functional outcome of surgery appears related. As the initial soft tissue anastomosis cannot be larger than (and is, on average, about 60% of) the area of the osteotomy, this emphasises the paramount importance of a large rhinostomy to the success of lacrimal surgery.

Toxicity of the chemiluminescent material Cyalume in anatomic assessment of the nasolacrimal system.

One of the most intriguing recent ideas for anatomic assessment of the nasolacrimal system is the use of chemiluminescence, whereby the entire system can be made visible in the physician's office. The potential toxicity of the chemiluminescent material Cyalume was evaluated through a clinical and pathological study of 34 rabbit eyes exposed ot it in various ways. When Cyalume was sealed in the nasolacrimal system, simulating clinical blockage, there were no toxic effects, even after 30 to 40 days, and only minimal side effects occurred with similarly prolonged subcutaneous exposure to the material. However, subtarsorrhaphic, subconjunctival and intra-aqueous deposits had caused serious complications in high proportions of eyes after 30 to 40 days. Similar toxic effects occurred, though, in all control eyes treated with Ethiodan (iophendylate), a contrast medium commonly and safely used in dacryocystography, which was injected either subconjunctivally or into the anterior chamber. Thus, Cyalume should have minimal toxicity when used clinically in the proposed fashion, provided extravasation of the material is carefully avoided.