Nasolacrimal System Aeration on Computed Tomographic Imaging: Sex and Age Variation

Evaluation of nasolacrimal canal morphology in different facial skeletal relationships

BACKGROUND

Abnormal morphological variations of nasolacrimal canal (NLC) and its lack of understanding contributes to acquired injuries during craniomaxillofacial surgical procedures which leads untoward postoperative complications like nasolacrimal obstruction (NLO) and epiphora.

PURPOSE

The purpose of this study was to determine dimensional and volumetric morphological variations of nasolacrimal canal in various facial skeletal relationships which aid in performing a precise and safe surgery.

MATERIALS AND METHODS

This retrospective cohort study involved dimensional and volumetric analysis of nasolacrimal canal procured from computed tomography scans of 47 individuals grouped as ClassI, Class II and Class III, and unilateral cleft lip and palate (UCLP) groups. The outcome variables included length of NLC, volume of NLC, distance between the inferior orifice of the NLC to nasal floor, distance between inferior orifice of NLC to canine apex and distance between inferior orifice of NLC to central incisor apex. The objectives were to analyse morphological variation of NLC in different facial skeletal relationships and to evaluate the variation with change in facial sides and its relationship with surrounding structures.

RESULTS

Volume of the NLC was found significant in Class I and UCLP population (p < 0.05) with the greatest volume in the UCLP group. The mean linear and volumetric measurements between the right and left sides were found insignificant among all groups. Inferior orifice of NLC from canine apex were farthest in Class III and nearest in the UCLP group (p < 0.05). There was no significant association between outcome variables and skeletal base configuration.

CONCLUSION

NLC demonstrates dimensional and anthropometric variations between different skeletal relationships and this study is inevitable in understanding the probability of NLC injury during maxillofacial surgeries.

Air spaces neighbouring the infraorbital canal

OBJECTIVE

The infraorbital canal (IOC) courses through the roof of the maxillary sinus (MS). Different grading systems concerning the topography of the IOC have been proposed. Further, it has been suggested that a transantral IOC would be morphologically related to Haller's cells (HCs). However, we hypothesized that this is not necessarily the case. Hence, we aimed to study the anatomical possibilities of the air spaces located medially to the IOC.

MATERIALS AND METHODS

The cone-beam computed tomography (CBCT) files of 40 adult patients were retrospectively evaluated.

RESULTS

The transantral type of IOC was found in 32.5% of patients. The infraorbital recesses of the MS were found medial to the IOC in 20% of patients. As referred to the nasolacrimal canal, these recesses were either prelacrimal (appearing as false isolated air cells) or retrolacrimal (appearing as false HCs). True HCs were found in 10% of patients. They were located medial to the IOC and they drained into the ethmoidal infundibulum (EI), which was distinct from the MS drainage. In 15% of patients, aerated nasolacrimal ducts (NLDs) were found anterior to the EI and medial to the antral angle. They were capable of masquerading either a HC or an infraorbital recess of the MS.

CONCLUSION

Previous classifications of the IOC, which related it to HCs, were reviewed and the evidence was found to be insufficient to assess the HC-related topography of the IOC. Therefore, to achieve the accurate anatomical identification of the air spaces neighbouring the IOC, the infraorbital recesses of the MS, the HCs, and the aerated NLDs should be carefully discriminated within the antero-supero-medial antral angle.

Comparative study of the clinical profile of chronic dacryocystitis and chronic rhinosinusitis after external dacryocystorhinostomy

Purpose

To compare the clinical profile of patients with chronic dacryocystitis (CDC) with and without associated chronic rhinosinusopathies who had been submitted to external dacryocystorhinostomy (EDCR).

Methods

This was a retrospective, observational, and longitudinal study that included all patients diagnosed with CDC who were submitted to EDCR at the Antonio Pedro University Hospital. Patients were divided into two groups, with and without rhinosinusopathies (Group I and Group II, respectively). The following variables were assessed to compare the Group I and Group II: age, ethnicity, epiphora, discharge by expression of the lacrimal sac, duration of the CDC, and previous history of CDC exacerbation.

Results

The study included a total of 78 patients, 22 patients (28.2%) in Group I and 56 patients (71.8%) in Group II. The mean age was 64.3 (±19.7) years. In Group I and II predominated elderly, female, and White (p=0.93, p=0.38, p=0.77). In relation to the clinical characteristics, most of the patients presented epiphora and discharge by compression of the lacrimal sac in both Groups (p=0.61, p=0.44). In relation to a previous history of exacerbations of the CDC, six patients in Group I and four patients in Group II presented it as purulent discharge (p=0.04).

Conclusion

Chronic rhinosinusopathies may favor episodes of exacerbations of chronic dacryocystitis in particular with the presence of purulent discharge.

TFOS DEWS II Sex, Gender, and Hormones Report

One of the most compelling features of dry eye disease (DED) is that it occurs more frequently in women than men. In fact, the female sex is a significant risk factor for the development of DED. This sex-related difference in DED prevalence is attributed in large part to the effects of sex steroids (e.g. androgens, estrogens), hypothalamic-pituitary hormones, glucocorticoids, insulin, insulin-like growth factor 1 and thyroid hormones, as well as to the sex chromosome complement, sex-specific autosomal factors and epigenetics (e.g. microRNAs). In addition to sex, gender also appears to be a risk factor for DED. "Gender" and "sex" are words that are often used interchangeably, but they have distinct meanings. "Gender" refers to a person's self-representation as a man or woman, whereas "sex" distinguishes males and females based on their biological characteristics. Both gender and sex affect DED risk, presentation of the disease, immune responses, pain, care-seeking behaviors, service utilization, and myriad other facets of eye health. Overall, sex, gender and hormones play a major role in the regulation of ocular surface and adnexal tissues, and in the difference in DED prevalence between women and men. The purpose of this Subcommittee report is to review and critique the nature of this role, as well as to recommend areas for future research to advance our understanding of the interrelationships between sex, gender, hormones and DED.

Preoperative Computed Tomography Findings for Patients with Nasolacrimal Duct Obstruction or Stenosis

Purpose

To identify and analyze the role of preoperative computed tomography (CT) in patients with tearing symptoms with nasolacrimal duct obstruction (NLDO).

Methods

We retrospectively reviewed the medical records and CT results on 218 patients who complained of tearing symptoms with NLDO between January 2014 and December 2014. All patients were recruited from Kim's Eye Hospital's outpatient clinic and assessed by clinical history, examination, and CT to evaluate periocular pathology and nasolacrimal drainage system. Patients with abnormal findings assessed by preoperative CT were further reviewed.

Results

CT was performed on 218 patients (average age, 58.2 ± 11.9 years). Of these, 196 (89.9%) had endonasal dacryocystorhinostomy, 14 (6.4%) declined surgery, and 8 (3.7%) were inoperable due to abnormal CT findings. Soft tissue opacity was the most common finding which 243 cases (85.9%) of 283 obstructed nasolacrimal duct and 89 cases (81.7%) of 109 non-obstructed nasolacrimal duct showed it. Thirty-nine (17.8%) of 218 patients showed either maxillary sinusitis or ethmoidal sinusitis and 32 (14.7%) of 218 patients presented with periocular inflammation. Other abnormal CT findings included septal deviations, previous fractures, masses, and structural abnormalities of nasal cavity.

Conclusions

Preoperative CT imaging is useful in the assessment of both nasolacrimal drainage and nearby anatomical structures. This information will be helpful in planning surgical interventions and management of NLDO.

Three-Dimensional Reconstruction of the Bony Nasolacrimal Canal by Automated Segmentation of Computed Tomography Images

Objective

To apply a fully automated method to quantify the 3D structure of the bony nasolacrimal canal (NLC) from CT scans whereby the size and main morphometric characteristics of the canal can be determined.

Design

Cross-sectional study.

Subjects

36 eyes of 18 healthy individuals.

Methods

Using software designed to detect the boundaries of the NLC on CT images, 36 NLC reconstructions were prepared. These reconstructions were then used to calculate NLC volume. The NLC axis in each case was determined according to a polygonal model and to 2^nd, 3^rd and 4^th degree polynomials. From these models, NLC sectional areas and length were determined. For each variable, descriptive statistics and normality tests (Kolmogorov-Smirnov and Shapiro-Wilk) were established.

Main Outcome Measures

Time for segmentation, NLC volume, axis, sectional areas and length.

Results

Mean processing time was around 30 seconds for segmenting each canal. All the variables generated were normally distributed. Measurements obtained using the four models polygonal, 2^nd, 3^rd and 4^th degree polynomial, respectively, were: mean canal length 14.74, 14.3, 14.80, and 15.03 mm; mean sectional area 15.15, 11.77, 11.43, and 11.56 mm²; minimum sectional area 8.69, 7.62, 7.40, and 7.19 mm²; and mean depth of minimum sectional area (craniocaudal) 7.85, 7.71, 8.19, and 8.08 mm.

Conclusion

The method proposed automatically reconstructs the NLC on CT scans. Using these reconstructions, morphometric measurements can be calculated from NLC axis estimates based on polygonal and 2^nd, 3^rd and 4^th polynomial models.