Diversity in Lacrimal Pathway Morphology Among Japanese Patients with Congenital Nasolacrimal Duct Obstruction

Abstract

Abstract Objective: This prospective observational study aimed to explore the diversity in lacrimal pathway morphology among patients with congenital nasolacrimal duct obstruction (CNLDO) by examining dacryocystography (DCG) images. Methods: The study involved 64 patients who underwent DCG prior to undergoing general anesthesia surgery for unilateral CNLDO. Several parameters were measured from the sagittal section DCG images: (1) The angle between the lacrimal sac and the nasolacrimal duct, (2) The angle between the superior orbital rim, the center of the lacrimal sac, and the nasolacrimal duct, (3) The length of the lacrimal sac, (4) The length of the bony nasolacrimal duct. Additionally, following parameters were measured from coronal section images: (5) The angle formed by the lacrimal sac and the nasolacrimal duct, (6) The angle formed by the lacrimal sac concerning the midline. Results: The average age of the patients was 34.3 months, ranging from 14 to 84 months. The mean ± standard deviation of the measurements of the above parameters were (1) − 1.2 ± 16.5° (range, − 44.6° to + 46.6°), (2) − 5.0 ± 10.3° (range, − 24.0° to + 19.0°), (3) 10.2 ± 2.4 mm (range, 6.5 mm to 16.0 mm), (4) 8.0 ± 2.5 mm (range, 3.1 mm to 14.8 mm), (5) 15.6 ± 11.2° (range, − 16.8° to + 41.0°), (5) 15.1 ± 5.2° (range, + 3.3° to + 29.8°). All parameters, except for parameter (3), conformed to a normal distribution. Conclusions: This study offers valuable anthropometric data derived from DCG images, and the results emphasize the substantial variability in lacrimal pathway morphology among individuals. What is already known on this topic. Comprehending the morphology of the lacrimal pathway is crucial for the success of probing in CNLDO patients. Nevertheless, there is a scarcity of studies delving into the detailed analysis of the lacrimal pathway in pediatric CNLDO. What this study adds This study represents the first attempt to measure anthropometric parameters of the lacrimal drainage system in patients with CNLDO using DCG images. Moreover, probing with straight probes was considered anatomically infeasible in 25.0% of cases in the patients included in this study. How this study might affect research, practice or policy The results underscore significant variations in the morphology of the lacrimal drainage system among individuals. This information is pivotal for enhancing our understanding of anatomical diversities in CNLDO patients, potentially influencing both diagnostic approaches and treatment strategies.