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 included 64 patients who underwent DCG before undergoing general anesthesia probing for unilateral CNLDO. Several parameters were measured from the sagittal section DCG images: (1) the angle between the lacrimal sac (LS) and the nasolacrimal duct (NLD), (2) the angle between the superior orbital rim, the center of the LS, and the NLD, and (3) the length of the LS, (4) the length of the bony NLD. Additionally, the following parameters were measured from coronal section images: (5) the angle formed by the LS and the NLD and (6) the angle formed by the LS concerning the midline. Results: The average age of the patients was 34.3 months (range: 14–84 months). The mean ± standard deviation of the measurements of the above parameters was (1) -1.2° ± 16.5° (range: -44.6°–46.6°), (2) -5.0° ± 10.3° (range: -24.0°–19.0°), (3) 10.2 ± 2.4 mm (range: 6.5–16.0 mm), (4) 8.0 ± 2.5 mm (range: 3.1–14.8 mm), and (5) 15.6 ± 11.2° (range: -16.8°–41.0°), (5) 15.1 ± 5.2° (range: 3.3°–29.8°). All parameters, except for parameter (3), conformed to a normal distribution. Conclusions: This study provides valuable anthropometric data derived from DCG images, and the results highlight the substantial variability in lacrimal pathway morphology among patients with CNLDO. These findings have the potential to influence both diagnostic and treatment strategies. What is already known on this topic? Comprehending the morphology of the lacrimal pathway is crucial for the success of probing in patients with CNLDO. However, studies that delve into the detailed analysis of the lacrimal pathway in pediatric CNLDO are limited. What this study adds This study reports 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 included patients 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 patients with CNLDO, potentially influencing both diagnostic approaches and treatment strategies. This includes considerations such as conducting an anatomical evaluation of the lacrimal pathway and making informed decisions in selecting probe forms before undertaking procedures.