Understanding the developmental anatomy of the lacrimal sac fossa (LF) and nasolacrimal canal (NLC) is critical for paediatric lacrimal diseases. This observational study analysed cranial CT images of 144 paediatric patients undergoing imaging for non-ocular conditions and 80 adults with phthisis bulbi as a matched comparison. Measurements included LF vertical dimension (height) and anteroposterior dimension (width), NLC diameter and vertical dimension, and frontal process of the maxilla (FPM) structures. Developmental changes were assessed using the generalised additive model (GAM), with structural comparisons between children and adults. Children enrolled had an even distribution in age and gender (77 males and 67 females, average ages of 9.83 and 9.44 years, respectively). Except for the proportion of FPM contributing to the LF and inferior LF height (part below the operculum of middle turbinate), which showed minimal age-related change, the GAM model revealed that most structures grew rapidly before age 10, then slowed. The NLC vertical dimension exhibited the fastest growth, increasing approximately threefold from birth to adulthood, while other structures generally increased by 1.5 to 2 times. Males consistently had larger dimensions than females in most measurements. Differences compared to adults were more significant in children under 10. The various segments of the lacrimal drainage system exhibit different developmental patterns in children. While most LF and NLC structures grow rapidly before age 10, a few remains minimal age-related change. This study provides predictive values by age, which may serve as useful references for surgical planning in CNLDO.
Wang et al. (Tue,) studied this question.