Clinical Efficacy of Orbital Computed Tomographic Assessment in Determination of the Optimal Length of the Jones Tube in Endo CDCR

Abstract

Purpose: To investigate whether preoperative orbital computed tomography (CT) may be useful for predicting the optimal length of the Jones tube and determining the predictive parameters of orbital CT that are associated with the optimal length of Jones tubes in endoscopic conjunctivodacryocystorhinostomy (CDCR). Methods: The medical records of 36 patients (42 eyes) who underwent endoscopic CDCR with Jones tube insertion and preoperative orbital CT from March 2018 to April 2022 were retrospectively evaluated. Analyzing the orbital CT films using the Picture Archiving and Communication System, the distance from the lacrimal fossa to the nasal septum was measured in coronal and axial views. Results: In the successful group, the length of the inserted Jones tube was significantly correlated with the length difference between the inserted tube and the diagonal length measured in the axial view (r=−0.485, P=0.030). Equivalency of the length verified in the operating room and length measured on orbital CT were demonstrated as follows: diagonal length measured in axial view (Da), horizontal length between the medial eyeball to the nasal septum in coronal view (Hc) and the estimated length (Ej) in axial view with α=tan30° and α=tan25°. Conclusion: The optimal length of the Jones tube is best predicted using the length of the lacrimal fossa to nasal septum in coronal and axial views. Preoperative orbital CT assessments can be noninvasive and useful in predicting adequate lengths of the Jones tube.