Imaging in Disorders of the Lacrimal Drainage System

Abstract

Imaging in Disorders of the Lacrimal Drainage SystemVarious imaging modalities have been described for the anatomical and functional assessment of the lacrimal drainage system. Computed tomography (CT) and computed tomographic dacryocystography (CT DCG) are the most useful investigations. There are other investigations for the functional integrity of the lacrimal drainage system. This chapter presents an overview of all available modalities with special emphasis on CT DCG. The available modalities described in the literature include computed tomography, computed tomographic dacryocystography, ultrasound, magnetic resonance imaging, magnetic resonance dacryocystography, scintigraphy and digital subtraction dacryocystography [1][2][3][4][5].Although in complex situations like posttraumatic NLD obstruction imaging of the lacrimal system is often indicated [6] but in primary acquired nasolacrimal duct obstruction (PANDO), radiological investigations are generally not advised. This is because the diagnosis can often be reached through a battery of clinical tests including regurgitation test, probing syringing and the fluorescein dye test [7,8]. However, in certain selective cases of PANDO (mentioned below), radiological evaluation must be done to avoid failures. CT DCG is a widely used imaging modality and is considered a gold standard method for the evaluation of the lacrimal drainage system [9,10].