Imaging of Lacrimal System

The role of imaging for abnormal tear-flow dynamics is controversial, with some suggesting imaging to be mandatory in every patient with nasolacrimal duct obstruction (NLDO) and others considering it only for very specific indications. Several imaging techniques—including ultrasonography, dacryoscintigraphy, contrast dacryocystography (DCG), computed tomography (CT) or magnetic resonance imaging (MRI)—are available for lacrimal investigation, and choice is dependent upon the suspected pathology. Imaging is useful in case of major craniofacial anomalies, for redo surgery where the clinical signs are uncertain, when a tumour is suspected, in case of mass-like inflammatory lesions of the lacrimal system, and where endoscopic surgery is planned. Recently, the number of requests for DCGs has markedly decreased, as the history and outpatient tests are usually sufficient for diagnosis. Where there is concern for a structural lesion, CT is the preferred investigation. Although expensive, time-consuming and the images prone to movement artefact, MRI with contrast offers some advantages over other techniques by giving high-resolution of the soft tissues within and around the lacrimal drainage system.