Dacryoscintigraphy: Rediscovering an underutilized test

Learning Objectives 1. Review the anatomy and physiology of the lacrimal system as well as the pathophysiology of epiphora. 2. Understand how dacryoscintigraphy is performed, including advanced techniques such as quantitation, and interpreted. 3. Be familiar with contrast dacryocystography and the in-office tests ophthalmologists use in evaluating epiphora.

Epiphora, or excess tearing, is a common problem encountered by ophthalmologists. A subset of patients have epiphora due to nasolacrimal duct obstruction and in-office testing with fluorescein and saccharine have been criticized for inadequate sensitivity. Dacryoscintigraphy was developed in 1972 as a functional assessment of tear movement through the nasolacrimal system. Contrast dacryocystography, an x-ray or CT based technique, and a possible role for SPECT-CT will be examined. We reviewed 51 consecutive dacryoscintigrams from two institutions performed since 2009 and selected cases that exemplify key findings including normal flow, partial and complete nasolacrimal duct obstruction, and pre- and post-surgical findings. Advanced techniques such as quantitative assessment will also be addressed. The anatomy and physiology of the eye with special attention to the lacrimal system will be discussed and related to the dacryoscintigram. An ophthalmologist's perspective on when to utilize dacryoscintigraphy and how it is employed in the pre- and post-surgical setting will aid nuclear medicine physicians in approaching ophthalmologists in areas where dacryoscintigraphy is underutilized. Finally, readers will assess what they have learned by interpreting a set of dacryoscintigrams and comparing their impressions to that of an expert reader.