Learning Objectives: Understand the methods available to measure Eustachian tube dysfunction.

Background: Eustachian tube (ET) dysfunction is a common but poorly understood cause of patient symptoms and an important factor in the development of middle ear pathology. Despite this, there are no specific tests of ET function in widespread clinical use. A renewed interest in treatments for ET dysfunction has led to a demand for methods of imeasuring ET function non-invasively.

Objective: To identify currently available tests and imaging modalities to assess ET function and, where possible, report on their accuracy.

Methods: Narrative systematic review. Tests and imaging methods in included studies were required to measure a physiological function of the ET, or play a role in the diagnosis of poor ET function.

Results: While many tests of ET function have been developed, with some in routine clinical use, all have significant limitations. Published accuracy data are limited and of variable quality due to the range of comparative tests and the spectrum of otological disorders associated with ET dysfunction. CT and MRI are best suited to identifying features associated with obstructive or patulous ET dysfunction

Conclusions: Currently, no single test or imaging modality can be used to diagnose ET dysfunction, but there is some evidence that diagnostic accuracy can be improved by combining the results of different objective tests and patient-reported outcome measures. Further development of ET function tests is required to facilitate the accurate diagnosis of patients and allow outcome reporting for new interventions.