Optical Coherence Tomography for Quantitative Point-of-Care Ear Imaging

To determine whether an optical coherence tomography (OCT) otoscope can provide quantitative morphological measurements of the tympanic membrane (TM) that distinguish abnormal ears from normal controls.

Patients with ear disease and normal volunteers were imaged using an OCT otoscope. Integrated video otoscopy with simultaneous OCT imaging guided probe positioning. OCT volumes (< 5 s each) were acquired and fused to generate wide-field volumetric images of the TM and middle ear (ME). Datasets were analyzed using semi-automated segmentation to quantify TM thickness and surface morphology.

Fifty-five subjects (63 ears; 16 normal, 10 retraction pockets, 17 postoperative, 10 perforations, 10 cholesteatomas) were imaged. OCT volumetric imaging consistently distinguished normal, pathologic, and postoperative TMs. Mean TM thickness was significantly greater in all pathologic and postoperative groups compared to controls (p < 0.05). Surface gradient mapping demonstrated a characteristic pattern in normal TMs that was disrupted in disease states, with retraction pockets showing broad regions of low gradient consistent with a flattened contour. Longitudinal imaging demonstrated the ability to track disease progression; in one case, a retraction pocket progressed over 1 year to contact the cochlear promontory with associated focal thickening.

OCT otoscopy enables rapid, noninvasive, point-of-care volumetric imaging of the TM and ME. It provides quantitative metrics that improve diagnostic accuracy and allow objective monitoring of disease progression. OCT otoscopy has the potential to become a valuable tool in routine clinical practice.