A novel device that weds the capabilities of low-coherence tomography (LCT) and optical coherence tomography (OCT) identified bacterial biofilms, which have been linked to chronic otitis media (OM). The technology could inform understanding of chronic OM and enable early detection and treatment monitoring, according to a study published online May 28 in Proceedings of the National Academy of Sciences.    

Chronic OM poses clinical management challenges; patients do not present with noticeable symptoms and diagnosis can be difficult with standard methods, according to background information in the study. Standard otoscopy provides limited sensitivity and specificity, at 74 percent and 60 percent, respectively.

“The noninvasive, high-resolution depth-ranging and imaging capabilities of LCI/OCT offer the potential for applications in the middle ear, specifically for the detection and quantification of biofilms,” wrote Cac T. Nguyen, from the department of electrical and computer engineering at University of Illinois at Urbana. The methods leverage broadband optical light to generate images of tissue microstructures.

Nguyen and colleagues used an LCI/OCT to analyze the middle ears of 20 adults—13 infected patients and seven normal controls—and identify the presence of biofilms.

The researchers acquired approximately 18,537 LCI scans and 742 OCT images from each subject. Among the subjects with chronic OM, a high percentage of LCI data was classified as abnormal and OCT images showed a biofilm attached to the tympanic membrane (TM). In contrast, nearly all LCI scans from normal ears were classified as normal.

“Based on our clinical study, a percentage of abnormal LCI scans exceeding 25 percent is considered evidence for presence of a biofilm, whereas more than 70 percent abnormal LCI is considered evidence of the presence of a large biofilm occupying a significant portion of the TM. This wide range of percentage of abnormal LCI scans suggests the potential for noninvasive monitoring of spatial development and regression of biofilms within the middle ear,” wrote Nguyen et al.