OCT imaging of endolymphatic hydrops in mice: association with hearing loss

Abstract

Background The etiology of Ménière’s disease (MD) is still not completely clear, but it is believed to be associated with endolymphatic hydrops (EH), which is characterized by auditory functional disorders. Vasopressin injection in C57BL/6J mice can induce EH and serve as a model for MD. Optical Coherence Tomography (OCT) has shown its advantages as a non-invasive imaging method for observing EH. Aim Investigating the relationship between hearing loss and EH to assist clinical hearing assessments and indicate the severity of hydrops. Methods C57BL/6J mice received 50 μg/100g/day vasopressin injections to induce EH. Auditory function was assessed using auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE). OCT was used to visualize the cochlea. Result OCT observed accumulation of fluid within the scala media in the cochlear apex. ABR showed significant hearing loss after 4 weeks. DPOAE revealed low-frequency hearing loss at 2 weeks and widespread damage across frequencies at 4 weeks. Conclusion The development of hearing loss in mouse models of MD is consistent with EH manifestations. Significance This study demonstrates the possibility of indirectly evaluating the extent of EH through auditory assessment and emphasizes the significant value of OCT for imaging cochlear structures.