The status of the contralateral ear in established unilateral Meniere's disease

Objectives/Hypothesis: To determine the incidence of measurable audiometric changes in the contralateral ear and clinical bilateral Meniere's disease in individuals with longstanding established unilateral Meniere's disease. Study Design: Analysis of data in an ongoing prospective study. Methods: One hundred and one patients who were treated with intratympanic gentamicin installation for disabling unilateral Meniere's disease were followed up for a minimum of 2 years. The mean follow-up time between the initial diagnosis to the last audiogram conducted was 12 +/- 7 (range 2-45) years, and the mean follow-up between the first and last audiograms conducted in our clinic was 5 +/- 3 (range 2-15) years. The incidence of Meniere's disease (clinical diagnosis) as compared with audiometric changes in the contralateral ear was analyzed. Results: Compared with several published reports, the development of bilateral Meniere's disease in our series within the described observation period was much lower (5%). The incidence of contralateral isolated hearing loss in the low frequencies was 16% (average threshold of .25 and .5 kHz of 25 dB or more). The time interval between the initial diagnosis and the onset of contralateral findings ranged from 0 to 26 years. Conclusion: In our experience, individuals with disabling longstanding unilateral disease are not likely to develop bilateral disease. However, a small but significant percentage of patients have audiometric changes in the low frequencies of the contralateral ear (.25, .5 kHz).