The width of the external aperture of the vestibular aqueduct was measured in patients with Meniere's disease in three-dimensional images. The aperture on the side affected by Meniere's disease was significantly narrower than in normal ears or ears with chronic otitis media. The aperture on the opposite (healthy) ear in unilateral Meniere's disease was also significantly narrower than that in normal ear or with chronic otitis media. Thus, it appears that the aqueduct in Meniere's disease is incompletely developed and that this abnormality is related to the pathogenesis. Also, in unilateral Meniere's disease the opposite ear is at high risk of developing the disease eventually.
