Video pneumatic otoscopy for the diagnosis of otitis media with effusion: a quantitative approach.

Pneumatic otoscopy is most helpful for optimally assessing the presence of a middle ear effusion (MEE). To evaluate the diagnostic usefulness and to obtain objective parameters of video pneumatic otoscope (VPO) in ears with MEE, we measured the minimal and maximal pressures in the external auditory canal and recorded the movement of the tympanic membrane (TM) during VPO in 28 ears with MEE and 13 healthy ears. The movements of the TM at static stage, positive and negative pressure stages of VPO were analyzed in terms of the position of the umbo and the angle and length of the malleus. The percent volume of air space out of the total tympanomastoid air cell system (the air index) was obtained from the temporal bone CT, and was used as a reference standard. As a result, minimal pressure and the movement of the umbo from negative pressure stage in ears with MEE were significantly different from the normal ears. The minimal pressure, maximal pressure and the movement of umbo from negative pressure to static stage were significantly correlated with the air index. These results may suggest useful parameters for quantitative analysis of VPO for the visual diagnosis of MEE.