Thread: What is the diagnostic significance of the otologic "light reflex"?

What is the diagnostic significance of the otologic "light reflex"?

The light reflex on otoscopic examination is often described in the normal ear as a triangle of light on the TM with the apex extending from the umbo. Although some practitioners believe that an aberrance of this finding signifies disease, the light reflex generally has limited diagnostic importance.

The light reflex occurs because the TM is conical in shape, and light from the otoscope hitting this cone will create a triangular reflection in the anterior-inferior quadrant. The theory behind use of the "light reflex" is that, if the TM's conical shape is altered, for example, by bulging laterally from an acute purulent fluid collection, the "light reflex" disappears.

However, the "light reflex" can be present in pathologic ears, for example, when fluid or thick secretions in the middle ear are not enough to alter the shape of the TM and abolish the reflex. In otolaryngologic practice, a description of the otoscopic exam does not include mention of the "light reflex."

very good.