[Structure and magnetic resonance imaging of the fiber connection between Whitnall's ligament and the superior wall of the orbit].
To confirm the structure of the fiber connection between Whitnall's ligament and the superior wall of the orbit, we observed ten orbits of five Japanese cadavers by magnetic resonance imaging (MRI) and dissection. Our findings were as follows: MRI showed a well-circumscribed low-intensity signal at the fiber connection. Preaponeurotic fat was prominent, and the fibers originating from Whitnall's ligament were fused at the lower face of the capsule of the preaponeurotic fat in four cadavers. The fibers originating from the upper face of the fat were attached to the superior periorbit (minimum width, 15 mm). The fifth cadaver had little preaponeurotic fat and few fibers. These anatomic differences may be within the normal range of variation. We believe that the fibers support Whitnall's ligament and help to retract preaponeurotic fat during levator muscle contraction as the eye opens.