[Observation of the eyelid structure with opening and closing of the eye in magnetic resonance imaging].

To confirm the changes in the upper eyelid structure during normal movements such as opening and closing we observed the changes with magnetic resonance imaging and obtained the following results. (1) In the anterior lobe of the upper eyelid, the lower part moves more than the upper part. (2) The tarsus slides toward posterior and upper direction when the eye opens. (3) The orbital septum and the orbital fat move posteriorly and thicken when the eye opens. (4) When the eye opens Whitnall's ligament moves posteriorly with a little change of the acting vector direction of the levator muscle. (5) Aponeurosis of the levator muscle clearly separates from Müller's muscle when the eye opens. (6) We suspected that there is some suspending tissue of Whitnall's ligament that consists of a membranous or mesh-like structure in the orbital fat above the levator muscle.