THE ROLE OF MULLERS MUSCLE RECONSIDERED

It is a traditional teaching that tile levator aponeurosis is the main transmitter of the levator palpebrae muscle. However, there are sever al points that raise doubts in this fundamental concept of the levator aponeurosis as being the primary interconnecting mechanism in upper L id elevation. Despite the structural integrity of the levator complex, drooping of ale upper eyelids is seen to develop in situations such a s Horner's syndrome and ill times of excessive fatigue and sleepiness. Amid the controversy in the literature regarding the specific role of the levator aponeurosis in tile lid-elevating mechanism, we have obse rved that the levator aponeurosis fails to make constant attachment to tile tarsal plate. This has led us to speculate on the possible rule of the posterior lamella - Muller's muscle - as the primary transmitte r of the levator muscle action to the tarsal plate.