The Fallacy of the Levator Expansion Theory

Asian upper blepharoplasty

“…According to some reports, the attachment of superficial fibers of the levator aponeurosis to the skin causes wrinkles and lid creases [6][7][8]. Likewise, it was reported that Asian people had more subcutaneous fat and retro-orbicularis oculi fat, and that pre-aponeurotic fat is located in front of the tarsal plate because the orbital septum meets the levator aponeurosis at the lower tarsal border [9].…”

The Causative Factors or Characteristics of the Asian Double Eyelid

“…6,12,13 Hence, it has been postulated that when an upper eyelid is thick, a single eyelid is formed, and when it is thin, a double eyelid is created. 9 The purpose of the present study is to clarify the possible causative factors in Asian double eyelid formation by analyzing the microscopic findings in upper eyelid specimens.…”

“…(Ophthal Plast Reconstr Surg 2012;28:376-381) D ifferent theories have been proposed to explain the causative factor of Asian double eyelid, with the 2 main possible factors being the terminal branch of the levator aponeurosis, 1-8 and thickness of the upper eyelid tissues. 7,[9][10][11][12][13][14] For many years, Sayoc's theory 1 of the "levator expansion" was used to explain double eyelid formation. According to this theory, fibers extending from the levator aponeurosis in a double eyelid penetrate the orbicularis oculi muscle, and reach the overlying dermis, 2 thus creating an eyelid crease during eyelid opening.…”

“…8 Different factors that influence the thickness of the upper eyelid may also play a role in creating a single or double eyelid. 9 These include the thickness of the skin, 7,10,11 the subcutaneous tissue 7,12 and the suborbicularis fibroadipose tissue; 6,7 and inferior drooping of the preaponeurotic fat pad, 4,6,7,9,12 and fusional height between the levator aponeurosis and the orbital septum. 6,12,13 Hence, it has been postulated that when an upper eyelid is thick, a single eyelid is formed, and when it is thin, a double eyelid is created.…”

“…7,[9][10][11][12][13][14] For many years, Sayoc's theory 1 of the "levator expansion" was used to explain double eyelid formation. According to this theory, fibers extending from the levator aponeurosis in a double eyelid penetrate the orbicularis oculi muscle, and reach the overlying dermis, 2 thus creating an eyelid crease during eyelid opening.…”