Abstract
Purpose: :
This study was performed to clarify the detailed anatomic relationship between the Müller’s muscle and the tarsus in Korean eyelids
Methods: :
Eight upper eyelids of 4 formalin-fixed Korean cadavers (4 males; age range 48~69 years; mean age 60.2 years) were examined. Three perpendicularly dissected sections with a 2-mm thickness were obtained from each eyelid, one section from the midline and one section each from a 3 mm distance at the lateral and medial lid edges of the tarsus. The samples were embedded in paraffin and stained with hematoxylin-eosin, Masson trichrome, and anti-smooth muscle actin antibody.
Results: :
The posterior side of Müller’s muscle was firmly attached to the conjunctiva and the anterior side was loosely attached to the levator apponeurosis. The thickness of Müller’s muscle ranged from 0.5 to 1.2 mm and Müller’s muscle was widely distributed through the lid to both lid margins. Especially, Müller’s muscle did not insert directly into the tarsus; instead, muscle tissues were tapered around the tarsus. It was also observed that fibrous connective tissue crossed between the tarsus and the insertion of Müller’s muscle in strand form. Meanwhile, the mean distance between the tarsus and Müller’s muscle was calculated; the insertion was 1.15 ± 0.52 mm from the tarsus at the center cut, and 2.28 ± 0.63 mm, and 2.88 ± 0.69 mm from the tarsus at the lateral and medial edges, respectively. Therefore, the Müller’s muscle insertion was positioned more inferior into the tarsus at the center than at the lateral and medial edges.
Conclusions: :
This study revealed that Müller’s muscle did not insert directly into the tarsus and the level of the insertion points was different between the midline and both lid margins. This fundamental study may be helpful in estimating the appropriate amount and range of resection in Müller's muscle surgeries, in order to improve surgical results.
Keywords: eyelid • microscopy: light/fluorescence/immunohistochemistry • anatomy