title: Ultrasound biomicroscopy of the upper eyelid structures in normal eyelids.
abstract: OBJECTIVE
  To evaluate the normal upper eyelid structures quantitatively and qualitatively using ultrasound biomicroscopy (UBM).
  
  
  METHODS
  Sixteen upper eyelids of 16 healthy subjects with no eyelid problems were evaluated with UBM. The orbicularis oculi muscle, levator aponeurosis, Müller muscle-conjunctival complex, and tarsus were imaged centrally just above the tarsus, and the tarsus was imaged just above the eyelid margin. The thickness of these structures was measured primary gaze. The measurements of levator aponeurosis and Müller muscle-conjunctival complex were repeated in upgaze.
  
  
  RESULTS
  Of 16 patients, 8 were men and 8 were women. Eight were more than 40 years old and eight were younger. Orbicularis oculi muscle and Müller muscle-conjunctival complex were echo-dense, while levator aponeurosis and tarsus were echo-lucent. The mean thickness was 0.74 +/- 0.11 mm for orbicularis oculi muscle, 0.44 +/- 0.67 mm for levator aponeurosis, 0.91 +/- 0.15 mm for tarsus, and 0.38 +/- 0.64 mm for Müller muscle-conjunctival complex. There was no significant difference in the thickness of these structures between the patients younger than 40 years old and older patients, or between male and female patients (p > 0.05). In upgaze, the increases in thickness of levator aponeurosis and Müller muscle-conjunctival complex were a mean of 53% and 32%, respectively.
  
  
  CONCLUSIONS
  UBM is an easy, non-invasive test used to visualize normal eyelid structures. It can be used in the diagnosis and follow-up of eyelid problems. The normal upper eyelid structures showed no significant differences based on age or gender.
authors.affiliation: Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA.
authors.forename: Hakan
authors.initials: H
authors.lastname: Demirci
authors.forename: Christine C
authors.initials: CC
authors.lastname: Nelson
mesh_terms: D000328:Adult; D000368:Aged; D005143:Eyelids / Q000000981:diagnostic imaging* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D033401:Microscopy, Acoustic; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000000981:diagnostic imaging* / Q000502:physiology