title: Lower eyelid tensometry in younger and older normal subjects.
abstract: OBJECTIVE
  This study aimed to establish normative and repeatability data for lower eyelid tensometry (LET) using a newly developed eyelid tensometer.
  
  
  METHODS
  In this prospective consecutive observational case series, 32 normal adult subjects, comprising 12 younger (aged 29+/-5 years, 6M:6F) and 20 older subjects (aged 74+/-6 years, 10M:10F), underwent LET. In the younger group, LET was measured for postero-anterior (PA), nasal and temporal displacement. Duplicate measurements were taken and these were repeated on a separate occasion. Associations between repeated measurements and between right and left eyes were determined and the coefficient of repeatability for PA measurements was estimated. Differences in LET between males and females were determined using ANOVA. Only PA tensions, with duplicate measurements, were assessed in the older group, and age effects were determined.
  
  
  RESULTS
  Mean temporal tension in the younger group was 7.8+/-2.9 mN (milliNewtons)/mm, while nasal tension was 13.0+/-4.6 mN/mm and PA tension was 11.2+/-5.3 mN/mm. There was a good correlation between interoccasion PA measurements (r=0.82-0.84, P<0.005) and between the right and left eyes (r=0.48, P<0.005). The coefficient of repeatability for PA tension was 1.8 mN/mm. In the younger group, overall eyelid tension (for all directions) for males was significantly higher than for females (ANOVA, P=0.03). For measurements in older subjects on a single occasion, PA tension was 11.1+/-3.5 mN/mm and in younger subjects 12.8+/-4.2 mN/mm (P=0.22).
  
  
  CONCLUSIONS
  LET is rapid, repeatable, feasible, and acceptable. PA tension was the most repeatable measurement. Younger males had higher eyelid tension than females, and there was no significant reduction in PA tension with age.
authors.affiliation: The Ocular Plastics Unit, The Prince of Wales Hospital and the University of New South Wales, Sydney, Australia. if@student.unsw.edu.au
authors.forename: I C
authors.initials: IC
authors.lastname: Francis
authors.forename: F
authors.initials: F
authors.lastname: Stapleton
authors.forename: K
authors.initials: K
authors.lastname: Ehrmann
authors.forename: M T
authors.initials: MT
authors.lastname: Coroneo
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology; D000704:Analysis of Variance; D001696:Biomechanical Phenomena / Q000295:instrumentation; D005143:Eyelids / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D012727:Sex Characteristics