title: Variations in corneal biomechanical parameters and central corneal thickness during the menstrual cycle.
abstract: OBJECTIVE
  To assess variations in the biomechanical properties and central corneal thickness (CCT) throughout the female menstrual cycle.
  
  
  METHODS
  Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin Israel.
  
  
  METHODS
  Case series.
  
  
  METHODS
  Young healthy women were prospectively recruited. Every participant was assessed at the beginning of the menstrual cycle, at ovulation, and at the end of the cycle. At every time point, corneal hysteresis (CH) and the corneal resistance factor (CRF) were measured with the Ocular Response Analyzer and the CCT was measured with an ultrasonic pachymeter.
  
  
  RESULTS
  Twenty-two eyes of 22 women (mean age 19.5 years ± 1.5 [SD]) were included. The CH was statistically significantly decreased at ovulation (10.1 mm Hg) compared with the beginning (11.1 mm Hg, P<.001) and the end (11.4 mm Hg, P<.001) of the cycle. The CRF was also significantly decreased at ovulation (9.8 mm Hg) compared with the beginning (10.6 mm Hg, P<.001) and the end (10.5 mm Hg, P<.001) of the cycle. The central cornea was thinnest at the beginning (535 μm) and statistically significantly thicker at ovulation (542 μm, P<.001) and at the end of the menstrual cycle (543 μm, P<.001).
  
  
  CONCLUSIONS
  The CCT and biomechanical parameters significantly varied during the menstrual cycle. The CH and CRF were temporarily decreased at ovulation. The cornea was thinnest at the beginning and thicker at ovulation and at the end of the cycle. Such corneal changes may be important to consider during screening of candidates for laser refractive surgery.
authors.affiliation: Department of Ophthalmology, Assaf Harofeh Medical Center, Tel Aviv University, Zerifin, Israel. doctor.goldich@gmail.com
authors.forename: Yakov
authors.initials: Y
authors.lastname: Goldich
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Barkana
authors.forename: Eran
authors.initials: E
authors.lastname: Pras
authors.forename: Alexander
authors.initials: A
authors.lastname: Fish
authors.forename: Yossi
authors.initials: Y
authors.lastname: Mandel
authors.forename: Ami
authors.initials: A
authors.lastname: Hirsh
authors.forename: Nir
authors.initials: N
authors.lastname: Tsur
authors.forename: Yair
authors.initials: Y
authors.lastname: Morad
authors.forename: Isaac
authors.initials: I
authors.lastname: Avni
authors.forename: David
authors.initials: D
authors.lastname: Zadok
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D003315:Cornea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D007986:Luteinizing Hormone / Q000652:urine; D008597:Menstrual Cycle / Q000502:physiology*; D011446:Prospective Studies; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D007986:Luteinizing Hormone