title: Effects of Valsalva Maneuver on Ocular Biometric Parameters: Optical Low-Coherence Reflectometry Biometer Study.
abstract: OBJECTIVE
  To evaluate the effects of the Valsalva Maneuver (VM) on ocular biometry and intraocular pressure (IOP).
  
  
  METHODS
  This prospective observational study included 55 eyes of 55 healthy volunteers. Axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), corneal curvature (K-steep, K-flat and K-mean), corneal diameter (WtW), and pupil diameter (PD) were measured with a LenStar LS 900® biometer at rest and during VM. The IOP was also measured at rest and during VM measurements were compared.
  
  
  RESULTS
  The VM did not have any significant influence on AL, WtW, K-flat, and K-mean (p > 0.05), but it decreased K-steep significantly (p < 0.001). Moreover, CCT and ACD decreased significantly during VM (p < 0.001), but VM increased IOP, PD (p < 0.001), and LT significantly (p = 0.002).
  
  
  CONCLUSIONS
  The VM might reversibly change in IOP and ocular biometry, so it should be considered during anterior segment examinations.
authors.affiliation: a Department of Ophtalmology , Gaziantep University School of Medicine , Gaziantep , Turkey and.
authors.forename: Alper
authors.initials: A
authors.lastname: Mete
authors.affiliation: b Department of Ophthalmology , Şehitkamil State Hospital , Gaziantep , Turkey.
authors.forename: Sabit
authors.initials: S
authors.lastname: Kimyon
authors.affiliation: b Department of Ophthalmology , Şehitkamil State Hospital , Gaziantep , Turkey.
authors.forename: İrfan
authors.initials: İ
authors.lastname: Uzun
authors.affiliation: a Department of Ophtalmology , Gaziantep University School of Medicine , Gaziantep , Turkey and.
authors.forename: Necip
authors.initials: N
authors.lastname: Kara
mesh_terms: D000328:Adult; D000867:Anterior Chamber / Q000033:anatomy & histology*; D058452:Axial Length, Eye / Q000033:anatomy & histology*; D001699:Biometry; D003315:Cornea / Q000033:anatomy & histology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D007908:Lens, Crystalline / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014636:Valsalva Maneuver / Q000502:physiology*; D055815:Young Adult
keywords: Corneal morphology; intraocular pressure; ocular biometry