title: Effects of Valsalva's manoeuvre on intraocular pressure.
abstract: We examined the effects of breath holding against a closed glottis (Valsalva's manoeuvre) on intraocular pressure (IOP) in four groups of volunteer subjects: 37 healthy young control subjects, 10 patients with chronic open-angle glaucoma, 11 age-matched control subjects and 8 glaucoma suspects. IOP was recorded by one person using a Digilab 30R/T Pneuma-Tonometer. Chart recordings of the IOP were measured independently by a second investigator. Recordings were taken before, during and 5 minutes after the seated subject exhaled into an aneroid manometer to a pressure of 25 to 35 cm H2O. There was marked variability in the individual responses to Valsalva's manoeuvre in all four groups, with substantial increases (to +9.5 mm Hg) and decreases (to -4.0 mm Hg) in IOP seen. The mean change in IOP during Valsalva's manoeuvre was a small, statistically insignificant decrease in all four groups. The mean change in IOP following Valsalva's manoeuvre was a larger, but still clinically small, decrease. The clinician should be aware of the individual variability in IOP changes with Valsalva's manoeuvre.
authors.affiliation: Department of Ophthalmology, Dalhousie University, Halifax, NS.
authors.forename: P E
authors.initials: PE
authors.lastname: Rafuse
authors.forename: D W
authors.initials: DW
authors.lastname: Mills
authors.forename: P L
authors.initials: PL
authors.lastname: Hooper
authors.forename: T S
authors.initials: TS
authors.lastname: Chang
authors.forename: R
authors.initials: R
authors.lastname: Wolf
mesh_terms: D000328:Adult; D002908:Chronic Disease; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D009798:Ocular Hypertension / Q000503:physiopathology*; D014065:Tonometry, Ocular; D014636:Valsalva Maneuver