title: [Transitory intrathoracic and -abdominal pressure elevation in the history of 64 patients with normal pressure glaucoma].
abstract: BACKGROUND
  As one pathogenetic factor in normal-tension glaucoma an individually elevated sensitivity of lamina cribrosa regarding intraocular pressure fluctuations is postulated. Aim of this study was to evaluate patients with normal-tension glaucoma for the exposure to potential, clinically undetected transient elevations of intraocular tension due to increased intrathoracic and -abdominal pressure.
  
  
  METHODS
  A survey of 64 patients of the "Erlanger Glaucoma registry" with normal-tension glaucoma (NTG) and 64 patients with primary open angle glaucoma (pOAG) as control group were performed with regard to activities respectively diseases causing intrathoracic or -abdominal pressure elevation (1. weight lifting, 2. playing high resistance wind instruments, 3. chronic asthma/cough, 4. obstruction of the urinary system, 5. constipation). Both groups were matched regarding age (median: 61 years), sex (24 male, 40 female), visual field defects (mean defect: NTG 4.4; pOAG 4.7), visual acuity (median 1.0 +/- 0.2) and systemic diseases (diabetes mellitus, hypertension, cardiac disease).
  
  
  RESULTS
  Among patients with NTG there were 45% (29/64 patients) with activities respectively diseases causing intrathoracic or intraabdominal pressure elevation in their medical history compared to 11% (7/64) among patients with pOAG. Male patients with normal-tension glaucoma showed with 62% the highest frequency of such activities (among them 4/24 high resistance wind instrument playing, 5/24 urinary system obstructions, 4/24 long time weight lifting). Female patients with normal-tension glaucoma most frequently presented with a history of weight lifting (11/40).
  
  
  CONCLUSIONS
  Patients with glaucomatous optic nerve atrophy without evident intraocular pressure elevation compared to patients with pOWG more frequently report activities or diseases causing intrathoracic/-abdominal pressure elevation in their medical history. This may suggest an additional pathomechanism in normal-tension glaucoma. Therefore patients may be adviced on these potential risk factors.
authors.affiliation: Augenklinik mit Poliklinik der Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen. Doreen.Krist@augenimed.uni-erlangen.de
authors.forename: D
authors.initials: D
authors.lastname: Krist
authors.forename: C
authors.initials: C
authors.lastname: Cursiefen
authors.forename: A
authors.initials: A
authors.lastname: Jünemann
mesh_terms: D000005:Abdomen / Q000503:physiopathology; D003248:Constipation / Q000503:physiopathology; D003371:Cough / Q000503:physiopathology; D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D011312:Pressure / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D013909:Thorax / Q000503:physiopathology; D014545:Urinary Calculi / Q000503:physiopathology; D014891:Weight Lifting