title: The force required to induce hemivein pulsation is associated with the site of maximum field loss in glaucoma.
abstract: OBJECTIVE
  To determine the factors associated with central retinal vein pulsation changes in glaucoma and identify any hemiretinal vein pulsation changes and their association with sectoral visual field loss.
  
  
  METHODS
  One hundred twenty-six patients with glaucoma and 40 normal subjects had automated perimetry, blood pressure, and intraocular pressure measured. A hemifield sensitivity loss was calculated from the upper and lower halves of each field. Those without spontaneous venous pulsation on the optic disc had an ophthalmodynamometer applied, to measure the minimum ophthalmodynamometric force (ODF) necessary to induce venous pulsation. When ODF was restricted to the hemiveins, the force needed to induce pulsation in each hemivein was measured.
  
  
  RESULTS
  Eighty-three patients with glaucoma had no spontaneous venous pulsation. The minimum ODF was strongly correlated with mean deviation (Spearman rank r = -0.475, P < 0.0001). Mixed linear regression analysis showed that mean deviation (P < 0.0001) and pulse blood pressure (P < 0.0001) were significantly associated with minimum ODF. There was a strong association between differences in hemifield sensitivity loss and in hemivein ODF (rank r = 0.369, P < 0.0001, n = 80). Multiple linear regression modeling demonstrated that lower hemivein ODF was independently associated with upper field loss (P = 0.003) and upper hemivein ODF with lower field loss (P < 0.0001).
  
  
  CONCLUSIONS
  These venous pulsation findings in glaucoma are independent of blood pressure. The hemifield and hemivein association suggests that the major hemivein change is adjacent to the site of major disc damage.
authors.affiliation: Lions Eye Institute, University of Western Australia, Nedlands, WA, Australia. whmorgan@cyllene.uwa.edu.au
authors.forename: William H
authors.initials: WH
authors.lastname: Morgan
authors.forename: Chandrakumar
authors.initials: C
authors.lastname: Balaratnasingam
authors.forename: Martin L
authors.initials: ML
authors.lastname: Hazelton
authors.forename: Phillip H
authors.initials: PH
authors.lastname: House
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Cringle
authors.forename: Dao-Yi
authors.initials: DY
authors.lastname: Yu
mesh_terms: D000368:Aged; D001794:Blood Pressure; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D009884:Ophthalmodynamometry; D009898:Optic Disk / Q000098:blood supply; D011673:Pulsatile Flow / Q000502:physiology*; D012169:Retinal Vein / Q000502:physiology*; D014786:Vision Disorders / Q000503:physiopathology*; D058609:Visual Field Tests; D014794:Visual Fields