Article Text

Download PDFPDF

Pulsatile ocular blood flow: the effect of the Valsalva manoeuvre in open angle and normal tension glaucoma: a case report and prospective study
  1. J C Khan1,
  2. E H Hughes2,
  3. B D Tom3,
  4. J P Diamond4
  1. 1AMD Study, Box 261, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 2QQ, UK
  2. 2University Division of Ophthalmology, Bristol Eye Hospital, Lower Maudlin Street, Bristol BS7 8EG, UK
  3. 3Centre for Applied Medical Statistics, Department of Public Health and Primary Care, University of Cambridge, Institute of Public Health, University Forvie Site, Robinson Way, Cambridge CB2 2SR, UK
  4. 4Bristol Eye Hospital, Lower Maudlin Street, Bristol BS1 2LX, UK
  1. Correspondence to: Jane Khan

Abstract

Aim: A case of severe normal tension glaucoma is reported in a trumpet player, along with a study investigating the association between glaucoma and raised intrathoracic pressure, using measurements of pulsatile ocular blood flow (POBF).

Methods: Three patient groups were studied; normals (n = 34), untreated primary open angle glaucoma (POAG) (n = 20), and untreated normal tension glaucoma (NTG) (n = 22), with a total of 76 patients who underwent measurements of POBF using the OBF pneumotonometer at rest and while forcibly exhaling through a mouthpiece connected to a mercury manometer (30 mm Hg) (Valsalva manoeuvre).

Results: POBF fell during Valsalva in all groups with the greatest predictor being the resting value of POBF. There was no evidence of significant differences in the mean change in POBF occurring during the Valsalva manoeuvre for the three groups studied before or after adjusting for the sex, the resting POBF, and the resting IOP of the patients (p = 0.294 and p = 0.542, respectively). However, statistically significant associations were found between the change in POBF and sex (p = 0.049), resting POBF (p<0.0001) and resting IOP (p = 0.032). Males had a greater drop, on average, in POBF during Valsalva manoeuvre than females after adjusting for the other factors. Additionally, there was a significant difference in the mean change in IOP during Valsalva for the three groups (p = 0.002), with the difference occurring between the normal and POAG groups (p<0.005). The POAG group had, on average, a drop in IOP during Valsalva, while the other two groups had an increase in IOP. Also noted was a significant difference in the distributions of the risk factors among the three groups (p = 0.002).

Conclusions: This study demonstrates no difference between groups with respect to resting or Valsalva POBF, but does demonstrate a possible trend with respect to IOP, with a drop in IOP occurring during Valsalva in the POAG group. There is, however, much variability in the data left unexplained by our models. Thus, unfortunately, we cannot advise our trumpet player whether his NTG is directly related to his trumpet playing.

  • Valsalva manoeuvre
  • glaucoma
  • pulsatile flow
View Full Text

Statistics from Altmetric.com

Footnotes

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.