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Changes in optic nerve head blood flow in children with cerebral malaria and acute papilloedema
  1. N A V Beare2,
  2. C E Riva3,
  3. T E Taylor5,
  4. M E Molyneux2,
  5. K Kayira4,
  6. V A White6,
  7. S Lewallen7,
  8. S P Harding1
  1. 1St Paul’s Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
  2. 2Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Blantyre, Malawi
  3. 3Institute for Research in Ophthalmology, Sion, Switzerland
  4. 4Blantyre Malaria Project, Queen Elizabeth Central Hospital, Blantyre
  5. 5Michigan State University, East Lancing, Michigan, USA
  6. 6Department of Pathology and Ophthalmology, Vancouver General Hospital, University of British Columbia, Canada
  7. 7Kilimanjaro Centre for Community Ophthalmology, Tumaini University, Moshi, Tanzania
  1. Correspondence to:
 N A V Beare
 St Paul’s Eye Unit, Royal Liverpool University Hospital, Liverpool L7 8XP, UK; nbeare{at}btinternet.com

Abstract

Objective: To investigate capillary blood flow in the optic nerve head (ONH) of children with cerebral malaria.

Methods: Malawian children with cerebral malaria admitted to a paediatric research ward were examined by direct and indirect ophthalmoscopy. ONH blood flow was measured using laser Doppler flowmetry (LDF) in suitable patients. Mean blood volume and velocity were obtained from 30 to 60 s recordings from the temporal ONH and used to calculate blood flow. These were compared with admission variables, funduscopic findings and disease outcomes.

Results: 45 children with cerebral malaria had LDF recordings; 6 subsequently died and 5 survivors had neurological sequelae. 12 (27%) had papilloedema. The mean microvascular blood volume was higher in patients with papilloedema (3.28 v 2.54 arbitrary units, p = 0.002). The blood velocity correlated directly with haematocrit (r = 0.46, p = 0.001) and inversely with blood glucose (r = −0.49, p = 0.001).

Conclusion: The increase in ONH microvascular blood volume in papilloedema measured by LDF is consistent with current theories of pathogenesis of papilloedema. LDF has potential as a tool to distinguish papilloedema from pseudopapilloedematous disc swellings. The relationship between blood velocity and haematocrit may relate to levels of sequestration in cerebral malaria.

  • CNS, central nervous system
  • LDF, laser Doppler flowmetry
  • ONH, optic nerve head

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Footnotes

  • Funding: This study was funded by The Foundation for the Prevention of Blindness. Clinical care of patients was under a programme funded by The Wellcome Trust, and the US National Institutes of Health (grant number NIH R01 AI34969).

  • Competing interests: None declared.

  • Ethical approval: This study was approved by the University of Malawi College of Medicine Research Ethics Committee, Malawi. The study was explained to parents or guardians of eligible patients in their own language, and consent was obtained before enrolment.

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