Rheological behaviour of vitreous humour

Andreia F. Silva, Manuel A. Alves, Monica S. N. Oliveira

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The vitreous humour (VH) is a complex biofluid that occupies a large portion of the eyeball between the lens and the retina, and exhibits non-Newtonian rheological properties that are key for its function in the eye. It is often possible to distinguish two different phases in VH, known as liquid and gel phases (Sebag, 1987). In this work, we present a detailed rheological characterisation of the two phases of the VH under shear and extensional flow conditions. Healthy New Zealand rabbit eyes were used to measure the surface tension and the shear and extensional rheological properties of VH in different phase conformations and at different times after dissection. The results show that VH liquid phase exhibits a surface tension of 47.8 mN/m, a shear thinning behaviour reaching a viscosity plateau around 10-3 Pa.s for shear rates above 1000 s-1, and an average relaxation time of 9.7 ms in extensional flow. Interestingly, both VH phases present higher storage modulus than loss modulus and the measurements performed with VH gel phase 4±1 hours after dissection exhibit the highest moduli values. The compliance measurements for the gel phase show a viscoelastic gel behaviour and that compliance values decrease substantially with time after dissection. Our results show that the two VH phases exhibit viscoelastic behaviour, but with distinct rheological characteristics, consistent with a gel phase mostly composed of collagen entangled by hyaluronan and a second phase mainly composed of hyaluronan in aqueous solution.
LanguageEnglish
Pages1-21
Number of pages21
JournalRheologica Acta
Early online date7 Feb 2017
DOIs
Publication statusE-pub ahead of print - 7 Feb 2017

Fingerprint

Gels
Dissection
dissection
gels
Hyaluronic Acid
Surface tension
interfacial tension
liquid phases
shear
shear thinning
Shear thinning
retina
rabbits
New Zealand
Liquids
collagens
Collagen
shear flow
Relaxation time
Shear deformation

Keywords

  • vitreous humour
  • biorheology
  • biofluid
  • rheology

Cite this

Silva, Andreia F. ; Alves, Manuel A. ; Oliveira, Monica S. N. / Rheological behaviour of vitreous humour. In: Rheologica Acta. 2017 ; pp. 1-21.
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Rheological behaviour of vitreous humour. / Silva, Andreia F.; Alves, Manuel A.; Oliveira, Monica S. N.

In: Rheologica Acta, 07.02.2017, p. 1-21.

Research output: Contribution to journalArticle

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