Effect of ocular shape and vascular geometry on retinal hemodynamics: a computational model

Andrea Dziubek, Giovanna Guidoboni, Alon Harris, Anil N. Hirani, Edmond Rusjan, William Thistleton

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

A computational model for retinal hemodynamics accounting for ocular curvature is presented. The model combines (i) a hierarchical Darcy model for the flow through small arterioles, capillaries and small venules in the retinal tissue, where blood vessels of different size are comprised in different hierarchical levels of a porous medium; and (ii) a one-dimensional network model for the blood flow through retinal arterioles and venules of larger size. The non-planar ocular shape is included by (i) defining the hierarchical Darcy flow model on a two-dimensional curved surface embedded in the three-dimensional space; and (ii) mapping the simplified one-dimensional network model onto the curved surface. The model is solved numerically using a finite element method in which spatial domain and hierarchical levels are discretized separately. For the finite element method, we use an exterior calculus-based implementation which permits an easier treatment of non-planar domains. Numerical solutions are verified against suitably constructed analytical solutions. Numerical experiments are performed to investigate how retinal hemodynamics is influenced by the ocular shape (sphere, oblate spheroid, prolate spheroid and barrel are compared) and vascular architecture (four vascular arcs and a branching vascular tree are compared). The model predictions show that changes in ocular shape induce non-uniform alterations of blood pressure and velocity in the retina. In particular, we found that (i) the temporal region is affected the least by changes in ocular shape, and (ii) the barrel shape departs the most from the hemispherical reference geometry in terms of associated pressure and velocity distributions in the retinal microvasculature. These results support the clinical hypothesis that alterations in ocular shape, such as those occurring in myopic eyes, might be associated with pathological alterations in retinal hemodynamics.

Original languageEnglish (US)
Pages (from-to)893-907
Number of pages15
JournalBiomechanics and Modeling in Mechanobiology
Volume15
Issue number4
DOIs
StatePublished - Aug 1 2016

Keywords

  • Finite element exterior calculus
  • Hierarchical porous medium
  • Mathematical modeling
  • Ocular curvature
  • Retinal hemodynamics
  • Vascular network

ASJC Scopus subject areas

  • Biotechnology
  • Modeling and Simulation
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Effect of ocular shape and vascular geometry on retinal hemodynamics: a computational model'. Together they form a unique fingerprint.

Cite this