The retinal arterial network structure can be altered by systemic diseases such as hypertension and diabetes. In order to compare the energy requirement for maintaining retinal blood flow and vessel wall metabolism between normal and hypertensive subjects, 3D hypothetical models of a representative retinal arterial bifurcation were constructed based on topological features derived from retinal images. Computational analysis of blood flow was performed, which accounted for the non-Newtonian rheological properties of blood and peripheral vessel resistance. The results suggested that the rate of energy required to maintain the blood flow and wall metabolism is much lower for normal subjects than for hypertensives, with the latter requiring 49.2% more energy for an entire retinal arteriolar tree. Among the several morphological factors, length-to-diameter ratio was found to have the most significant influence on the overall energy requirement.

References

1.
Joussen
,
A. M.
,
Gardner
,
T. W.
,
Kirchhof
,
B.
, and
Ryan
,
S. J.
, 2007,
Retinal Vascular Disease
,
Springer
,
New York.
2.
Hughes
,
A. D.
,
Martinez-Perez
,
E.
,
Jabbar
,
A.
,
Hassan
,
A.
,
Witt
,
N. W.
,
Mistry
,
P. D.
,
Chapman
,
N.
,
Stanton
,
A. V.
,
Beevers
,
G.
,
Pedrinelli
,
R.
,
Parker
,
K. H.
, and
Thom
,
S. A.
, 2006, “
Quantification of Topological Changes in Retinal Vascular Architecture in Essential and Malignant Hypertension
,”
J. Hypertens.
,
24
, pp.
889
894
.
3.
Wong
,
T. Y.
,
Klein
,
R.
,
Klein
,
B. E.
,
Meuer
,
S. M.
, and
Hubbard
,
L. D.
, 2003, “
Retinal Vessel Diameters and their Associations with Age and Blood Pressure
,”
Invest. Ophthalmol. Vis. Sci.
,
44
, pp.
4644
4650
.
4.
Wong
,
T. Y.
, and
McIntosh
,
R.
, 2005, “
Systemic Associations of Retinal Microvascular Signs: A Review of Recent Population-Based Studies
,”
Ophthalmic. Physiol. Optics
,
25
, pp.
195
204
.
5.
Stanton
,
A. V.
,
Wasan
,
B.
,
Cerutti
,
A.
,
Ford
,
S.
,
Marsh
,
R.
,
Sever
,
P. P.
,
Thom
,
S. A.
, and
Hughes
,
A. D.
, 1995, “
Vascular Network Changes in the Retina with Age and Hypertension
,”
J. Hypertens.
,
13
, pp.
1724
1728
.
6.
Wong
,
T. Y.
,
Shankar
,
A.
,
Klein
,
R.
,
Klein
,
B. E.
, and
Hubbard
,
L. D.
, 2005, “
Retinal Arteriolar Narrowing, Hypertension, and Subsequent Risk of Diabetes Mellitus
,”
Arch. Intern. Med.
,
165
, pp.
1060
1065
.
7.
Murray
,
C. D.
, 1926, “
The Physiological Principle of Minimum Work. I. The Vascular System and the Cost of Blood Volume
,”
Proc. Natl. Acad. Sci.
,
12
, pp.
207
214
.
8.
Revellin
,
R.
,
Rousset
,
F.
,
Baud
,
D.
, and
Bonjour
,
J.
, 2009, “
Extension of Murray’s Law using a Non-Newtonian Model of Blood Flow
,”
Theor. Biol. Med. Model.
,
15
, pp.
6
7
.
9.
Martinez-Perez
,
M. E.
,
Hughes
,
A. D.
,
Stanton
,
A. V.
,
Thom
,
S. A.
,
Chapman
,
N.
,
Bharath
,
A. A.
, and
Parker
,
K. H.
, 2002, “
Retinal Vascular Tree Morphology: A Semi-Automatic Quantification
,”
IEEE Trans. Biomed. Eng.
,
49
, pp.
912
917
.
10.
Zamir
,
M.
, and
Medeiros
,
J. A.
, 1982, “
Arterial Branching in Man and Monkey
,”
J. Gen. Physiol.
,
79
, pp.
353
360
.
11.
Hughes
,
A. D.
,
Wong
,
T. Y.
,
Witt
,
N.
,
Evans
,
R.
,
Thom
,
S. A.
,
Klein
,
B. E.
,
Chaturvedi
,
N.
, and
Klein
,
R.
, 2009, “
Determinants of Retinal Microvascular Architecture in Normal Subjects
,”
Microcirculation
,
16
, pp.
159
166
.
12.
Martinez-Perez
,
M. E.
, 2000, “
Computer Analysis of the Geometry of the Retinal Vasculature
,” Ph. D. thesis, Imperial College London.
13.
Liu
,
D.
,
Wood
,
N. B.
,
Witt
,
N.
,
Hughes
,
A. D.
,
Thom
,
S. A.
, and
Xu
,
X. Y.
, 2009, “
Computational Analysis of Oxygen Transport in the Retinal Arterial Network
,”
Current Eye Res.
,
31
, pp.
945
956
.
14.
Fahraeus
,
R.
, and
Lindqvist
,
T.
, 1931, “
The Viscosity of the Blood in Narrow Capillary Tubes
,”
Am. J. Physiol.
,
96
, pp.
562
568
.
15.
Pries
,
A. R.
,
Secomb
,
T. W.
,
Gaehtgens
,
P.
, and
Gross
,
J. F.
, 1990, “
Blood Flow in Microvascular Networks - Experiments and Simulation
,”
Circ. Res.
,
67
, pp.
826
834
.
16.
Pries
,
A. R.
,
Secomb
,
T. W.
, and
Gaehtgens
,
P.
, 1996, “
Biophysical Aspects of Blood Flow in the Microvasculature
,”
Cardiovasc. Res.
,
32
, pp.
654
66
17.
Pries
,
A. R.
, and
Secomb
,
T. W.
, 2005, “
Microvascular Blood Viscosity in vivo and the Endothelial Surface Layer
,”
Am. J. Physiol. Heart Circ Physiol.
,
289
, pp.
H2657
H2664
.
18.
Fung
,
Y. C.
, 1993,
Biomechanics, Mechanical properties of living tissues
,
Springer-Verlag
,
New York.
19.
Iftimia
,
N. V.
,
Hammer
,
D. X.
,
Bigelow
,
C. E.
,
Rosen
,
D. I.
,
Ustun
,
T.
,
Ferrante
,
A. A.
,
Vu
,
D.
, and
Ferguson
,
R. D.
, 2006, “
Toward Non–Invasive Measurement of Blood Hematocrit using Spectral Domain Low Coherence Interferometry and Retinal Tracking
,”
Opt. Express
,
14
, pp.
3377
3388
.
20.
Ganesan
,
P.
,
He
,
S.
, and
Xu
,
H.
, 2010, “
Analysis of Retinal Circulation using an Image-Based Network Model of Retinal Vasculature
,”
Microvasc Res.
,
80
, pp.
99
109
.
21.
Mayrovitz
,
H. N.
, and
Roy
,
J.
, 1983, “
Microvascular Blood Flow: Evidence Indicating a Cubic Dependence on Arteriolar Diameter
,”
Am. J. Physiol. Heart. Circ. Physiol.
,
245
, pp.
H1031
H1038
.
22.
McGeown
,
J. G.
, 2002,
Physiology: A Core Text With Self-Assessment
,
Elsevier/Churchill Livingstone
,
Philidelphia
.
23.
Diem
,
K.
, and
Lentner
,
C.
, 1970,
Scientific Tables
,
Ciba-Geigy
,
Basel, Switzerland
.
24.
Taber
,
L.
, 1998, “
An Optimization Principle for Vascular Radius Including the Effects of Smooth Muscle Tone
,”
Biophys. J.
,
74
, pp.
109
114
.
25.
Howard
,
R. O.
, and
Sears
,
M. L.
, 1964, “
Metabolism of Retinal Blood Vessels of Human and Rhesus Monkeys Studied with the Cartesian Diver
,”
Invest Ophthalmol.
,
3
, pp.
432
440
.
26.
Baleanu
,
D.
,
Ritt
,
M.
,
Harazny
,
J.
,
Heckmann
,
J.
,
Schmieder
,
R. E.
, and
Michelson
,
G.
, 2009, “
Wall-to-Lumen Ratio of Retinal Arterioles and Arteriole-To-Venule Ratio of Retinal Vessels in Patients with Cerebrovascular Damage
,”
Invest. Ophthalmol. Vis. Sci.
,
50
, pp.
4351
4359
.
27.
Heagerty
,
A. M.
,
Aalkjaer
,
C.
,
Bund
,
S. J.
,
Korsgaard
,
N.
, and
Mulvany
,
M. J.
, 1993, “
Small Artery Structure in Hypertension: Dual Processes of Remodelling and Growth
,”
Hypertension
,
21
, pp.
391
397
.
28.
Ritt
,
M.
, and
Schmieder
,
R. E.
, 2009, “
Wall-to–Lumen Ratio of Retinal Arterioles as a Tool to Assess Vascular Changes
,”
Hypertension
,
54
, pp.
384
387
.
29.
Ritt
,
M.
,
Harazny
,
J. M.
,
Ott
,
C.
,
Schneider
,
M. P.
,
Schlaich
,
M. P.
,
Michelson
,
G.
, and
Schmieder
,
R. E.
, 2009, “
Wall-to-Lumen Ratio of Retinal Arterioles is Related with Urinary Albumin Excretion and Altered Vascular Reactivity to Infusion of the Nitric Oxide Synthase Inhibitor N-Monomethyl-L-Arginine
,”
J. Hypertens.
,
27
, pp.
2201
2208
.
30.
Olson
,
R. M.
, 1974, “
Human Carotid Artery Wall Thickness, Diameter, and Blood Flow by a Noninvasive Technique
,”
J. Appl. Physiol.
,
37
, pp.
955
960
.
31.
Rizzoni
,
D.
,
De Ciuceis
,
C.
,
Porteri
,
E.
,
Paiardi
,
S.
,
Boari
,
G. E.
,
Mortini
,
P.
,
Cornali
,
C.
,
Cenzato
,
M.
,
Rodella
,
L. F.
,
Borsani
,
E.
,
Rizzardi
,
N.
,
Platto
,
C.
,
Rezzani
,
R.
, and
Rosei
,
E. A.
, 2009, “
Altered Structure of Small Cerebral Arteries in Patients with Essential Hypertension
,”
J. Hypertens.
,
27
, pp.
838
845
.
32.
Chapman
,
N.
,
Witt
,
N.
,
Gao
,
X.
,
Bharath
,
A. A.
,
Stanton
,
A. V.
,
Thom
,
S. A.
, and
Hughes
,
A. D.
, 2001, “
Computer Algorithms for the Automated Measurement of Retinal Arteriolar Diameters
,”
Br. J. Ophthalmol.
,
85
, pp.
74
79
.
33.
Durst
,
F.
,
Ray
,
S.
,
Unsal
,
B.
, and
Bayoumi
,
O. A.
, 2005, “
The Development Lengths of Laminar Pipe and Channel Flows
,”
J. Fluids Eng.
,
127
, pp.
1154
1160
.
34.
Poole
,
R. J.
, and
Ridley
,
B. S.
, 2007, “
Development-Length Requirements for Fully Developed Laminar Pipe Flow of Inelastic Non-Newtonian Liquids
,”
J. Fluids Eng.
,
129
, pp.
1281
1287
.
35.
Lew
,
H. S.
, and
Fung
,
Y. C.
, 1970, “
Entry Flow into Blood Vessels at Arbitrary Reynolds Number
,”
J. Biomech.
,
3
, pp.
23
28
.
36.
Guenther
,
A. E.
,
Conley
,
A. J.
,
van Orden
,
D. E.
,
Farley
,
D. B.
, and
Ford
,
S. P.
, 1988, “
Structural and Mechanical Changes of Uterine Arteries during Pregnancy in the Pig
,”
J. Animal Sci.
,
66
, pp.
3144
3152
.
You do not currently have access to this content.