Abstract
Purpose: To verify that a visual fixation protocol with cued eye blinks achieves sufficient stability for magnetic resonance imaging (MRI) blood-flow measurements and to determine if choroidal blood flow (ChBF) changes with age in humans.
Methods: The visual fixation stability achievable during an MRI scan was measured in five normal subjects using an eye-tracking camera outside the MRI scanner. Subjects were instructed to blink immediately after recorded MRI sound cues but to otherwise maintain stable visual fixation on a small target. Using this fixation protocol, ChBF was measured with MRI using a 3 Tesla clinical scanner in 17 normal subjects (24-68 years old). Arterial and intraocular pressures (IOP) were measured to calculate perfusion pressure in the same subjects.
Results: The mean temporal fluctuations (standard deviation) of the horizontal and vertical displacements were 29 ± 9 μm and 38 ± 11 μm within individual fixation periods, and 50 ± 34 μm and 48 ± 19 μm across different fixation periods. The absolute displacements were 67 ± 31 μm and 81 ± 26 μm. ChBF was negatively correlated with age (R = -0.7, p = 0.003), declining 2.7 ml/100 ml/min per year. There were no significant correlations between ChBF versus perfusion pressure, arterial pressure, or IOP. There were also no significant correlations between age versus perfusion pressure, arterial pressure, or IOP. Multiple regression analysis indicated that age was the only measured independent variable that was significantly correlated with ChBF (p = 0.03).
Conclusions: The visual fixation protocol with cued eye blinks was effective in achieving sufficient stability for MRI measurements. ChBF had a significant negative correlation with age.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1059-1067 |
| Number of pages | 9 |
| Journal | Current Eye Research |
| Volume | 39 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 1 2014 |
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Keywords
- Choroidal basal blood flow
- eigh-resolution MRI
- eye tracking
- visual fixation
ASJC Scopus subject areas
- Ophthalmology
- Sensory Systems
- Cellular and Molecular Neuroscience
Cite this
Choroidal blood flow decreases with age : An MRI study. / Nateras, Oscar San Emeterio; Harrison, Joseph M.; Muir, Eric R.; Zhang, Yi; Peng, Qi; Chalfin, Steven; Gutierrez, Juan E.; Johnson, Daniel A.; Kiel, Jeffrey W.; Duong, Timothy Q.
In: Current Eye Research, Vol. 39, No. 10, 01.10.2014, p. 1059-1067.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Choroidal blood flow decreases with age
T2 - An MRI study
AU - Nateras, Oscar San Emeterio
AU - Harrison, Joseph M.
AU - Muir, Eric R.
AU - Zhang, Yi
AU - Peng, Qi
AU - Chalfin, Steven
AU - Gutierrez, Juan E.
AU - Johnson, Daniel A.
AU - Kiel, Jeffrey W.
AU - Duong, Timothy Q.
PY - 2014/10/1
Y1 - 2014/10/1
N2 - Purpose: To verify that a visual fixation protocol with cued eye blinks achieves sufficient stability for magnetic resonance imaging (MRI) blood-flow measurements and to determine if choroidal blood flow (ChBF) changes with age in humans.Methods: The visual fixation stability achievable during an MRI scan was measured in five normal subjects using an eye-tracking camera outside the MRI scanner. Subjects were instructed to blink immediately after recorded MRI sound cues but to otherwise maintain stable visual fixation on a small target. Using this fixation protocol, ChBF was measured with MRI using a 3 Tesla clinical scanner in 17 normal subjects (24-68 years old). Arterial and intraocular pressures (IOP) were measured to calculate perfusion pressure in the same subjects.Results: The mean temporal fluctuations (standard deviation) of the horizontal and vertical displacements were 29 ± 9 μm and 38 ± 11 μm within individual fixation periods, and 50 ± 34 μm and 48 ± 19 μm across different fixation periods. The absolute displacements were 67 ± 31 μm and 81 ± 26 μm. ChBF was negatively correlated with age (R = -0.7, p = 0.003), declining 2.7 ml/100 ml/min per year. There were no significant correlations between ChBF versus perfusion pressure, arterial pressure, or IOP. There were also no significant correlations between age versus perfusion pressure, arterial pressure, or IOP. Multiple regression analysis indicated that age was the only measured independent variable that was significantly correlated with ChBF (p = 0.03).Conclusions: The visual fixation protocol with cued eye blinks was effective in achieving sufficient stability for MRI measurements. ChBF had a significant negative correlation with age.
AB - Purpose: To verify that a visual fixation protocol with cued eye blinks achieves sufficient stability for magnetic resonance imaging (MRI) blood-flow measurements and to determine if choroidal blood flow (ChBF) changes with age in humans.Methods: The visual fixation stability achievable during an MRI scan was measured in five normal subjects using an eye-tracking camera outside the MRI scanner. Subjects were instructed to blink immediately after recorded MRI sound cues but to otherwise maintain stable visual fixation on a small target. Using this fixation protocol, ChBF was measured with MRI using a 3 Tesla clinical scanner in 17 normal subjects (24-68 years old). Arterial and intraocular pressures (IOP) were measured to calculate perfusion pressure in the same subjects.Results: The mean temporal fluctuations (standard deviation) of the horizontal and vertical displacements were 29 ± 9 μm and 38 ± 11 μm within individual fixation periods, and 50 ± 34 μm and 48 ± 19 μm across different fixation periods. The absolute displacements were 67 ± 31 μm and 81 ± 26 μm. ChBF was negatively correlated with age (R = -0.7, p = 0.003), declining 2.7 ml/100 ml/min per year. There were no significant correlations between ChBF versus perfusion pressure, arterial pressure, or IOP. There were also no significant correlations between age versus perfusion pressure, arterial pressure, or IOP. Multiple regression analysis indicated that age was the only measured independent variable that was significantly correlated with ChBF (p = 0.03).Conclusions: The visual fixation protocol with cued eye blinks was effective in achieving sufficient stability for MRI measurements. ChBF had a significant negative correlation with age.
KW - Choroidal basal blood flow
KW - eigh-resolution MRI
KW - eye tracking
KW - visual fixation
UR - http://www.scopus.com/inward/record.url?scp=84907206614&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84907206614&partnerID=8YFLogxK
U2 - 10.3109/02713683.2014.892997
DO - 10.3109/02713683.2014.892997
M3 - Article
C2 - 24655028
AN - SCOPUS:84907206614
VL - 39
SP - 1059
EP - 1067
JO - Current Eye Research
JF - Current Eye Research
SN - 0271-3683
IS - 10
ER -