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Compact Laser Doppler Flowmeter (LDF) Fundus Camera for the Assessment of Retinal Blood Perfusion in Small Animals.

Mentek M, Truffer F, Chiquet C, Godin-Ribuot D, Amoos S, Loeuillet C, Bernabei M, Geiser M - PLoS ONE (2015)

Bottom Line: Here we present the results obtained with a new rodent-adapted compact fundus camera based on laser Doppler flowmetry (LDF).Inter-day reproducibility was good (0.79 and 0.7, respectively).Upon ocular blood flow cessation, the retinal artery velocity signal substantially decreased, whereas the ONH signal did not significantly vary, suggesting that it could mostly be attributed to tissue light scattering.

View Article: PubMed Central - PubMed

Affiliation: HP2 laboratory, Grenoble Alpes University, 38000, Grenoble, France; INSERM U1042 laboratory, 38000, Grenoble, France.

ABSTRACT

Purpose: Noninvasive techniques for ocular blood perfusion assessment are of crucial importance for exploring microvascular alterations related to systemic and ocular diseases. However, few techniques adapted to rodents are available and most are invasive or not specifically focused on the optic nerve head (ONH), choroid or retinal circulation. Here we present the results obtained with a new rodent-adapted compact fundus camera based on laser Doppler flowmetry (LDF).

Methods: A confocal miniature flowmeter was fixed to a specially designed 3D rotating mechanical arm and adjusted on a rodent stereotaxic table in order to accurately point the laser beam at the retinal region of interest. The linearity of the LDF measurements was assessed using a rotating Teflon wheel and a flow of microspheres in a glass capillary. In vivo reproducibility was assessed in Wistar rats with repeated measurements (inter-session and inter-day) of retinal arteries and ONH blood velocity in six and ten rats, respectively. These parameters were also recorded during an acute intraocular pressure increase to 150 mmHg and after heart arrest (n = 5 rats).

Results: The perfusion measurements showed perfect linearity between LDF velocity and Teflon wheel or microsphere speed. Intraclass correlation coefficients for retinal arteries and ONH velocity (0.82 and 0.86, respectively) indicated strong inter-session repeatability and stability. Inter-day reproducibility was good (0.79 and 0.7, respectively). Upon ocular blood flow cessation, the retinal artery velocity signal substantially decreased, whereas the ONH signal did not significantly vary, suggesting that it could mostly be attributed to tissue light scattering.

Conclusion: We have demonstrated that, while not adapted for ONH blood perfusion assessment, this device allows pertinent, stable and repeatable measurements of retinal blood perfusion in rats.

No MeSH data available.


Related in: MedlinePlus

Power spectra analysis during the three experimental conditions.Variation of power spectra at baseline, during the IOP experiment and after heart arrest, for velocity of retinal artery (black lines) and optic nerve head (gray lines). Each period of the experiment is represented by the corresponding mean power spectrum: baseline (solid line), increased IOP at 150 mmHg (dashed line) and after heart arrest (dotted line). Upper right corner of the figure represents zoomed power spectra between 0 and 1000 Hz (gray area).
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pone.0134378.g007: Power spectra analysis during the three experimental conditions.Variation of power spectra at baseline, during the IOP experiment and after heart arrest, for velocity of retinal artery (black lines) and optic nerve head (gray lines). Each period of the experiment is represented by the corresponding mean power spectrum: baseline (solid line), increased IOP at 150 mmHg (dashed line) and after heart arrest (dotted line). Upper right corner of the figure represents zoomed power spectra between 0 and 1000 Hz (gray area).

Mentions: After heart arrest, VelART and VelONH were decreased by 81 ± 3% (p = 0.04) and 41 ± 15% (p = 0.04), respectively, compared to previous values. Fig 7 shows representative power spectra during baseline, intraocular hypertension and immediately following heart arrest.


Compact Laser Doppler Flowmeter (LDF) Fundus Camera for the Assessment of Retinal Blood Perfusion in Small Animals.

Mentek M, Truffer F, Chiquet C, Godin-Ribuot D, Amoos S, Loeuillet C, Bernabei M, Geiser M - PLoS ONE (2015)

Power spectra analysis during the three experimental conditions.Variation of power spectra at baseline, during the IOP experiment and after heart arrest, for velocity of retinal artery (black lines) and optic nerve head (gray lines). Each period of the experiment is represented by the corresponding mean power spectrum: baseline (solid line), increased IOP at 150 mmHg (dashed line) and after heart arrest (dotted line). Upper right corner of the figure represents zoomed power spectra between 0 and 1000 Hz (gray area).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4520556&req=5

pone.0134378.g007: Power spectra analysis during the three experimental conditions.Variation of power spectra at baseline, during the IOP experiment and after heart arrest, for velocity of retinal artery (black lines) and optic nerve head (gray lines). Each period of the experiment is represented by the corresponding mean power spectrum: baseline (solid line), increased IOP at 150 mmHg (dashed line) and after heart arrest (dotted line). Upper right corner of the figure represents zoomed power spectra between 0 and 1000 Hz (gray area).
Mentions: After heart arrest, VelART and VelONH were decreased by 81 ± 3% (p = 0.04) and 41 ± 15% (p = 0.04), respectively, compared to previous values. Fig 7 shows representative power spectra during baseline, intraocular hypertension and immediately following heart arrest.

Bottom Line: Here we present the results obtained with a new rodent-adapted compact fundus camera based on laser Doppler flowmetry (LDF).Inter-day reproducibility was good (0.79 and 0.7, respectively).Upon ocular blood flow cessation, the retinal artery velocity signal substantially decreased, whereas the ONH signal did not significantly vary, suggesting that it could mostly be attributed to tissue light scattering.

View Article: PubMed Central - PubMed

Affiliation: HP2 laboratory, Grenoble Alpes University, 38000, Grenoble, France; INSERM U1042 laboratory, 38000, Grenoble, France.

ABSTRACT

Purpose: Noninvasive techniques for ocular blood perfusion assessment are of crucial importance for exploring microvascular alterations related to systemic and ocular diseases. However, few techniques adapted to rodents are available and most are invasive or not specifically focused on the optic nerve head (ONH), choroid or retinal circulation. Here we present the results obtained with a new rodent-adapted compact fundus camera based on laser Doppler flowmetry (LDF).

Methods: A confocal miniature flowmeter was fixed to a specially designed 3D rotating mechanical arm and adjusted on a rodent stereotaxic table in order to accurately point the laser beam at the retinal region of interest. The linearity of the LDF measurements was assessed using a rotating Teflon wheel and a flow of microspheres in a glass capillary. In vivo reproducibility was assessed in Wistar rats with repeated measurements (inter-session and inter-day) of retinal arteries and ONH blood velocity in six and ten rats, respectively. These parameters were also recorded during an acute intraocular pressure increase to 150 mmHg and after heart arrest (n = 5 rats).

Results: The perfusion measurements showed perfect linearity between LDF velocity and Teflon wheel or microsphere speed. Intraclass correlation coefficients for retinal arteries and ONH velocity (0.82 and 0.86, respectively) indicated strong inter-session repeatability and stability. Inter-day reproducibility was good (0.79 and 0.7, respectively). Upon ocular blood flow cessation, the retinal artery velocity signal substantially decreased, whereas the ONH signal did not significantly vary, suggesting that it could mostly be attributed to tissue light scattering.

Conclusion: We have demonstrated that, while not adapted for ONH blood perfusion assessment, this device allows pertinent, stable and repeatable measurements of retinal blood perfusion in rats.

No MeSH data available.


Related in: MedlinePlus