Laser speckle contrast imaging of blood flow in rat retinas using an endoscope.
Laser speckle contrast imaging (LSCI) offers a cost-effective means to image blood flow in vivo. However, it is not commonly used to image rodent retinas because of the challenges associated with imaging through the curved cornea and delivering light through the highly scattering lens. A solution to overcome these problems by using LSCI in conjunction with an endoscope to obtain high spatiotemporal blood flow images is described. Its utility is demonstrated by imaging blood flow changes in rat retinas using hyperoxic, hypercapnic, and visual (flicker) stimulations. Hypercapnia increases blood flow, hyperoxia decreases blood flow, and visual stimulation increases blood flow in the retina relative to basal conditions. The time-to-peak of the LSCI response to visual stimulation is also measured. This approach may prove useful to investigate dysregulation in blood flow-evoked responses in retinal diseases and to evaluate treatment strategies in rodents.
University of Texas Health Science Center, Research Imaging Institute, San Antonio, Texas 78229.
Adrien
A
Ponticorvo
Damon
D
Cardenas
Andrew K
AK
Dunn
Daniel
D
Ts'o
Timothy Q
TQ
Duong
D000818:Animals; D003952:Diagnostic Imaging / Q000295:instrumentation* / Q000379:methods*; D003935:Diagnostic Techniques, Cardiovascular / Q000295:instrumentation*; D019723:Endoscopes; D006439:Hemodynamics; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow; D012171:Retinal Vessels / Q000033:anatomy & histology* / Q000502:physiology*