Abstract
In this study, we reported a new technique based on laser speckle flowgraphy to record the ocular blood flow in rabbits under deep anesthesia, and proposed parameters to characterize retinal ischemia. We applied the proposed technique to study the correlation of blood flow between the eyes of normal non-anesthetized animals, and to characterize the occlusion of the internal carotid artery (ICA) and external carotid artery (ECA). We established a correlation in blood flow between the eyes of non-anesthetized animals, and derived two new parameters, namely, the laterality index and vascular perfusion estimate (VPE). Our experimental results from 16 eyes (of 13 New Zealand white rabbits) showed a reduction in ocular blood flow with a significant decrease in the VPE after the occlusion of the ECA (p < 0.001). A low/minimal effect on blood flow was observed with the occlusion of the ICA. In conclusion, we demonstrated a means for the real-time measurement of the ocular blood flow in rabbits under deep anesthesia by using laser speckle flowgraphy and the VPE as an indicator of successful occlusion. The proposed technique might be applicable in quantifying the efficacy of new drugs and interventions for the treatment of retinal ischemia.
Highlights
Animal models of retinal ischemia are indispensable in basic and applied research for the development of new therapeutic approaches and treatments of human disease
The well-established rabbit models of cerebral ischemia often require ligation or transection of the external carotid artery (ECA), e.g., the cerebral ischemia model developed by Yang et al, which requires the transection of the ECA to enter a guide wire into the ICA12, or the embolus model of cerebral ischemia developed by Lapchak et al, which requires the ligation of the ECA to prevent any blood clot from entering the ECA13
A variation between the blood flows is inevitably present. Data from both the eyes of non-anesthetized animals were obtained and categorized into two types, i.e., data from the eye with a higher mean blur rate (MBR) value and data from the eye with a lower MBR value. This was done because it has been observed that blood flow in both the eyes was mismatched and one eye had slightly higher MBR values than did the contralateral eye
Summary
Animal models of retinal ischemia are indispensable in basic and applied research for the development of new therapeutic approaches and treatments of human disease. Models of cerebral ischemia requiring ligation or transection of the common carotid artery (CCA) or ECA have been shown to develop retinal ischemia. These models exhibit deterioration of the systemic conditions, which in return leads to changes in ocular perfusion[7,10]. This study aimed to investigate how to assess dynamic changes in ocular blood flow before, during, and after the occlusion of the ECA and/or ICA in rabbits. We examined ocular blood flow changes before, during, and after retinal ischemia in one eye of each anesthetized animal. All the experiments were carried out using a LSFG-NAVI system (Softcare, Fukuoka, Japan) for rabbits
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
