Retinal Blood Flow Alterations During Progression of Diabetic Retinopathy

1983 ◽  
Vol 101 (2) ◽  
pp. 225-227 ◽  
Author(s):  
A. Yoshida ◽  
G. T. Feke ◽  
J. Morales-Stoppello ◽  
G. D. Collas ◽  
D. G. Goger ◽  
...  
2021 ◽  
Author(s):  
Fidan Jmor ◽  
John C. Chen

In this chapter, we review the basics of retinal vascular anatomy and discuss the physiologic process of retinal blood flow regulation. We then aim to explore the relationship between intraocular pressure and retinal circulation, taking into account factors that affect retinal hemodynamics. Specifically, we discuss the concepts of ocular perfusion pressure, baro-damage to the endothelium and transmural pressure in relation to the intraocular pressure. Finally, we demonstrate the inter-relationships of these factors and concepts in the pathogenesis of some retinal vascular conditions; more particularly, through examples of two common clinical pathologies of diabetic retinopathy and central retinal vein occlusion.


Ophthalmology ◽  
1986 ◽  
Vol 93 (5) ◽  
pp. 590-595 ◽  
Author(s):  
Juan E. Grunwald ◽  
Charles E. Riva ◽  
Alexander J. Brucker ◽  
Stephen H. Sinclair ◽  
Benno L. Petrig

2018 ◽  
Vol 2 (S1) ◽  
pp. 22-23
Author(s):  
Paras Vora ◽  
Nicholas Bell ◽  
Romulo Albuquerque ◽  
Jooyoung Cho ◽  
Gregory Botzet

OBJECTIVES/SPECIFIC AIMS: Diabetic retinopathy is an increasingly prevalent disease, difficult to screen for across the globe. We have developed and began optimizing an innovative technique to visualize and quantify retinal blood flow, to elucidate the role of the choroid in retinal pathologies such as diabetic retinopathy or choroidopathy. METHODS/STUDY POPULATION: Preliminary retinal was obtained from a surgical retina video library (Truvision, Goleta, CA, USA). Videos of different organs were recorded while vessels were occluded via a blood pressure cuff, using consumer-grade digital video cameras (NEX-5T, a7sii; Sony, New York, NY, USA). All other retinal videos were taken using a fundus camera (50×; Topcon, Oxland, NJ, USA) modified to support the above digital video cameras. All videos were processed using experimental software (MATLAB, Mathworks, Natick, MA, USA). RESULTS/ANTICIPATED RESULTS: Video imaging of the retina was optimized for lighting conditions and software requirements. Parameters were defined for the software imaging pipeline, such as frequency range of interest, sampling rate, and noise minimization. Software was developed to stabilize frames, accounting for eye saccades. Use of a biosensor enabled accurate measurement of pulse waveform, increasing signal-to-noise ratio. The optimal light requirements were determined such that adequate exposure of the retina is reproducible yet still comfortable for use in human subjects. DISCUSSION/SIGNIFICANCE OF IMPACT: This novel technique allows for an inexpensive, noninvasive, and reproducible ocular blood flow imaging platform. By optimizing this technique, we can proceed with our future plans for a pilot study to compare our imaging technique with the current standard, paving the way for future clinical studies.


Ophthalmology ◽  
1987 ◽  
Vol 94 (11) ◽  
pp. 1410-1415 ◽  
Author(s):  
Timothy J. Fallon ◽  
David L. Maxwell ◽  
Eva M. Kohner

Diabetes Care ◽  
2010 ◽  
Vol 33 (9) ◽  
pp. 2038-2042 ◽  
Author(s):  
B. Pemp ◽  
E. Polska ◽  
G. Garhofer ◽  
M. Bayerle-Eder ◽  
A. Kautzky-Willer ◽  
...  

2015 ◽  
Vol 56 (11) ◽  
pp. 6796 ◽  
Author(s):  
Faryan, Tayyari ◽  
Lee-Anne, Khuu ◽  
John G. Flanagan ◽  
Shaun, Singer ◽  
Michael H. Brent ◽  
...  

2021 ◽  
Vol 118 (51) ◽  
pp. e2112561118
Author(s):  
Samuel A. Mills ◽  
Andrew I. Jobling ◽  
Michael A. Dixon ◽  
Bang V. Bui ◽  
Kirstan A. Vessey ◽  
...  

Local blood flow control within the central nervous system (CNS) is critical to proper function and is dependent on coordination between neurons, glia, and blood vessels. Macroglia, such as astrocytes and Müller cells, contribute to this neurovascular unit within the brain and retina, respectively. This study explored the role of microglia, the innate immune cell of the CNS, in retinal vasoregulation, and highlights changes during early diabetes. Structurally, microglia were found to contact retinal capillaries and neuronal synapses. In the brain and retinal explants, the addition of fractalkine, the sole ligand for monocyte receptor Cx3cr1, resulted in capillary constriction at regions of microglial contact. This vascular regulation was dependent on microglial Cx3cr1 involvement, since genetic and pharmacological inhibition of Cx3cr1 abolished fractalkine-induced constriction. Analysis of the microglial transcriptome identified several vasoactive genes, including angiotensinogen, a constituent of the renin-angiotensin system (RAS). Subsequent functional analysis showed that RAS blockade via candesartan abolished microglial-induced capillary constriction. Microglial regulation was explored in a rat streptozotocin (STZ) model of diabetic retinopathy. Retinal blood flow was reduced after 4 wk due to reduced capillary diameter and this was coincident with increased microglial association. Functional assessment showed loss of microglial–capillary response in STZ-treated animals and transcriptome analysis showed evidence of RAS pathway dysregulation in microglia. While candesartan treatment reversed capillary constriction in STZ-treated animals, blood flow remained decreased likely due to dilation of larger vessels. This work shows microglia actively participate in the neurovascular unit, with aberrant microglial–vascular function possibly contributing to the early vascular compromise during diabetic retinopathy.


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