scholarly journals Orbital Doppler Evaluation of Blood Flow Velocities in Patients with Diabetic Retinopathy

2012 ◽  
Vol 9 (2-3) ◽  
pp. 104-111 ◽  
Author(s):  
Mehdi Karami ◽  
Mohsen Janghorbani ◽  
Alireza Dehghani ◽  
Karim Khaksar ◽  
Ahmad Kaviani
2012 ◽  
Vol 26 (2) ◽  
pp. 116 ◽  
Author(s):  
Mehdi Karami ◽  
Mohsen Janghorbani ◽  
Alireza Dehghani ◽  
Maryam Riahinejad

2019 ◽  
Vol 236 (04) ◽  
pp. 530-535
Author(s):  
Gabor Somfai ◽  
Thalmon Campagnoli ◽  
Jing Tian ◽  
Heinrich Gerding ◽  
William Smiddy ◽  
...  

Abstract Purpose Diabetic retinopathy (DR) is a microvascular disease characterized by capillary dropout and resultant retinal ischemia which then leads to retinal vascular remodeling. Our goal was to assess blood flow velocities in retinal collateral vessels in healthy and diabetic subjects with various stages of DR. Methods In our pilot study, we enrolled five eyes of five healthy subjects (H), five eyes of four subjects with diabetes and no retinopathy (DM), three eyes of three subjects with mild non-proliferative diabetic retinopathy (MDR), and five eyes of four subjects with proliferative diabetic retinopathy (PDR). Following routine ophthalmic examination, all subjects were imaged using a retinal function imager (RFI; Optical Imaging Inc., Rehovot, Israel). The built-in software of the RFI was used to identify and segment retinal collaterals with measurement of the blood flow velocities (BFV). One-way ANOVA was performed for BFV, followed by Newman-Keuls post hoc test. The level of significance was set at 5%. Results The total number of collateral segments involved in the study was 30, 31, 21, and 39 in the H, DM, MDR, and PDR groups, respectively. The BFVs in the collaterals were significantly lower in PDR (H: 1.86 ± 0.67, DM: 1.91 ± 0.71, MDR: 1.71 ± 0.53, PDR: 1.37 ± 0.58 mm/s). The PDR group showed a statistically significant difference in the comparisons to all groups (p = 0.012, p = 0.008, and p = 0.043 for the H, DM, and MDR groups, respectively), while no other comparisons between the groups were significant. Conclusion We observed decreased BFV in retinal collaterals in PDR that may be due to the extensive capillary dropout and retinal ischemia. Further studies are needed for the noninvasive functional assessment of retinal microvascular changes in DR to better understand the underlying pathophysiology.


2008 ◽  
Vol 22 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Natalie Werner ◽  
Neval Kapan ◽  
Gustavo A. Reyes del Paso

The present study explored modulations in cerebral blood flow and systemic hemodynamics during the execution of a mental calculation task in 41 healthy subjects. Time course and lateralization of blood flow velocities in the medial cerebral arteries of both hemispheres were assessed using functional transcranial Doppler sonography. Indices of systemic hemodynamics were obtained using continuous blood pressure recordings. Doppler sonography revealed a biphasic left dominant rise in cerebral blood flow velocities during task execution. Systemic blood pressure increased, whereas heart period, heart period variability, and baroreflex sensitivity declined. Blood pressure and heart period proved predictive of the magnitude of the cerebral blood flow response, particularly of its initial component. Various physiological mechanisms may be assumed to be involved in cardiovascular adjustment to cognitive demands. While specific contributions of the sympathetic and parasympathetic systems may account for the observed pattern of systemic hemodynamics, flow metabolism coupling, fast neurogenic vasodilation, and cerebral autoregulation may be involved in mediating cerebral blood flow modulations. Furthermore, during conditions of high cardiovascular reactivity, systemic hemodynamic changes exert a marked influence on cerebral blood perfusion.


Anaesthesia ◽  
2012 ◽  
Vol 67 (8) ◽  
pp. 936-936 ◽  
Author(s):  
P. Kundra ◽  
J. Velraj ◽  
U. Amirthalingam ◽  
S. Habeebullah ◽  
K. Yuvaraj ◽  
...  

1999 ◽  
Vol 9 (4) ◽  
pp. 198-200 ◽  
Author(s):  
Olaf Hoffmann ◽  
Markus Weih ◽  
Thomas von Münster ◽  
Stephan Schreiber ◽  
Karl Max Einhäupl ◽  
...  

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