TY  - JOUR
A1  - Smith, Wayne
A1  - Kotliar, Konstantin
A1  - Lammertyn, Leandi
A1  - Ramoshaba, Nthai E.
A1  - Vilser, Walthard
A1  - Huisman, Hugo W.
A1  - Schutte, Aletta E.
T1  - Retinal vessel caliber and caliber responses in true normotensive black and white adults: The African-PREDICT study
JF  - Microvascular Research
N2  - Purpose
Globally, a detrimental shift in cardiovascular disease risk factors and a higher mortality level are reported in some black populations. The retinal microvasculature provides early insight into the pathogenesis of systemic vascular diseases, but it is unclear whether retinal vessel calibers and acute retinal vessel functional responses differ between young healthy black and white adults.

Methods
We included 112 black and 143 white healthy normotensive adults (20–30 years). Retinal vessel calibers (central retinal artery and vein equivalent (CRAE and CRVE)) were calculated from retinal images and vessel caliber responses to flicker light induced provocation (FLIP) were determined. Additionally, ambulatory blood pressure (BP), anthropometry and blood samples were collected.

Results
The groups displayed similar 24 h BP profiles and anthropometry (all p > .24). Black participants demonstrated a smaller CRAE (158 ± 11 vs. 164 ± 11 MU, p < .001) compared to the white group, whereas CRVE was similar (p = .57). In response to FLIP, artery maximal dilation was greater in the black vs. white group (5.6 ± 2.1 vs. 3.3 ± 1.8%; p < .001).

Conclusions
Already at a young age, healthy black adults showed narrower retinal arteries relative to the white population. Follow-up studies are underway to show if this will be related to increased risk for hypertension development. The reason for the larger vessel dilation responses to FLIP in the black population is unclear and warrants further investigation.
Y1  - 2020
U6  - https://doi.org/10.1016/j.mvr.2019.103937
SN  - 0026-2862
VL  - 128
IS  - Article 103937
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Albanna, Walid
A1  - Conzen, Catharina
A1  - Weiss, Miriam
A1  - Clusmann, Hans
A1  - Fuest, Matthias
A1  - Mueller, Marguerite
A1  - Brockmann, Marc Alexander
A1  - Vilser, Walthard
A1  - Schmidt-Trucksäss, Arno
A1  - Hoellig, Anke
A1  - Seiz, Marcel
A1  - Thomé, Claudius
A1  - Kotliar, Konstantin
A1  - Schubert, Gerrit Alexander
T1  - Retinal Vessel Analysis (RVA) in the context of subarachnoid hemorrhage: A proof of concept study
JF  - PLoS ONE
N2  - Background
Timely detection of impending delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is essential to improve outcome, but poses a diagnostic challenge. Retinal vessels as an embryological part of the intracranial vasculature are easily accessible for analysis and may hold the key to a new and non-invasive monitoring technique. This investigation aims to determine the feasibility of standardized retinal vessel analysis (RVA) in the context of SAH.

Methods
In a prospective pilot study, we performed RVA in six patients awake and cooperative with SAH in the acute phase (day 2–14) and eight patients at the time of follow-up (mean 4.6±1.7months after SAH), and included 33 age-matched healthy controls. Data was acquired using a manoeuvrable Dynamic Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and neurovascular coupling.

Results
Image quality was satisfactory in the majority of cases (93.3%). In the acute phase after SAH, retinal arteries were significantly dilated when compared to the control group (124.2±4.3MU vs 110.9±11.4MU, p<0.01), a difference that persisted to a lesser extent in the later stage of the disease (122.7±17.2MU, p<0.05). Testing for neurovascular coupling showed a trend towards impaired primary vasodilation and secondary vasoconstriction (p = 0.08, p = 0.09 resp.) initially and partial recovery at the time of follow-up, indicating a relative improvement in a time-dependent fashion.

Conclusion
RVA is technically feasible in patients with SAH and can detect fluctuations in vessel diameter and autoregulation even in less severely affected patients. Preliminary data suggests potential for RVA as a new and non-invasive tool for advanced SAH monitoring, but clinical relevance and prognostic value will have to be determined in a larger cohort.
Y1  - 2016
U6  - https://doi.org/10.1371/journal.pone.0158781
SN  - 1932-6203
VL  - 11
IS  - 7
PB  - PLOS
CY  - San Francisco
ER  -