@article{KotliarHanssenEberhardtetal.2013,
  author    = {Kotliar, Konstantin and Hanssen, Henner and Eberhardt, Karla and Vilser, Walthard and Schmaderer, Christoph and Halle, Martin and Heemann, Uwe and Baumann, M.},
  title     = {Retinal pulse wave velocity in young male normotensive and mildly hypertensive subjects},
  series = {Microcirculation},
  journal   = {Microcirculation},
  publisher = {Wiley},
  address   = {Malden},
  issn      = {1549-8719},
  year      = {2013},
  language  = {en}
}
@article{KotliarMueckeVilseretal.2008,
  author    = {Kotliar, Konstantin and M{\"u}cke, Bruno and Vilser, Walthard and Schilling, Rudolf},
  title     = {Effect of aging on retinal artery blood column diameter measured along the vessel axis / Kotliar, Konstantin E. ; M{\"u}cke, Bruno ; Vilser, Walthard ; Schilling, Rudolf ; Lanzl, Ines M.},
  series = {Investigative Ophthalmology \& Visual Science, IOVS. 49 (2008), H. 5},
  journal   = {Investigative Ophthalmology \& Visual Science, IOVS. 49 (2008), H. 5},
  publisher = {-},
  isbn      = {0146-0404},
  pages     = {2094 -- 2102},
  year      = {2008},
  language  = {en}
}
@article{KotliarLanzlHanssenetal.2012,
  author    = {Kotliar, Konstantin and Lanzl, Ines M. and Hanssen, Henner and Eberhardt, Karla and Vilser, Walthard and Halle, Martin and Heemann, Uwe and Schmidt-Trucks{\"a}ss, Arno and Baumann, Marcus},
  title     = {Does increased blood pressure rather than aging influence retinal pulse wave velocity?},
  series = {Investigative Ophthalmology \& Visual Science, IOVS},
  volume    = {53},
  journal   = {Investigative Ophthalmology \& Visual Science, IOVS},
  number    = {4},
  publisher = {ARVO},
  address   = {Rockville, Md.},
  issn      = {0146-0404},
  doi       = {10.1167/iovs.11-8815},
  pages     = {2119 -- 2126},
  year      = {2012},
  abstract  = {Purpose: It was demonstrated previously that retinal pulse wave velocity (rPWV) as a measure of retinal arterial stiffness is increased in aged anamnestically healthy volunteers compared with young healthy subjects. Using novel methodology of rPWV assessment this finding was confirmed and investigated whether it might relate to the increased blood pressure usually accompanying the aging process, rather than to the aging itself. Methods: A total of 12 young 25.5-year-old (24.0-28.8) [median(1st quartile-3rd quartile)] and 12 senior 68.5-year-old (63.8-71.8) anamnestically healthy volunteers; and 12 senior 63.0-year-old (60.8-65.0) validated healthy volunteers and 12 young 33.0-year-old (29.5-35.0) hypertensive patients were examined. Time-dependent alterations of vessel diameter were assessed by the Dynamic Vessel Analyzer in a retinal artery of each subject. The data were filtered and processed using mathematical signal analysis and rPWVs were calculated. Results: rPWV amounted to 1200 (990-1470) RU (relative units)/s in the hypertensive group and to 1040 (700-2230) RU/s in anamnestically healthy seniors. These differed significantly from rPWVs in young healthy group (410 [280-500] RU/s) and in validated healthy seniors (400 [320-510] RU/s). rPWV associated with age and mean arterial pressure (MAP) in the pooled cohort excluded validated healthy seniors. In a regression model these associations remain when alternately adjusted for MAP and age. When including validated healthy seniors in the pooled cohort only association with MAP remains. Conclusions: Both aging (with not excluded cardiovascular risk factors) and mild hypertension are associated with elevated rPWV. rPWV increases to a similar extent both in young mildly hypertensive subjects and in aged anamnestically healthy persons. Healthy aging is not associated with increased rPWV.},
  language  = {en}
}
@article{KotliarNagelVilseretal.2010,
  author    = {Kotliar, Konstantin and Nagel, Edgar and Vilser, Walthard and Seidova, Seid-Fatima and Lanzl, Ines},
  title     = {Microstructural alterations of retinal arterial blood column along the vessel axis in systemic hypertension},
  series = {Investigative Ophthalmology \& Visual Science, IOVS},
  volume    = {51},
  journal   = {Investigative Ophthalmology \& Visual Science, IOVS},
  number    = {4},
  publisher = {-},
  isbn      = {0146-0404},
  pages     = {2165 -- 2172},
  year      = {2010},
  language  = {en}
}
@article{KotliarBaumannVilseretal.2011,
  author    = {Kotliar, Konstantin and Baumann, Marcus and Vilser, Walthard and Lanzl, Ines M.},
  title     = {Pulse wave velocity in retinal arteries of healthy volunteers},
  series = {British Journal of Ophthalmology (eBJO)},
  volume    = {95},
  journal   = {British Journal of Ophthalmology (eBJO)},
  number    = {11},
  publisher = {BMJ Publ. Group},
  address   = {London},
  isbn      = {1468-2079},
  pages     = {675 -- 679},
  year      = {2011},
  language  = {en}
}
@article{GarhoferBekBoehmetal.2010,
  author    = {Garhofer, Gerhard and Bek, Toke and Boehm, Andreas G. and Gherghel, Doina and Grundwald, Juan and Jeppesen, Peter and Kergoat, H{\´e}l{\`e}ne and Kotliar, Konstantin and Lanzl, Ines and Lovasik, John V. and Nagel, Edgar and Vilser, Walthard and Orgul, Selim and Schmetterer, Leopold},
  title     = {Use of the retinal vessel analyzer in ocular blood flow research},
  series = {Acta Ophthalmol},
  volume    = {88},
  journal   = {Acta Ophthalmol},
  number    = {7},
  isbn      = {1600-0420},
  pages     = {717 -- 722},
  year      = {2010},
  language  = {en}
}
@article{KotliarLanzlWittaetal.2000,
  author    = {Kotliar, Konstantin and Lanzl, Ines M. and Witta, Birka and Vilser, Walthard},
  title     = {Reaktion retinaler Gef{\"a}ßdurchmesser auf 100 \% O2-Atmung - funktionelle Messung mit dem Retinal Vessel Analyzer an 10 Probanden / Lanzl, Ines M. ; Witta, Birke ; Kotliar, Konstantin ; Vilser, Walthard},
  series = {Klinische Monatsbl{\"a}tter f{\"u}r Augenheilkunde. 217 (2000), H. 4},
  journal   = {Klinische Monatsbl{\"a}tter f{\"u}r Augenheilkunde. 217 (2000), H. 4},
  publisher = {-},
  isbn      = {1439-3999},
  pages     = {231 -- 235},
  year      = {2000},
  language  = {de}
}
@article{KotliarNagelVilseretal.2008,
  author    = {Kotliar, Konstantin and Nagel, Edgar and Vilser, Walthard and Lanzl, Ines M.},
  title     = {Functional in vivo assessment of retinal artery microirregularities in glaucoma / Kotliar, Konstantin E. ; Nagel, Edgar ; Vilser, Walthard ; Lanzl, Ines M.},
  series = {Acta Ophthalmologica. 86 (2008), H. 4},
  journal   = {Acta Ophthalmologica. 86 (2008), H. 4},
  publisher = {-},
  isbn      = {1755-3768},
  pages     = {424 -- 433},
  year      = {2008},
  language  = {en}
}
@article{AlbannaKotliarLuekeetal.2018,
  author    = {Albanna, Walid and Kotliar, Konstantin and L{\"u}ke, Jan Niklas and Alpdogan, Serdar and Conzen, Catharina and Lindauer, Ute and Clusmann, Hans and Hescheler, J{\"u}rgen and Vilser, Walthard and Schneider, Toni and Schubert, Gerrit Alexander},
  title     = {Non-invasive evaluation of neurovascular coupling in the murine retina by dynamic retinal vessel analysis},
  series = {Plos one},
  journal   = {Plos one},
  publisher = {PLOS},
  address   = {San Francisco},
  doi       = {10.1371/journal.pone.0204689},
  pages     = {14 Seiten},
  year      = {2018},
  abstract  = {Background Impairment of neurovascular coupling (NVC) was recently reported in the context of subarachnoid hemorrhage and may correlate with disease severity and outcome. However, previous techniques to evaluate NVC required invasive procedures. Retinal vessels may represent an alternative option for non-invasive assessment of NVC. Methods A prototype of an adapted retinal vessel analyzer was used to assess retinal vessel diameter in mice. Dynamic vessel analysis (DVA) included an application of monochromatic flicker light impulses in predefined frequencies for evaluating NVC. All retinae were harvested after DVA and electroretinograms were performed. Results A total of 104 retinal scans were conducted in 21 male mice (90 scans). Quantitative arterial recordings were feasible only in a minority of animals, showing an emphasized reaction to flicker light impulses (8 mice; 14 scans). A characteristic venous response to flicker light, however, could observed in the majority of animals. Repeated measurements resulted in a significant decrease of baseline venous diameter (7 mice; 7 scans, p < 0.05). Ex-vivo electroretinograms, performed after in-vivo DVA, demonstrated a significant reduction of transretinal signaling in animals with repeated DVA (n = 6, p < 0.001). Conclusions To the best of our knowledge, this is the first non-invasive study assessing murine retinal vessel response to flicker light with characteristic changes in NVC. The imaging system can be used for basic research and enables the investigation of retinal vessel dimension and function in control mice and genetically modified animals.},
  language  = {en}
}
@article{MalanHamerKaeneletal.2020,
  author    = {Malan, Leone and Hamer, Mark and K{\"a}nel, Roland von and Kotliar, Konstantin and Wyk, Roelof D. van and Lambert, Gavin W. and Vilser, Walthard and Ziemssen, Tjalf and Schlaich, Markus P. and Smith, Wayne and Magnusson, Martin and Wentzel, Annemarie and Myburgh, Carlien E. and Steyn, Hendrik S. and Malan, Nico T.},
  title     = {Delayed retinal vein recovery responses indicate both non-adaptation to stress as well as increased risk for stroke: the SABPA study},
  series = {Cardiovascular Journal of Africa},
  volume    = {26},
  journal   = {Cardiovascular Journal of Africa},
  number    = {31},
  publisher = {Clinics Cardive Publishing},
  address   = {Durbanville},
  issn      = {1680-0745},
  doi       = {10.5830/CVJA-2020-031},
  pages     = {1 -- 12},
  year      = {2020},
  language  = {en}
}
@article{ConzenAlbannaWeissetal.2018,
  author    = {Conzen, Catharina and Albanna, Walid and Weiss, Miriam and K{\"u}rten, David and Vilser, Walthard and Kotliar, Konstantin and Z{\"a}ske, Charlotte and Clusmann, Hans and Schubert, Gerrit Alexander},
  title     = {Vasoconstriction and Impairment of Neurovascular Coupling after Subarachnoid Hemorrhage: a Descriptive Analysis of Retinal Changes},
  series = {Translational Stroke Research},
  journal   = {Translational Stroke Research},
  number    = {9},
  publisher = {Springer Nature},
  address   = {Cham},
  issn      = {1868-601X},
  doi       = {10.1007/s12975-017-0585-8},
  pages     = {284 -- 293},
  year      = {2018},
  abstract  = {Impaired cerebral autoregulation and neurovascular coupling (NVC) contribute to delayed cerebral ischemia after subarachnoid hemorrhage (SAH). Retinal vessel analysis (RVA) allows non-invasive assessment of vessel dimension and NVC hereby demonstrating a predictive value in the context of various neurovascular diseases. Using RVA as a translational approach, we aimed to assess the retinal vessels in patients with SAH. RVA was performed prospectively in 24 patients with acute SAH (group A: day 5-14), in 11 patients 3 months after ictus (group B: day 90 ± 35), and in 35 age-matched healthy controls (group C). Data was acquired using a Retinal Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and NVC using flicker-light excitation. Diameter of retinal vessels—central retinal arteriolar and venular equivalent—was significantly reduced in the acute phase (p < 0.001) with gradual improvement in group B (p < 0.05). Arterial NVC of group A was significantly impaired with diminished dilatation (p < 0.001) and reduced area under the curve (p < 0.01) when compared to group C. Group B showed persistent prolonged latency of arterial dilation (p < 0.05). Venous NVC was significantly delayed after SAH compared to group C (A p < 0.001; B p < 0.05). To our knowledge, this is the first clinical study to document retinal vasoconstriction and impairment of NVC in patients with SAH. Using non-invasive RVA as a translational approach, characteristic patterns of compromise were detected for the arterial and venous compartment of the neurovascular unit in a time-dependent fashion. Recruitment will continue to facilitate a correlation analysis with clinical course and outcome.},
  language  = {en}
}
@article{SmithKotliarLammertynetal.2020,
  author    = {Smith, Wayne and Kotliar, Konstantin and Lammertyn, Leandi and Ramoshaba, Nthai E. and Vilser, Walthard and Huisman, Hugo W. and Schutte, Aletta E.},
  title     = {Retinal vessel caliber and caliber responses in true normotensive black and white adults: The African-PREDICT study},
  series = {Microvascular Research},
  volume    = {128},
  journal   = {Microvascular Research},
  number    = {Article 103937},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0026-2862},
  doi       = {10.1016/j.mvr.2019.103937},
  year      = {2020},
  abstract  = {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.},
  language  = {en}
}