@article{StreeseKotliarDeiserothetal.2020,
  author    = {Streese, Lukas and Kotliar, Konstantin and Deiseroth, Arne and Infanger, Denis and Gugleta, Konstantin and Schmaderer, Christoph and Hanssen, Henner},
  title     = {Retinal endothelial function in cardiovascular risk patients: A randomized controlled exercise trial},
  series = {Scandinavian Journal of Medicine and Science in Sports},
  volume    = {30},
  journal   = {Scandinavian Journal of Medicine and Science in Sports},
  number    = {2},
  publisher = {Wiley},
  address   = {Oxford},
  issn      = {1600-0838},
  doi       = {10.1111/sms.13560},
  pages     = {272 -- 280},
  year      = {2020},
  abstract  = {The aim of this study was to investigate, for the first time, the effects of high-intensity interval training (HIIT) on retinal microvascular endothelial function in cardiovascular (CV) risk patients. In the randomized controlled trial, middle-aged and previously sedentary patients with increased CV risk (aged 58 ± 6 years) with ≥ two CV risk factors were randomized into a 12-week HIIT (n = 33) or control group (CG, n = 36) with standard physical activity recommendations. A blinded examiner measured retinal endothelial function by flicker light-induced maximal arteriolar (ADmax) and venular (VDmax) dilatation as well as the area under the arteriolar (AFarea) and venular (VFarea) flicker curve using a retinal vessel analyzer. Standardized assessments of CV risk factors, cardiorespiratory fitness, and retinal endothelial function were performed before and after HIIT. HIIT reduced body mass index, fat mass, and low-density lipoprotein and increased muscle mass and peak oxygen uptake (VO2peak). Both ADmax (pre: 2.7 ± 2.1\%, post: 3.0 ± 2.2\%, P = .018) and AFarea (pre: 32.6 ± 28.4\%*s, post: 37.7 ± 30.6\%*s, P = .016) increased after HIIT compared with CG (ADmax, pre: 3.2 ± 1.8\%, post: 2.9 ± 1.8\%, P = .254; AFarea, pre: 41.6 ± 28.5\%*s, post: 37.8 ± 27.0\%*s, P = .186). Venular function remained unchanged after HIIT. There was a significant association between ∆-change VO2peak and ∆-changes ADmax and AFarea (P = .026, R² = 0.073; P = .019, R² = 0.081, respectively). 12-weeks of HIIT improved retinal endothelial function in middle-aged patients with increased CV risk independent of the reduction in classical CV risk factors. Exercise has the potential to reverse or at least postpone progression of small vessel disease in older adults with increased CV risk under standard medication. Dynamic retinal vessel analysis seems to be a sensitive tool to detect treatment effects of exercise interventions on retinal microvascular endothelial function in middle-aged individuals with increased CV risk.},
  language  = {en}
}
@article{RamoshabaHuismanLammertynetal.2020,
  author    = {Ramoshaba, Nthai E. and Huisman, Hugo W. and Lammertyn, Leandi and Kotliar, Konstantin and Schutte, Aletta E. and Smith, Wayne},
  title     = {Retinal microvasculature and masked hypertension in young adults: the African-PREDICT study},
  series = {Hypertension Research},
  journal   = {Hypertension Research},
  number    = {43},
  publisher = {Springer Nature},
  address   = {Osaka},
  issn      = {1348-4214},
  doi       = {10.1038/s41440-020-0487-0},
  pages     = {1231 -- 1238},
  year      = {2020},
  abstract  = {Masked hypertension is known to induce microvascular complications. However, it is unclear whether early microvascular changes are already occurring in young, otherwise healthy adults. We therefore investigated whether retinal microvascular calibers and acute responses to a flicker stimulus are related to masked hypertension. We used the baseline data of 889 participants aged 20-30 years who were taking part in the African Prospective study on the Early Detection and Identification of Cardiovascular Disease and Hypertension. Clinic and 24-h ambulatory blood pressure were measured. The central retinal artery equivalent (CRAE) and central retinal vein equivalent were calculated from fundus images, and retinal vessel dilation was determined in response to flicker light-induced provocation. A smaller CRAE was observed in those with masked hypertension vs. those with normotension (157.1 vs. 161.2 measuring units, P < 0.001). In forward multivariable-adjusted regression analysis, only CRAE was negatively related to masked hypertension [adjusted R² = 0.267, β = -0.097 (95\% CI = -0.165; -0.029), P = 0.005], but other retinal microvascular parameters were not associated with masked hypertension. In multivariable logistic regression analyses, masked hypertension [OR = 2.333, (95\% CI = 1.316; 4.241), P = 0.004] was associated with a narrower CRAE. In young healthy adults, masked hypertension was associated with retinal arteriolar narrowing, thereby reflecting early microvascular alterations known to predict cardiovascular outcomes in later life.},
  language  = {en}
}
@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{AlbannaConzenWeissetal.2016,
  author    = {Albanna, W. and Conzen, C. and Weiss, M. and Clusmann, H. and Fuest, M. and Mueller, M. and Brockmann, M.A. and Vilser, W. and Schmidt-Trucks{\"a}ss, A. and Hoellig, A. and Seiz, M. and Thom{\´e}, C. and Kotliar, Konstantin and Schubert, G.A.},
  title     = {Retinal Vessel Analysis (RVA) in the context of subarachnoid hemorrhage: A proof of concept study},
  series = {PLoS ONE},
  volume    = {11},
  journal   = {PLoS ONE},
  number    = {7},
  publisher = {PLOS},
  address   = {San Francisco},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0158781},
  pages     = {13 Seiten},
  year      = {2016},
  abstract  = {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.},
  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}
}
@article{KotliarVilserNageletal.2004,
  author    = {Kotliar, Konstantin and Vilser, Walthatd and Nagel, Edgar and Lanzl, Ines M.},
  title     = {Retinal vessel reaction in response to chromatic flickering light / Kotliar, Konstantin E. ; Vilser, Walthard ; Nagel, Edgar ; Lanzl, Ines M.},
  series = {Graefe's Archive for Clinical and Experimental Ophthalmology. 242 (2004), H. 5},
  journal   = {Graefe's Archive for Clinical and Experimental Ophthalmology. 242 (2004), H. 5},
  publisher = {-},
  isbn      = {1435-702X},
  pages     = {377 -- 392},
  year      = {2004},
  language  = {en}
}
@article{NeumaierKotliarHaerenetal.2021,
  author    = {Neumaier, Felix and Kotliar, Konstantin and Haeren, Roel Hubert Louis and Temel, Yasin and L{\"u}ke, Jan Niklas and Seyam, Osama and Lindauer, Ute and Clusmann, Hans and Hescheler, J{\"u}rgen and Schubert, Gerrit Alexander and Schneider, Toni and Albanna, Walid},
  title     = {Retinal Vessel Responses to Flicker Stimulation Are Impaired in Ca v 2.3-Deficient Mice—An in- vivo Evaluation Using Retinal Vessel Analysis (RVA)},
  series = {Frontiers in Neurology},
  volume    = {12},
  journal   = {Frontiers in Neurology},
  publisher = {Frontiers},
  doi       = {10.3389/fneur.2021.659890},
  pages     = {1 -- 11},
  year      = {2021},
  language  = {en}
}
@article{MenzelKotliarLanzl2009,
  author    = {Menzel, C. and Kotliar, Konstantin and Lanzl, I.},
  title     = {Retrospektive Untersuchung jahreszeitlich bedingter Einflussfaktoren auf den Augeninnendruck therapierter Glaukompatienten},
  series = {Der Ophthalmologe},
  volume    = {106},
  journal   = {Der Ophthalmologe},
  number    = {11},
  publisher = {-},
  isbn      = {1433-0423},
  pages     = {1006 -- 1011},
  year      = {2009},
  language  = {de}
}
@article{KappmeyerKotliarLanzl2009,
  author    = {Kappmeyer, K. and Kotliar, Konstantin and Lanzl, I. M.},
  title     = {Spielen von Blasinstrumenten und Augeninnendruck},
  series = {Zeitschrift f{\"u}r praktische Augenheilkunde \& augen{\"a}rztliche Fortbildung : ZPA},
  volume    = {Bd. 30},
  journal   = {Zeitschrift f{\"u}r praktische Augenheilkunde \& augen{\"a}rztliche Fortbildung : ZPA},
  issn      = {1436-0322},
  pages     = {169 -- 171},
  year      = {2009},
  language  = {de}
}
@article{PresslerEsefeldScherretal.2010,
  author    = {Pressler, Axel and Esefeld, Katrin and Scherr, Johannes and Ali, Mohammad and Hanssen, Henner and Kotliar, Konstantin and Lanzl, Ines and Halle, Martin and Kaemmerer, Harald and Schmidt-Trucks{\"a}ss, Arno and Hager, Alfred},
  title     = {Structural alterations of retinal arterioles in adults late after repair of aortic isthmic coarctation},
  series = {The American Journal of Cardiology},
  volume    = {105},
  journal   = {The American Journal of Cardiology},
  number    = {5},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0002-9149},
  doi       = {10.1016/j.amjcard.2009.10.070},
  pages     = {740 -- 744},
  year      = {2010},
  abstract  = {Patients after coarctation repair still have an increased risk of cardiovascular or cerebrovascular events. This has been explained by the persisting hypertension and alterations in the peripheral vessels. However, involvement of the central vessels such as the retinal arteries is virtually unknown. A total of 34 patients after coarctation repair (22 men and 12 women; 23 to 58 years old, age range 0 to 32 years at surgical repair) and 34 nonhypertensive controls underwent structural and functional retinal vessel analysis. Using structural analysis, the vessel diameters were measured. Using functional analysis, the endothelium-dependent vessel dilation in response to flicker light stimulation was assessed. In the patients after coarctation repair, the retinal arteriolar diameter was significantly reduced compared to that of the controls (median 182 μm, first to third quartile 171 to 197; vs 197 μm, first to third quartile 193 to 206; p <0.001). These findings were independent of the peripheral blood pressure and age at intervention. No differences were found for venules. The functional analysis findings were not different between the patients and controls (maximum dilation 3.5\%, first to third quartile 2.1\% to 4.5\% vs 3.6\%, first to third quartile 2.2\% to 4.3\%; p = 0.81), indicating preserved autoregulative mechanisms. In conclusion, the retinal artery diameter is reduced in patients after coarctation repair, independent of their current blood pressure level and age at intervention. As a structural marker of chronic vessel damage associated with past, current, or future hypertension, retinal arteriolar narrowing has been linked to stroke incidence. These results indicate an involvement of cerebral microcirculation in aortic coarctation, despite timely repair, and might contribute to explain the increased rate of cerebrovascular events in such patients.},
  language  = {en}
}