@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}
}
@inproceedings{IomdinaKiselevaKotliaretal.2020,
  author    = {Iomdina, Elena N. and Kiseleva, Anna A. and Kotliar, Konstantin and Luzhnov, Petr V.},
  title     = {Quantification of Choroidal Blood Flow Using the OCT-A System Based on Voxel Scan Processing},
  series = {2020 International Conference on Biomedical Innovations and Applications (BIA)},
  booktitle = {2020 International Conference on Biomedical Innovations and Applications (BIA)},
  isbn      = {978-1-7281-7073-2},
  doi       = {10.1109/BIA50171.2020.9244511},
  pages     = {41 -- 44},
  year      = {2020},
  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{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{HamouKotliarTanetal.2020,
  author    = {Hamou, Hussam Aldin and Kotliar, Konstantin and Tan, Sonny Kian and Weiß, Christel and Blume, Christian and Clusmann, Hans and Schubert, Gerrit Alexander and Albanna, Walid},
  title     = {Surgical nuances and placement of subgaleal drains for supratentorial procedures—a prospective analysis of efficacy and outcome in 150 craniotomies},
  series = {Acta Neurochirurgica},
  volume    = {2020},
  journal   = {Acta Neurochirurgica},
  number    = {162},
  publisher = {Springer Nature},
  address   = {Cham},
  issn      = {0942-0940},
  doi       = {10.1007/s00701-019-04196-6},
  pages     = {729 -- 736},
  year      = {2020},
  abstract  = {Background For supratentorial craniotomy, surgical access, and closure technique, including placement of subgaleal drains, may vary considerably. The influence of surgical nuances on postoperative complications such as cerebrospinal fluid leakage or impaired wound healing overall remains largely unclear. With this study, we are reporting our experiences and the impact of our clinical routines on outcome in a prospectively collected data set. Method We prospectively observed 150 consecutive patients undergoing supratentorial craniotomy and recorded technical variables (type/length of incision, size of craniotomy, technique of dural and skin closure, type of dressing, and placement of subgaleal drains). Outcome variables (subgaleal hematoma/CSF collection, periorbital edema, impairment of wound healing, infection, and need for operative revision) were recorded at time of discharge and at late follow-up. Results Early subgaleal fluid collection was observed in 36.7\% (2.8\% at the late follow-up), and impaired wound healing was recorded in 3.3\% of all cases, with an overall need for operative revision of 6.7\%. Neither usage of dural sealants, lack of watertight dural closure, and presence of subgaleal drains, nor type of skin closure or dressing influenced outcome. Curved incisions, larger craniotomy, and tumor size, however, were associated with an increase in early CSF or hematoma collection (p < 0.0001, p = 0.001, p < 0.01 resp.), and larger craniotomy size was associated with longer persistence of subgaleal fluid collections (p < 0.05). Conclusions Based on our setting, individual surgical nuances such as the type of dural closure and the use of subgaleal drains resulted in a comparable complication rate and outcome. Subgaleal fluid collections were frequently observed after supratentorial procedures, irrespective of the closing technique employed, and resolve spontaneously in the majority of cases without significant sequelae. Our results are limited due to the observational nature in our single-center study and need to be validated by supportive prospective randomized design.},
  language  = {en}
}
@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{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{AttarMerkKotliaretal.2019,
  author    = {Attar, Mandana Hossein Zadeh and Merk, Hans F. and Kotliar, Konstantin and Wurpts, Gerda and R{\"o}seler, Stefani and Moll-Slodowy, Silke and Plange, Johann and Baron, Jens Malte and Balakirski, Galina},
  title     = {The CD63 basophil activation test as a diagnostic tool for assessing autoimmunity in patients with chronic spontaneous urticaria},
  series = {European Journal of Dermatology},
  volume    = {29},
  journal   = {European Journal of Dermatology},
  number    = {6},
  doi       = {10.1684/ejd.2019.3680},
  pages     = {614 -- 618},
  year      = {2019},
  language  = {en}
}
@article{KodomskoiKotliarSchroederetal.2019,
  author    = {Kodomskoi, Leonid and Kotliar, Konstantin and Schr{\"o}der, Andreas and Weiss, Michael and Hille, Konrad},
  title     = {Suture-Probe Canaloplasty as an Alternative to Canaloplasty using the iTrack™ Microcatheter},
  series = {Journal of Glaucoma},
  journal   = {Journal of Glaucoma},
  number    = {Epub ahead of print},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {1057-0829},
  doi       = {10.1097/IJG.0000000000001321},
  year      = {2019},
  language  = {en}
}
@inproceedings{BlumAlbannaBenninghausetal.2019,
  author    = {Blum, Yannik and Albanna, Walid and Benninghaus, Anne and Kotliar, Konstantin},
  title     = {Vasomotion in retinal vessels of patients presenting post hemorrhagic hydrocephalus following subarachnoid hemorrhage},
  series = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen},
  booktitle = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen},
  editor    = {Staat, Manfred and Erni, Daniel},
  publisher = {Universit{\"a}t Duisburg-Essen},
  address   = {Duisburg},
  organization    = {MedTech Symposium},
  isbn      = {978-3-940402-22-6},
  doi       = {10.17185/duepublico/48750},
  pages     = {38 -- 39},
  year      = {2019},
  abstract  = {Clearance of blood components and fluid drainage play a crucial role in subarachnoid hemorrhage (SAH) and post hemorrhagic hydrocephalus (PHH). With the involvement of interstitial fluid (ISF) and cerebrospinal fluid (CSF), two pathways for the clearance of fluid and solutes in the brain are proposed. Starting at the level of capillaries, flow of ISF follows along the basement membranes in the walls of cerebral arteries out of the parenchyma to drain into the lymphatics and CSF [1]-[3]. Conversely, it is shown that CSF enters the parenchyma between glial and pial basement membranes of penetrating arteries [4]-[6]. Nevertheless, the involved structures and the contribution of either flow pathway to fluid balance between the subarachnoid space and interstitial space remains controversial. Low frequency oscillations in vascular tone are referred to as vasomotion and corresponding vasomotion waves are modeled as the driving force for flow of ISF out of the parenchyma [7]. Retinal vessel analysis (RVA) allows non-invasive measurement of retinal vessel vasomotion with respect to diameter changes [8]. Thus, the aim of the study is to investigate vasomotion in RVA signals of SAH and PHH patients.},
  language  = {en}
}