@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},
  publisher = {Wiley-Blackwell},
  address   = {Oxford},
  issn      = {1755-3768},
  doi       = {10.1111/j.1755-3768.2009.01587.x},
  pages     = {717 -- 722},
  year      = {2010},
  abstract  = {The present article describes a standard instrument for the continuous online determination of retinal vessel diameters, the commercially available retinal vessel analyzer. This report is intended to provide informed guidelines for measuring ocular blood flow with this system. The report describes the principles underlying the method and the instruments currently available, and discusses clinical protocol and the specific parameters measured by the system. Unresolved questions and the possible limitations of the technique are also discussed.},
  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 = {ARVO},
  address   = {Rockville, Md.},
  issn      = {0146-0404},
  doi       = {10.1167/iovs.09-3649},
  pages     = {2165 -- 2172},
  year      = {2010},
  abstract  = {Purpose: Image analysis by the retinal vessel analyzer (RVA) observes retinal vessels in their dynamic state online noninvasively along a chosen vessel segment. It has been found that high-frequency diameter changes in the retinal artery blood column along the vessel increase significantly in anamnestically healthy volunteers with increasing age and in patients with glaucoma during vascular dilation. This study was undertaken to investigate whether longitudinal sections of the retinal artery blood column are altered in systemic hypertension. Methods: Retinal arteries of 15 untreated patients with essential arterial hypertension (age, 50.9 ± 11.9 years) and of 15 age-matched anamnestically healthy volunteers were examined by RVA. After baseline assessment, a monochromatic luminance flicker (530-600 nm; 12.5 Hz; 20 s) was applied to evoke retinal vasodilation. Differences in amplitude and frequency of spatial artery blood column diameter change along segments (longitudinal arterial profiles) of 1 mm in length were measured and analyzed using Fourier transformation. Results: In the control group, average reduced power spectra (ARPS) of longitudinal arterial profiles did not differ when arteries changed from constriction to dilation. In the systemic hypertension group, ARPS during constriction, baseline, and restoration were identical and differed from ARPS during dilation (P < 0.05). Longitudinal arterial profiles in both groups showed significant dissimilitude at baseline and restoration (P < 0.05). Conclusions: The retinal artery blood column demonstrates microstructural alterations in systemic hypertension and is less irregular along the vessel axis during vessel dilation. These microstructural changes may be an indication of alterations in vessel wall rigidity, vascular endothelial function, and smooth muscle cells in this disease, leading to impaired perfusion and regulation.},
  language  = {en}
}