Retinal vascular analysis

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The retinal vessel analysis is a non-invasive examination methods of retinal -vials ( Ocular blood flow ), can also be taken in other areas of the body with the conclusions about the behavior and function of blood vessels. The method is mainly used by ophthalmologists, cardiologists, internists and neurologists as well as specialists from other fields.

Investigation method

There are two variants of the examination technique in which a special fundus camera, the Retinal Vessel Analyzer (a development by the Jena-based company Imedos), measures the diameter of certain small arteries and veins at the fundus. In static retinal vascular analysis, this is a snapshot; In the dynamic variant of the examination, a 12.5 Hz opto-electric flicker light is used to stimulate and quantify the change in the vessel diameter. This test can be carried out in different protocols, for example in the form of three times 20 seconds of flicker light with 80 seconds of recovery time in between. The examination is carried out when the patient's pupils are dilated using drugs; it is completely non-invasive.

Significance for diagnostics

The aim of the examination with the Retinal Vessel Analyzer is to assess the condition of the vessels at the fundus and to draw conclusions about their condition in other areas of the body. Numerous recent studies have documented that the analysis of the small retinal vessels allows a statement about the generalized vascular situation and is a predictor for risk factors. In particular, dynamic vascular analysis is apparently suitable for detecting vascular damage - for example due to aging processes or metabolic diseases - at an early stage.

For example, the working group led by Andreas Flammer from the Cardiological Clinic of the University of Zurich has used retinal vascular analysis (in international specialist literature RVA for retinal vessel analysi, abbreviated) in 74 patients with compensated heart failure, in 74 people with cardiovascular risk factors and in 74 control persons. It was shown that the flicker-induced dilation of arterioles in the retina was significantly reduced in the patients with heart failure. This parameter, known as FIDart (flicker induced dilatation of retinal arterioles), averaged 0.9% in the patient group, while it was 2.3% in the study participants with risk factors and 3.6% in the controls with healthy heart. This means that the smallest vessels in the retina show a reaction that is far below average in cardiac patients to a stimulus.

The working group led by Henner Hanssen from the Department of Preventive Sports Medicine at the University of Basel has demonstrated a connection between the retinal vessel diameter and a higher risk of hypertension , diabetes mellitus and obesity , the increased incidence of heart attacks and strokes and increased cardiac mortality. According to a new study by the working group, the diameter of the retinal vessels allows conclusions to be drawn about cardiorespiratory health. The preventive value of the analysis was highlighted by a large study (n = 10,470) from Boston: the investigators reclassified 21% of the female participants from "low risk" to the "intermediate risk" category, which required more intensive monitoring, due to the RVA.

A research group from the University of Munich and the Department of Medical Technology and Technomathematics at the FH Aachen used dynamic vascular analysis to examine three groups of people: patients with manifest Alzheimer's disease , people in the preliminary stages of this degenerative disease (MCI stage = mild cognitive impairment) and healthy control persons . The reaction of the smallest arteries and veins in the retina to the light stimulus differed in a characteristic way from that of the healthy in the Alzheimer's patients and in the study participants in the early stages of the disease; For example, the maximum expansion of the arterioles to the light stimulus was delayed and the small veins also showed a noticeable reaction pattern. According to the scientists, the vascular reaction to flicker light can be seen as a promising and easy-to-use future biomarker for the diagnosis and monitoring of Alzheimer's disease. These results were confirmed in 2019 by an Italian working group who documented a significantly changed behavior of the retinal vessels in patients with Alzheimer's and MCI and an inverse correlation of these anomalies with the level of beta-amyloid proteins in the spinal cord fluid.

Individual evidence

  1. ↑ Nägele MR et al .: Retinal microvascular dysfunction in heart failure. European Heart Journal 2018; 39: 47-56
  2. ^ H. Hanssen: Exercise-induced alerations of retinal vessel diameters and cardiovascular risk reduction in obesity. Atherosclerosis 2011; 216: 433-439.
  3. ↑ Braun G et al .: Association of cardiorespiratory fitness with retinal vessel diameters as a biomarker of cardiovascular risk, Microvasular Research 2018; 120: 36-40.
  4. ↑ Seidelmann SB et al .: Retinal Vessel Calibers in Predicting Long-Term Cardiovascular Outcomes.Circulation. 2016; 134: 1328-1338.
  5. ↑ Kotliar K. et al .: Altered neurovascular coupling as measured by optical imaging: a biomarker for Alzheimer's disease. SCIENTIFIC REPORTS | 7: 12906 | doi: 10.1038 / s41598-017-13349-5 , published online on October 10, 2017.
  6. ↑ Querques G et al .: Functional and morphological changes of the retinal vessels in Alzheimer's disease and mild cognitive impairment. Nature Scientic Reports 2019; 9:63.

literature

  • Ronald D. Barley: A reflection of the blood vessels. The New Zurich Times. 23rd November 2018
  • Ronald D. Gerste: Mirror image of the microvasculature. Deutsches Ärzteblatt 115 (48): A2234-A2238. November 30, 2018.
  • Waldmann NP et al .: The prognostic value of retinal vessel analysis in primary open-angle glaucoma. Acta Ophthalmologica 2016; 94 (6): e474-80.
  • Schuster AK et al .: Retinal vessel analysis and heart rate variability, International Journal of Cardiology 2014; 176: 1268-1269.

Web links

  • [1] Contribution to the "consultation hour" of Deutschlandfunk about retinal vascular analysis.