Flickerlichtprovokation bei Vasospastikern verglichen mit gesunden Kontrollpersonen

Zusammenfassung

Hintergrund: Die vaskuläre Dysregulation wird als Risikofaktor diverser Augenerkrankungen diskutiert. Zweck dieser Studie war die Evaluation der retinalen Gefäßantwort auf Flickerlicht bei gesunden Personen mit vasospastischer Diathese. Patienten und Methoden: 30 gesunde Personen kaukasischen Ursprungs, 18 – 35 Jahre alt, wurden für die Studie rekrutiert. Jeweils 15 Personen bildeten die vasospastische Gruppe, respektive die Kontrollgruppe. Vasospasmus war dabei definiert durch die Anamnese oft kalter Hände, sogar im Sommer, plus übereinstimmendem Resultat in der Nagelfalz-Kapillarmikroskopie. Die Kontrollgruppe wies weder das erste noch das zweite dieser Merkmale auf. Mithilfe des Retinal Vessel Analyser wurde die Reaktion des Gefäßdurchmessers auf Flickerlicht in 1 – 2 Papillendurchmessern Entfernung von der Papille gemessen. Aufgezeichnet wurden 3 Phasen Flickerlicht von 20 s Dauer, gefolgt von einer Grünlichtphase von 80 s Dauer. Die höchste Reaktion auf Flickerlicht wurde in jeder Flickerphase evaluiert und über die 3 Resultate gemittelt. Ergebnisse: Die maximale durchschnittliche Gefäßantwort im Verhältnis zur Basalphase erreichte auf der arteriellen Seite einen Mittelwert ± Standardabweichung von 2,9 ± 1,7 % in der vasospastischen Gruppe und von 4,8 ± 2,6 % in der Kontrollgruppe (t = 2,34; p = 0,025). Die venöse Gefäßantwort war in beiden Gruppen vergleichbar. Schlussfolgerungen: In der Studie wiesen Personen mit vasospastischer Anamnese eine im Vergleich zur Kontrollgruppe veränderte Gefäßreaktion auf Flickerlicht auf.

Abstract

Background: Vascular dysregulation is considered to be a risk factor in several ophthalmic diseases. The purpose of this study was to evaluate the reaction of retinal vessels to flicker light in otherwise healthy subjects with a vasospastic propensity. Patients and Methods: Thirty healthy Caucasians, aged between 18 – 35 years were recruited for this study and grouped into vasospastics, based on a history of frequent cold hands, even in summer, with concordant findings in nailfold capillary microscopy, or as controls, if such a history was absent. The reaction of the retinal vascular diameter to flicker light was observed in a distance of two to three discs diameters away from the optic nerve head with the retinal vessel analyser. Three phases of flicker light of twenty seconds followed by baseline light phases of eighty seconds were recorded. The maximal vasodilatory amplitude of each flicker phase was determined and the results averaged. Results: The maximal average dilatory amplitude at the arterial side reached (mean ± SD) 2.9 ± 1.7 % and 4.8 ± 2.6 % of the baseline amplitude respectively in vasospastic subjects and in healthy controls (t = 2.34; p = 0.025). The reaction at the venous side was statistically comparable in both groups. Conclusions: Otherwise healthy, vasospastic subject disclosed an altered reaction of the retinal vasculature to flicker light in this study.

Schlüsselwörter

Flickerlicht - Netzhaut-Gefäßnetz - Retinal Vessel Analyser - vaskuläre Dysregulation - Vasospasmus

Key words

flicker light - retinal vasculature - retinal vessel analyser - vascular dysregulation - vasospasm

Literatur

• 1 Buerk D G, Riva C E, Cranstoun S D. Nitric oxide has a vasodilatory role in cat optic nerve head during flicker stimuli.  Microvasc Res. 1996;  52 13-26
• 2 Delaey C, De Voorde van J. Regulatory mechanisms in the retinal and choroidal circulation.  Ophthalmic Res. 2000;  32 249-256
• 3 Dorner G T, Garhofer G, Kiss B. et al . Nitric oxide regulates retinal vascular tone in humans.  Am J Physiol Heart Circ Physiol. 2003;  285 H631-H636
• 4 Falsini B, Riva C E, Logean E. Flicker-evoked changes in human optic nerve blood flow: relationship with retinal neural activity.  Invest Ophthalmol Vis Sci. 2002;  43 2309-2316
• 5 Flammer J. The vascular concept of glaucoma.  Surv Ophthalmol. 1994;  38 (Suppl) S3-S6
• 6 Flammer J, Mozaffarieh M. What is the present pathogenetic concept of glaucomatous optic neuropathy?.  Surv Ophthalmol. 2007;  52 (Suppl 2) S162-S173
• 7 Flammer J, Orgul S, Costa V P. et al . The impact of ocular blood flow in glaucoma.  Prog Retin Eye Res. 2002;  21 359-393
• 8 Flammer J, Pache M, Resink T. Vasospasm, its role in the pathogenesis of diseases with particular reference to the eye.  Prog Retin Eye Res. 2001;  20 319-349
• 9 Formaz F, Riva C E, Geiser M. Diffuse luminance flicker increases retinal vessel diameter in humans.  Curr Eye Res. 1997;  16 1252-1257
• 10 Garhofer G, Zawinka C, Huemer K H. et al . Flicker light-induced vasodilatation in the human retina: effect of lactate and changes in mean arterial pressure.  Invest Ophthalmol Vis Sci. 2003;  44 5309-5314
• 11 Gasser P. Capillary blood cell velocity in finger nailfold: characteristics and reproducibility of the local cold response.  Microvasc Res. 1990;  40 29-35
• 12 Gasser P. Video-nailfold-microscopy and local cold test: morphological and hemodynamic correlates in 124 healthy subjects.  Vasa. 1991;  20 244-251
• 13 Gasser P, Dubler B. Development of instrumental and technical measurement aspects for clinical capillary microscopy.  Z Rheumatol. 1996;  55 260-266
• 14 Gherghel D, Orgul S, Dubler B. et al . Is vascular regulation in the central retinal artery altered in persons with vasospasm?.  Arch Ophthalmol. 1999;  117 1359-1362
• 15 Grieshaber M C, Flammer J. Blood flow in glaucoma.  Curr Opin Ophthalmol. 2005;  16 79-83
• 16 Grieshaber M C, Flammer J. Does the blood-brain barrier play a role in Glaucoma?.  Surv Ophthalmol. 2007;  52 (Suppl 2) S115-S121
• 17 Haefliger I O, Flammer J, Beny J L. et al . Endothelium-dependent vasoactive modulation in the ophthalmic circulation.  Prog Retin Eye Res. 2001;  20 209-225
• 18 Humphrey J D. Vascular adaptation and mechanical homeostasis at tissue, cellular, and sub-cellular levels.  Cell Biochem Biophys. 2008;  50 53-78
• 19 Jeppesen P, Sanye-Hajari J, Bek T. Increased blood pressure induces a diameter response of retinal arterioles that increases with decreasing arteriolar diameter.  Invest Ophthalmol Vis Sci. 2007;  48 328-331
• 20 Kotliar K E, Vilser W, Nagel E. et al . Retinal vessel reaction in response to chromatic flickering light.  Graefe’s Arch Clin Exp Ophthalmol. 2004;  242 377-392
• 21 Michelson G, Patzelt A, Harazny J. Flickering light increases retinal blood flow.  Retina. 2002;  22 336-343
• 22 Nagel E, Vilser W. Autoregulative behavior of retinal arteries and veins during changes of perfusion pressure: a clinical study.  Graefe’s Arch Clin Exp Ophthalmol. 2004;  242 13-17
• 23 Nagel E, Vilser W. Flicker observation light induces diameter response in retinal arterioles: a clinical methodological study.  Br J Ophthalmol. 2004;  88 54-56
• 24 Nagel E, Vilser W, Lanzl I. Comparison of diameter response of retinal arteries and veins to flickering light. A clinical study with healthy people.  Ophthalmologe. 2005;  102 787-793
• 25 Nagel E, Vilser W, Lanzl I. Age, blood pressure, and vessel diameter as factors influencing the arterial retinal flicker response.  Invest Ophthalmol Vis Sci. 2004;  45 1486-1492
• 26 Pache M, Nagel E, Flammer J. Reproducibility of measurements with the retinal vessel analyzer under optimal conditions.  Klin Monatsbl Augenheilkd. 2002;  219 523-527
• 27 Polak K, Dorner G, Kiss B. et al . Evaluation of the Zeiss retinal vessel analyser.  Br J Ophthalmol. 2000;  84 1285-1290
• 28 Polak K, Schmetterer L, Riva C E. Influence of flicker frequency on flicker-induced changes of retinal vessel diameter.  Invest Ophthalmol Vis Sci. 2002;  43 2721-2726
• 29 Pournaras C J, Rungger-Brandle E, Riva C E. et al . Regulation of retinal blood flow in health and disease.  Prog Retin Eye Res. 2008;  27 284-330
• 30 Prunte C, Orgul S, Flammer J. Abnormalities of microcirculation in glaucoma: facts and hints.  Curr Opin Ophthalmol. 1998;  9 50-55
• 31 Riva C E, Logean E, Falsini B. Visually evoked hemodynamical response and assessment of neurovascular coupling in the optic nerve and retina.  Prog Retin Eye Res. 2005;  24 183-215
• 32 Schmetterer L, Polak K. Role of nitric oxide in the control of ocular blood flow.  Prog Retin Eye Res. 2001;  20 823-847
• 33 Vilser W, Nagel E, Lanzl I. Retinal Vessel Analysis – new possibilities.  Biomed Tech (Berl). 2002;  47 (Suppl 1) 682-685
• 34 Wagenfeld L, Himpel O, Galambos P. et al . Protective effects of nebivolol on oxygen free radical-induced vasoconstrictions in vitro.  Med Sci Monit. 2008;  14 BR109-BR112
• 35 Yanagisawa M, Kurihara H, Kimura S. et al . A novel potent vasoconstrictor peptide produced by vascular endothelial cells.  Nature. 1988;  332 411-415