Purchase this article with an account.
J. Sanye Hajari, P. Jeppesen, T. Bek; The Diameter Response of Retinal Arterioles and Venules During Increased Blood Pressure Induced by Isometric Exercise . Invest. Ophthalmol. Vis. Sci. 2005;46(13):3906.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: An increase in the arterial blood pressure induces a decrease in the diameter of retinal arterioles in order to maintain the capillary blood flow constant (autoregulation). This is accompanied by changes in the diameter of retinal venules, but the physiological significance of these changes is unknown. We therefore studied the relation between the diameter response in large retinal arterioles and venules after an increase in the blood pressure induced by isometric exercise. Methods: One eye of each of nineteen healthy volunteers, three females and sixteen males (mean age: 30±5 SD years) were examined. The diameter of a retinal arteriole and the corresponding venule was measured using the Retinal Vessel Analyzer before, during, and after an increase in the arterial blood pressure induced by isometric exercise when lifting a hand weight in one arm. Simultaneously the blood pressure was measured on the other arm. Results: During isometric exercise nine persons showed constriction of the arteriole of –4.4±0.9%. These persons showed a dilation of the corresponding venule of 1.0±0.3% (p = 0.01). The other ten persons showed dilatation of the arteriole of 0.8±0.2% with no significant change in the diameter response 0.1±0.5% (p = 0.9) of the corresponding venule. Conclusions: The diameter response of retinal arterioles secondary to increased blood pressure shows large individual variation among normal individuals. The diameter response of retinal venules is more complex, probably depending on oscillations in the choroidal blood flow and other factors. An elucidation of these factors may help understanding flow disturbances in retinal disease.
This PDF is available to Subscribers Only