View clinical trials related to Retina; Change.
Filter by:The marketing of electronic cigarettes (e-cigarettes) in 2003 was initially intended to present a healthier alternative to smokers. Subsequently, it became an extremely widespread fashion phenomenon, especially among young people. It thus contributes to attracting new consumers thanks to its modern and technological presentation, combined with a panoply of captivating fragrances. In 2014, the FDA still does not recognize this practice as a substitute for smoking intended to limit it, and several recent studies have demonstrated the potential harmful effects of e-cigarettes on health. Indeed, the latter also have pulmonary effects reminiscent of those of the original cigarette, namely breathing difficulties or even lung inflammation. In addition, a potential impact on the vascular system has recently been highlighted by the use of these e-cigarettes. Thus, their components can lead to vascular changes in the reactivity of blood vessels, an increase in blood pressure or even endothelial dysfunction and vascular and cerebral oxidative stress. The aim of this study is to detect these phenomena at the level of the retinal circulation, window of the central nervous system, in order to be able to confirm the acute vascular impacts of the use of an e-cigarette. In addition, the vascular and metabolic impacts due to the potential toxicity of the other components of these e-cigarettes could be investigated. Finally, the comparison between patients who are smokers and occasional smokers will provide a better understanding of the different acute and chronic effects of nicotine.
Microperimetry is a relatively new and extremely sensitive method of assessing visual function. It projects light stimuli onto a defined area of the retina to map retinal perceptual thresholds. Participants look at a focal point and press a button to indicate when they have seen a light stimulus. The stimuli vary in intensity to find the participant's visual sensitivity. Microperimetry is carried out in low light conditions. Before testing, participants must adapt to the low light conditions in a process called 'dark adaptation.' Currently there is no consensus on the optimal time needed for dark adaptation. Investigators know that visual sensitivity differs in differing light conditions. Failing to sufficiently dark-adapt may therefore adversely affect test results. The aim of this study is to establish the optimal length of dark adaptation for microperimetry performance in healthy volunteers. On day 1, participants will undergo training field tests to reduce a learning effect affecting the results. Tests will then be performed following 5 mins adaptation, 10 mins adaptation and 30mins adaptation, On day 2, participants will perform testing following no adaptation time, 15 mins adaptation, and 20 mins adaptation. Statistics will be used to determine the effect of adaptation time on average threshold measures.