Analysis of Retinal Vasodilation after Flicker Light Stimulation in Relation to Vasospastic Propensity

2006 ◽  
Vol 47 (9) ◽  
pp. 4034 ◽  
Author(s):  
Konstantin Gugleta ◽  
Claudia Zawinka ◽  
Ines Rickenbacher ◽  
Asan Kochkorov ◽  
Robert Katamay ◽  
...  
Keyword(s):  
Light Stimulation ◽  
Flicker Light

Retinal Venous Oxygen Saturation Increases by Flicker Light Stimulation

2011 ◽  
Vol 52 (1) ◽  
pp. 274 ◽  
Author(s):  
Martin Hammer ◽  
Walthard Vilser ◽  
Thomas Riemer ◽  
Fanny Liemt ◽  
Susanne Jentsch ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Light Stimulation ◽  
Venous Oxygen Saturation ◽  
Flicker Light

Dynamic Responses in Retinal Vessel Caliber With Flicker Light Stimulation in Eyes With Diabetic Retinopathy

2014 ◽  
Vol 55 (8) ◽  
pp. 5207 ◽  
Author(s):  
Laurence S. Lim ◽  
Lieng H. Ling ◽  
Peng Guan Ong ◽  
Wallace Foulds ◽  
E. Shyong Tai ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Retinal Vessel ◽  
Dynamic Responses ◽  
Light Stimulation ◽  
Retinal Vessel Caliber ◽  
Flicker Light

scholarly journals Effect of Diffuse Luminance Flicker Light Stimulation on Total Retinal Blood Flow Assessed With Dual-Beam Bidirectional Doppler OCT

2017 ◽  
Vol 58 (2) ◽  
pp. 1167 ◽  
Author(s):  
Gerold C. Aschinger ◽  
Leopold Schmetterer ◽  
Klemens Fondi ◽  
Valentin Aranha Dos Santos ◽  
Gerald Seidel ◽  
...  
Keyword(s):  
Blood Flow ◽  
Retinal Blood Flow ◽  
Light Stimulation ◽  
Dual Beam ◽  
Doppler Oct ◽  
Flicker Light

Retinal vessels functionality in eyes with central serous chorioretinopathy

2017 ◽  
Vol 102 (2) ◽  
pp. 210-214 ◽  
Author(s):  
Livia Tomasso ◽  
Lucia Benatti ◽  
Alessandro Rabiolo ◽  
Adriano Carnevali ◽  
Ilaria Zucchiatti ◽  
...  
Keyword(s):  
Dynamic Analysis ◽  
Central Serous Chorioretinopathy ◽  
Choroidal Thickness ◽  
Venous Stasis ◽  
Retinal Vessels ◽  
Ophthalmological Examination ◽  
Light Stimulation ◽  
Dynamic Vessel Analyzer ◽  
Control Subjects ◽  
Flicker Light

PurposeTo analyse static characteristics and dynamic functionality of retinal vessels in eyes with central serous chorioretinopathy (CSCR) by means of Dynamic Vessel Analyzer (DVA).MethodsPatients presenting with treatment-naïve CSCR and normal subjects (controls) matched for age and sex between May 2015 and November 2015 were enrolled in the study. Participants underwent a complete ophthalmological examination, including dynamic and static retinal vessels analysis by DVA.ResultsA total of 28 eyes of 28 subjects (14 eyes for each group) were included in the analysis. Dynamic analysis during stimulation by flickering light showed mean venous dilation of 3.3%±2.0% in patients with CSCR and 5.5%±2.6% in controls (p=0.0258); mean arterial dilation did not differ between patients and controls (3.2%±2.5% and 4.2%±1.5%, p=0.2). No differences were reported at static retinal analysis between patients with CSCR and control subjects. Subfoveal choroidal thickness as evaluated by optical coherence tomography was 438.6±86.1 µm in CSCR eyes, significantly increased compared with control subjects (301.5±72.5 µm, p=0.0001).ConclusionsDynamic analysis revealed a reduced retinal venous dilation in response to flicker light stimulation in CSCR eyes. The decreased retinal vein response to flicker light stimulation, possibly due to increased sympathetic tone and potentially leading to venous stasis, together with the increased choroidal thickness may help understand CSCR and give insights in its pathogenesis.

Impaired retinal microvascular function predicts long-term adverse events in patients with cardiovascular disease

2020 ◽  
Author(s):  
James D Theuerle ◽  
Ali H Al-Fiadh ◽  
Fakir M Amirul Islam ◽  
Sheila K Patel ◽  
Louise M Burrell ◽  
...  
Keyword(s):  
Risk Factors ◽  
Cardiovascular Risk ◽  
Endothelial Dysfunction ◽  
Cardiovascular Events ◽  
Retinal Vessel ◽  
Light Stimulation ◽  
Traditional Risk Factors ◽  
Flicker Light ◽  
Retinal Arteriolar

Abstract Aims Endothelial dysfunction is a precursor to the development of symptomatic atherosclerosis. Retinal microvascular reactivity to flicker light stimulation is a marker of endothelial function and can be quantified in vivo. We sought to determine whether retinal microvascular endothelial dysfunction predicts long-term major adverse cardiovascular events (MACE). Methods and results In a single-centre prospective observational study, patients with coronary artery disease (CAD) or cardiovascular risk factors underwent dynamic retinal vessel assessment in response to flicker light stimulation and were followed up for MACE. Retinal microvascular endothelial dysfunction was quantified by measuring maximum flicker light-induced retinal arteriolar dilatation (FI-RAD) and flicker light-induced retinal venular dilatation (FI-RVD). In total, 252 patients underwent dynamic retinal vessel assessment and 242 (96%) had long-term follow-up. Of the 242 patients, 88 (36%) developed MACE over a median period of 8.6 years (interquartile range 6.0–9.1). After adjustment for traditional risk factors, patients within the lowest quintile of FI-RAD had the highest risk of MACE [odds ratio (OR) 5.21; 95% confidence interval (CI) 1.78–15.28]. Patients with lower FI-RAD were also more likely to die (OR 2.09; 95% CI 1.00–4.40, per standard deviation decrease in FI-RAD). In Kaplan–Meier analysis, patients with FI-RAD responses below the cohort median of 1.4% exhibited reduced MACE-free survival (55.5 vs. 71.5%; log-rank P = 0.004). FI-RVD was not predictive of MACE. Conclusion Retinal arteriolar endothelial dysfunction is an independent predictor of MACE in patients with CAD or cardiovascular risk factors. Dynamic retinal vessel analysis may provide added benefit to traditional risk factors in stratifying patients at risk for cardiovascular events.

scholarly journals Quantitative Retinal and Choroidal Blood Flow During Light, Dark Adaptation and Flicker Light Stimulation in Rats Using Fluorescent Microspheres

2013 ◽  
Vol 38 (2) ◽  
pp. 292-298 ◽  
Author(s):  
Yen-Yu I. Shih ◽  
Lin Wang ◽  
Bryan H. De La Garza ◽  
Guang Li ◽  
Grant Cull ◽  
...  
Keyword(s):  
Blood Flow ◽  
Dark Adaptation ◽  
Light Stimulation ◽  
Fluorescent Microspheres ◽  
Choroidal Blood Flow ◽  
Flicker Light

scholarly journals Altered states phenomena induced by visual flicker light stimulation

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253779
Author(s):  
Marie Therese Bartossek ◽  
Johanna Kemmerer ◽  
Timo Torsten Schmidt
Keyword(s):  
Rating Scale ◽  
Mood State ◽  
Altered States ◽  
Subjective Experiences ◽  
Light Stimulation ◽  
Geometric Patterns ◽  
Neuronal Mechanisms ◽  
Neo Five Factor Inventory ◽  
Highly Correlated ◽  
Flicker Light

Flicker light stimulation can induce short-term alterations in consciousness including hallucinatory color perception and geometric patterns. In the study at hand, the subjective experiences during 3 Hz and 10 Hz stroboscopic light stimulation of the closed eyes were assessed. In a within-subjects design (N = 24), we applied the Positive and Negative Affect Schedule (mood state), time perception ratings, the Altered State of Consciousness Rating Scale, and the Phenomenology of Consciousness Inventory. Furthermore, we tested for effects of personality traits (NEO Five-Factor Inventory-2 and Tellegen Absorption Scale) on subjective experiences. Such systematic quantification improves replicability, facilitates comparisons between pharmacological and non-pharmacological techniques to induce altered states of consciousness, and is the prerequisite to study their underlying neuronal mechanisms. The resulting data showed that flicker light stimulation-induced states were characterized by vivid visual hallucinations of simple types, with effects strongest in the 10 Hz condition. Additionally, participants’ personality trait of Absorption scores highly correlated with the experienced alterations in consciousness. Our data demonstrate that flicker light stimulation is capable of inducing visual effects with an intensity rated to be similar in strength to effects induced by psychedelic substances and thereby support the investigation of potentially shared underlying neuronal mechanisms.

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