Retinal Vascular Density as A Novel Biomarker of Acute Renal Injury after Acute Coronary Syndrome.

Iodinated contrast agent (ICA)-induced acute kidney injury (AKI) following acute coronary syndrome (ACS) is a frequent complication, which may lead to chronic kidney disease and increased mortality. Optical coherence tomography angiography (OCT-A) of the retina is new tool delivering a rapid and noninvasive assessment of systemic microvascularization, which is potentially involved in the occurrence of ICA-induced AKI. Between October 2016 and March 2017, 452 ACS patients were admitted to our cardiac intensive care unit. OCT-A was performed within 48 h after the ICA injection. Patients with a history of retinal disease were excluded. The patients included were divided into two groups depending on whether or not AKI occurred after injection of ICA, according to KDIGO criteria. Of the 216 patients included, 21 (10%) presented AKI. AKI was significantly associated with age, Mehran score, GRACE score, and NT-proBNP. AKI patients had significantly lower retinal vascular density (RVD)) and had more frequent low RVD (81% vs 45%, P = 0.002). Adding low RVD to the Mehran score and the NT-proBNP, or to the GRACE score and the NT-proBNP, significantly improved their predictive values, suggesting that systemic microvascular involvement remains incompletely addressed by either standard risk scores or factors known to be associated with ICA-induced AKI.

The EYE-MI Pilot Study: A Prospective Acute Coronary Syndrome Cohort Evaluated With Retinal Optical Coherence Tomography Angiography.

Purpose: To evaluate the association between retinal microvasculature (vascular density) on optical coherence tomography-angiography (OCT-A) and the cardiovascular profile of patients hospitalized for acute coronary syndrome (ACS). Methods: EYE-Myocardial Infarction (EYE-MI) study is a prospective cross-sectional study in the Cardiology Intensive Care Unit of Dijon University Hospital. Retinal OCT-A was performed for each patient within 2 days after admission. Superficial retinal capillary plexus (SCP) vascular density was measured. The population was divided into tertiles according to OCT-A data. Results: Overall, 237 cases were retained for analysis. Patients in the tertile with the lowest retinal vascular density (RVD) were older, and more frequently had systemic hypertension and diabetes. Moreover, American Heart Association (AHA) risk and Global Registry of Acute Coronary Events (GRACE) scores were higher and left ventricular ejection fraction (LVEF) was lower in these patients. In multivariate analysis, the AHA risk score (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.04-1.09; P < 0.001) and LVEF (OR, 0.95; 95% CI, 0.93-0.98; P = 0.001) were significantly associated with the lowest tertile of RVD. The association between RVD and a high-risk cardiovascular profile was confirmed by a moderate correlation with the GRACE scores (Spearman r = -0.33, P < 0.001). Conclusions: SCP density measured on OCT-A was associated with the cardiovascular risk profile and with impaired LVEF in patients with a high-risk cardiovascular status. In the future, quantitative retinal microvascular data could be considered a good surrogate of the cardiovascular risk profile and could improve cardiovascular risk assessments.

General practice and the Internet revolution. Use of an Internet social network to communicate information on prevention in France.

The popularity of social networks and the huge number of exchanges have made them immensely important for the communication of information. This French study explored prevention in hereditary breast cancer using a social Internet network to communicate information. The principal objective was to inform French women aged from 20 to 50 years, using the social network Facebook, about the warning signs of breast cancer in cases of a predisposition to the disease due to a genetic mutation. The secondary objectives were to inform people about screening. An information page entitled "hereditary breast cancer: and if I was concerned?" was distributed in 3 different ways: from friend to friend, via groups of persons, and by targeted advertising. Four articles and 11 messages were distributed over 27 days. The total number of visits for this period amounted to 1019. A total of 81 percent of the Internauts were women and 55 percent of the visitors were aged between 25 and 44 years. Other information campaigns concerning public health issues could be conducted using this tool. A legal framework is necessary to preserve the quality of the medical information provided. This new means of communication, used for prevention purposes, will add to other frequently used methods of communication.

Experimental evidence of Brillouin-induced polarization wheeling in highly birefringent optical fibers.

We study the influence of Stimulated Brillouin Scattering on the polarization stabilization of a light beam propagating in a highly-birefringent optical fiber. In particular, due to a saturation effect, we find that the output polarization lies on a ring when the polarization is represented onto the Poincaré sphere.

Spectral incoherent solitons: a localized soliton behavior in the frequency domain.

We show both theoretically and experimentally in an optical fiber system that a noninstantaneous nonlinear environment supports the existence of spectral incoherent solitons. Contrary to conventional solitons, spectral incoherent solitons do not exhibit a confinement in the spatiotemporal domain, but exclusively in the frequency domain. The theory reveals that the causality condition inherent to the nonlinear response function is the key property underlying the existence of spectral incoherent solitons. These solitons constitute nonequilibrium stable states of the incoherent field and are shown to be robust with respect to binary collisions.

Asymptotic properties of incoherent waves propagating in an all-optical regenerators line.

We present an original method to generate optical pulse trains with random time-interval values from incoherent broadband sources. More precisely, our technique relies on the remarkable properties of a line made of cascaded self-phase modulation-based optical regenerators. Depending on the regenerator parameters, various regimes with noticeably different physical behaviors can be reported.

Velocity locking of incoherent nonlinear wave packets.

We show both theoretically and experimentally in an optical fiber system that a set of incoherent nonlinear waves irreversibly evolves to a specific equilibrium state, in which the individual wave packets propagate with identical group velocities. This intriguing process of velocity locking can be explained in detail by simple thermodynamic arguments based on the kinetic wave theory. Accordingly, the selection of the velocity-locked state is shown to result from the natural tendency of the isolated wave system to approach the state that maximizes the nonequilibrium entropy.

Incoherent solitons in instantaneous response nonlinear media.

We show theoretically and experimentally in an optical fiber system that solitons can be spontaneously generated from incoherent light in an instantaneous response nonlinear Kerr medium. The theory reveals that the unexpected existence of these incoherent solitons relies on a phase-locking mechanism, which leads to the emergence of a mutual coherence between the incoherent waves that constitute the soliton.

Simultaneous achievement of polarization attraction and Raman amplification in isotropic optical fibers.

We present a theoretical analysis and experimental demonstration of the combined effects of polarization attraction and Raman amplification in isotropic optical fibers. The polarization attraction process is based on four-wave mixing interaction of counterpropagating pump and signal waves. We show that this technique can be used for the design of a highly efficient nonlinear system that permits the simultaneous processing of repolarization and amplification of light waves in dielectric media.