Diabetic Macular Edema - Diagnostics and Treatment Guidelines.

Together with diabetic retinopathy, diabetic macular edema (DME) ranks among the most common causes of severe loss of vision in working adults. Due to recent developments in imaging methods, new classification schemes of DME have been created. In addition to this, new treatment options have been introduced (new intravitreal drugs as well as treatment protocols). At the same time laser, surgical as well as combination therapy is still available. In this paper we evaluate the current knowledge about DME diagnostic and treatment options and formulate recommended guidelines for the management of DME.

Diabetic Retinopathy ­ Diagnostics and Treatment Guidelines

Diabetic retinopathy is one of the most common complications of diabetes mellitus and represents a serious health, social and economic problem. With the expected increase in the number of patients with diabetes, it is becoming the leading cause of severe vision loss in the working-age population.  The presented guidelines summarize the current knowledge about this disease in order to standardize and update the procedures for the diagnosis, classification and treatment of diabetic retinopathy.

Diabetic Retinopathy and Diabetic Macular Edema - Screening.

Diabetic retinopathy (DR) and diabetic macular edema (DME) are leading causes of severe visual loss in the working population. Therefore, both DR and DME have a significant socioeconomic and health impact, which taking into account the epidemiologic predictions is expected to increase.  A crucial role in the management of DR and DME (not only for individuals, but also for the population) is played by an adequate screening program. This is based on the structure and organization of the healthcare system, the latest scientific developments in diagnostics (imaging) as well as technological advancements in computing (artificial intelligence, telemedicine) and their practical use. The recommendation presented by World Health Organization is also important. This paper evaluates all these factors, including evidence-based medicine reports and experience from existing DR and DME screening programs in comparable countries. Based on an evaluation of these parameters, recommended guidelines have been formulated for screening for DR and DME in the Czech Republic, including linkage to the Czech National Screening Center and the organization of the healthcare system.

Ultrashort spin-orbit torque generated by femtosecond laser pulses.

To realize the very objective of spintronics, namely the development of ultra-high frequency and energy-efficient electronic devices, an ultrafast and scalable approach to switch magnetic bits is required. Magnetization switching with spin currents generated by the spin-orbit interaction at ferromagnetic/non-magnetic interfaces is one of such scalable approaches, where the ultimate switching speed is limited by the Larmor precession frequency. Understanding the magnetization precession dynamics induced by spin-orbit torques (SOTs) is therefore of great importance. Here we demonstrate generation of ultrashort SOT pulses that excite Larmor precession at an epitaxial Fe/GaAs interface by converting femtosecond laser pulses into high-amplitude current pulses in an electrically biased p-i-n photodiode. We control the polarity, amplitude, and duration of the current pulses and, most importantly, also their propagation direction with respect to the crystal orientation. The SOT origin of the excited Larmor precession was revealed by a detailed analysis of the precession phase and amplitude at different experimental conditions.

LATERAL TARSAL STRIP TECHNIQUE IN CORRECTION OF EYELID ECTROPION AND ENTROPION.

BACKGROUND: Ectropion and entropion are eyelid malpositions associated with a number of unpleasant symptoms. One of several surgical methods that can correct these problems is referred to as the lateral tarsal strip technique. In this paper, we evaluate the postoperative results and quality of this technique. We also examine the complications associated with this surgical method. METHODS: The study took place from April 2018 to April 2020 at the Military University Hospital in Prague. The operation was performed by two surgeons. The study included 43 eyes of 33 patients (17 women and 16 men), average age was 79 years. Before the operation, 23 eyes were affected by ectropion and 20 eyes affected by entropion, 35 of the 43 were cases of involutional origin. The study does not include patients who underwent other surgical techniques. RESULTS: There were no perioperative or postoperative complications in the entropion surgery group. Successful correction was achieved, and adverse symptoms disappeared in 91.3% of cases. Correct position of the eyelid was not achieved in two cases. For patients with ectropion, surgical correction was successful in 95% of cases. Ectropion persisted after surgery only in one patient. CONCLUSION:   The lateral tarsal strip technique is a safe, reliable and highly effective surgical technique. Correction of eyelid malposition was achieved in more than 90% of cases. The vast majority of patients were satisfied and reported relief from preoperative symptoms.

Metformin therapy and risk of cancer in patients after heart transplantation.

BACKGROUND: Diabetes mellitus (DM) and malignancy are recognized among the most common complications increasing mortality in patients after heart transplantation (HTx). Clinical trials have shown a higher risk for different types of tumours in diabetic patients. This risk is potentiated by immunosuppressive therapy in transplant patients. Biguanide metformin has been shown to exhibit anti-tumour activity and we tried to find out whether this effect is valid for heart transplant patients. METHODS: We retrospectively analysed a group of 497 patients, who undergone HTx in our centre between 1998 and 2019. The primary outcome was any malignancy during the 15-year follow-up period and patient's survival. RESULTS: Out of the 497 patients enrolled in the study, 279 (56 %) had diabetes and 52 (19 %) were treated with metformin. Fifteen-year survival in treated patients without malignancy was 93 %, the remainder for the DM patients was 56 %, with survival in non-DM patients being 74 %. Untreated diabetic patients had 4.7 times higher chance of malignancy than those on metformin (p = 0.01). Fifteen-year survival in metformin treated patients was 53 %, in other DM patients 44 %, and in non-DM patients 51 %. CONCLUSION: Our study showed a significantly lower incidence of malignancies in metformin-treated patients and slightly better overall survival (Tab. 2, Fig. 3, Ref. 19) Keywords: biguanide, heart graft, malignancy, diabetes mellitus, survival.

DIAGNOSIS THAT MIMIC PACHYCHOROID DISEASES OF MACULA - CASE REPORTS.

Pachychoroid disease of retina is a spectrum of diseases manifested by thickening and hyperperfusion of the choroid with changes in the sensory part of the retina. The main unit of this group is central serous chorioretinopathy (CSC). In practice, we often encounter other conditions, which are manifested by thickening of the choroid and changes in the retina, but they cannot be classified as pachychoroid diseases. The aim of this study is to point out on a series of 3 case reports the difficulties in the differential diagnosis of retinal diseases in which we find thickening of the choroid. Case report 1: 42-year-old patient treated for central serous chorioretinopathy. After optical coherence tomography (OCT), fluorescence angiography (FAG) and indocyanine green angiography (ICG) the diagnosis was changed to choroidal hemangioma and he was treated with photodynamic therapy (PDT) which led to a reduction of the hemangioma. Case report 2: A 30-year-old patient treated for ankylosing spondylitis comes for visual impairment in the left eye. On OCT the condition resembled chronic CSC. The patient suffered from a febrile exanthema a few days ago. Serological testing for coxsackievirus was positive and the diagnosis was changed to acute chorioretinitis in coxsackievirus infection. Oral treatment with prednisone was successful. Case report 3: A 46-year-old patient was treated conservatively for CSC. After FAG and ICG, a solitary dilated choroidal vessel was found in the area of the papillomacular bundle with leakage under the sensory epithelium which was diagnosed as choroidal macrovessel. We performed PDT with a very good anatomical effect. Conclusion: Precise differentiation of these mentioned diseases from pachychoroid retinal diseases was essential in choosing the appropriate therapy. The use of all modern imaging methods of the retina and choroid plays a key role in determining the diagnosis. Key words: pachychoroid disease, central serous chorioretinopathy, choroidal hemangioma, chorioretinitis, coxsackievirus, choroidal macrovessel.

Voigt effect-based wide-field magneto-optical microscope integrated in a pump-probe experimental setup.

In this work, we describe an experimental setup for a spatially resolved pump-probe experiment with an integrated wide-field magneto-optical (MO) microscope. The MO microscope can be used to study ferromagnetic materials with both perpendicular-to-plane and in-plane magnetic anisotropy via polar Kerr and Voigt effects, respectively. The functionality of the Voigt effect-based microscope was tested using an in-plane magnetized ferromagnetic semiconductor (Ga,Mn)As. It was revealed that the presence of mechanical defects in the (Ga,Mn)As epilayer alters significantly the magnetic anisotropy in their proximity. The importance of MO experiments with simultaneous temporal and spatial resolutions was demonstrated using a (Ga,Mn)As sample attached to a piezoelectric transducer, which produces a voltage-controlled strain. We observed a considerably different behavior in different parts of the sample that enabled us to identify sample parts where the epilayer magnetic anisotropy was significantly modified by the presence of the piezoelectric transducer and where it was not. Finally, we discuss the possible applicability of our experimental setup for the research of compensated antiferromagnets, where only MO effects even in magnetic moments are present.

Biomarkers in Immunoglobulin Light Chain Amyloidosis.

Immunoglobulin light chain amyloidosis (AL amyloidosis - ALA) is a monoclonal gammopathy characterized by presence of aberrant plasma cells producing amyloidogenic immunoglobulin light chains. This leads to formation of amyloid fibrils in various organs and tissues, mainly in heart and kidney, and causes their dysfunction. As amyloid depositing in target organs is irreversible, there is a big effort to identify biomarker that could help to distinguish ALA from other monoclonal gammopathies in the early stages of disease, when amyloid deposits are not fatal yet. High throughput technologies bring new opportunities to modern cancer research as they enable to study disease within its complexity. Sophisticated methods such as next generation sequencing, gene expression profiling and circulating microRNA profiling are new approaches to study aberrant plasma cells from patients with light chain amyloidosis and related diseases. While generally known mutation in multiple myeloma patients (KRAS, NRAS, MYC, TP53) were not found in ALA, number of mutated genes is comparable. Transcriptome of ALA patients proves to be more similar to monoclonal gammopathy of undetermined significance patients, moreover level of circulating microRNA, that are known to correlate with heart damage, is increased in ALA patients, where heart damage in ALA typical symptom.Key words: amyloidosis - plasma cell - genome - transcriptome - microRNA.

Czech Registry of Monoclonal Gammopathies - Technical Solution, Data Collection and Visualisation.

BACKGROUND: The Registry of Monoclonal Gammopathies (RMG) was established by the Czech Myeloma Group in 2007. RMG is a registry designed for the collection of clinical data concerning diagnosis, treatment, treatment results and survival of patients with monoclonal gammopathies. Data on patients with monoclonal gammopathy of undetermined significance (MGUS), Waldenström macroglobulinaemia (WM), multiple myeloma (MM) or primary AL ("amyloid light-chain") amyloidosis are collected in the registry. DATA: Nineteen Czech centres and four Slovak centres currently contribute to the registry. The registry currently contains records on more than 5,000 patients with MM, almost 3,000 patients with MGUS, 170 patients with WM and 26 patients with primary AL amyloidosis, i.e. more than 8,000 records on patients with monoclonal gammopathies altogether. RESULTS: This paper describes technology employed for the collection, storage and subsequent online visualisation of data. The CLADE-IS platform is introduced as a new system for the collection and storage of data from the registry. The form structure and functions of the new system are described for all diagnoses in general; these functions facilitate data entry to the registry and minimise the error rate in data. Publicly available online visualisations of data on patients with MGUS, WM, MM or primary AL amyloidosis from all Czech or Slovak centres are introduced, together with authenticated visualisations of data on patients with MM from selected centres. CONCLUSION: The RMG represents a data basis that makes it possible to monitor the disease course in patients with monoclonal gammopathies on the population level.Key words: Registry of Monoclonal Gammopathies - RMG - registries - monoclonal gammopathies - CLADE-IS - data visualisation - database.

Control of antiferromagnetic spin axis orientation in bilayer Fe/CuMnAs films.

Using x-ray magnetic circular and linear dichroism techniques, we demonstrate a collinear exchange coupling between an epitaxial antiferromagnet, tetragonal CuMnAs, and an Fe surface layer. A small uncompensated Mn magnetic moment is observed which is antiparallel to the Fe magnetization. The staggered magnetization of the 5 nm thick CuMnAs layer is rotatable under small magnetic fields, due to the interlayer exchange coupling. This allows us to obtain the x-ray magnetic linear dichroism spectra for different crystalline orientations of CuMnAs in the (001) plane. This is a key parameter for enabling the understanding of domain structures in CuMnAs imaged using x-ray magnetic linear dichroism microscopy techniques.

Association between the heart rate early after heart transplantation and the long term clinical outcomes.

BACKGROUND: A strong correlation between a lower heart rate and survival has been demonstrated in various patient populations. The optimal heart rate for heart transplant patients is still unknown. The aim of our study was to evaluate the association between an early heart rate and survival after heart transplantation. MATERIAL AND METHODS: We retrospectively analysed a group of 330 patients, who underwent heart transplantation in our institution from 1994 to 2014 and complete datasets, including 24-hour heart rate monitoring one month after the heart transplantation. Patients were divided in 2 groups: Group A (n = 278) with the average 24-hour heart rate <90 bpm, and Group B (n = 52) with ≥ 90 bpm. RESULTS: The average period of monitoring was 7.5 ± 5.3 years. No differences in baseline characteristics were observed in both groups of recipients and respective donors. One-year survival in groups A and B was 92 % and 81 %, respectively; 5-year survival was 79 % and 60 %, respectively; and 10-year survival was 66 % and 50 %, respectively (p = 0.001). CONCLUSION: Increased heart rate in the early post-transplant period was significantly associated with a poorer survival rate in patients after heart transplantation (Tab. 2, Fig. 1, Ref. 25).

Experimental design approach for deposition optimization of RF sputtered chalcogenide thin films devoted to environmental optical sensors.

The development of the optical bio-chemical sensing technology is an extremely important scientific and technological issue for diagnosis and monitoring of diseases, control of industrial processes, environmental detection of air and water pollutants. Owing to their distinctive features, chalcogenide amorphous thin films represent a keystone in the manufacture of middle infrared integrated optical devices for a sensitive detection of biological or environmental variations. Since the chalcogenide thin films characteristics, i.e. stoichiometric conformity, structure, roughness or optical properties can be affected by the growth process, the choice and control of the deposition method is crucial. An approach based on the experimental design is undoubtedly a way to be explored allowing fast optimization of chalcogenide film deposition by means of radio frequency sputtering process. Argon (Ar) pressure, working power and deposition time were selected as potentially the most influential factors among all possible. The experimental design analysis confirms the great influence of the Ar pressure on studied responses: chemical composition, refractive index in near-IR (1.55 µm) and middle infrared (6.3 and 7.7 µm), band-gap energy, deposition rate and surface roughness. Depending on the intended application and therefore desired thin film characteristics, mappings of the experimental design meaningfully help to select suitable deposition parameters.

Inertial displacement of a domain wall excited by ultra-short circularly polarized laser pulses.

Domain wall motion driven by ultra-short laser pulses is a pre-requisite for envisaged low-power spintronics combining storage of information in magnetoelectronic devices with high speed and long distance transmission of information encoded in circularly polarized light. Here we demonstrate the conversion of the circular polarization of incident femtosecond laser pulses into inertial displacement of a domain wall in a ferromagnetic semiconductor. In our study, we combine electrical measurements and magneto-optical imaging of the domain wall displacement with micromagnetic simulations. The optical spin-transfer torque acts over a picosecond recombination time of the spin-polarized photo-carriers that only leads to a deformation of the initial domain wall structure. We show that subsequent depinning and micrometre-distance displacement without an applied magnetic field or any other external stimuli can only occur due to the inertia of the domain wall.

Selective binocular vision loss in two subterranean caviomorph rodents: Spalacopus cyanus and Ctenomys talarum.

To what extent can the mammalian visual system be shaped by visual behavior? Here we analyze the shape of the visual fields, the densities and distribution of cells in the retinal ganglion-cell layer and the organization of the visual projections in two species of facultative non-strictly subterranean rodents, Spalacopus cyanus and Ctenomys talarum, aiming to compare these traits with those of phylogenetically closely related species possessing contrasting diurnal/nocturnal visual habits. S. cyanus shows a definite zone of frontal binocular overlap and a corresponding area centralis, but a highly reduced amount of ipsilateral retinal projections. The situation in C. talarum is more extreme as it lacks of a fronto-ventral area of binocular superposition, has no recognizable area centralis and shows no ipsilateral retinal projections except to the suprachiasmatic nucleus. In both species, the extension of the monocular visual field and of the dorsal region of binocular overlap as well as the whole set of contralateral visual projections, appear well-developed. We conclude that these subterranean rodents exhibit, paradoxically, diurnal instead of nocturnal visual specializations, but at the same time suffer a specific regression of the anatomical substrate for stereopsis. We discuss these findings in light of the visual ecology of subterranean lifestyles.

PET/CT in giant cell arteritis: High 18F-FDG uptake in the temporal, occipital and vertebral arteries / PET/TC en la arteritis de células gigantes: alta acumulación de 18F-FDG en las arterias temporal, occipital y vertebral

18F-FDG PET/CT imaging is useful in patients with fever of unknown origin and can detect giant cell arteritis in extracranial large arteries. However, it is usually assumed that temporal arteries cannot be visualized with a PET/CT scanner due to their small diameter. Three patients with clinical symptoms of temporal arteritis were examined using a standard whole body PET/CT protocol (skull base - mid thighs) followed by a head PET/CT scan using the brain protocol. High 18F-FDG uptake in the aorta and some arterial branches were detected in all 3 patients with the whole body protocol. Using the brain protocol, head imaging led to detection of high 18F-FDG uptake in temporal arteries as well as in their branches (3 patients), in occipital arteries (2 patients) and also in vertebral arteries (3 patients) (AU)

El estudio con 18F-FDG PET/TC es útil en los pacientes con fiebre de origen desconocido y puede detectar la arteritis de células gigantes en las grandes arterias extracraneales. Sin embargo, por lo general se supone que las arterias temporales no pueden ser visualizadas por medio de PET/TC porque su diámetro es pequeño. Se examinó a tres pacientes con arteritis temporal mediante el protocolo PET/TC estándar de cuerpo completo (base del cráneo - mitad del muslo) seguido del protocolo PET/TC de cabeza para cerebro. En los tres pacientes se observó la alta acumulación de 18F-FDG en la aorta y en algunas arterias. Mediante el protocolo para cerebro se observó la intensa acumulación de 18F-FDG en las arterias temporales y sus ramas (3 pacientes), en las arterias occipitales (2 pacientes) y también en las arterias vertebrales (3 pacientes) (AU)

Multiple-stable anisotropic magnetoresistance memory in antiferromagnetic MnTe.

Commercial magnetic memories rely on the bistability of ordered spins in ferromagnetic materials. Recently, experimental bistable memories have been realized using fully compensated antiferromagnetic metals. Here we demonstrate a multiple-stable memory device in epitaxial MnTe, an antiferromagnetic counterpart of common II-VI semiconductors. Favourable micromagnetic characteristics of MnTe allow us to demonstrate a smoothly varying zero-field antiferromagnetic anisotropic magnetoresistance (AMR) with a harmonic angular dependence on the writing magnetic field angle, analogous to ferromagnets. The continuously varying AMR provides means for the electrical read-out of multiple-stable antiferromagnetic memory states, which we set by heat-assisted magneto-recording and by changing the writing field direction. The multiple stability in our memory is ascribed to different distributions of domains with the Néel vector aligned along one of the three magnetic easy axes. The robustness against strong magnetic field perturbations combined with the multiple stability of the magnetic memory states are unique properties of antiferromagnets.

PET/CT in giant cell arteritis: High 18F-FDG uptake in the temporal, occipital and vertebral arteries.

18F-FDG PET/CT imaging is useful in patients with fever of unknown origin and can detect giant cell arteritis in extracranial large arteries. However, it is usually assumed that temporal arteries cannot be visualized with a PET/CT scanner due to their small diameter. Three patients with clinical symptoms of temporal arteritis were examined using a standard whole body PET/CT protocol (skull base - mid thighs) followed by a head PET/CT scan using the brain protocol. High 18F-FDG uptake in the aorta and some arterial branches were detected in all 3 patients with the whole body protocol. Using the brain protocol, head imaging led to detection of high 18F-FDG uptake in temporal arteries as well as in their branches (3 patients), in occipital arteries (2 patients) and also in vertebral arteries (3 patients).

Pulsed laser deposited GeTe-rich GeTe-Sb2Te3 thin films.

Pulsed laser deposition technique was used for the fabrication of Ge-Te rich GeTe-Sb2Te3 (Ge6Sb2Te9, Ge8Sb2Te11, Ge10Sb2Te13, and Ge12Sb2Te15) amorphous thin films. To evaluate the influence of GeTe content in the deposited films on physico-chemical properties of the GST materials, scanning electron microscopy with energy-dispersive X-ray analysis, X-ray diffraction and reflectometry, atomic force microscopy, Raman scattering spectroscopy, optical reflectivity, and sheet resistance temperature dependences as well as variable angle spectroscopic ellipsometry measurements were used to characterize as-deposited (amorphous) and annealed (crystalline) layers. Upon crystallization, optical functions and electrical resistance of the films change drastically, leading to large optical and electrical contrast between amorphous and crystalline phases. Large changes of optical/electrical properties are accompanied by the variations of thickness, density, and roughness of the films due to crystallization. Reflectivity contrast as high as ~0.21 at 405 nm was calculated for Ge8Sb2Te11, Ge10Sb2Te13, and Ge12Sb2Te15 layers.

Long-range and high-speed electronic spin-transport at a GaAs/AlGaAs semiconductor interface.

Spin-valves or spin-transistors in magnetic memories and logic elements are examples of structures whose functionality depends crucially on the length and time-scales at which spin-information is transferred through the device. In our work we employ spatially resolved optical pump-and-probe technique to investigate these fundamental spin-transport parameters in a model semiconductor system. We demonstrate that in an undoped GaAs/AlGaAs layer, spins are detected at distances reaching more than ten microns at times as short as nanoseconds. We have achieved this unprecedented combination of long-range and high-speed electronic spin-transport by simultaneously suppressing mechanisms that limit the spin life-time and the mobility of carriers. By exploring a series of structures we demonstrate that the GaAs/AlGaAs interface can provide superior spin-transport characteristics whether deposited directly on the substrate or embedded in complex semiconductor heterostructures. We confirm our conclusions by complementing the optical experiments with dc and terahertz photo-conductivity measurements.