Molecular Pathogenesis of Ischemic and Hemorrhagic Strokes: Background and Therapeutic Approaches.

Stroke represents one of the neurological diseases most responsible for death and permanent disability in the world. Different factors, such as thrombus, emboli and atherosclerosis, take part in the intricate pathophysiology of stroke. Comprehending the molecular processes involved in this mechanism is crucial to developing new, specific and efficient treatments. Some common mechanisms are excitotoxicity and calcium overload, oxidative stress and neuroinflammation. Furthermore, non-coding RNAs (ncRNAs) are critical in pathophysiology and recovery after cerebral ischemia. ncRNAs, particularly microRNAs, and long non-coding RNAs (lncRNAs) are essential for angiogenesis and neuroprotection, and they have been suggested to be therapeutic, diagnostic and prognostic tools in cerebrovascular diseases, including stroke. This review summarizes the intricate molecular mechanisms underlying ischemic and hemorrhagic stroke and delves into the function of miRNAs in the development of brain damage. Furthermore, we will analyze new perspectives on treatment based on molecular mechanisms in addition to traditional stroke therapies.

Metabolic memory in diabetic foot syndrome (DFS): MICRO-RNAS, single nucleotide polymorphisms (SNPs) frequency and their relationship with indices of endothelial function and adipo-inflammatory dysfunction.

BACKGROUND: Diabetic foot is a significant cause of morbidity in diabetic patients, with a rate that is approximately twice that of patients without foot ulcers. "Metabolic memory" represents the epigenetic changes induced by chronic hyperglycaemia, despite the correction of the glucose levels themselves. These epigenetic modifications appear to perpetuate the damage caused by persistently elevated glucose levels even in their absence, acting at various levels, mostly affecting the molecular processes of diabetic ulcer healing. METHODS: The aim of our cross-sectional study was to analyse a cohort of patients with diabetes with and without lower limb ulcers. We examined the effects of epigenetic changes on miRNA 126, 305, and 217 expression and the frequency of the SNPs of genes encoding inflammatory molecules (e.g., IL-6 and TNF-alpha) and their correlations with serum levels of proangiogenic molecules (e.g., ENOS, VEGF and HIF-1alpha) and several adipokines as well as with endothelial dysfunction, assessed noninvasively by reactive hyperaemia peripheral artery tonometry. Between March 2021 and June 2022, 110 patients were enrolled into the study: 50 diabetic patients with diabetic foot injuries, 40 diabetic patients without ulcerative complications and 20 nondiabetic patients as the control group. RESULTS: Diabetic subjects with lower limb ulcerative lesions exhibited higher levels of inflammatory cytokines, such as VEGF (191.40 ± 200 pg/mL vs. 98.27 ± 56.92 pg/mL vs. 71.01 ± 52.96 pg/mL; p = 0.22), HIF-1alpha (40.18 ± 10.80 ng/mL vs. 33.50 ± 6.16 ng/mL vs. 33.85 ± 6.84 ng/mL; p = 0.10), and Gremlin-1 (1.72 ± 0.512 ng/mL vs. 1.31 ± 0.21 ng/mL vs. 1.11 ± 0.19 ng/mL; p < 0.0005), than those without lower limb ulcers and healthy controls. Furthermore, we observed that miR-217-5p and miR-503-5p were 2.19-fold (p < 0.05) and 6.21-fold (p = 0.001) more highly expressed in diabetic foot patients than in healthy controls, respectively. Additionally, diabetic patients without lower limb ulcerative complications showed 2.41-fold (p = 0) and 2.24-fold (p = 0.029) higher expression of miR-217-5p and miR-503-5p, respectively, than healthy controls. Finally, diabetic patients with and without ulcerative complications of the lower limbs showed higher expression of the VEGFC2578A CC polymorphism (p = 0.001) and lower expression of the VEGFC2578A AC polymorphism (p < 0.005) than the healthy control population. We observed a significant increase in Gremlin-1 levels in patients with diabetic foot, suggesting that this inflammatory adipokine may serve as a predictive marker for the diagnosis of diabetic foot. CONCLUSIONS: Our results highlighted that patients with diabetic foot showed predominant expression of the VEGF C2578A CC polymorphism and reduced expression of the AC allele. Additionally, we found an overexpression of miR-217-5p and miR-503-5p in diabetic patients with and without diabetic foot syndrome compared with healthy controls. These results align with those reported in the literature, in which the overexpression of miR-217-5p and miR-503-5p in the context of diabetic foot is reported. The identification of these epigenetic modifications could therefore be helpful in the early diagnosis of diabetic foot and the treatment of risk factors. However, further studies are necessary to confirm this hypothesis.

Algorithm of the major and minor diagnostic criteria for active myopic choroidal neovascularization.

PURPOSE: To propose an algorithm of the major and minor diagnostic criteria for macular myopic choroidal neovascularization (mCNV). METHODS: This single-center, retrospective, cross-sectional study was based in Istituto Auxologico Italiano, Milan, Italy. Two authors evaluated the clinical and imaging parameters of eyes with high myopia (spherical equivalent of -6D or less) and suspected to have naïve, recurrent, or inactive mCNV. Recordings of the eyes that met the inclusion criteria were then independently evaluated by two other senior retinal specialists. Fluorescein angiography (FA), spectral domain optical coherence tomography (SD-OCT), and OCT angiography were used for multimodal imaging. RESULTS: One-hundred and twenty-two eyes (n = 107; 39 men, 68 women) were included in the study. The mean patient age was 66 years (range, 22-89 years). There were 83 and 39 eyes in the active mCNV and control groups, respectively. The best diagnostic algorithm had positive- and negative-predictive values of 89% and 85%, respectively, and was based on four criteria: leakage/staining on FA, retinal thickening, fuzzy area on SD-OCT, and recent metamorphopsia. When excluding FA-derived findings, retinal pigment epithelium (RPE) features played a diagnostic role in 33 eyes (27%). Twenty-seven eyes with active mCNV (32%) did not have the fuzzy area. Taken singularly, no clinical or imaging parameter had both sensitivity and specificity greater than 78%. Matching of 2 or 3 biomarkers did not yield a sensitivity or specificity greater than 79%. Sensitivities and specificities ≥ 90% were found in ten criteria combinations that included four to five biomarkers. The most frequent were metamorphopsia, fuzzy area, retinal thickening, and leakage. Less frequently, they included hemorrhage, staining, and RPE features such as elevation, flattening, and focal interruption. For all the parameters, the agreement between the investigators was good (Cohen k ≥ 0.66), being the lowest when detecting the ELM interruption within the lesion. CONCLUSIONS: A combination of at least four clinical and biological markers yielded the highest positive- and negative-predictive values. More ("major") and less ("minor") frequent diagnostic criteria are proposed.

A Smart Wearable Sensor System for Counter-Fighting Overweight in Teenagers.

PEGASO is a FP7-funded project whose goal is to develop an ICT and mobile-based platform together with an appropriate strategy to tackle the diffusion of obesity and other lifestyle-related illnesses among teenagers. Indeed, the design of an engaging strategy, leveraging a complementary set of technologies, is the approach proposed by the project to promote the adoption of healthy habits such as active lifestyle and balanced nutrition and to effectively counter-fight the emergence of overweight and obesity in the younger population. A technological key element of such a strategy sees the adoption of wearable sensors to monitor teenagers' activities, which is at the basis of developing awareness about the current lifestyle. This paper describes the experience carried out in the framework of the PEGASO project in developing and evaluating wearable monitoring systems addressed to adolescents. The paper describes the methodological approach based on the co-designing of such a wearable system and the main results that, in the first phase, involved a total of 407 adolescents across Europe in a series of focus groups conducted in three countries for the requirements definition phase. Moreover, it describes an evaluation process of signal reliability during the usage of the wearable system. The main results described here are: (a) a prototype of the standardized experimental protocol that has been developed and applied to test signal reliability in smart garments; (b) the requirements definition methodology through a co-design activity and approach to address user requirements and preferences and not only technological specifications. Such co-design approach is able to support a higher system acceptance and usability together with a sustained adoption of the solution with respect to the traditional technology push system development strategy.

Wearable monitoring devices for assistive technology: case studies in post-polio syndrome.

The correct choice and customization of an orthosis are crucial to obtain the best comfort and efficiency. This study explored the feasibility of a multivariate quantitative assessment of the functional efficiency of lower limb orthosis through a novel wearable system. Gait basographic parameters and energetic indexes were analysed during a Six-Minute Walking Test (6-MWT) through a cost-effective, non-invasive polygraph device, with a multichannel wireless transmission, that carried out electro-cardiograph (ECG); impedance-cardiograph (ICG); and lower-limb accelerations detection. Four subjects affected by Post-Polio Syndrome (PPS) were recruited. The wearable device and the semi-automatic post-processing software provided a novel set of objective data to assess the overall efficiency of the patient-orthosis system. Despite the small number of examined subjects, the results obtained with this new approach encourage the application of the method thus enlarging the dataset to validate this promising protocol and measuring system in supporting clinical decisions and out of a laboratory environment.

Two potentially distinct pathways to geographic atrophy in age-related macular degeneration characterized by quantitative fundus autofluorescence.

BACKGROUND/AIMS: To demonstrate two distinct pathways to geographic atrophy (GA) that originate from soft drusen/ pigment epithelial detachments (PEDs) and subretinal drusenoid deposits (SDDs), respectively, and are characterized by their final quantitative autofluorescence (qAF) levels. METHODS: 23 eyes of 18 patients with GA underwent spectral-domain optical coherence tomography (SD-OCT) and qAF imaging on the qAF-ready Heidelberg Spectralis. 52 GA Regions-of-interest (ROIs), or clusters of adjacent lesions, were selected, and the ROIs were divided into groups by the dominant iAMD precursors on prior serial tracked SD-OCT scans. Mean qAF values and structural SD-OCT findings of groups were compared. RESULTS: Group 1 lesions (soft drusen/PED precursors, 18/52) were isolated, with lower mean qAF (35.88 ± 12.75 units); group 3 lesions (SDD precursors, 12/52) were multilobular, with significantly higher mean qAF (71.62 ± 12.12 units, p < 0.05). Group 2 lesions, (mixed precursors, 22/52) had intermediate mean qAF (58.13 ± 67.92 units). Significantly greater prevalence of split RPE/ Bruch's membrane complex in SDD-associated GA, suggesting basal laminar deposit (BLamD), than in drusen-associated lesions was the major structural difference. CONCLUSION: Quantitative autofluorescence (qAF) of GA lesions may reflect two distinct pathogenic pathways and structural outcomes, originating from soft drusen/PED and subretinal drusenoid deposits (SDDs), with the final qAF values lower or higher, respectively. Basal laminar deposit specifically in and adjacent to SDD-associated lesions may account for their greater autofluorescence. The potential importance of this paradigm is that it could direct, simplify and facilitate research on geographic atrophy by dividing the disease into two components that may be studied separately.

Suprachoroidal haemhorrage and vortex vein varix: A potential association.

PURPOSE: To report on the association between a vortex vein varix and suprachoroidal hemorrhage. CASE DESCRIPTION: A healthy 60 years-old man with high myopia (-10 diopters) was seen because of sudden paracentral metamorphopsias after emesis. Multimodal imaging included Spectral-Domain Optical Coherence Tomography (SD-OCT), ultrasonography and retinal angiography with fluorescein and indocyanine green. His vision was 20/20 but clinical assessment and imaging procedures evaluations showed a suprachoroidal hemorrhage in the temporal part of the para-macular area. The lesion corresponded to a mild hypo-fluorescence area on fluorescein angiography and to a massive detachment of the inner part of the choroid from the suprachoroidal space on SD-OCT. Indocyanine green angiography disclosed engorgement of a big choroidal vessel in the area of the lesion. An adjacent vortex vein varix was found on SD-OCT. A few weeks later the suprachoroidal hemorrhage resolved spontaneously, whereas the vortex vein varix persisted. CONCLUSION: We speculate that vortex vein varixes might represent a risk factor for the occurrence of suprachoroidal hemorrhage in high myopia and that this association may be worth investigating. SUMMARY STATEMENT: In a high myopia suprachoroidal hemorrhage might be secondary to vortex vein varixes.

Myopic Simple Hemorrhage Presenting as Radial Hemorrhage in Henle's Fiber Layer.

This case report describes a simple hemorrhage (SH) presenting as radial hemorrhage in Henle's fiber layer (HFL) in a patient with high myopia. A 26-year-old girl with high myopia was referred to our center for sudden onset of decreased vision and a central scotoma in the right eye (OD). Best corrected visual acuity (BCVA) was 20/100 OD. Fundus examination showed a stellate intraretinal hemorrhage in the fovea of the OD. The hemorrhage was organized in a peculiar petaloid pattern with feathery distal edges, suggesting localization within the radially oriented HFL. The presence of both choroidal neovascularization and microvascular abnormalities consistent with macular telangiectasia type 2 (MacTel 2) were excluded. Based on these findings, a diagnosis of myopic SH was made. At 4-month follow-up BCVA OD spontaneously improved to 20/40, without any treatment been ever administered to the patient. Spectral-domain optical coherence tomography OD showed reabsorption of the hemorrhage and almost complete restoration of the foveal architecture. The intraretinal location and spread of the hemorrhage into the HFL in our patient are an unusual presentation of SH, which vividly highlights the anatomy of the fovea. Since fibers in HFL are quite delicate and loosely arranged, this layer is very susceptible to deposition of transudates, exudates, hemorrhage, and other products. Radial hemorrhage in HFL has been originally reported in 4 patients as complication of MacTel 2. It has been previously postulated that it may represent a characteristic finding in MacTel 2 that may develop as a result of microvascular abnormalities of the deep retinal capillary plexus. On the contrary, our data suggest that radial hemorrhage in the HFL does not represent a characteristic finding of MacTel 2, but must rather be considered a non-specific sign with multiple possible etiologies.

OCT Biomarkers in Neovascular Age-Related Macular Degeneration: A Narrative Review.

Age-related macular degeneration (AMD) is the leading cause of legal blindness in elderly people. Neovascular AMD (nAMD) is responsible for the majority of cases of severe visual loss in eyes with AMD. Optical coherence tomography (OCT) is the most widely used technology for the diagnosis and follow-up of nAMD patients, which is widely used to study and guide the clinical approach, as well as to predict and evaluate treatment response. The aim of this review is to describe and analyze various structural OCT-based biomarkers, which have practical value during both initial assessment and treatment follow-up of nAMD patients. While central retinal thickness has been the most common and one of the first OCT identified biomarkers, today, other qualitative and quantitative biomarkers provide novel insight into disease activity and offer superior prognostic value and better guidance for tailored therapeutic management. The key importance of retinal fluid compartmentalization (intraretinal fluid, subretinal fluid, and subretinal pigment epithelium (RPE) fluid) will be discussed firstly. In the second part, the structural alterations of different retinal layers in various stages of the disease (photoreceptors layer integrity, hyperreflective dots, outer retinal tubulations, subretinal hyperreflective material, and retinal pigment epithelial tears) will be analyzed in detail. The last part of the review will focus on how alterations of the vitreoretinal interface (vitreomacular adhesion and traction) and of the choroid (sub-RPE hyperreflective columns, prechoroidal clefts, choroidal caverns, choroidal thickness and choroidal volume, and choroidal vascular index) interact with nAMD progression. OCT technology is evolving very quickly, and new retinal biomarkers are continuously described. This up-to-date review article provides a comprehensive description on how structural OCT-based biomarkers provide a valuable tool to monitor the progression of the disease and the treatment response in nAMD patients. Thus, in this perspective, clinicians will be able to allocate hospital resources in the best possible way and tailor treatment to the individual patient's needs.

Optical coherence tomography angiography and arterial hypertension: A role in identifying subclinical microvascular damage?

INTRODUCTION: To evaluate retinal microvasculature modifications by means of optical coherence tomography angiography in human subjects diagnosed with arterial hypertension and to assess potential clinical relevance for early diagnosis. METHODS: A cross-sectional study of 30 subjects affected by arterial hypertension compared to a matched cohort of healthy patients was conducted. Patients were evaluated by the Outpatient Clinic for Hypertension and the Retina Center, University of Insubria, Varese, Italy. Patients were divided into three groups: Group 1-healthy subjects, Group 2-patients first diagnosed with hypertension, and Group 3-patients with treated hypertension. Optical coherence tomography angiography was performed applying different analysis protocols for macula and optic disk, using an AngioVue OCTA System on an Optovue device. Morphological data were compared to and correlated with clinical vascular parameters, to evaluate preclinical microvascular damage. RESULTS: A significant reduction in deep vascular layer density (Group 1: 59.2% ± 1.5% standard deviation; Group 2: 59.2% ± 2.2% standard deviation; Group 3: 57.8% ± 2.6% standard deviation; p < 0.05) as well as an enlargement of the deep foveal avascular zone area (Group 1: 0.34 ± 0.09 mm2; Group 2: 0.36 ± 0.07 mm2; Group 3: 0.39 ± 0.1 mm2; p < 0.05) was measured in patients with first diagnosed hypertension and in treated patients compared to healthy subjects. We also observed a significant decrease in mean foveal choroidal thickness in affected patients compared to controls (Group 1: 319.68 ± 61.72 µm standard deviation; Group 2: 251.04 ± 63.1 µm standard deviation; Group 3: 262.65 ± 51.08 µm standard deviation; p < 0.05). Our preliminary data did not show a significant correlation with microalbuminuria levels. DISCUSSION: Retinal vascular density showed pathological modifications between healthy subjects and hypertensive patients. These preliminary findings suggest that optical coherence tomography angiography may identify pathological markers of an early hypertensive damage and help monitor disease progression with potential therapeutic advantages.

Lamellar Macular Holes: The Role of Microperimetry in Functional Assessment.

INTRODUCTION: The aim of our observational cross-sectional study was to evaluate the association between visual function and anatomical characteristics of LMH, considering in particular different subtypes of LMH and their features. MATERIALS AND METHODS: This observational clinical study has been conducted in the Ophthalmology Clinic, ASST-Sette Laghi, University of Insubria of Varese-Como, Italy. Included patients underwent a complete ophthalmological examination, as well as MP1 microperimetry evaluation and optical coherence tomography (OCT). Two experienced masked observers evaluated OCT imaging in order to assess the integrity of the photoreceptor layer (interdigitation zone and ellipsoid zone: IZ/EZ) and the external limiting membrane (ELM). RESULTS: Twenty-five patients affected by an LMH were evaluated. Eighteen eyes of 18 patients met the study criteria and were included. Based on morphological and functional data, LMHs were divided into two subgroups: tractional (tLMH) and degenerative (dLMH). We identified 11 tLMHs and seven dLMHs. Functional parameters showed a significative difference in visual acuity and retinal sensitivity between the two groups, respectively: (sample median and the interquartile range) 0.0 (0.0; 0.09) LogMAR vs 0.15 (0.09; 0.52) LogMAR and 16.2 (14.2; 17.7) dB vs 10.0 (7.5; 11.8) dB (p < 0.05). Fixation was predominantly central in 90.9% of tLMH vs 71.4% of dLMH and stable in 81.8% tLMH vs 42.9% dLMH, but the differences were not statistically significant. Tractional and degenerative LMHs showed no significant differences in central foveal thickness. Conversely, LMH depth and horizontal diameters appeared different between the two groups. Tractional LMH showed a greater depth 257 (205; 278) µm vs 190 (169; 249) µm, whereas degenerative LMH showed a greater horizontal diameter 653 (455; 750) µm vs 429 (314; 620) µm (p < 0.05). IZ/EZ line was unaffected in 81.8% of tLMHs eyes versus 14.3% of dLMHs eyes (p < 0.05). Visual acuity and retinal sensitivity were higher in eyes with integrity of both IZ/EZ and ELM compared to those with a disruption of one or both layers (p < 0.05). CONCLUSION: Two different subtypes of LMH showed peculiar functional aspects due to their morphological features. Tractional LMHs revealed higher visual acuity and retinal sensibility due to the relative preservation of the outer retinal layers compared to degenerative LMHs. Moreover, we underlined the importance of microperimetry to better identify functional defects in macular degenerative pathologies.

Outer Retinal Thickness and Fundus Autofluorescence in Geographic Atrophy.

PURPOSE: Most studies of fundus autofluorescence (FAF) in geographic atrophy (GA) have been nonquantitative, with inadequate registration of image modalities. Furthermore, as pointed out in the recent Consensus Definition for Atrophy Associated with Age-Related Macular Degeneration on OCT, it is unclear whether decreased FAF would be correlated exclusively with a single category of OCT-defined atrophy. We sought to determine how FAF intensity in eyes with GA correlates with structural changes of the outer retina and choroid as seen on co-registered spectral domain OCT (SD-OCT) images. DESIGN: Retrospective cross-sectional. PARTICIPANTS: Twenty eyes of 11 patients with GA secondary to non-neovascular age-related macular degeneration (AMD). METHODS: Spectral domain OCT and FAF images for each eye were co-registered using MATLAB (MathWorks Inc, Natick, MA). On B-scans, the choroid, retinal pigment epithelium (RPE), photoreceptor (PR) layer, and outer nuclear layer (ONL) were segmented. Regions of interest (ROIs) including all atrophic and border regions were selected manually on the FAF scans. Regions of interest were subdivided into quartiles of FAF level to correlate with retinal thickness measurements taken along the B-scans. Mean choroid, RPE, PR, and ONL thicknesses were compared across quartiles using an analysis of variance factorial design testing for interaction effects, adjusted for repeated measures (on both eyes) with a within-subjects factor. RESULTS: Seventeen eyes of 10 patients were selected for analysis. The mean choroidal thicknesses were not significantly different across FAF quartiles, but the overall differences in mean RPE, PR layer, and ONL thicknesses across quartiles were statistically significant (analysis of variance, P < 0.001, P < 0.001, and P = 0.015, respectively). Post hoc analysis demonstrated significant differences in thickness among quartiles 1, 2, and 3 for the RPE and PR layers (Tukey, P < 0.01 in each case). The FAF quartiles within GA did not correlate exclusively with single categories of Consensus Definition for Atrophy Associated with Age-Related Macular Degeneration-defined atrophy. CONCLUSIONS: Not only RPE but also PR layer thickness on SD-OCT varies significantly with FAF levels in GA. This suggests that although the RPE cells are losing thickness and function, evidenced by decreased FAF from fluorophores, delicate PR cells also succumb early in the disease process. These relationships should be pursued as a possibly better-detailed mechanism in GA.