Visual dysfunction and its correlation with retinal changes in patients with Parkinson’ s disease: an observational cross-sectional study

Objectives: To evaluate visual dysfunction and its correlation with structural changes in the retina in patients with Parkinson’s disease (PD). Methods: Patients with PD (n=37) and controls (n=37) were included in an observational cross- sectional study, and underwent visual acuity (VA), colour vision (using the Farnsworth and Lanthony desaturated D15 colour tests) and contrast sensitivity vision (CSV; using the Pelli-Robson chart and CSV 1000E test) evaluation to measure visual dysfunction. Structural measurements of the retinal nerve fibre layer (RNFL), and macular and ganglion cell layer (GCL) thicknesses, were obtained using spectral domain optical coherence tomography (SD-OCT). Comparison of obtained data, and correlation analysis between functional and structural results were performed. Results: VA (in all different contrast levels) and all CSV spatial frequencies were significantly worse in patients with PD than in controls. Colour vision was significantly affected based on the Lanthony colour test. Significant GCL loss was observed in the minimum GCL+inner plexiform layer. A clear tendency towards a reduction in several macular sectors (central, outer inferior, outer temporal and superior (inner and outer)) and in the temporal quadrant of the RNFL thickness was observed, although the difference was not significant. CSV was the functional parameter most strongly correlated with structural measurements in PD. Colour vision was associated with most GCL measurements. Macular thickness was strongly correlated with macular volume and functional parameters (r>0.70, p<0.05). Conclusions: Patients with PD had visual dysfunction that correlated with structural changes evaluated by SD-OCT. GCL measurements may be reliable indicators of visual impairment in patients with PD

Relationship between visual dysfunction and retinal changes in patients with multiple sclerosis.

Aim To evaluate structural changes in the retina and their correlation with visual dysfunction in patients with multiple sclerosis. Methods Patients with multiple sclerosis (n = 84) and healthy controls (n = 84) underwent structural eval- uation of the retinal nerve fiber layer, and macular and ganglion cell layer thicknesses using Spectral domain optical coherence tomography (SD-OCT). All subjects underwent high and low contrast visual acuity, color vision (using the Farnsworth and L ´Anthony desaturated D15 color tests), and contrast sensitivity vision using the Pelli Robson chart and CSV 1000E test. Results Macular, retinal nerve fiber layer, and ganglion cell layer thinning was observed in multiple sclerosis patients compared to healthy controls (p<0.05). High- and low-contrast visual acu- ity and contrast sensitivity vision at four different spatial frequencies were significantly reduced in comparison with healthy subjects (p<0.05). Macular, retinal nerve fiber layer and ganglion cell layer measurements correlated with high and low contrast visual acuity, and contrast sensitivity vision. Contrast sensitivity vision was the functional parameter that most strongly correlated with the structural measurements in multiple sclerosis and was associ- ated with ganglion cell layer measurements. The L ´Anthony color vision score (age-cor- rected color confusion index) was associated with macular measurements. Conclusions Patients with multiple sclerosis had visual dysfunction that correlated with structural changes evaluated by SD-OCT. Macular and ganglion cell layer measurements may be good indicators of visual impairment in multiple sclerosis patients

Alzheimer's Disease: a Review of its Visual System Neuropathology. Optical Coherence Tomography-a Potential Role As a Study Tool in Vivo

Alzheimer's disease (AD) is a prevalent, long-term progressive degenerative disorder with great social impact. It is currently thought that, in addition to neurodegeneration, vascular changes also play a role in the pathophysiology of the disease. Visual symptoms are frequent and are an early clinical manifestation; a number of psychophysiologic changes occur in visual function, including visual field defects, abnormal contrast sensitivity, abnormalities in color vision, depth perception deficits, and motion detection abnormalities. These visual changes were initially believed to be solely due to neurodegeneration in the posterior visual pathway. However, evidence from pathology studies in both animal models of AD and humans has demonstrated that neurodegeneration also takes place in the anterior visual pathway, with involvement of the retinal ganglion cells' (RGCs) dendrites, somata, and axons in the optic nerve. These studies additionally showed that patients with AD have changes in retinal and choroidal microvasculature. Pathology findings have been corroborated in in-vivo assessment of the retina and optic nerve head (ONH), as well as the retinal and choroidal vasculature. Optical coherence tomography (OCT) in particular has shown great utility in the assessment of these changes, and it may become a useful tool for early detection and monitoring disease progression in AD. The authors make a review of the current understanding of retinal and choroidal pathological changes in patients with AD, with particular focus on in-vivo evidence of retinal and choroidal neurodegenerative and microvascular changes using OCT technology.info:eu-repo/semantics/publishedVersio

Gut microbiota and sirtuins in obesity-related inflammation and bowel dysfunction

Obesity is a chronic disease characterized by persistent low-grade inflammation with alterations in gut motility. Motor abnormalities suggest that obesity has effects on the enteric nervous system (ENS), which controls virtually all gut functions. Recent studies have revealed that the gut microbiota can affect obesity and increase inflammatory tone by modulating mucosal barrier function. Furthermore, the observation that inflammatory conditions influence the excitability of enteric neurons may add to the gut dysfunction in obesity. In this article, we discuss recent advances in understanding the role of gut microbiota and inflammation in the pathogenesis of obesity and obesity-related gastrointestinal dysfunction. The potential contribution of sirtuins in protecting or regulating the circuitry of the ENS under inflamed states is also considered

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency–Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research

Timing, complications, and safety of tracheotomy in critically ill patients with COVID-19

Importance: The current coronavirus disease 2019 (COVID-19) pandemic has led to unprecedented needs for invasive ventilation, with 10% to 15% of intubated patients subsequently requiring tracheotomy. Objective: To assess the complications, safety, and timing of tracheotomy performed for critically ill patients with COVID-19. Design, Setting, and Participants: This prospective cohort study assessed consecutive patients admitted to the intensive care unit (ICU) who had COVID-19 that required tracheotomy. Patients were recruited from March 16 to April 10, 2020, at a tertiary referral center. Exposures: A surgical tracheotomy was performed for all patients following recommended criteria for use of personal protective equipment (PPE). Main Outcomes and Measures: The number of subthyroid operations, the tracheal entrance protocol, and use of PPE. Infections among the surgeons were monitored weekly by reverse-transcriptase polymerase chain reaction of nasopharyngeal swab samples. Short-term complications, weaning, and the association of timing of tracheotomy (early [≤10 days] vs late [>10 days]) with total required days of invasive ventilation were assessed. Results: A total of 50 patients (mean [SD] age, 63.8 [9.2] years; 33 [66%] male) participated in the study. All tracheotomies were performed at the bedside. The median time from intubation to tracheotomy was 9 days (interquartile range, 2-24 days). A subthyroid approach was completed for 46 patients (92%), and the tracheal protocol was adequately achieved for 40 patients (80%). Adequate PPE was used, with no infection among surgeons identified 4 weeks after the last tracheotomy. Postoperative complications were rare, with minor bleeding (in 6 patients [12%]) being the most common complication. The successful weaning rate was higher in the early tracheotomy group than in the late tracheotomy group (adjusted hazard ratio, 2.55; 95% CI, 0.96-6.75), but the difference was not statistically significant. There was less time of invasive mechanical ventilatory support with early tracheotomy compared with late tracheotomy (mean [SD], 18 [5.4] vs 22.3 [5.7] days). The reduction of invasive ventilatory support was achieved at the expense of the pretracheotomy period. Conclusions and Relevance: In this cohort study, with the use of a standardized protocol aimed at minimizing COVID-19 risks, bedside open tracheotomy was a safe procedure for patients and surgeons, with minimal complications. Timing of tracheotomy may be important in reducing time of invasive mechanical ventilation, with potential implications to intensive care unit availability during the COVID-19 pandemic.</p