64 research outputs found
COVID-19 AdenoviralVector Vaccine and Central Retinal Vein Occlusion
Purpose: The purpose of this article is to report a case of sudden onset ischemic retinal central vein occlusion after a second dose of COVID-19 adenoviral vector vaccine.Case report/observations: A 54-year-old woman with systemic arterial hypertension developed ischemic central retinal vein occlusion in her right eye on day 2 after the second dose of COVID-19 adenoviral vector vaccine ChAdOx1 nCoV-19/AZD1222, Oxford-AstraZeneca.Conclusion: Adenoviral vector vaccine promotes both cellular and humoral immune responses, increasing the level of inflammatory cytokines. These cytokines are the same implied in the possible pathogenesis of central retinal vein occlusion. Subsequently, we recommend informing patients at risk of possible ocular adverse events, which require urgent evaluation
Myopia: Mechanisms and Strategies to Slow Down Its Progression
This topical review aimed to update and clarify the behavioral, pharmacological, surgical, and optical strategies that are currently available to prevent and reduce myopia progression. Myopia is the commonest ocular abnormality; reinstated interest is associated with high and increasing prevalence, especially but not, in the Asian population and progressive nature in children. The growing global prevalence seems to be associated with both genetic and environmental factors such as spending more time indoor and using digital devices, particularly during the coronavirus disease 2019 pandemic. Various options have been assessed to prevent or reduce myopia progression in children. In this review, we assess the effects of several types of measures, including spending more time outdoor, optical interventions such as the bifocal/progressive spectacle lenses, soft bifocal/multifocal/extended depth of focus/orthokeratology contact lenses, refractive surgery, and pharmacological treatments. All these options for controlling myopia progression in children have various degrees of efficacy. Atropine, orthokeratology/peripheral defocus contact and spectacle lenses, bifocal or progressive addition spectacles, and increased outdoor activities have been associated with the highest, moderate, and lower efficacies, respectively
Tamponade or filling effect: changes of forces in myopic eyes
Myopia is the most common ocular abnormality. Its high and growing prevalence has contributed to a recent surge in surgical interest in the disorder, since retinal detachment in eyes with high myopia differs from that in emmetropic eyes or eyes with low myopia. The myopic eye, because of its specific anatomy, poses special challenges that need to be overcome to ensure the appropriate use of vitreous substitutes. However, intraocular tamponades have shown great potential for revolutionizing retinal detachment surgery and vitreomacular surgery in general in myopic eyes. We provide an updated review of the clinical use of vitreous substitutes in the myopic eye, paying particular attention to analyzing the ideal function of endotamponade agents and comparing the effects of these agents on the physical and biological properties of the eye
Macular Holes: Main Clinical Presentations, Diagnosis, and Therapies
Macular holes are a spectrum of retinal diseases that comprehends full-thickness macular holes (FTMHs), refractory/recurrent macular holes, lamellar macular holes (LMHs), myopic macular holes (MMHs), traumatic macular holes, and macular holes secondary to other retinal pathologies or injuries. There are various classifications of the subtypes of macular hole, and only in recent times researchers defined a common nomenclature, especially thanks to the evolution in retinal imaging, offered by new instruments like the swept-source OCT. The proposed therapies for macular holes are different and range from a "wait-and-see" approach to the vitrectomy, with different results in each subtype of macular hole. This narrative review has the purpose to investigate the available evidence in literature to give a summary of the knowledge about these retinal pathologies
Current Trends about Inner Limiting Membrane Peeling in Surgery for Epiretinal Membranes
The inner limiting membrane (ILM) is the basement membrane of the Müller cells and can act as a scaffold for cellular proliferation in the pathophysiology of disorders affecting the vitreomacular interface. The atraumatic removal of the macular ILM has been proposed for treating various forms of tractional maculopathy in particular for macular pucker. In the last decade, the removal of ILM has become a routine practice in the surgery of the epiretinal membranes (ERMs), with good anatomical results. However many recent studies showed that ILM peeling is a procedure that can cause immediate traumatic effects and progressive modification on the underlying inner retinal layers. Moreover, it is unclear whether ILM peeling is helpful to improve vision after surgery for ERM. In this review, we describe the current understanding about ILM peeling and highlight the beneficial and adverse effects associated with this surgical procedure
The Mu2e Crystal Calorimeter: An Overview
The Mu2e experiment at Fermilab will search for the standard model-forbidden, charged lepton flavour-violating conversion of a negative muon into an electron in the field of an aluminium nucleus. The distinctive signal signature is represented by a mono-energetic electron with an energy near the muon's rest mass. The experiment aims to improve the current single-event sensitivity by four orders of magnitude by means of a high-intensity pulsed muon beam and a high-precision tracking system. The electromagnetic calorimeter complements the tracker by providing high rejection power in muon to electron identification and a seed for track reconstruction while working in vacuum in presence of a 1 T axial magnetic field and in a harsh radiation environment. For 100 MeV electrons, the calorimeter should achieve: (a) a time resolution better than 0.5 ns, (b) an energy resolution <10%, and (c) a position resolution of 1 cm. The calorimeter design consists of two disks, each loaded with 674 undoped CsI crystals read out by two large-area arrays of UV-extended SiPMs and custom analogue and digital electronics. We describe here the status of construction for all calorimeter components and the performance measurements conducted on the large-sized prototype with electron beams and minimum ionizing particles at a cosmic ray test stand. A discussion of the calorimeter's engineering aspects and the on-going assembly is also reported
Mu2e Crystal Calorimeter Readout Electronics: Design and Characterisation
The Mu2e experiment at Fermi National Accelerator Laboratory will search for the charged-lepton flavour-violating neutrinoless conversion of negative muons into electrons in the Coulomb field of an Al nucleus. The conversion electron with a monoenergetic 104.967 MeV signature will be identified by a complementary measurement carried out by a high-resolution tracker and an electromagnetic calorimeter, improving by four orders of magnitude the current single-event sensitivity. The calorimeter—composed of 1348 pure CsI crystals arranged in two annular disks—has a high granularity, 10% energy resolution and 500 ps timing resolution for 100 MeV electrons. The readout, based on large-area UV-extended SiPMs, features a fully custom readout chain, from the analogue front-end electronics to the digitisation boards. The readout electronics design was validated for operation in vacuum and under magnetic fields. An extensive radiation hardness certification campaign certified the FEE design for doses up to 100 krad and 1012 n1MeVeq/cm2 and for single-event effects. A final vertical slice test on the final readout chain was carried out with cosmic rays on a large-scale calorimeter prototype
Housing Tenure and Job Search Behaviour. A Different Analysis of the Impact of the UK Jobseeker’s Allowance
This paper investigates the relation between job search effort and housing tenure by focussing on the impact of the UK Jobseeker's Allowance reform introduced in the UK in 1996. Theory suggests that a tightening in job search requirements, as implied by this reform, raises movements off benefit of non-employed with low search intensity and this effect adjusts in size depending on the different housing tenure. Average Treatment Effect estimates confirm that the impact of the reform on the claimant outflow rate is related to housing tenure
Systemic thromboembolic adverse events in patients treated with intravitreal anti-VEGF drugs for neovascular age-related macular degeneration: an update
Introduction: Intravitreal anti-VEGF is the most effective therapy for wet AMD, although systemic effects on the endothelium cannot be excluded. Areas covered: The purpose of this review was to evaluate risk of thromboembolic events associated with intravitreal anti-VEGF. Expert opinion: Current data are insufficient to confirm the safety of these compounds, due to the paucity of specific studies. Thus, pharmacovigilance for all anti-VEGF should be improved to verify the true role of anti-VEGF in the occurrence of systemic adverse events
Comparison of smartphone ophthalmoscopy with slit-lamp biomicroscopy for grading diabetic retinopathy
Purpose To assess the accuracy and reliability of smartphone ophthalmoscopy, we compared the ability of a smartphone ophthalmoscope with that of a slit-lamp biomicroscope to grade diabetic retinopathy (DR) in patients with diabetes mellitus (DM). Design Clinical-based, prospective, comparative instrument study. Methods This comparative clinical study was performed in 120 outpatients (240 eyes) with type 1 or type 2 DM. After pupil dilation, the patients underwent smartphone ophthalmoscopy with the D-Eye device, followed by dilated retinal slit-lamp examination, to grade DR according to a 5-step scale. Results Overall exact agreement between the 2 methods was observed in 204 of 240 eyes (85%) (simple κ = 0.78; CI 0.71-0.84) and agreement within 1 step was observed in 232 eyes (96.7%). Compared to biomicroscopy, the sensitivity and specificity of smartphone ophthalmoscopy for the detection of clinically significant macular edema were 81% and 98%, respectively. Smartphone ophthalmoscopy and biomicroscopy could not be used to examine the fundus and grade DR in 9 eyes (3.75%) and 4 eyes (1.7%), respectively, because of cataract and/or small pupil diameter. Conclusion Smartphone ophthalmoscopy showed considerable agreement with dilated retinal biomicroscopy for the grading of DR. The portability, affordability, and connectivity of a smartphone ophthalmoscope make smartphone ophthalmoscopy a promising technique for community screening programs
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