Diseño de lentes intraoculares asféricas

Actualmente, es sabido que la catarata es una opacificación del cristalino debida a la pérdida de la disposición y organización de las fibras cristalinianas, y no es esta afección algo que carezca de relevancia, pues, según la Organización Mundial de la Salud (OMS), las cataratas no operadas son la principal causa de ceguera a nivel mundial. Si bien no existe ningún tratamiento médico que haya demostrado su eficacia para impedir su desarrollo o progresión, la intervención quirúrgica mediante facoemulsificación ha resultado ser una de las soluciones más idóneas, constituyendo el 70-80% de toda cirugía ocular y siendo la intervención más frecuente de todas las que se practican en el área oftalmológica. No obstante, el simple hecho de retirar el cristalino implica eliminar su contribución al poder refractor del globo ocular, al mismo tiempo que comprometer la capacidad acomodativa del sistema visual. Atendiendo a ello, una de las soluciones a las que se puede recurrir es a la implantación de lentes intraoculares (LIOs). En concreto, la implantación de LIOs monofocales asféricas permite neutralizar el error refractivo en visión lejana, además de evitar un incremento de la aberración esférica (AE) del globo ocular. A lo largo del tiempo, se han desarrollado LIOs asféricas que producen AE negativa y AE neutra. La primera de ellas es capaz de neutralizar de forma parcial o total la AE positiva proviniente de la córnea, de forma que la AE sea mínima o nula tras su implantación. En contraste, la LIO asférica libre de AE sigue otro parámetro de diseño con el fin de que la AE final sea igual al valor de la AE corneal, es decir, la LIO libre de AE no introduce AE en el sistema. Realizar un estudio comparativo del comportamiento de ambos modelos de LIOs asféricos, mediante el programa informático OSLO, es el objetivo principal de este trabajo. Durante el estudio, todos los diseños fueron sometidos a descentramientos e inclinaciones. Asimismo, se estudió cómo una cirugía refractiva corneal puede condicionar una posterior implantación de este tipo de LIOs. *Todos los modelos parten de una potencia total de +10.00, +21.00 y +32.00 (D), espesor de borde (eb) de 0.25 (mm) e índice de refracción correspondiente al polimetilmetacrilato (PMMA)

Add-on inhaled budesonide in the treatment of hospitalised patients with COVID-19 : a randomised clinical trial

SARS-CoV-2 vaccines have been extremely effective to reduce the incidence of severe COVID19 [1-3], but effective and safe treatments of the acute infection are still limited [4, 5]. An uncontrolled pulmonary inflammatory response to SARS-CoV-2 is considered a key pathogenic mechanism of COVID19 progression [6], so systemic dexamethasone is recommended in severe cases [5, 7]. On the other hand, in very mild patients at home inhaled corticosteroids (ICS) may prevent disease progression [8-11]. Whether ICS prevent disease progression too in patients hospitalised because of COVID19 has not been explored before. Accordingly, we designed an investigator-initiated, open-label, randomised clinical trial (RCT) to explore the efficacy of adding inhaled budesonide to usual care to prevent disease progression in patients hospitalised because of COVID19 pneumonia. We also monitored carefully the safety of this intervention since there are concerns about the use of systemic corticosteroids in other viral (influenza) lung infections [12]

Pregnancy Outcomes and SARS-CoV-2 Infection: The Spanish Obstetric Emergency Group Study

Pregnant women who are infected with SARS-CoV-2 are at an increased risk of adverse perinatal outcomes. With this study, we aimed to better understand the relationship between maternal infection and perinatal outcomes, especially preterm births, and the underlying medical and interventionist factors. This was a prospective observational study carried out in 78 centers (Spanish Obstetric Emergency Group) with a cohort of 1347 SARS-CoV-2 PCR-positive pregnant women registered consecutively between 26 February and 5 November 2020, and a concurrent sample of PCR-negative mothers. The patients' information was collected from their medical records, and the association of SARS-CoV-2 and perinatal outcomes was evaluated by univariable and multivariate analyses. The data from 1347 SARS-CoV-2-positive pregnancies were compared with those from 1607 SARS-CoV-2-negative pregnancies. Differences were observed between both groups in premature rupture of membranes (15.5% vs. 11.1%, p < 0.001); venous thrombotic events (1.5% vs. 0.2%, p < 0.001); and severe pre-eclampsia incidence (40.6 vs. 15.6%, p = 0.001), which could have been overestimated in the infected cohort due to the shared analytical signs between this hypertensive disorder and COVID-19. In addition, more preterm deliveries were observed in infected patients (11.1% vs. 5.8%, p < 0.001) mainly due to an increase in iatrogenic preterm births. The prematurity in SARS-CoV-2-affected pregnancies results from a predisposition to end the pregnancy because of maternal disease (pneumonia and pre-eclampsia, with or without COVID-19 symptoms)

Upper Mississippian to lower Pennsylvanian biostratigraphic correlation of the Sahara Platform successions on the northern margin of Gondwana (Morocco, Algeria, Libya)

Revision of several important Carboniferous stratigraphic successions in basins in the Saharan Platform allows us to propose distinct biostratigraphical boundaries for the upper Viséan, lower and upper Serpukhovian and lower Bashkirian, with the latter boundary separating upper Mississippian from lower Pennsylvanian strata. The boundaries are not only defined primarily by foraminifers but also incorporate ammonoid and conodont data. This study shows that the positioning of some boundaries differs significantly from previous studies in the region.For the studied interval, it can be recognized that two well-defined tectonic events were widespread in the entire Sahara Platform: a mostly late Viséan event and a latest Serpukhovian-early Bashkirian event. Both tectonic events show a marked tendency to become younger eastward, and they are compared to the intra-Viséan phase of the Variscan Orogeny and the main phase of this orogeny, respectively