Clinical aspects of malarial retinopathy: a critical review.

This review will provide a better understanding of a set of signs known as malarial retinopathy. The discovery of this retinopathy in association with cerebral malaria is important because it best distinguishes patients with true cerebral malaria from those with coma due to other causes and incidental Plasmodium falciparum parasitemia. Identifying a comatose patient with malarial retinopathy increases the likelihood of an accurate severe or cerebral malaria diagnosis. As the World Health Organization does not specify that malarial retinopathy is one of the factors included in determining a cerebral malaria diagnosis, there are significant false-positive diagnoses of cerebral malaria. Once a cerebral malaria diagnosis is assigned, other possibilities and treatments are often excluded making an incorrect diagnosis of cerebral malaria potentially fatal. However, Plasmodium falciparum may also contribute to coma in some children with retinopathy-negative cerebral malaria, as this group is still not clinically well characterized, so all children with the WHO definition of cerebral malaria should be treated for severe malaria. Nevertheless, by raising awareness about malarial retinopathy, there could be a greater potential to accurately diagnose cerebral malaria and thus achieve more positive patient outcomes in the future. This literary review aims to raise awareness of the retinopathy by defining what it is to non-experts, explaining its pathology, clarifying the techniques needed to accurately diagnose malarial retinopathy, as well as the barriers that prevent clinicians from providing a proper diagnosis in malaria-endemic regions; and finally, discuss future directions to continue the study of malarial retinopathy.

Characteristics and outcomes of severe COVID-19 in hospitalized patients with cardiovascular diseases in the Amazonian region of Brazil: a retrospective cohort.

The northern region of Brazil is already vulnerable to other infectious diseases and it was no different in COVID-19. However, cardiovascular diseases still lead the causes of death. Thus, the objective of this study is to identify the clinical predictors and outcome of severe COVID-19 in hospitalized patients with and without CVD in this region of the Amazon. A retrospective cohort, referring to the notifications from January 1 to December 31, 2020, including cases confirmed by molecular testing. The study consisted of 9223 confirmed cases for COVID-19. Of these, 6011 (65.17%) did not have cardiovascular disease and 3212 (34.83%) had some cardiovascular disease. The significance of deaths was in the age group of < 1 to 59 CVD carriers (< 0.001). Predictor of mortality were invasive ventilation for patients with CVD, (OR 23,688 CI 18,180-30,866), followed by chronic kidney disease (OR 2442 CI 1568-3740), dyspnea (OR 2312 CI 1817-3941), respiratory distress (OR 1523 CI 1210-2919), cough (OR 1268 CI 1005-1599), Lower oxygen saturation 95% (OR 1281 CI 1039-1579), diabetes mellitus (OR 1267 CI 1050-1528) and age (OR 1051 CI 1044-1058). Carriers of CVD had a lower survival rate (< 0.0001). The order of the predictors of death differed among the non-carriers, as well as the high odds ratio in the predictors of CVD, only cough was an independent predictor. The age group under 59 years was associated with deaths. We also show the shorter survival in CVD carriers, as well as the higher cardiovascular morbidity rate than other studies in the literature.

Effect of the Decrease in Luminance Noise Range on Color Discrimination of Dichromats and Trichromats.

Color vision assessment can be done using pseudoisochromatic stimuli, which has a luminance noise to eliminate brightness differences between the target and background of the stimulus. It is not clear the influence of the luminance noise on color discrimination. We investigated the effect of change in the luminance noise limits on color discrimination. Eighteen trichromats and ten congenital dichromats (eight protans, two deutans) had their color vision evaluated by the Cambridge Colour Test, and were genetically tested for diagnostic confirmation. The stimuli were composed of a mosaic of circles in a 5° circular field. A subset of the circles differed in chromaticity from the remaining field, forming a letter C. Color discrimination was estimated in stimulus conditions differing in luminance noise range: (i) 6-20 cd/m2; (ii) 8-18 cd/m2; (iii) 10-16 cd/m2; and (iv) 12-14 cd/m2. Six equidistant luminance values were used within the luminance noise limits with the mean stimulus luminance maintained constant under all conditions. A four-alternative, forced-choice method was applied to feed a staircase procedure to estimate color discrimination thresholds along eight chromatic axes. An ellipse model was adjusted to the eight color discrimination thresholds. The parameters of performance were threshold vector lengths and the ellipse area. Results were compared using the Kruskal-Wallis test with a significance level of 5%. The linear function model was applied to analyze the dependence of the discrimination parameters on the noise luminance limits. The first derivative of linear function was used as an indicator of the rate of change in color discrimination as a function of luminance noise changes. The rate of change of the ellipse area as a function of the luminance range in dichromats was higher than in trichromats (p < 0.05). Significant difference was also found for individual thresholds in half of the axes we tested. Luminance noise had a greater effect on color discrimination ability of dichromats than the trichromats, especially when the chromaticities were close to their protan and deutan color confusion lines.