Hypertension is the leading risk factor of cardiovascular disease and has profound effects on both the structure and function of the microvasculature. Abnormalities of the retinal vasculature may reflect the degree of microvascular damage due to hypertension, and these changes can be detected with fundus photographs. This study aimed to use deep learning technique that can detect subclinical features appearing below the threshold of a human observer to explore the effect of hypertension on morphological features of retinal microvasculature. We collected 2012 retinal photographs which included 1007 from patients with a diagnosis of hypertension and 1005 from normotensive control. By method of vessel segmentation, we removed interference information other than retinal vasculature and contained only morphological information about blood vessels. Using these segmented images, we trained a small convolutional neural networks (CNN) classification model and used a deep learning technique called Gradient-weighted Class Activation Mapping (Grad-CAM) to generate heat maps for the class "hypertension". Our model achieved an accuracy of 60.94%, a specificity of 51.54%, a precision of 59.27%, and a recall of 70.48%. The AUC was 0.6506. In the heat maps for the class "hypertension", red patchy areas were mainly distributed on or around arterial/venous bifurcations. This indicated that the model has identified these regions as being the most important for predicting hypertension. Our study suggested that the effect of hypertension on retinal microvascular morphology mainly occurred at branching of vessels. The change of the branching pattern of retinal vessels was probably the most significant in response to elevated blood pressure.
Keywords: myocardial infarction, recurrent stroke, risk factors of stroke s u m m a r y Background: Recurrent stroke is often devastating, and can cause severe disability or death. Risk factors associated with recurrent strokes unrelated to atrial fibrillation have been well identified; however, it remains to be further elucidated whether the risk factors for recurrent stroke are the same in young as in older patients. Methods: Data from 1017 stroke patients unrelated to atrial fibrillation were retrospectively reviewed. Risk factors analyzed included sex, smoking history, previous history of ischemic stroke or transient ischemic attack, hypertension, diabetes mellitus, coronary atherosclerotic heart disease, and previous myocardial infarction. All patients were followed up via telephone 1 year after their initial strokes. Logistic regression was used to assess the associations between the various factors and risk of recurrent stroke events. Results: Predictive independent risk factors of recurrent stroke in older men included previous history of myocardial infarction [odds ratio (OR), 6.761; 95% confidence interval (CI), 1.030e44.371], ischemic stroke or transient ischemic attack (OR, 2.496; 95% CI, 1.567e3.976), diabetes mellitus (OR, 1.986; 95% CI, 1.223e3.227), and coronary atherosclerotic disease (OR, 1.733; 95% CI, 1.010e2.974). In young men, hypertension (OR, 1.709; 95% CI, 1.104e2.645), coronary atherosclerotic heart disease (OR, 1.812; 95% CI, 1.129e2.911), and previous history of ischemic stroke or transient ischemic attack (OR, 2.317; 95% CI, 1.580e3.397) were independent risk factors of recurrent strokes. Conclusion: The predictive independent risk factors of recurrent stroke differ between young and older stroke patients. Our findings may help guide the prevention of recurrent strokes.
Introduction To evaluate and compare the efficacy and safety of YAG laser vitreolysis in treating symptomatic vitreous floaters of complete posterior vitreous detachment (PVD) and non-PVD. Methods In this prospective cohort study, 51 eyes with symptomatic floaters were treated with YAG laser vitreolysis. Participants were divided into complete PVD and non-PVD groups. Objective visual quality measures including the Strehl ratio (SR), internal spherical aberration (SA), internal comatic aberration (CA), internal high-order aberration (HOA), area ratio of modulation transfer function (MTFa) and Vitreous Floaters Symptom Questionnaire (VFSQ-13) scores were used to compare the efficacy of YAG laser vitreolysis treatment between two groups. Results The mean age of all patients was 56.80 ± 10.82 years old. In total, 36 of 51 (70.59%; 95% CI 58.10–83.10) patients reported their symptoms as significant or complete improvement after YAG laser vitreolysis treatment. Post-treatment MTFa, internal SA and internal HOA were significantly better compared to baseline (26.19 ± 14.73 vs. 29.19 ± 17.98, p = 0.013; 0.05 ± 0.05 vs. 0.04 ± 0.04, p = 0.031 and 0.23 ± 0.22 vs. 0.16 ± 0.07, p = 0.044; respectively) in all eyes. Twenty-nine of 51 (56.86%) eyes had floaters of non-PVD type. Significant or complete subjective improvements in the PVD group and non-PVD group were 72.73% and 68.97% ( p = 0.344), respectively. Conclusions Improved subjective and objective visual quality in participants with symptomatic floaters following YAG laser vitreolysis was found in both groups. The efficacy of YAG laser vitreolysis was comparable in floaters of complete PVD and non-PVD types. Supplementary Information The online version contains supplementary material available at 10.1007/s40123-021-00422-6.
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