Fundus photography (FP) is a crucial technique for diagnosing the progression of ocular and systemic diseases in clinical studies, with wide applications in early clinical screening and diagnosis. However, due to the non-uniform illumination and imbalanced intensity caused by various reasons, the quality of fundus images is often severely weakened, brings challenges for automated screening, analysis and diagnosis of diseases. To resolve this problem, we developed strongly constrained generative adversarial networks (SCGAN). The results demonstrate that the quality of various datasets were more significantly enhanced based on SCGAN, simultaneously more effectively retaining tissue and vascular information under various experimental conditions . Furthermore, the clinical effectiveness and robustness of this model was validated by showing its improved ability in vascular segmentation as well as disease diagnosis. Our study provides a new comprehensive approach for FP and also possesses the potential capacity to advance artificial intelligence-assisted ophthalmic examination.

Background and Purpose Whereas whether metformin reduce all-cause, cardiovascular mortality, and incidence of cardiovascular events in patients with cardiac diseases remains inconclusive. Experimental Approach PubMed and Embase were searched up to May 2020 with a registration in PROSPERO (CRD42020189905) were collected. This article includes randomized controlled trials (RCT) and cohort studies. Hazard ratio (HR) with 95% CI was pooled across various trials by a random-effects model. Risk of bias was accounted as per Cochrane and Newcastle-Ottawa Scale (NOS) guidelines. Key Results This article enrolled 48 articles (1999-2020) for qualitative synthesis and identified 26 articles (33 studies in total, 61,704 patients) for final quantitative synthesis. Compared with non-metformin control, metformin is associated with reduced all-cause mortality (HR: 0.90; 95% CI: 0.83, 0.98; P = 0.01), cardiovascular mortality (HR: 0.89; 95% CI: 0.85, 0.94; P < 0.0001), incidence of coronary revascularization (HR: 0.79; 95% CI: 0.64, 0.98; P = 0.03), and heart failure (HR: 0.90; 95% CI: 0.87, 0.94; P < 0.0001) in patients with cardiac diseases, whereas metformin is not associated with reduced incidence of myocardial infarction (HR: 0.97; 95% CI: 0.80, 1.17; P = 0.73), angina (HR: 0.29; 95% CI: 0.04, 2.35; P = 0.25), and stroke (HR: 0.95; 95% CI: 0.78, 1.16; P = 0.59). Conclusion and Implications Metformin reduces all-cause mortality, cardiovascular mortality, incidence of coronary revascularization, and heart failure of patients with cardiac diseases, whereas metformin is not associated with reduced incidence of myocardial infarction, angina, and stroke.