Recent evidence suggests there is a link between metabolic diseases and gut microbiota. To investigate the gut microbiota composition and fecal metabolic phenotype in diabetic retinopathy (DR) patients. DNA was extracted from 50 fecal samples (21 individuals with type 2 diabetes mellitus-associated retinopathy (DR), 14 with type 2 diabetes mellitus but without retinopathy (DM) and 15 sex- and age-matched healthy controls) and then sequenced by high-throughput 16S rDNA analysis. Liquid chromatography mass spectrometry (LC-MS)-based metabolomics was simultaneously performed on the samples. A significant difference in the gut microbiota composition was observed between the DR and healthy groups and between the DR and DM groups. At the genus level, Faecalibacterium, Roseburia, Lachnospira and Romboutsia were enriched in DR patients compared to healthy individuals, while Akkermansia was depleted. Compared to those in the DM patient group, five genera, including Prevotella, were enriched, and Bacillus, Veillonella, and Pantoea were depleted in DR patients. Fecal metabolites in DR patients significantly differed from those in the healthy population and DM patients. The levels of carnosine, succinate, nicotinic acid and niacinamide were significantly lower in DR patients than in healthy controls. Compared to those in DM patients, nine metabolites were enriched, and six were depleted in DR patients. KEGG annotation revealed 17 pathways with differentially abundant metabolites between DR patients and healthy controls, and only two pathways with differentially abundant metabolites were identified between DR and DM patients, namely, the arginine-proline and α-linolenic acid metabolic pathways. In a correlation analysis, armillaramide was found to be negatively associated with Prevotella and Subdoligranulum and positively associated with Bacillus. Traumatic acid was negatively correlated with Bacillus. Our study identified differential gut microbiota compositions and characteristic fecal metabolic phenotypes in DR patients compared with those in the healthy population and DM patients. Additionally, the gut microbiota composition and fecal metabolic phenotype were relevant. We speculated that the gut microbiota in DR patients may cause alterations in fecal metabolites, which may contribute to disease progression, providing a new direction for understanding DR.

AimsThe purpose of this study is to investigate whether gene polymorphisms of the vascular endothelial growth factor A (VEGF-A) and its receptor (VEGFR-2) have a pharmacogenetics effect on the anti-VEGF treatment for neovascular age-related macular degeneration (nAMD).MethodsWe carried out a meta-analysis focusing on the relationship between VEGF-related gene polymorphisms and treatment response of nAMD.ResultsFor the single nucleotide polymorphisms (SNPs) within VEGF-A and VEGFR-2, anti-VEGF treatment was much more effective in patients with nAMD having rs833061 (CC vs TT:OR=2.222, 95% CI 1.252 to 3.944, p=0.006; CT vs TT: OR=2.537,95% CI 1.478 to 4.356, p=0.001 and CC vs CT+TT: OR=2.362, 95% CI 1.414 to 3.946, p=0.001), particularly for Asians (CC vs TT: OR=2.903, 95% CI 1.150 to 7.330, p=0.024; CT vs TT: OR=3.849, 95% CI 1.522 to 9.733, p=0.004 and CC vs CT+TT: OR=3.339, 95% CI 1.369 to 8.145, p=0.008, respectively). In subgroup analysis, rs833061 was more likely to be a predictor of response to anti-VEGF therapy specifically when ranibizumab (RBZ) only regime was adopted or visual acuity (VA) was taken as the standardised assessment of outcome. No association with response to anti-VEGF treatment was detected for the other eight polymorphisms.ConclusionsPharmacogenetics of VEGF-A polymorphism rs833061 may play a positive role in response to anti-VEGF therapy for nAMD.

Macular edema (ME) is the main cause of visual impairment in patients with retinal vein occlusion (RVO). The degree of ME affects the prognosis of RVO patients, while it lacks objective laboratory biomarkers. We aimed to compare aqueous humor samples from 28 patients with retinal vein occlusion macular edema (RVO-ME) to 27 age- and sex-matched controls by ultra-high-performance liquid chromatography equipped with quadrupole time-of-flight mass spectrometry, so as to identify the key biomarkers and to increase the understanding of the mechanism of RVO-ME at the molecular level. Through univariate and multivariate statistical analyses, we identified 60 metabolites between RVO-ME patients and controls and 40 differential metabolites in mild RVO-ME [300 μm ≤ central retinal thickness (CRT) < 400 μm] patients compared with severe RVO-ME (CRT ≥ 400 μm). Pathway enrichment analysis showed that valine, leucine, and isoleucine biosynthesis; ascorbate and aldarate metabolism; and pantothenate and coenzyme A biosynthesis were significantly altered in RVO-ME in comparison with controls. Compared with mild RVO-ME, degradation and biosynthesis of valine, leucine, and isoleucine; histidine metabolism; beta-alanine metabolism; and pantothenate and coenzyme A biosynthesis were significantly changed in severe RVO-ME. Furthermore, the receiver operating characteristic (ROC) curve analysis revealed that adenosine, threonic acid, pyruvic acid, and pyro-L-glutaminyl-l-glutamine could differentiate RVO-ME from controls with an area under the curve (AUC) of >0.813. Urocanic acid, diethanolamine, 8-butanoylneosolaniol, niacinamide, paraldehyde, phytosphingosine, 4-aminobutyraldehyde, dihydrolipoate, and 1-(beta-D-ribofuranosyl)-1,4-dihydronicotinamide had an AUC of >0.848 for distinguishing mild RVO-ME from severe RVO-ME. Our study expanded the understanding of metabolomic changes in RVO-ME, which could help us to have a good understanding of the pathogenesis of RVO-ME.

BackgroundAge-related macular degeneration (AMD) can cause vision loss or blindness in elderly. The associations between single nucleotide polymorphism (SNP) and AMD in Chinese Tujia ethnic minority group are still unclear.MethodsA total of 2122 Tujia volunteers were recruited and 197 of them were diagnosed with AMD (either dry or wet type).Then the blood specimens of these 197 AMD patients and 404 controls from the remaining 1925 normal Tujia volunteers were collected to detect the frequencies of 39 chosen SNPs. The Bonferroni method was used to correct the P values from the Fisher’s exact test.ResultsThe mean age of the 197 AMD patients(113 males and 84 females) was 68.4197 years old. No significant differences in allelic and genotypic frequencies were found for all the 39 SNPs between the patients and controls. However, weak correlations between 10 SNPs (CFH rs1329428 TT genotype, CFH rs3753394 CC genotype and T allele, CFH rs1410996 AA genotype, CFH rs800292 AA genotype, CFH rs800292 A allele, VEGF rs833061 TT genotype and C allele, VEGF rs2010963 CG genotype, VEGFR2 rs1531289 TT genotype, ARMS2 rs10490924 TT genotype, KCTD10 rs238104 GC genotype, rs1531289 T allele and ARMS2 rs10490924 T allele) and AMD were shown.ConclusionsThe effects of 39 SNPs have found no associations with the morbidity of AMD in Chinese Tujia ethnic minority group.Electronic supplementary materialThe online version of this article (10.1186/s12881-019-0756-4) contains supplementary material, which is available to authorized users.

We aimed to investigate the prevalence and causes of visual impairment (VI) in an elderly Tujia ethnic rural population in Southwest China. From June 1 to December 31, 2018, a random cluster sampling survey was conducted among Tujia individuals aged 50 years or older in the rural areas of Qianjiang District County in Chongqing. The sampling design used village-based clusters of approximately equal size (1000 people). The sampling frame was composed of 110 clusters including 26,527 adults aged 50 years or older; 10 clusters (2556 adults) were randomly selected, and 2122 subjects were examined. Ophthalmologic examinations and questionnaires were administered to all the participants. Low vision and blindness were defined using best-corrected visual acuity (BCVA) and presenting visual acuity, according to The World Health Organization standard. The prevalence of VI was estimated, and causes of VI were identified. The participation rate was 83.0%. The prevalence of VI was 15.2% (BCVA 8.0%). In the study population, the prevalence of low vision and blindness increased with age ( P < .05) and was higher among those with a low education level ( P < .01). The majority of VI was attributed to cataracts (50.0%) and uncorrected refractive error (35.7%). With BCVA, cataract (79.3%) was the most common cause of VI, followed by age-related macular degeneration (10.7%). The main causes of VI in Tujia ethnic were cataracts and refractive errors. Both cataracts and refractive errors are curable eye diseases; thus, local health institutions need to adopt a more active eye care project as a strategy to prevent blindness.