MiR-9-3 hypermethylation is associated with stages of diabetic retinopathy.

Purpose: To investigate the potential relation between methylation of miR-9-3 and stages of diabetic retinopathy (DR). Additionally, we explored whether miR-9-3 methylation impacts the serum levels of Vascular Endothelial Growth Factor (VEGF). Methods: A cross-sectional study was conducted with 170 participants with type 2 diabetes, including a control group (n = 64) and a diabetes retinopathy group (n = 106), which was further divided into NPDR (n = 58) and PDR (n = 48) subgroups. Epidemiological, clinical, anthropometric, biochemical ELISA assay were analysed. DNA extracted from leukocytes was used to profile miR-9-3 methylation using PCR-MSP. Results: MiR-9-3 hypermethylated profile was higher in the DR group (p < 0.001) and PDR subgroup compared to DM2 control group (p < 0.001). The hypermethylated profile in the PDR subgroup was also higher compared to NPDR subgroup (p < 0.001). There was no difference between DM2 control and NPDR group (p = 0.234). Logistic regression showed that miR-9-3 hypermethylation increases the odds of presenting DR (OR: 2.826; p = 0.002) and PDR (OR: 5.472; p < 0.001). In addition, hypermethylation of miR-9-3 in the DR and NPDR subgroup was associated with higher serum VEGF-A levels (p = 0.012 and p = 0.025, respectively). Conclusion: The methylation profile of the miR-9-3 promoter increases the risk of developing PDR. Higher levels of VEGF-A are associated with miR-9-3 hypermethylated profile in patients in the DR and NPDR stages. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-024-01411-9.

Metabolomic analysis of retinopathy stages and amputation in type 2 diabetes.

BACKGROUND: Diabetic retinopathy (DR) and limb amputation are frequent complications of diabetes that cannot always be explained by blood glucose control. Metabolomics is a science that is currently being explored in the search for biomarkers or profiles that identify clinical conditions of interest. OBJECTIVE: This study aimed to analyze, using a metabolomic approach, peripheral blood samples from type 2 diabetes mellitus (DM2) individuals, compared with those with diabetic retinopathy and limb amputation. METHODS: The sample consisted of 128 participants, divided into groups: control, DM2 without DR (DM2), non-proliferative DR (DRNP), proliferative DR (DRP), and DM2 amputated (AMP). Metabolites from blood plasma were classified by spectra using nuclear magnetic resonance (NMR), and the metabolic routes of each group using metaboanalyst. RESULTS: We identified that the metabolism of phenylalanine, tyrosine, and tryptophan was discriminant for the DRP group. Histidine biosynthesis, on the other hand, was statistically associated with the AMP group. The results of this work consolidate metabolites such as glutamine and citrulline as discriminating for DRP, and the branched-chain amino acids as important for DR. CONCLUSIONS: The results demonstrate the relationship between the metabolism of ketone bodies, with acetoacetate metabolite being discriminating for the DRP group and histidine being a significant metabolite in the AMP group, when compared to the DM2 group.

Comparative transcriptome analysis of endothelial progenitor cells of HbSS patients with and without proliferative retinopathy.

Among sickle cell anemia (SCA) complications, proliferative sickle cell retinopathy (PSCR) is one of the most important, being responsible for visual impairment in 10-20% of affected eyes. The aim of this study was to identify differentially expressed genes (DEGs) present in pathways that may be implicated in the pathophysiology of PSCR from the transcriptome profile analysis of endothelial progenitor cells. RNA-Seq was used to compare gene expression profile of circulating endothelial colony-forming cells (ECFCs) from HbSS patients with and without PSCR. Furthermore, functional enrichment analysis and protein-protein interaction (PPI) networks were performed to gain further insights into biological functions. The differential expression analysis identified 501 DEGs, when comparing the groups with and without PSCR. Furthermore, functional enrichment analysis showed associations of the DEGs in 200 biological processes. Among these, regulation of mitogen-activated protein (MAP) kinase activity, positive regulation of phosphatidylinositol 3-kinase (PI3K), and positive regulation of Signal Transducer and Activator of Transcription (STAT) receptor signaling pathway were observed. These pathways are associated with angiogenesis, cell migration, adhesion, differentiation, and proliferation, important processes involved in PSCR pathophysiology. Moreover, our results showed an over-expression of VEGFC (vascular endothelial growth factor-C) and FLT1 (Fms-Related Receptor Tyrosine Kinase 1) genes, when comparing HbSS patients with and without PSCR. These results may indicate a possible association between VEGFC and FLT1 receptor, which may activate signaling pathways such as PI3K/AKT and MAPK/ERK and contribute to the mechanisms implicated in neovascularization. Thus, our findings contain preliminary results that may guide future studies in the field, since the molecular mechanisms of PSCR are still poorly understood.

Metabolic impact of the VDR rs1544410 in diabetic retinopathy.

AIMS: To investigate the association between BsmI and DM2 in patients with and without DR and to correlate with clinical parameters in a population in northeastern Brazil. METHODS: Cross-sectional case-control study in which data were collected from 285 individuals, including 128 patients with DM2 and 157 with DR. Clinical, biochemical and anthropometric parameters were analyzed, in addition to the single nucleotide polymorphism (SNP) BsmI of the VDR gene (rs1544410), genotyped by PCR-RFLP. RESULTS: In the DR group we found a greater number of patients using insulin therapy (p = 0.000) and with longer duration of DM2 (p = 0.000), in addition to higher serum creatinine values (p = 0.001). Higher fasting glucose levels and higher frequency of insulinoterapy were independently observed in patients with DR and b allele carriers, when compared to BB. CONCLUSION: The association of the bb/Bb genotypes (rs1544410) of the VDR gene with increased blood glucose levels and insulinoterapy may represent worse glicemic control in rs1544410 b allele carriers in DR Latin American individuals.

Transcriptomics and network analysis highlight potential pathways in the pathogenesis of pterygium.

Pterygium is a common ocular surface condition frequently associated with irritative symptoms. The precise identity of its critical triggers as well as the hierarchical relationship between all the elements involved in the pathogenesis of this disease are not yet elucidated. Meta-analysis of gene expression studies represents a novel strategy capable of identifying key pathogenic mediators and therapeutic targets in complex diseases. Samples from nine patients were collected during surgery after photo documentation and clinical characterization of pterygia. Gene expression experiments were performed using Human Clariom D Assay gene chip. Differential gene expression analysis between active and atrophic pterygia was performed using limma package after adjusting variables by age. In addition, a meta-analysis was performed including recent gene expression studies available at the Gene Expression Omnibus public repository. Two databases including samples from adults with pterygium and controls fulfilled our inclusion criteria. Meta-analysis was performed using the Rank Production algorithm of the RankProd package. Gene set analysis was performed using ClueGO and the transcription factor regulatory network prediction was performed using appropriate bioinformatics tools. Finally, miRNA-mRNA regulatory network was reconstructed using up-regulated genes identified in the gene set analysis from the meta-analysis and their interacting miRNAs from the Brazilian cohort expression data. The meta-analysis identified 154 up-regulated and 58 down-regulated genes. A gene set analysis with the top up-regulated genes evidenced an overrepresentation of pathways associated with remodeling of extracellular matrix. Other pathways represented in the network included formation of cornified envelopes and unsaturated fatty acid metabolic processes. The miRNA-mRNA target prediction network, also reconstructed based on the set of up-regulated genes presented in the gene ontology and biological pathways network, showed that 17 target genes were negatively correlated with their interacting miRNAs from the Brazilian cohort expression data. Once again, the main identified cluster involved extracellular matrix remodeling mechanisms, while the second cluster involved formation of cornified envelope, establishment of skin barrier and unsaturated fatty acid metabolic process. Differential expression comparing active pterygium with atrophic pterygium using data generated from the Brazilian cohort identified differentially expressed genes between the two forms of presentation of this condition. Our results reveal differentially expressed genes not only in pterygium, but also in active pterygium when compared to the atrophic ones. New insights in relation to pterygium's pathophysiology are suggested.

Association of genetic variants rs641153 (CFB), rs2230199 (C3), and rs1410996 (CFH) with age-related macular degeneration in a Brazilian population.

This study aimed to investigate the association among genetic variants of the complement pathway CFB R32Q (rs641153), C3 R102G (rs2230199), and CFH (rs1410996) with age-related macular degeneration (AMD) in a sample of the Brazilian population. In a case-control study, 484 AMD patients were classified according to the clinical age-related maculopathy grading system (CARMS) and compared to 479 unrelated controls. The genetic variants rs1410996 of complement H (CFH), rs641153 of complement factor B (CFB), and rs2230199 of complement 3 (C3) were evaluated through polymerase chain reaction (PCR) and direct sequencing. The associations between single nucleotide polymorphisms (SNPs) and AMD, adjusted by age, were assessed by using logistic regression models. A statistically significant association was observed between AMD risk and rs2230199 variant with an OR of 2.01 (P = 0.0002) for CG individuals compared to CC individuals. Regarding the comparison of advanced AMD versus the control group, the OR was 2.12 (P = 0.0036) for GG versus AA genotypes for rs1410996 variant. Similarly, the OR for rs2230199 polymorphism was 2.3034 (P = 5.47e-05) when comparing CG individuals to CC carriers. In contrast, the rs641153 variant showed a significant protective effect against advanced AMD for GA versus GG genotype (OR = 0.4406; P = 0.0019). When comparing wet AMD versus controls, a significant association was detected for rs1410996 variant (OR = 2.16; P = 0.0039) comparing carriers of the homozygous GG versus AA genotype, as well as in the comparisons of GG (OR = 3.0713; P = 0.0046) and CG genotypes (OR = 2.2249; P = 0.0002) versus CC genotype for rs2230199 variant, respectively. The rs641153 variant granted a significant protective effect against wet AMD for GA versus GG genotypes (OR = 0.4601; P = 0.0044). Our study confirmed the risk association between rs2230199 and rs1410996 variants and AMD, and the protective role against AMD for rs641153 variant.

Ocular Manifestations and Neuropathy in Type 2 Diabetes Patients With Charcot Arthropathy.

Objective: Diabetes can affect the eye in many ways beyond retinopathy. This study sought to evaluate ocular disease and determine any associations with peripheral neuropathy (PN) or cardiac autonomic neuropathy (CAN) in type 2 diabetes (T2D) and Charcot arthropathy (CA) patients. Design: A total of 60 participants were included, 16 of whom were individuals with T2D/CA, 21 of whom were individuals with T2D who did not have CA, and 23 of whom were healthy controls. Ocular surface evaluations were performed, and cases of dry eye disease (DED) were determined using the Ocular Surface Disease Index (OSDI) questionnaire, ocular surface staining, Schirmer test, and Oculus Keratograph 5M exams. All variables were used to classify DED and ocular surface disorders such as aqueous deficiency, lipid deficiency, inflammation, and ocular surface damage. Pupillary and retinal nerve fiber measurements were added to the protocol in order to broaden the scope of the neurosensory ocular evaluation. PN and CAN were ascertained by clinical examinations involving the Neuropathy Disability Score (for PN) and Ewing's battery (for CAN). Results: Most ocular variables evaluated herein differed significantly between T2D patients and controls. When the controls were respectively compared to patients with T2D and to patients with both T2D and CA, they differed substantially in terms of visual acuity (0.92 ± 0.11, 0.73 ± 0.27, and 0.47 ± 0.26, p=0.001), retinal nerve fiber layer thickness (96.83 ± 6.91, 89.25 ± 10.44, and 80.37 ± 11.67 µm, p=0.03), pupillometry results (4.10 ± 0.61, 3.48 ± 0.88, and 2.75 ± 0.81 mm, p=0.0001), and dry eye symptoms (9.19 ± 11.71, 19.83 ± 19.08, and 24.82 ± 24.40, p=0.03). DED and ocular surface damage also differed between individuals with and without CA, and were associated with PN and CAN. Conclusion: CA was found to be significantly associated with the severity of ocular findings. DED in cases of CA was also associated with PN and CAN. These findings suggest that intrinsic and complex neurosensory impairment in the eyes, peripheral sensory nerves, and the autonomic nervous system are somehow connected. Thus, a thorough ocular evaluation may be useful to highlight neurological complications and the impact of diabetes on ocular and systemic functions and structures.

Evaluation of APOE polymorphisms and the risk for age-related macular degeneration in a Southeastern Brazilian population.

This study aimed to evaluate the role of APOE polymorphisms (rs429358 and rs7412) in the risk of age-related macular degeneration in a sample of the Southeastern Brazilian population. Seven hundred and five unrelated individuals were analyzed, 334 with age-related macular degeneration (case group), and 371 without the disease (control group). In the case group, patients were further stratified according to disease phenotypes, divided into dry and wet age-related macular degeneration, and non-advanced and advanced age-related macular degeneration. APOE polymorphisms (rs429358 and rs7412) were evaluated through polymerase chain reaction and direct sequencing. In the comparison of cases vs. controls, none of the associations reached statistical significance, considering the Bonferroni-adjusted P-value, although there was a suggestive protection for the E3/E4 genotype (OR = 0.626; P-value = 0.037) and E4 carriers (OR = 0.6515; P-value = 0.047). Statistically significant protection for both the E3/E4 genotype and E4 carriers was observed in the comparisons: advanced age-related macular degeneration vs. controls (OR = 0.3665, P-value = 0.491 × 10-3 and OR = 0.4031, P-value = 0.814 × 10-3, respectively), advanced age-related macular degeneration vs. non-advanced age-related macular degeneration (OR = 0.2529, P-value = 0.659 × 10-4 and OR = 0.2692, P-value = 0.631 × 10-4, respectively). In the comparison of wet age-related macular degeneration vs. control, protection was statistically significant only for E3/E4 (OR = 0.4052, P-value = 0.001). None of the comparisons demonstrated any significant association for E2 genotypes or E2 carriers in age-related macular degeneration risk in this study. Findings suggest a protective role of the E4 haplotype in the APOE gene in the risk for advanced and wet forms of age-related macular degeneration, in a sample of the Brazilian population. To our knowledge, this is the first Brazilian study to show the association between APOE polymorphisms and age-related macular degeneration.

Macular phototoxicity after corneal cross-linking.

PURPOSE: To assess potential vascular, structural, and functional changes to the macula in patients with keratoconus that underwent ultraviolet A (UVA)-riboflavin-mediated corneal collagen cross-linking (CXL) therapy. PATIENTS AND METHODS: Seventeen eyes from 17 patients of age 16 years or older with keratoconus undergoing CXL treatment were studied. The same eye served as its own control (before CXL vs after CXL). Eyes were evaluated in terms of best-corrected visual acuity (BCVA), refractive error, intraocular pressure, Amsler grid, retinography, fluorescein angiography, autofluorescence, and spectral domain optical coherence tomography (SD-OCT) prior to CXL and 7 and 30 days after treatment. Multifocal electroretinography (mfERG) was recorded prior to and 7 days after CXL. RESULTS: Mean (SD) BCVA by logMAR chart was 0.47 (±0.12) pre-CXL, 0.55 (±0.15) 7 days post-CXL (P=0.57), and 0.46 (±0.10) 30 days post-CXL (P=0.87). Mean (SD) SD-OCT central macular thickness (µm) was 253.62 (±20.9) pre-CXL, 260.5 (±18.7) 7 days post-CXL (P=0.48), and 256.44 (±21.6) 30 days post-CXL (P=0.69). In 12 eyes, mfERG revealed a statistically significant increase (P=0.0353) in P1 latency (ms) of ring four from the pre-CXL period (39.45±2.05) to 7 days post-CXL (41.04±1.28) period. Regression analysis showed that the increase in P1 latency was correlated with the increase in central macular thickness (P=0.027). Furthermore, nine patients experienced a significant decrease in P1 amplitudes of rings 1 (P=0.0014), 2 (P=0.0029), 3 (P=0.0037), 4 (P=0.0014), and 5 (P=0.0012) from pre-CXL to 7 days post-CXL. Conclusion: In this pilot study, most of the patients exhibited slight changes in their mfERG parameters and OCT thickness, despite a lack of vascular abnormalities observed on fluorescein angiography/autofluorescence imaging, no alteration in BCVA, and no reports of symptoms. These changes could, therefore, be categorized as a mild subclinical effect of the corneal cross-linking procedure.

Recurrent idiopathic neuroretinitis as a spectrum of atypical optic neuritis: a case report and literature review.

Recurrent idiopathic neuroretinitis is an inflammatory optic neuropathy characterized by optic nerve edema and macular star, associated with painless and recurrent episodes of visual loss, poor visual prognosis, and visual field defects related to nerve fiber layer injury. The disorder is sometimes mistaken for atypical optic neuritis. However, early diagnosis is important for visual recovery. Long-term immunosuppression has been shown to reduce the rate of recurrence and protect against severe and irreversible vision loss.

Recurrent idiopathic neuroretinitis as a spectrum of atypical optic neuritis: a case report and literature review / Neurorretinite recorrente idiopática como espectro da neurite óptica atípica: relato de caso e revisão da literatura

ABSTRACT Recurrent idiopathic neuroretinitis is an inflammatory optic neuropathy characterized by optic nerve edema and macular star, associated with painless and recurrent episodes of visual loss, poor visual prognosis, and visual field defects related to nerve fiber layer injury. The disorder is sometimes mistaken for atypical optic neuritis. However, early diagnosis is important for visual recovery. Long-term immunosuppression has been shown to reduce the rate of recurrence and protect against severe and irreversible vision loss.

RESUMO Neurorretinite recorrente idiopática é uma neuropatia óptica inflamatória caracterizada por edema do nervo óptico e estrela macular associada a episódios recorrentes de perda visual indolor, baixo prognóstico visual e desfeitos de campo visual relacionados a injúria da camada de fibras nervosas. Essa condição pode ser confundida com neurite óptica atípica e seu correto diagnóstico é importante para o prognóstico visual, uma vez que a imunossupressão continua previne episódios recorrentes que podem levar a perda visual severa e irreversível.