The Wisconsin Epidemiologic Study of Diabetic Retinopathy: XXII the twenty-five-year progression of retinopathy in persons with type 1 diabetes

Diabetic retinopathy: A review on its pathophysiology and novel treatment modalities

Diabetes mellitus (DM) is a chronic metabolic non-communicable disease with the ability to cause serious microvascular and macrovascular complications throughout the body, including in the eye. Diabetic retinopathy (DR), present in one-third of patients with diabetes, is a vision-threatening complication caused by uncontrolled diabetes, which greatly affects the retinal blood vessels and the light-sensitive inner retina, eventually leading to blindness. Several epidemiological studies elucidate that DR can vary by age of onset, duration, types of diabetes, and ethnicity. Recent studies show that the pathogenesis of diabetic retinopathy has spread its roots beyond merely being the result of hyperglycemia. The complexity of its etiopathology and diagnosis makes therapeutic intervention challenging. This review throws light on the pathological processes behind DR, the cascade of events that follow it, as well as the available and emerging treatment options.

Diabetic retinopathy as an independent marker of cardiovascular disease in type 1 diabetes: Results from a nationwide longitudinal matched case-cohort study

PURPOSE

To investigate diabetic retinopathy (DR) as a potential marker of cardiovascular disease (CVD) in adults with type 1 diabetes attending the Danish DR-screening programme and non-diabetes adults.

METHODS

In this registry-based matched case-cohort study, we identified 16 547 adults with type 1 diabetes, who were registered in the Danish Registry of Diabetic Retinopathy (DiaBase). Each case was age- and sex-matched by five non-diabetes individuals (n = 82 399), and odds ratios (ORs) and hazard ratios (HRs) were estimated for incident and upcoming CVD in multivariable models.

RESULTS

Adults with type 1 diabetes (median age 44.5 years, 57.6% male) were more likely to have prevalent CVD (OR 1.29; 95% CI, 1.20-1.38) and to develop CVD within 5 years (HR 1.19; 95% CI, 1.08-1.30) as compared to non-diabetes control. However, adults without DR were less likely to develop CVD (HR 0.84; 95% CI, 0.72-0.97) compared to the reference population. For adults with type 1 diabetes, there was an increasing risk for incident CVD for increasing levels of DR (HR 1.33, 1.95, 1.71 and 2.39 for DR-levels 1-4, respectively). Patients with CVD at the time of the first screening had a higher risk to develop DR during follow-up (HR 1.23; 95% CI, 1.02-1.49).

CONCLUSION

In a nationwide matched case-cohort study adjusted for potential confounders, DR was identified as an independent marker of prevalent and incident CVD in type 1 diabetes with increasing risk demonstrated for higher levels of DR. Likewise, CVD also independently predicted the risk of incident DR.

Advanced cardiovascular physiology in an individual with type 1 diabetes after 10-year ketogenic diet

Adults with type 1 diabetes (T1D) have an elevated risk for cardiovascular disease (CVD) compared with the general population. HbA1c is the primary modifiable risk factor for CVD in T1D. Fewer than 1% of patients achieve euglycemia (<5.7% HbA1c). Ketogenic diets (KD; ≤50 g carbohydrate/day) may improve glycemia and downstream vascular dysfunction in T1D by reducing HbA1c and insulin load. However, there are concerns regarding the long-term CVD risk from a KD. Therefore, we compared data collected in a 60-day window in an adult with T1D on exogenous insulin who consumed a KD for 10 years versus normative values in those with T1D (T1D norms). The participant achieved euglycemia with an HbA1c of 5.5%, mean glucose of 98 [5] mg/dL (median [interquartile range]), 90 [11]% time-in-range 70-180 mg/dL (T1D norms: 1st percentile for all), and low insulin requirements of 0.38 ± 0.03 IU/kg/day (T1D norms: 8th percentile). Seated systolic blood pressure (SBP) was 113 mmHg (T1D norms: 18th percentile), while ambulatory awake SBP was 132 ± 15 mmHg (T1D target: <130 mmHg), blood triglycerides were 69 mg/dL (T1D norms: 34th percentile), low-density lipoprotein was 129 mg/dL (T1D norms: 60th percentile), heart rate was 56 beats/min (T1D norms: >1SD below the mean), carotid-femoral pulse wave velocity was 7.17 m/s (T1D norms: lowest quartile of risk), flow-mediated dilation was 12.8% (T1D norms: >1SD above mean), and cardiac vagal baroreflex gain was 23.5 ms/mmHg (T1D norms: >1SD above mean). Finally, there was no indication of left ventricular diastolic dysfunction from echocardiography. Overall, these data demonstrate below-average CVD risk relative to T1D norms despite concerns regarding the long-term impact of a KD on CVD risk.NEW & NOTEWORTHY Adults with type 1 diabetes (T1D) have a 10-fold higher risk for cardiovascular disease (CVD) compared with the general population. We assessed cardiovascular health metrics in an adult with T1D who presented with a euglycemic HbA1c after following a ketogenic diet for the past 10 years. Despite concerns about the ketogenic diet increasing CVD risk, the participant exhibited below-average CVD risk relative to others with T1D when considering all outcomes together.

Association of systemic and demographic risk factors with prevalence of retinopathy in US adults with prediabetes

BACKGROUND/OBJECTIVES

To investigate the relative contribution of systemic risk factors to retinopathy in prediabetes using a nationally representative cohort in the US.

SUBJECTS/METHODS

A group of 2098 participants aged ≥40 years with available HbA1c and gradable retinal images from the National Health and Nutrition Examination Survey 2005-2008 were included in this retrospective cross-sectional analysis. Participants were stratified into control, prediabetes, and diabetes groups based on HbA1c and anti-hyperglycaemic medication use. Logistic regression was used to assess the contribution of potential systemic risk factors to retinopathy prevalence.

RESULTS

The prevalence of retinopathy in the prediabetes group was 7.69%. Multivariable logistic regression revealed an inverse association of female sex (OR, 0.25; 95% CI, 0.08-0.74; p = 0.02), eGFR (OR, 0.98; 95% CI, 0.96-1.00; p = 0.04), and fasting glucose levels (OR, 0.92; 95% CI 0.87-0.98; p = 0.02) with retinopathy in individuals with prediabetes and a positive association with a Race/Ethnicity classification of "Other" (OR, 6.05; 95% CI, 1.65-22.1; p = 0.01). Comparison of ORs between groups indicated differential associations of "Other" race, fasting glucose, and C-reactive protein (CRP) with retinopathy in prediabetes compared with diabetes.

CONCLUSIONS

The prevalence of retinopathy among individuals with prediabetes in the NHANES database is similar to other studies. Our findings suggest that nonglycemic metabolic risk factors may be especially relevant to the risk of retinopathy in prediabetes and extend the previously suggested protective effect of female sex on retinopathy in diabetes to prediabetes. The increased odds of retinopathy in underrepresented racial/ethnic groups in the setting of prediabetes also have implications for risk assessment in this population.

Plasma metabolomics identifies key metabolites and improves prediction of diabetic retinopathy: development and validation across multi-national cohorts

PURPOSE

To identify longitudinal metabolomic fingerprints of diabetic retinopathy (DR) and evaluate their utility in predicting DR development and progression.

DESIGN

Multicenter, multi-ethnic cohort study.

PARTICIPANTS

This study included 17,675 participants with baseline pre-diabetes/diabetes, in accordance with the 2021 American Diabetes Association guideline, and free of baseline DR from the UK Biobank (UKB); and an additional 638 diabetic participants from the Guangzhou Diabetic Eye Study (GDES) for external validation.

METHODS

Longitudinal DR metabolomic fingerprints were identified through nuclear magnetic resonance assay in UKB participants. The predictive value of these fingerprints for predicting DR development were assessed in a fully withheld test set. External validation and extrapolation analyses of DR progression and microvascular damage were conducted in the GDES cohort. Model assessments included the C-statistic, net classification improvement (NRI), integrated discrimination improvement (IDI), calibration, and clinical utility in both cohorts.

MAIN OUTCOME MEASURES

DR development, progression, and retinal microvascular damage.

RESULTS

Of 168 metabolites, 118 were identified as candidate metabolomic fingerprints for future DR development. These fingerprints significantly improved the predictability for DR development beyond traditional indicators (C-statistic: 0.802, 95% CI, 0.760-0.843 vs. 0.751, 95% CI, 0.706-0.796; P = 5.56×10-4). Glucose, lactate, and citrate were among the fingerprints validated in the GDES cohort. Using these parsimonious and replicable fingerprints yielded similar improvements for predicting DR development (C-statistic: 0.807, 95% CI, 0.711-0.903 vs. 0.617, 95% CI, 0.494, 0.740; P = 1.68×10-4) and progression (C-statistic: 0.797, 95% CI, 0.712-0.882 vs. 0.665, 95% CI, 0.545-0.784; P = 0.003) in the external cohort. Improvements in NRIs, IDIs, and clinical utility were also evident in both cohorts (all P <0.05). In addition, lactate and citrate were associated to microvascular damage across macular and optic disc regions (all P <0.05).

CONCLUSIONS

Metabolomic profiling has proven effective in identifying robust fingerprints for predicting future DR development and progression, providing novel insights into the early and advanced stages of DR pathophysiology.

An Epigenome-Wide Association Study of DNA Methylation and Proliferative Retinopathy over 28 Years in Type 1 Diabetes

Purpose

To perform a prospective epigenome-wide association study of DNA methylation (DNAm) and 28-year proliferative diabetic retinopathy (PDR) incidence in type 1 diabetes (T1D).

Design

Prospective observational cohort study.

Participants

The Pittsburgh Epidemiology of Diabetes Complications (EDC) study of childhood-onset (< 17 years) T1D.

Methods

Stereoscopic fundus photographs were taken in fields 1, 2, and 4 at baseline, 2, 4, 6, 8, 16, 23, and 28 years after DNAm measurements. The photos were graded using the modified Airlie House System. In those free of PDR at baseline (n = 265; mean T1D duration of 18 years at baseline), whole blood DNAm (EPIC array) at 683 597 CpGs was analyzed in Cox models for time to event. Associations between significant CpGs and clinical risk factors were assessed; genetic variants associated with DNAm were identified (methylation quantitative trait loci [meQTLs]). Mendelian randomization was used to examine evidence of causal associations between DNAm and PDR. Post hoc regional and functional analyses were performed.

Main Outcome Measures

Proliferative diabetic retinopathy was defined as the first instance of a grade of ≥ 60 in at least 1 eye or pan-retinal photocoagulation for PDR. Follow-up time was calculated from the study visit at which DNAm data were available (baseline) until PDR incidence or censoring (December 31, 2018 or last follow-up).

Results

PDR incidence was 53% over 28-years' follow-up. Greater DNAm of cg27512687 (KIF16B) was associated with reduced PDR incidence (P = 6.3 × 10-9; false discovery rate [FDR]: < 0.01); 113 cis-meQTLs (P < 5 × 10-8) were identified. Mendelian randomization analysis using the sentinel meQTL as the instrumental variable supported a potentially causal association between cg27512687 and PDR. Cg27512687 was also associated with lower pulse rate and albumin excretion rate and higher estimated glomerular filtration rate, but its association with PDR remained independently significant after adjustment for those factors. In regional analyses, DNAm of FUT4, FKBP1A, and RIN2 was also associated with PDR incidence.

Conclusions

DNA methylation of KIF16B, FUT4, FKBP1A, and RIN2 was associated with PDR incidence, supporting roles for epigenetic regulation of iron clearance, developmental pathways, and autophagy in PDR pathogenesis. Further study of those loci may provide insight into novel targets for interventions to prevent or delay PDR in T1D.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Role of Systemic Factors in Improving the Prognosis of Diabetic Retinal Disease and Predicting Response to Diabetic Retinopathy Treatment

Topic

To review clinical evidence on systemic factors that might be relevant to update diabetic retinal disease (DRD) staging systems, including prediction of DRD onset, progression, and response to treatment.

Clinical relevance

Systemic factors may improve new staging systems for DRD to better assess risk of disease worsening and predict response to therapy.

Methods

The Systemic Health Working Group of the Mary Tyler Moore Vision Initiative reviewed systemic factors individually and in multivariate models for prediction of DRD onset or progression (i.e., prognosis) or response to treatments (prediction).

Results

There was consistent evidence for associations of longer diabetes duration, higher glycosylated hemoglobin (HbA1c), and male sex with DRD onset and progression. There is strong trial evidence for the effect of reducing HbA1c and reducing DRD progression. There is strong evidence that higher blood pressure (BP) is a risk factor for DRD incidence and for progression. Pregnancy has been consistently reported to be associated with worsening of DRD but recent studies reflecting modern care standards are lacking. In studies examining multivariate prognostic models of DRD onset, HbA1c and diabetes duration were consistently retained as significant predictors of DRD onset. There was evidence of associations of BP and sex with DRD onset. In multivariate prognostic models examining DRD progression, retinal measures were consistently found to be a significant predictor of DRD with little evidence of any useful marginal increment in prognostic information with the inclusion of systemic risk factor data apart from retinal image data in multivariate models. For predicting the impact of treatment, although there are small studies that quantify prognostic information based on imaging data alone or systemic factors alone, there are currently no large studies that quantify marginal prognostic information within a multivariate model, including both imaging and systemic factors.

Conclusion

With standard imaging techniques and ways of processing images rapidly evolving, an international network of centers is needed to routinely capture systemic health factors simultaneously to retinal images so that gains in prediction increment may be precisely quantified to determine the usefulness of various health factors in the prognosis of DRD and prediction of response to treatment.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Prostanoid signaling in retinal vascular diseases

The vasculature of the retina is exposed to systemic and local factors that have the capacity to induce several retinal vascular diseases, each of which may lead to vision loss. Prostaglandin signaling has arisen as a potential therapeutic target for several of these diseases due to the diverse manners in which these lipid mediators may affect retinal blood vessel function. Previous reports and clinical practices have investigated cyclooxygenase (COX) inhibition by nonsteroidal anti-inflammatory drugs (NSAIDs) to address retinal diseases with varying degrees of success; however, targeting individual prostanoids or their distinct receptors affords more signaling specificity and poses strong potential for therapeutic development. This review offers a comprehensive view of prostanoid signaling involved in five key retinal vascular diseases: retinopathy of prematurity, diabetic retinopathy, age-related macular degeneration, retinal occlusive diseases, and uveitis. Mechanistic and clinical studies of these lipid mediators provide an outlook for therapeutic development with the potential to reduce vision loss in each of these conditions.

Are soluble E-selectin, ICAM-1, and VCAM-1 potential predictors for the development of diabetic retinopathy in young adults, 15-34 years of age? A Swedish prospective cohort study

The aim of this study was to determine plasma levels of three adhesion molecules that may contribute to the development of diabetic retinopathy; soluble endothelial selectin (sE-selectin), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1), in young adults, aged 15-34 years at diagnosis of diabetes, to find potential predictors for development of retinopathy, and to evaluate their relation to diabetes associated autoantibodies. Participants with type 1 (n = 169) and type 2 diabetes (n = 83) were selected from the complications trial of the Diabetes Incidence Study in Sweden and classified in two subgroups according to presence (n = 80) or absence (n = 172) of retinopathy as determined by retinal photography at follow-up 8-10 years after diagnosis of diabetes. Blood samples were collected at diagnosis in 1987-88. The levels of sE-selectin, sICAM-1, and sVCAM-1 were analysed by enzyme-linked immunosorbent assay and islet cell antibodies by a prolonged two-colour immunofluorescent assay. Mean HbA1c (p<0.001) and clinical characteristics: mean body mass index (p = 0.019), systolic blood pressure (p = 0.002), diastolic blood pressure (p = 0.003), male gender (p = 0.026), and young age at diagnosis of diabetes (p = 0.015) remained associated with development of retinopathy in type 1 diabetes. However, in a multivariate analysis only HbA1c remained as a risk factor. sE-selectin was significantly higher in the group with type 2 diabetes and retinopathy, compared to the group with type 2 diabetes without retinopathy (p = 0.04). Regarding sE-selectin, sICAM-1, and sVCAM-1 in participants with type 1 diabetes, no differences were observed between the groups with or without retinopathy. This trial confirmed the role of HbA1c and clinical characteristics as predictors for development of retinopathy in type 1 diabetes. sE-selectin stands out as a potential predictor for development of retinopathy in type 2 diabetes, whereas a predictive role for sICAM-1 and sVCAM-1 could not be identified neither for type 1 nor type 2 diabetes.

Metabolic memory and diabetic retinopathy: Legacy of glycemia and possible steps into future

The response of retinal pathology to interventions in diabetic retinopathy (DR) is often independent of the glycated hemoglobin (HbA1c) values at the point of care. This is despite glucose control being one of the strongest risk factors for the development and progression of DR. Previous preclinical and clinical research has indicated metabolic memory, whereby past cumulative glucose exposure may continue to impact DR for a prolonged period. Preclinical studies have evaluated punitive metabolic memory through poor initial control of DM, whereas clinical studies have evaluated protective metabolic memory through good initial control of DM. In this narrative review, we evaluate the preclinical and clinical evidence regarding metabolic memory and discuss how this may form the basis of preventive care for DR by inducing "metabolic amnesia" in people with a history of uncontrolled diabetes in the past. While our review suggested mitochondrial biology may be one such target, research is still far from a possible clinical trial. We discuss the challenges in such research.

Real-world sex differences in type 2 diabetes patients treated with GLP-1 receptor agonists

AIMS

To evaluate the determinants of cardiovascular (CV) protection in men and women treated with glucagon-like peptide-1 receptor agonists (GLP1-RA).

METHODS

Retrospective cohort study of 550 patients (43% women), with and without established CV disease, followed at a single center after the first prescription of a GLP1-RA. We analyzed the determinants of major adverse cardiovascular events (MACE) in men and women.

RESULTS

The rate of MACE was similar between sexes. In primary prevention, among men, older age (HR 1.13, 95 % C.I. 1.05-1.22; P = 0.001) and GLP-1 RA withdrawal by time (HR 2.77, 95 % C.I. 1.15-6.68; P = 0.023) increased the HR for MACE. Among women, significant predictors of MACE were diabetes duration (HR 1.05, C.I. 1.01-1.10; P = 0.020), GLP-1 withdrawal by time (HR 2.84, 95 % C.I. 1.13-7.10; P = 0.026) and BMI at GLP-1 RA withdrawal (HR 1.08, 95 % C.I. 1.01-1.15; P = 0.026). For individuals with prior CV disease, the HR for MACE was solely impacted by GLP-1 withdrawal over time in males (HR 2.18, 95 % C.I. 1.10-4.30; P = 0.025) and by older age at GLP-1 RA initiation (HR 1.17, 95 % C.I. 1.03-1.33; P = 0.015) in females.

CONCLUSIONS

Although MACE rates were similar, the factors contributing to MACE differed by sex.

Impact of anti-VEGF treatment on development of proliferative diabetic retinopathy in routine clinical practice

BACKGROUND

This study evaluated impact of anti-vascular endothelial growth factor (VEGF) treatment on proliferative diabetic retinopathy (PDR) development among patients with non-proliferative diabetic retinopathy (NPDR) in US real-world clinical practice.

METHODS

This was a retrospective analysis of electronic medical records (Vestrum Health; January 2013 to June 2019) of eyes with baseline NPDR, without DME, and naïve to anti-VEGF treatment at index DR diagnosis. Eyes that received anti-VEGF and/or laser treatment over the course of study before development of PDR constituted the treated cohort while the remaining including those treated with laser constituted the anti-VEGF naïve cohort. Survival analysis via Kaplan-Meier method evaluated time to DME and PDR development by baseline NPDR severity, with anti-VEGF treatment as censoring variable. Baseline factors affecting PDR development were analyzed using Cox multivariable regression, censoring for anti-VEGF treatment.

RESULTS

Among anti-VEGF-naive eyes, cumulative incidence of DME in eyes with mild (n = 70,050), moderate (n = 39,116), and severe NPDR (n = 10,692) at baseline was 27.1%, 51.2%, and 60.6%. Multivariable regression analysis identified baseline NPDR severity as the most significant predictor of PDR development over 48 months (hazard ratio [HR] [95% confidence interval {CI}] of 2.69 (2.65-2.72) for moderate vs mild NPDR and 6.51 (6.47-6.55) for severe vs mild NPDR). Cumulative incidence (95% CI) of PDR was 7.9% (7.4%-8.3%), 20.9%, (20.0%-21.7%) and 46.8% (44.4%-49.2%) over 48 months in eyes with mild, moderate, and severe NPDR at baseline, respectively. Among treated eyes with baseline severe NPDR, cumulative incidence of PDR at 48 months was 50.1% in eyes treated with laser (n = 546; HR [95% CI] vs no treatment: 0.8 [0.7-1.0]), 27.4% in eyes treated with anti-VEGF (n = 923; HR [95% CI]: 0.4 [0.4-0.5]), and 25.6% in eyes treated with anti-VEGF plus laser (n = 293; HR [95% CI]: 0.5 [0.4-0.7]) compared with 49.9% in eyes with no treatment (n = 8930).

CONCLUSIONS

DME and PDR development rates increased with increasing baseline NPDR severity. Approximately half of anti-VEGF‒naive eyes with severe NPDR progressed to PDR within 4 years in US clinical practice. The progression rate from severe NPDR to PDR was approximately halved with anti-VEGF versus no treatment.

Presence and development of diabetic retinopathy in 16 999 patients with type 1 diabetes in the Danish Registry of Diabetic Retinopathy

PURPOSE

To evaluate the five-year incidence of diabetic retinopathy (DR) and associated risk markers in patients with type 1 diabetes in the national Danish DR-screening programme.

METHODS

Based on national data, we included all 16 999 patients with type 1 diabetes in the Danish Registry of Diabetic Retinopathy, who attended the national screening programme in the period 2013-2018. According to the worse eye at first screening, DR was classified (levels 0-4) and linked with various national health registries to retrieve information on diabetes duration, systemic comorbidity, and medication.

RESULTS

At first screening, median age and duration of diabetes were 45.0 and 16.7 years, and 57.5% were males. The prevalence and five-year incidences for DR and progression to proliferative DR (PDR) were 44.2%, 8.9% and 2.0%, respectively. In multivariable Cox models, the incidence endpoints were associated with duration of diabetes (hazard ratio [HR] 1.76, 95% confidence interval [CI] 1.63-1.89, and HR 2.04, 95% CI 1.73-2.40 per 10 years), moderately low Charlson Comorbidity Index score (HR 1.27, 95% CI 1.10-1.47, and HR 2.80, 95% CI 2.23-3.51), and use of blood pressure lowering medication (HR 1.20, 95% CI 1.05-1.36, and HR 1.98, 95% CI 1.53-2.57).

CONCLUSION

In a study of all patients with type 1 diabetes from the Danish DR-screening programme, we identified duration of diabetes, systemic disease and use of anti-hypertensive treatment as consistent risk markers for incident and progressive DR.

Obesity, body fat distribution and eye diseases

BACKGROUND

The prevalence of obesity, a chronic disease, is increasing, and obesity is now considered a global epidemic. Eye diseases are also increasing worldwide and have serious repercussions on quality of life as well as increasingly high costs for the community. The relationships between obesity and ocular pathologies are not yet well clarified and are not pathologically homogeneous: they seem to be somehow linked to excess body fat, especially to the distribution of adipose tissue and its ectopic deposits.

PURPOSE

Our objective was to examine the associations between obesity and anthropometric indices, including body mass index (BMI), waist circumference (WC), and the waist/hip ratio (WHR), and the risk of most widespread eye diseases, with particular attention given to the most significant metabolic mechanisms.

METHODS

This article provides a narrative overview of the effect of obesity and anthropometric measurements of body fat on prevalent eye diseases. We used the MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library databases from 1984 to 2024. In addition, we hand-searched references from the retrieved articles and explored a number of related websites. A total of 153 publications were considered.

RESULTS

There is significant evidence that obesity is associated with several eye diseases. Waist circumference (WC) and the waist/hip ratio (WHR) have been observed to have stronger positive associations with eye diseases than BMI.

CONCLUSIONS

Obesity must be considered a significant risk factor for eye diseases; hence, a multidisciplinary and multidimensional approach to treating obesity, which also affects ocular health, is important. In the prevention and treatment of eye diseases related to obesity, lifestyle factors, especially diet and physical activity, as well as weight changes, both weight loss and weight gain, should not be overlooked.

LEVEL OF EVIDENCE

Level V narrative review.

Socioeconomic Disparities and Emergency Department Visits for Diabetic Retinopathy in California

Purpose: To investigate the association between neighborhood-level socioeconomic factors, quantified by the Distressed Communities Index, and emergency department visits for diabetic retinopathy (DR). Methods: All patients who presented to the emergency department for DR in California were analyzed using the State Emergency Department Database (2018-2020). Patients were stratified by Distressed Communities Index score and DR severity. Logistic regression was applied to explore the independent correlation between Distressed Communities Index scores and proliferative DR (PDR). Results: Of 2 725 195 emergency department visits for diabetic patients, Distressed Communities Index data were available for 2 459 577 (90.3%); 39 693 were for DR, including 13 617 (34.3%) for PDR. Hispanics (44.2%) were the largest racial/ethnic group to present for PDR, followed by non-Hispanic Whites (19.6%) and non-Hispanic Blacks (19.3%). A significant association was observed between the Distressed Communities Index and emergency department visits for PDR, with distressed neighborhoods having the highest incidence (adjusted odds ratio [aOR], 1.63; 95% CI, 1.20-2.23; P = .001). Other predictors included Hispanic ethnicity (aOR, 2.21; 95% CI, 1.97-2.48; P < .001) and Black race (aOR, 1.46; 95% CI, 1.28-1.67; P < .001) compared with White race and having Medicaid (aOR, 1.37; 95% CI, 1.13-1.65; P = .001) compared with private insurance. Conclusions: The Distressed Communities Index identified patients residing in the most distressed neighborhoods as being at the highest risk for presenting to the emergency department for PDR based on 7 socioeconomic factors. Policymakers may consider the Distressed Communities Index as a tool for targeting DR prevention strategies and improving healthcare accessibility.

Impact of Gender on Chronic Complications in Participants With Type 2 Diabetes: Evidence From a Cross-Sectional Study

INTRODUCTION

This study aimed to assess and compare the prevalence of diabetes complications between men and women with Type 2 diabetes (T2D), as well as how gender relates to these complications.

METHODS

In this cross-sectional study, complications of diabetes, including coronary artery disease (CAD), retinopathy, neuropathy and diabetic kidney disease (DKD), were evaluated in 1867 participants with T2D. Additionally, baseline characteristics of the individuals, including anthropometric measurements, metabolic parameters and the use of dyslipidaemia drugs and antihyperglycaemic agents, were assessed. Gender differences in complications were examined using the chi-squared test. Multivariate logistic regression was employed to investigate the relationship between gender and T2D complications, with and without adjusting for the characteristics of the studied population.

RESULTS

In the studied population, 62.1% had at least one complication, and complications were 33.5% for DKD, 29.6% for CAD, 22.9% for neuropathy and 19.1% for retinopathy. The prevalence of CAD and neuropathy was higher in men. However, DKD and retinopathy were more prevalent among women. Odds ratios of experiencing any complication, CAD and retinopathy in men compared with women were 1.57 (95% CI: 1.27-2.03), 2.27 (95% CI: 1.72-2.99) and 0.72 (95% CI: 0.52-0.98), respectively, after adjusting for demographic factors, anthropometric measures, metabolic parameters and the consumption of dyslipidaemia drugs and antihyperglycaemic agents.

CONCLUSION

The prevalence of diabetes complications was significantly higher in men with diabetes, highlighting the need for better treatment adherence. CAD was associated with the male gender, whereas retinopathy was associated with the female gender. Men and women with diabetes should be monitored closely for CAD and retinopathy, respectively, regardless of their age, diabetes duration, anthropometric measures, laboratory findings and medications.

The Determination of Diabetes Utilities, Costs, and Effects Model: A Cost-Utility Tool Using Patient-Level Microsimulation to Evaluate Sensor-Based Glucose Monitoring Systems in Type 1 and Type 2 Diabetes: Comparative Validation

OBJECTIVES

To assess the accuracy and validity of the Determination of Diabetes Utilities, Costs, and Effects (DEDUCE) model, a Microsoft-Excel-based tool for evaluating diabetes interventions for type 1 and type 2 diabetes.

METHODS

The DEDUCE model is a patient-level microsimulation, with complications predicted based on the Sheffield and Risk Equations for Complications Of type 2 diabetes models for type 1 and type 2 diabetes, respectively. For this tool to be useful, it must be validated to ensure that its complication predictions are accurate. Internal, external, and cross-validation was assessed by populating the DEDUCE model with the baseline characteristics and treatment effects reported in clinical trials used in the Fourth, Fifth, and Ninth Mount Hood Diabetes Challenges. Results from the DEDUCE model were evaluated against clinical results and previously validated models via mean absolute percentage error or percentage error.

RESULTS

The DEDUCE model performed favorably, predicting key outcomes, including cardiovascular disease in type 1 diabetes and all-cause mortality in type 2 diabetes. The model performed well against other models. In the Mount Hood 9 Challenge comparison, error was below the mean reported from comparator models for several outcomes, particularly for hazard ratios.

CONCLUSIONS

The DEDUCE model predicts diabetes-related complications from trials and studies well when compared with previously validated models. The model may serve as a useful tool for evaluating the cost-effectiveness of diabetes technologies.

Aldose Reductase as a Key Target in the Prevention and Treatment of Diabetic Retinopathy: A Comprehensive Review

The escalating global prevalence of diabetes mellitus (DM) over the past two decades has led to a persistent high incidence of diabetic retinopathy (DR), necessitating screening for early symptoms and proper treatment. Effective management of DR aims to decrease vision impairment by controlling modifiable risk factors including hypertension, obesity, and dyslipidemia. Moreover, systemic medications and plant-based therapy show promise in advancing DR treatment. One of the key mechanisms related to DR pathogenesis is the polyol pathway, through which aldose reductase (AR) catalyzes the conversion of glucose to sorbitol within various tissues, including the retina, lens, ciliary body and iris. Elevated glucose levels activate AR, leading to osmotic stress, advanced glycation end-product formation, and oxidative damage. This further implies chronic inflammation, vascular permeability, and angiogenesis. Our comprehensive narrative review describes the therapeutic potential of aldose reductase inhibitors in treating DR, where both synthetic and natural inhibitors have been studied in recent decades. Our synthesis aims to guide future research and clinical interventions in DR management.

An Eye for A Foot: Alarming Unawareness of Diabetic Retinopathy Among Diabetic Foot Patients

This study aims to determine the awareness of diabetic retinopathy in patients hospitalized for diabetic foot ulcers, examine their clinical and demographic characteristics, and evaluate their treatment needs. In this prospective study, 62 consequent patients with diabetic foot ulcers who were hospitalized for further treatment in Diabetic Foot Department between June and August 2023 were subjected to ophthalmological examinations. Detailed anterior and posterior segment examinations were performed. Clinical and demographic characteristics and HbA1c levels were recorded. Thirty-nine patients (62.9%) were male and 23 (37.1%) were female. The mean age was 61 ± 11.4 years. The patients had diabetes mellitus (DM) for an average of 19.2 ± 9.6 years. The average HbA1c value of the patients was 9 ± 2.3%. Minor amputation was performed in 35 of 62 patients (56.5%) during treatment. Thirty-one patients (50%) were unaware of the risk of diabetic retinopathy. Of those "unaware" 31 patients, 26 (83.9%) had diabetic retinopathy. Diabetic retinopathy was detected in 57 patients (91.9%) and 3-month interval ophthalmological follow-up screening was recommended for 77 eyes. Eighty percent of the patients never had ophthalmological examination. Intravitreal (IV) injection was performed in 44 eyes, panretinal photocoagulation (PRP) in 2 eyes, and intravenous injection + PRP + vitreoretinal surgery in one eye. Diabetic foot ulcers and diabetic retinopathy are often accompanied by each other. Patients should be informed about this and strongly encouraged to undergo routine ophthalmological examinations, especially when they have advanced diabetic foot disease. Diabetic foot surgeons should keep in mind that a poor eye cannot detect diabetic foot problems.

Protective Factors and the Pathogenesis of Complications in Diabetes

Chronic complications of diabetes are due to myriad disorders of numerous metabolic pathways that are responsible for most of the morbidity and mortality associated with the disease. Traditionally, diabetes complications are divided into those of microvascular and macrovascular origin. We suggest revising this antiquated classification into diabetes complications of vascular, parenchymal, and hybrid (both vascular and parenchymal) tissue origin, since the profile of diabetes complications ranges from those involving only vascular tissues to those involving mostly parenchymal organs. A major paradigm shift has occurred in recent years regarding the pathogenesis of diabetes complications, in which the focus has shifted from studies on risks to those on the interplay between risk and protective factors. While risk factors are clearly important for the development of chronic complications in diabetes, recent studies have established that protective factors are equally significant in modulating the development and severity of diabetes complications. These protective responses may help explain the differential severity of complications, and even the lack of pathologies, in some tissues. Nevertheless, despite the growing number of studies on this field, comprehensive reviews on protective factors and their mechanisms of action are not available. This review thus focused on the clinical, biochemical, and molecular mechanisms that support the idea of endogenous protective factors, and their roles in the initiation and progression of chronic complications in diabetes. In addition, this review also aimed to identify the main needs of this field for future studies.

Use of Diabetes Technologies and Retinopathy in Adults With Type 1 Diabetes

Importance

Diabetic retinopathy (DR) is a complication of diabetes that can lead to vision loss. Outcomes of continuous glucose monitoring (CGM) and insulin pump use in DR are not well understood.

Objective

To assess the use of CGM, insulin pump, or both, and DR and proliferative diabetic retinopathy (PDR) in adults with type 1 diabetes (T1D).

Design, Setting, and Participants

A retrospective cohort study of adults with T1D in a tertiary diabetes center and ophthalmology center was conducted from 2013 to 2021, with data analysis performed from June 2022 to April 2023.

Exposure

Use of diabetes technologies, including insulin pump, CGM, and both CGM and insulin pump.

Main Outcomes and Measures

The primary outcome was development of DR or PDR. A secondary outcome was the progression of DR for patients in the longitudinal cohort. Multivariable logistic regression models assessed for development of DR and PDR and association with CGM and insulin pump use.

Results

A total of 550 adults with T1D were included (median age, 40 [IQR, 28-54] years; 54.4% female; 24.5% Black or African American; and 68.4% White), with a median duration of diabetes of 20 (IQR, 10-30) years, and median hemoglobin A1c (HbA1c) of 7.8% (IQR, 7.0%-8.9%). Overall, 62.7% patients used CGM, 58.2% used an insulin pump, and 47.5% used both; 44% (244 of 550) of the participants had DR at any point during the study. On univariate analysis, CGM use was associated with lower odds of DR and PDR, and CGM with pump was associated with lower odds of PDR (all P < .05), compared with no CGM use. Multivariable logistic regression adjusting for age, sex, race and ethnicity, diabetes duration, microvascular and macrovascular complications, insurance type, and mean HbA1c, showed that CGM was associated with lower odds of DR (odds ratio [OR], 0.52; 95% CI, 0.32-0.84; P = .008) and PDR (OR, 0.42; 95% CI, 0.23-0.75; P = .004), compared with no CGM use. In the longitudinal analysis of participants without baseline PDR, 79 of 363 patients (21.8%) had progression of DR during the study.

Conclusions and Relevance

In this cohort study of adults with T1D, CGM use was associated with lower odds of developing DR and PDR, even after adjusting for HbA1c. These findings suggest that CGM may be useful for diabetes management to mitigate risk for DR and PDR.

Efficacy of adipose-derived mesenchymal stem cell therapy in the treatment of chronic micro- and macrovascular complications of diabetes

Diabetes mellitus is a highly prevalent disease characterized by hyperglycaemia that damages the vascular system, leading to micro- (retinopathy, neuropathy, nephropathy) and macrovascular diseases (cardiovascular disease). There are also secondary complications of diabetes (cardiomyopathy, erectile dysfunction or diabetic foot ulcers). Stem cell-based therapies have become a promising tool targeting diabetes symptoms and its chronic complications. Among all stem cells, adipose-derived mesenchymal stem cells (ADMSCs) are of great importance because of their abundance, non-invasive isolation and no ethical limitations. Characteristics that make ADMSCs good candidates for cell-based therapy are their wide immunomodulatory properties and paracrine activities through the secretion of an array of growth factors, chemokines, cytokines, angiogenic factors and anti-apoptotic molecules. Besides, after transplantation, ADMSCs show great ex vivo expansion capacity and differentiation to other cell types, including insulin-producing cells, cardiomyocytes, chondrocytes, hepatocyte-like cells, neurons, endothelial cells, photoreceptor-like cells, or astrocytes. Preclinical studies have shown that ADMSC-based therapy effectively improved visual acuity, ameliorated polyneuropathy and foot ulceration, arrested the development and progression of diabetic kidney disease, or alleviated the diabetes-induced cardiomyocyte hypertrophy. However, despite the positive results obtained in animal models, there are still several challenges that need to be overcome before the results of preclinical studies can be translated into clinical applications. To date, there are several clinical trials or ongoing trials using ADMSCs in the treatment of diabetic complications, most of them in the treatment of diabetic foot ulcers. This narrative review summarizes the most recent outcomes on the usage of ADMSCs in the treatment of long-term complications of diabetes in both animal models and clinical trials.

The causal effect of hypertension, intraocular pressure, and diabetic retinopathy: a Mendelian randomization study

Background

Previous research has indicated a vital association between hypertension, intraocular pressure (IOP), and diabetic retinopathy (DR); however, the relationship has not been elucidated. In this study, we aim to investigate the causal association of hypertension, IOP, and DR.

Methods

The genome-wide association study (GWAS) IDs for DR, hypertension, and IOP were identified from the Integrative Epidemiology Unit (IEU) Open GWAS database. There were 33,519,037 single-nucleotide polymorphisms (SNPs) and a sample size of 1,030,836 for DR. There were 16,380,466 SNPs and 218,754 participants in the hypertension experiment. There were 9,851,867 SNPs and a sample size of 97,465 for IOP. Univariable, multivariable, and bidirectional Mendelian randomization (MR) studies were conducted to estimate the risk of hypertension and IOP in DR. Moreover, causality was examined using the inverse variance weighted method, and MR results were verified by numerous sensitivity analyses.

Results

A total of 62 SNPs at the genome-wide significance level were selected as instrumental variables (IVs) for hypertension-DR. The results of univariable MR analysis suggested a causal relationship between hypertension and DR and regarded hypertension as a risk factor for DR [p = 0.006, odds ratio (OR) = 1.080]. A total of 95 SNPs at the genome-wide significance level were selected as IVs for IOP-DR. Similarly, IOP was causally associated with DR and was a risk factor for DR (p = 0.029, OR = 1.090). The results of reverse MR analysis showed that DR was a risk factor for hypertension (p = 1.27×10-10, OR = 1.119), but there was no causal relationship between DR and IOP (p > 0.05). The results of multivariate MR analysis revealed that hypertension and IOP were risk factors for DR, which exhibited higher risk scores (p = 0.001, OR = 1.121 and p = 0.030, OR = 1.124, respectively) than those in univariable MR analysis. Therefore, hypertension remained a risk factor for DR after excluding the interference of IOP, and IOP was still a risk factor for DR after excluding the interference of hypertension.

Conclusion

This study validated the potential causal relationship between hypertension, IOP, and DR using MR analysis, providing a reference for the targeted prevention of DR.

The role of statins in diabetic retinopathy

Diabetes mellitus is a growing global public health issue estimated to affect around 600 million people by 2040 [1]. It occurs in populations throughout the world, is increasing in both the developing world and high-income countries and also affects young, working-age people. Ocular involvement in diabetes occurs early in the disease and is present in over a third of diabetes mellitus Type 2 patients at the time of diagnosis. Blindness due to diabetic retinopathy (DR) remains a leading cause of adult-onset blindness, [1] which results from disruption of retinal vasculature, ischemia and its consequences and exudation causing macular edema. The prevalence of diabetic retinopathy is increasing at a greater rate than other causes of blindness including cataract, refractive errors, age-related macular degeneration and glaucoma. Compared to cataract and refractive error, management of diabetic retinopathy requires vast medical resources, including trained medical practitioners able to perform ocular injections and ophthalmologists for laser treatments and retinal surgery. This creates a significant burden on medical services as care for these patients lasts decades.

Healthcare Resource Utilization and Costs in an At-Risk Population With Diabetic Retinopathy

Purpose

Several investigators have suggested the cost-effectiveness of earlier screening, management of risk factors, and early treatment for diabetic retinopathy (DR). We aimed to evaluate the extent of health care utilization and cost of delayed care by insurance type in a vulnerable patient population.

Methods

A retrospective analysis of patients with DR was conducted using electronic medical record (EMR) data from January 2014 to December 2020 at Denver Health Medical Center, a safety net institution. Patients were classified by disease severity and insurance status. DR-specific costs were assessed via Current Procedural Terminology (CPT) codes over a 24-month follow-up period.

Results

Among the 313 patients, a higher proportion of non-English speaking patients were uninsured. Rates of proliferative DR at presentation differed across insurance groups (62% of uninsured, 42% of discount plan, and 33% of Medicare/Medicaid, P = 0.016). There was a significant difference in the total median cost between discount plan patients ($1258, interquartile range [IQR] = $0 - $5901) and both Medicare patients ($751, IQR = $0, $7148, P = 0.037) and Medicaid patients ($593, IQR = $0 - $6299, P = 0.025).

Conclusions

There were higher rates of proliferative DR at presentation among the uninsured and discount plan patients and greater total median cost in discount plan patients compared to Medicare or Medicaid. These findings prioritize mitigating gaps in insurance coverage and barriers to preventative care among vulnerable populations.

Translational Relevance

Advanced diabetic disease and increased downstream health care utilization and cost vary across insurance type, suggesting improved access to preventative care is needed in these specific at-risk populations.

Non-invasive skin autofluorescence as a screening method for diabetic retinopathy

Diabetic retinopathy (DR) is a public health problem and a common cause of blindness. It is diagnosed by fundus examination; however, this is a costly and time-consuming method. Non-invasive skin autofluorescence (SAF) may be an accessible, fast and simple alternative for screening and early diagnosis of DR. The aim of this study was to evaluate the accuracy of SAF as a screening method for DR. A systematic search of MEDLINE, Scopus, and Web of Science databases was performed. Random effects models for sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR), diagnostic odds ratio (dOR) value and 95% CIs were used to calculate test accuracy. In addition, hierarchical summary receiver operating characteristic curves (HSROC) were used to summarise the overall test performance. Four studies were included in the meta-analysis. Pooled sensitivity and specificity were 0.79 (95% CI 0.72-0.88; I2  = 0.0%) and 0.54 (95% CI 0.32-0.92; I2  = 97.0%), respectively. The dOR value for the diagnosis of DR using SAF was 5.11 (95% CI 1.81-14.48: I2  = 85.9%). The PRL was 2.17 (95% CI 0.62-7.64) and the NRL was 0.27 (95% CI 0.07-1.03). Heterogeneity was not relevant in sensitivity and considerable in specificity. The 95% confidence region of the HSROC included all studies. SAF as a screening test for DR shows sufficient accuracy for its use in clinical settings. SAF may be an appropriate method for DR screening, and further research is needed to recommend it as a diagnostic method.

Short-Term Effects of Adding Topical Ketorolac to Intravitreal Bevacizumab in Diabetic Macular Edema: A Crossover Randomized Clinical Trial

Purpose

To evaluate the short-term additive effects of topical ketorolac to intravitreal bevacizumab (IVB) in the management of center-involved diabetic macular edema (CI-DME).

Methods

In a randomized double-masked placebo-controlled crossover clinical trial, eyes with CI-DME and the best-corrected visual acuity (BCVA) between (20/40) and (20/400) were included. These eyes should have had at least one intravitreal anti-VEGF injection in the preceding two months. They were randomized into two groups; while both groups received two IVB injections with a six-week interval, one group received topical ketorolac every 6 hr in the first interval and artificial tears every 6 hr as a placebo in the second interval and the other group received the same medications using a crossover method. The main outcome measures were changes in BCVA and central macular thickness (CMT).

Results

Fifty-seven eyes of 35 patients with CI-DME were included in the study. The mean BCVA improvement was -0.09 ± 0.47 logMAR in the periods of receiving ketorolac and -0.03 ± 0.12 logMAR in the periods of placebo treatment, respectively (P = 0.99). Corresponding changes in CMT were -13.1 ± 170.1 and +11.7 ± 157.7 µm in the ketorolac and placebo periods, respectively (P = 0.322). The treatment effect was not statistically significant regarding both BCVA and CMT changes. Statistical analysis also disclosed that the carryover effect was insignificant for BCVA and CMT. Although the period effect was not significant for BCVA, it was at a meaningful level for CMT changes (P = 0.012).

Conclusion

This crossover clinical trial demonstrated that in the course of DME treatment with IVB injections, topical ketorolac did not have any additive beneficial effect at least during a six-week period.

Association between Glucose-lowering Treatments and Risk of Diabetic Retinopathy in People with Type 2 Diabetes: A Nationwide Cohort Study

INTRODUCTION

Glycaemic variability is possibly linked to the development of diabetic retinopathy, and newer second-line glucose-lowering treatments in type 2 diabetes might reduce glycaemic variability.

AIM

This study aimed to investigate whether newer second-line glucose-lowering treatments are associated with an alternative risk of developing diabetic retinopathy in people with type 2 diabetes.

METHODS

A nationwide cohort of people with type 2 diabetes on second-line glucose-lowering treatment regimens in 2008-2018 was extracted from the Danish National Patient Registry. Adjusted time to diabetic retinopathy was estimated with a Cox Proportional Hazards model. The model was adjusted for age, sex, diabetes duration, alcohol abuse, treatment start year, education, income, history of late-diabetic complications, history of non-fatal major adverse cardiovascular events, history of chronic kidney disease, and history of hypoglycaemic episodes.

RESULTS

Treatment regimens of metformin + basal insulin (HR: 3.15, 95% CI: 2.42-4.10) and metformin + glucagon-like peptide-1 receptor agonist (GLP-1-RA, HR: 1.46, 95% CI: 1.09-1.96) were associated with an increased risk of diabetic retinopathy compared with metformin + dipeptidyl peptidase-4 inhibitors (DPP-4i). Treatment with metformin + sodium-glucose cotransporter-2 inhibitor (SGLT2i, HR: 0.77, 95% CI: 0.28-2.11) was associated with the numerically lowest risk of diabetic retinopathy compared with all regimens investigated.

CONCLUSION

Findings from this study indicate that basal insulin and GLP-1-RA are suboptimal second- line choices for people with type 2 diabetes at risk of developing diabetic retinopathy. However, many other considerations concerning the choice of second-line glucose-lowering treatment for type 2 diabetes patients should be taken into account.

Regression of Neovascularization after Panretinal Photocoagulation Combined with Anti-VEGF Injection for Proliferative Diabetic Retinopathy-A Review

Proliferative diabetic retinopathy (PDR) poses a significant therapeutic problem that often results in severe visual loss. Panretinal photocoagulation (PRP) has long been a mainstay treatment for this condition. Conversely, intravitreal anti-VEGF therapy has served as an alternative treatment for PDR. This review aimed to evaluate the effects of PRP combined with anti-VEGF therapy on the regression of neovascularization (NV), including functional outcomes and incidence of complications. The MEDLINE database was searched for articles evaluating regression of NV using a combination of the following terms: "proliferative diabetic retinopathy", "anti-VEGF", "panretinal photocoagulation", and "combined treatment". The search yielded a total of 22 articles. The analysis of their results indicated PRP combined with ant-VEGF therapy as superior over PRP alone in the management of PDR. Combination treatment yields better and faster regression of NV and a lower incidence of serious complications, such as vitreous hemorrhage and the need for pars plana vitrectomy. Nevertheless, complete regression of NV is not achieved in a significant proportion of patients. Further research is needed to establish the most effective schedule for intravitreal injections as an adjunct to PRP. The current literature shows that in some cases, cessation of anti-VEGF injection in combination treatment for PDR can lead to relapse of NV.

Efficacy of intravitreal bevacizumab on diabetic macular oedema in an African population

PURPOSE

To evaluate the short-term effect of intravitreal bevacizumab (avastin) injection on visual outcomes of patients with diabetic macular oedema.

METHODS

A retrospective cross-sectional study was conducted to evaluate 39 eyes of thirty-nine patients (mean age ± SD: 61.4 ± 15.0 years) that received intravitreal bevacizumab injection (1.25 mg in 0.05 ml) as treatment for diabetic macular oedema between January 2014 and July 2019 in Ghana. Data on visual acuity and central macular thickness before treatment and 6 weeks post-treatment were collected and analysed using paired t-test. Ordinary least squares linear regression analysis was also conducted to determine the relationship between improvement in visual acuity and central macular thickness after treatment and other predictor variables.

RESULTS

The mean ± SD visual acuity (LogMAR-equivalent of Snellen) of patients with diabetic macular oedema significantly improved from 0.84 ± 0.58 LogMAR before treatment to 0.69 ± 0.58 LogMAR at 6 weeks post-treatment (mean difference: 0.15 ± 0.32 LogMAR; 95% CI: 0.04 to 0.25; p = 0.01). Mean macular thickness ± SD on the other hand, reduced significantly (p < 0.001) from 316.54 ± 75.35 μm before treatment to 275.54 ± 57.43 μm after treatment. While age and worse pre-treatment visual acuity predicted improvement in visual acuity after treatment, a higher central macular thickness before treatment predicted an improvement in central macular thickness after intravitreal bevacizumab injection.

CONCLUSION

Treatment with intravitreal bevacizumab injection produces short-term improvement in vision and reduction in central macular thickness in African patients with diabetic macular oedema.

Comparison of Optical Coherence Tomography Angiography Findings between Healthy Children and Children with Type 1 Diabetes Mellitus and Autoimmune Thyroiditis

Objective

The aim of this study was to compare the development of early diabetic retinopathy (DR) findings, a microvascular complication, between patients with isolated type 1 diabetes mellitus (T1DM) (Group 1), concurrent T1DM and autoimmune thyroiditis (AT) (Group 2), and healthy controls (Group 3), who were matched for age, sex, number, and body mass index for comparison.

Methods

This was a prospective observational study that included individuals aged 10-20 years, and patients in Groups 1 and 2 had been followed up for ≥5 years. None of them developed clinical DR during the follow-up period. Optical coherence tomography angiography (OCTA) was used to evaluate the foveal avascular zone (FAZ) and parafoveal vascular density (PVD) for the development of early DR. OCTA findings were compared between patients and healthy controls.

Results

Thirty-five individuals were included in each of the groups. The mean FAZ and PVD differed significantly between the three groups (FAZ, p=0.016; PVD, p=0.006). The mean FAZ was higher in Groups 1 and 2 than in Group 3 (p=0.013 and p=0.119, respectively). The mean PVD was lower in Groups 1 and 2 than in Group 3 (p=0.007, respectively). No significant difference was found between Groups 1 and 2 in terms of the mean FAZ and PVD (p=0.832 and p=0.653, respectively). The mean glycated hemoglobin (HbA1c) level was significantly correlated with FAZ and PVD (FAZ: r=0.496, p<0.001; PVD: r=-0.36, p=0.001).

Conclusion

In patients with T1DM who did not develop clinical DR, OCTA findings revealed an increase in FAZ, which was associated with higher HbA1c levels. The mean PVD was significantly lower in the group with coexisting AT and T1DM than in the control group. These results suggest that the coexistence of AT and T1DM can contribute to the development of microvascular complications. However, studies with larger patient series are required.

Retinal changes and cardiac biomarker assessment in relation to chronic kidney disease: a single centre study

BACKGROUND

The prevalence of chronic kidney disease (CKD) is rising in Malaysia. Early detection is necessary to prevent disease progression, especially in terms of cardiovascular (CV) risk, the main cause of death in end-stage renal disease (ESRD). Retinal changes have proven to be a good predictor of CKD whereas cardiac biomarkers are useful in cardiovascular risk stratification. We aimed to demonstrate the correlation between retinal changes and cardiac biomarkers with CKD.

METHODS

This single-centre cross-sectional study was conducted among patients with CKD stages 3, 4, and 5 (not on dialysis) from the Nephrology Clinic, Universiti Kebangsaan Malaysia Medical Centre. A total of 84 patients were recruited with an even distribution across all three stages. They underwent fundus photography where images were analysed for vessel calibre (central retinal venular equivalent (CRVE), central retinal arterial equivalent (CRAE), and tortuosity indices. Optical coherence tomography was used to measure macular volume. Blood samples were sent for laboratory measurement of high-sensitivity C-reactive protein (hs-CRP) and asymmetric dimethylarginine (ADMA). These parameters were analysed in relation to CKD.

RESULTS

The mean age was 58.8 ± 11.7 years, with 52.4% male and 47.6% female patients. Among them, 64.3% were diabetics. Retinal vessel tortuosity (r = -0.220, p-value = 0.044) had a negative correlation with the estimated glomerular filtration rate (eGFR). CRVE showed a positive correlation with proteinuria (r = 0.342, p = 0.001) but negative correlation with eGFR (r = -0.236, p = 0.031). Hs-CRP positively correlated with proteinuria (r = 0.313, p = 0.04) and negatively correlated with eGFR (r = -0.370, p = 0.001). Diabetic patients had a higher CRVE compared to non-diabetic patients (p = 0.02). History of ischaemic heart disease was associated with a smaller macula volume (p = 0.038). Male gender (r2 = 0.066, p = 0.031) and HbA1c had a positive influence (r2 = 0.066, p = 0.047) on retinal vessel tortuosity. There was a positive influence of age (r2 = 0.183, p = 0.012) and hs-CRP (r2 = 0.183, p = 0.045) on CRVE. As for macula volume, it negatively correlated with diabetes (r2 = 0.015, p = 0.040) and positively correlated with smoking (r2 = 0.015, p = 0.012).

CONCLUSION

Our study showed that eGFR value affects retinal vessel tortuosity, CRVE and hs-CRP. These parameters bear potential to be used as non-invasive tools in assessing CKD. However, only macula volume may be associated with CVD risk among the CKD population.

LONGITUDINAL MICROVASCULAR AND NEURONAL RETINAL EVALUATION IN PATIENTS WITH DIABETES MELLITUS TYPES 1 AND 2 AND GOOD GLYCEMIC CONTROL

PURPOSE

To evaluate microvascular and neuronal changes over 3 years in patients with Type 1/2 diabetes mellitus (DM1/DM2), good metabolic control, and no signs of diabetic retinopathy.

METHODS

In this prospective, longitudinal study, 20 DM1, 48 DM2, and 24 controls underwent macular optical coherence tomography and optical coherence tomography angiography at baseline and after 3 years. Following parameters were considered: thickness of the central macula, retinal nerve fiber layer, ganglion cell (GCL+/GCL++) complex; perfusion and vessel density and fractal dimension at the superficial and deep capillary plexuses; choriocapillaris flow deficits; and foveal avascular zone metrics. MATLAB and ImageJ were used for optical coherence tomography angiography scans analyses.

RESULTS

The mean HbA1c was 7.4 ± 0.8% in DM1 and 7.2 ± 0.8% in DM2 at baseline, with no change at 3 years. No eye developed diabetic retinopathy. In longitudinal analyses, perfusion density at superficial capillary plexuses ( P = 0.03) and foveal avascular zone area and perimeter ( P < 0.0001) significantly increased in DM2 compared with other groups. No longitudinal changes occurred in optical coherence tomography parameters. In comparisons within groups, DM2 had a significant thinning of GCL++ in the outer ring, decreased perfusion density at deep capillary plexuses and choriocapillaris flow deficits, and increase in foveal avascular zone perimeter and area in deep capillary plexuses; DM1 had an increase in foveal avascular zone perimeter in deep capillary plexuses ( P < 0.001 for all comparisons).

CONCLUSION

Longitudinal data showed significant microvascular retinal changes in DM2. No changes were detected in neuronal parameters and in DM1. Longer and larger studies are needed to confirm these preliminary data.

Competing risks analysis for neutrophil to lymphocyte ratio as a predictor of diabetic retinopathy incidence in the Scottish population

BACKGROUND

Diabetic retinopathy (DR) is a major sight-threatening microvascular complication in individuals with diabetes. Systemic inflammation combined with oxidative stress is thought to capture most of the complexities involved in the pathology of diabetic retinopathy. A high level of neutrophil-lymphocyte ratio (NLR) is an indicator of abnormal immune system activity. Current estimates of the association of NLR with diabetes and its complications are almost entirely derived from cross-sectional studies, suggesting that the nature of the reported association may be more diagnostic than prognostic. Therefore, in the present study, we examined the utility of NLR as a biomarker to predict the incidence of DR in the Scottish population.

METHODS

The incidence of DR was defined as the time to the first diagnosis of R1 or above grade in the Scottish retinopathy grading scheme from type 2 diabetes diagnosis. The effect of NLR and its interactions were explored using a competing risks survival model adjusting for other risk factors and accounting for deaths. The Fine and Gray subdistribution hazard model (FGR) was used to predict the effect of NLR on the incidence of DR.

RESULTS

We analysed data from 23,531 individuals with complete covariate information. At 10 years, 8416 (35.8%) had developed DR and 2989 (12.7%) were lost to competing events (death) without developing DR and 12,126 individuals did not have DR. The median (interquartile range) level of NLR was 2.04 (1.5 to 2.7). The optimal NLR cut-off value to predict retinopathy incidence was 3.04. After accounting for competing risks at 10 years, the cumulative incidence of DR and deaths without DR were 50.7% and 21.9%, respectively. NLR was associated with incident DR in both Cause-specific hazard (CSH = 1.63; 95% CI: 1.28-2.07) and FGR models the subdistribution hazard (sHR = 2.24; 95% CI: 1.70-2.94). Both age and HbA1c were found to modulate the association between NLR and the risk of DR.

CONCLUSIONS

The current study suggests that NLR has a promising potential to predict DR incidence in the Scottish population, especially in individuals less than 65 years and in those with well-controlled glycaemic status.

Macular Thickness Fluctuations in Eyes With Diabetic Macular Edema Treated With Intravitreal Steroid

BACKGROUND AND OBJECTIVE

Macular thickness fluctuations (MTF) over time may be more predictive of visual outcomes than absolute macular thickness in patients with diabetic macular edema (DME) treated with anti-vascular endothelial growth factor (anti-VEGF). It is unclear whether this association exists in DME patients treated with intravitreal steroids or whether steroids confer reduced MTF versus anti-VEGF treatments.

PATIENTS AND METHODS

MTF was compared before and after initiation of steroids in DME patients treated with intravitreal steroids. A mixed-effects linear regression model was used to determine the association between MTF and best-corrected visual acuity (BCVA).

RESULTS

Mean 12-month MTF significantly decreased after steroid initiation (61.1 μm versus 53.5 μm, P = 0.04, n = 105 eyes). Mean BCVA after 12 months was not significantly different from baseline. No significant association between post-steroid MTF and 12-month BCVA was found.

CONCLUSION

Steroid treatment decreases MTF while BCVA remains stable in DME patients previously treated with anti-VEGF. [Ophthalmic Surg Lasers Imaging Retina 2023;54:454-460.].

Retinal Photoreceptors and Microvascular Changes in the Assessment of Diabetic Retinopathy Progression: A Two-Year Follow-Up Study

BACKGROUND

With the increasing global incidence of diabetes mellitus (DM), diabetic retinopathy (DR) has become one of the leading causes of blindness in developed countries. DR leads to changes in retinal neurons and microcirculation. Rtx1TM (Imagine Eyes, Orsay, France) is a retinal camera that allows histological visualisations of cones and retinal microcirculation throughout the DM duration.

OBJECTIVE

This study aimed to analyse the cones and retinal microvascular changes in 50 diabetic individuals and 18 healthy volunteers. The patients participated in the initial visit and two follow-up appointments, one and two years after the study, beginning with Rtx1TM image acquisition, visual acuity assessment, macular OCT scans and blood measurements.

RESULTS

The study revealed significant differences in the cone density, mosaic arrangement and vascular morphology between healthy and diabetic patients. The final measurements showed decreased photoreceptor and microvascular parameters in the DR group compared with the control group. Furthermore, in the 2-year follow-up, both groups' Rtx1TM-acquired morphological changes were statistically significant.

CONCLUSIONS

Rtx1TM technology was successfully used as a non-invasive method of photoreceptors and retinal vasculature assessment over time in patients with diabetic retinopathy. The study revealed a trend toward more vascular morphological changes occurring over time in diabetic patients.

Assessment of Prevalence and Risk Factors for Diabetic Retinopathy in Patients with Type 1 and Type 2 Diabetes Examined at a Tertiary Care

Introduction: Diabetic retinopathy (DR) is a microvascular complication of diabetes mellitus and the leading cause of visual impairment and blindness. The aim of the study was to estimate and compare the prevalence of DR and to determine an association between DR and systemic risk factors in hospitalized type 1 (DMT1) and type 2 (DMT2) diabetic patients. Material and methods: We analyzed 260 patients with diabetes, 43 with DMT1 and 217 with DMT2. The following data were collected: age, gender, type and duration of diabetes, glycemic control, blood pressure, estimated glomerular filtration rate, ophthalmologic examinations and routine biochemical parameters. Results: Out of the total number of 260 patients, 77 (29.6%) had non-proliferative DR (NPDR), 21 (8.1%) had proliferative DR (PDR), 29 (11.1%) had diabetic macular edema (DME), and 69 (23.5%) had diabetic cataracts. Forty-three (16.5%) patients were previously diagnosed with DMT1 and 217 (83.5%) with DMT2. The duration of diabetes was not significantly longer in DMT1 (12.8±11.2 years) in comparison to DMT2 (11.07±8.1 years). The prevalence of NPDR and PDR did not differ statistically in either groups. DME was more prevalent in DMT2 than in DMT1 (P<0.05). Diabetic cataract was found in 26.7% vs. 6.7% of patients with DMT2 and DMT1, respectively (p<0.01). The duration of diabetes significantly correlated with NPDR and PDR in DMT1 (r=o.31, p<0.05; r=0.55, p<0.001, respectively). In DMT2, significant correlations were found between the duration of diabetes and cataract, NPDR, PDR and DME (r=0.31, p<0.001; r=0.43 p<0.01, r=0.16 p<0.05 and r=0.20 p<0.01, respectively). Fasting plasma glucose (FPG) significantly correlated with PDR (r=0.258, p<0.05), while HbA1c with DME (r= 0.15 p<0.05). Conclusion: The duration of diabetes and hyperglycemia were associated with DR in both types of diabetes.

Assessment of Parafoveal Diabetic Macular Ischemia on Optical Coherence Tomography Angiography Images to Predict Diabetic Retinal Disease Progression and Visual Acuity Deterioration

Importance

The presence of diabetic macular ischemia (DMI) on optical coherence tomography angiography (OCTA) images predicts diabetic retinal disease progression and visual acuity (VA) deterioration, suggesting an OCTA-based DMI evaluation can further enhance diabetic retinopathy (DR) management.

Objective

To investigate whether an automated binary DMI algorithm using OCTA images provides prognostic value on DR progression, diabetic macular edema (DME) development, and VA deterioration in a cohort of patients with diabetes.

Design, Setting, and Participants

In this cohort study, DMI assessment of superficial capillary plexus and deep capillary plexus OCTA images was performed by a previously developed deep learning algorithm. The presence of DMI was defined as images exhibiting disruption of fovea avascular zone with or without additional areas of capillary loss, while absence of DMI was defined as images presented with intact fovea avascular zone outline and normal distribution of vasculature. Patients with diabetes were recruited starting in July 2015 and were followed up for at least 4 years. Cox proportional hazards models were used to evaluate the association of the presence of DMI with DR progression, DME development, and VA deterioration. Analysis took place between June and December 2022.

Main Outcomes and Measures

DR progression, DME development, and VA deterioration.

Results

A total of 321 eyes from 178 patients were included for analysis (85 [47.75%] female; mean [SD] age, 63.39 [11.04] years). Over a median (IQR) follow-up of 50.41 (48.16-56.48) months, 105 eyes (32.71%) had DR progression, 33 eyes (10.28%) developed DME, and 68 eyes (21.18%) had VA deterioration. Presence of superficial capillary plexus-DMI (hazard ratio [HR], 2.69; 95% CI, 1.64-4.43; P < .001) and deep capillary plexus-DMI (HR, 3.21; 95% CI, 1.94-5.30; P < .001) at baseline were significantly associated with DR progression, whereas presence of deep capillary plexus-DMI was also associated with DME development (HR, 4.60; 95% CI, 1.15-8.20; P = .003) and VA deterioration (HR, 2.12; 95% CI, 1.01-5.22; P = .04) after adjusting for age, duration of diabetes, fasting glucose, glycated hemoglobin, mean arterial blood pressure, DR severity, ganglion cell-inner plexiform layer thickness, axial length, and smoking at baseline.

Conclusions and Relevance

In this study, the presence of DMI on OCTA images demonstrates prognostic value for DR progression, DME development, and VA deterioration.

Comparison of the Effectiveness of Intravitreal Bevacizumab Injections with and without Simultaneous Cataract Surgery in Diabetic Patients with Macular Edema

Intravitreal bevacizumab (IVB), often injected during cataract surgery, is currently the main treatment for diabetic macular edema. This retrospective study aimed to compare the effectiveness of IVB injections alone and during cataract surgery in patients with diabetic macular edema. We examined 43 eyes in 40 patients who underwent cataract surgery with simultaneous IVB injections 3-12 months after IVB injections alone. Best-corrected visual acuity and central subfield macular thickness (CMT) were measured 1-month post-injection. The CMTs of the same eyes with IVB-only first and combined-treatment procedures later were 384 ± 149 vs. 315 ± 109 μm pretreatment (p = 0.0002), and after 1 month, they were 319 ± 102 vs. 419 ± 183 μm (p < 0.0001). In the IVB-only procedure, 56.1% of eyes had CMT < 300 μm 1 month after the injection compared to 32.5% after the combined treatment. Therefore, on average, when IVB was administered during cataract surgery, CMT increased, whereas after IVB injection alone, it effectively decreased. More prospective trials with large sample sizes are needed to evaluate the effectiveness of IVB injection performed simultaneously with cataract surgery.

Determinants of diabetic retinopathy in Ethiopia: A systematic review and meta-analysis

INTRODUCTION

Diabetic retinopathy (DR) is the primary retinal vascular complication of diabetes mellitus and a leading cause of visual impairment and blindness. It affects the global diabetic population. In Ethiopia, about one-fifth of diabetic patients were affected by DR, but there were inconsistent finding across studies about the determinants factors of DR. Therefore, we aimed to identify the risk factors for DR among diabetic patients.

METHODS

We have accessed previous studies through an electronic web-based search strategy using PubMed, Google (Scholar), the Web of Science, and the Cochrane Library with a combination of search terms. The quality of each included article was assessed using the Newcastle Ottawa Assessment Scale. All statistical analyses were carried out using Stata version 14 software. The odds ratios of risk factors were pooled using a fixed-effect meta-analysis model. Heterogeneity was assessed using the Cochrane Q statistics and I-Square (I2). Furthermore, publication bias was detected based on the graphic asymmetry test of the funnel plot and/or Egger's test (p< 0.05).

RESULTS

The search strategy retrieved 1285 articles. After the removal of duplicate articles, 249 articles remained. Following further screening, about 18 articles were assessed for eligibility, of which three articles were excluded because of reporting without the outcome of interest, poor quality, and not full text. Finally, fifteen studies were reviewed for the final analysis. Co-morbid hypertension (HTN) (AOR 2.04, 95%CI: 1.07, 3.89), poor glycemic control (AOR = 4.36, 95%CI: 1.47, 12.90), and duration of diabetes illness (AOR = 3.83, 95%CI: 1.17, 12.55) were found to be confirmed associated factors of diabetic retinopathy.

CONCLUSION

In this study, co-morbid HTN, poor glycemic control, and longer duration of diabetes illness were found to be the determinant factors of DR. Aggressive treatment of co-morbid HTN and blood glucose, and regular eye screening should be implemented to reduce the occurrence of DR.

TRIAL REGISTRATION

The review protocol was registered in the international prospective register of systematic reviews (PROSPERO) with registration number PROSPERO: CRD42023416724.

New Insights on Dietary Polyphenols for the Management of Oxidative Stress and Neuroinflammation in Diabetic Retinopathy

Diabetic retinopathy (DR) is a neurodegenerative and vascular pathology that is considered one of the leading causes of blindness worldwide, resulting from complications of advanced diabetes mellitus (DM). Current therapies consist of protocols aiming to alleviate the existing clinical signs associated with microvascular alterations limited to the advanced disease stages. In response to the low resolution and limitations of the DR treatment, there is an urgent need to develop more effective alternative therapies to optimize glycemic, vascular, and neuronal parameters, including the reduction in the cellular damage promoted by inflammation and oxidative stress. Recent evidence has shown that dietary polyphenols reduce oxidative and inflammatory parameters of various diseases by modulating multiple cell signaling pathways and gene expression, contributing to the improvement of several chronic diseases, including metabolic and neurodegenerative diseases. However, despite the growing evidence for the bioactivities of phenolic compounds, there is still a lack of data, especially from human studies, on the therapeutic potential of these substances. This review aims to comprehensively describe and clarify the effects of dietary phenolic compounds on the pathophysiological mechanisms involved in DR, especially those of oxidative and inflammatory nature, through evidence from experimental studies. Finally, the review highlights the potential of dietary phenolic compounds as a prophylactic and therapeutic strategy and the need for further clinical studies approaching the efficacy of these substances in DR management.

Angiographic biomarkers are significant predictors of treatment response to intravitreal aflibercept in diabetic macular edema

This prospective single-center study aims to identify biomarkers that predict improvement in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) at 6 months, in 76 eyes with diabetic macular edema (DME) treated monthly with intravitreal aflibercept. At baseline, all patients underwent standardized imaging with color photography, optical coherence tomography (OCT), fluorescein angiography (FA) and OCT angiography (OCTA). Glycosylated hemoglobin, renal function, dyslipidemia, hypertension, cardiovascular disease and smoking were recorded. Retinal images were graded in a masked fashion. Baseline imaging, systemic and demographic variables were investigated to detect associations to BCVA and CRT change post aflibercept. Predictors of BCVA improvement included greater macular vessel density quantified using OCTA (p = 0.001) and low-density lipoprotein (LDL) ≥ 2.6 mmol/L (p = 0.017). Lower macular vessel density eyes showed a significant reduction in CRT but no BCVA improvement. Predictors of CRT reduction included peripheral non-perfusion seen on ultrawide-field FA (p = 0.005) and LDL ≥ 2.6 mmol/L (p < 0.001). Retinal angiographic biomarkers derived from OCTA and ultrawide-field FA may help predict functional and anatomic response to anti-vascular endothelial growth factor (VEGF) therapy in patients with DME. Elevated LDL is associated with treatment response in DME. These results may be used to better-select patients who will benefit from intravitreal aflibercept for treatment of DME.

Development and Validation of a Diabetic Retinopathy Risk Stratification Algorithm

OBJECTIVE

Although diabetic retinopathy is a leading cause of blindness worldwide, diabetes-related blindness can be prevented through effective screening, detection, and treatment of disease. The study goal was to develop risk stratification algorithms for the onset of retinal complications of diabetes, including proliferative diabetic retinopathy, referable retinopathy, and macular edema.

RESEARCH DESIGN AND METHODS

Retrospective cohort analysis of patients from the Kaiser Permanente Northern California Diabetes Registry who had no evidence of diabetic retinopathy at a baseline diabetic retinopathy screening during 2008-2020 was performed. Machine learning and logistic regression prediction models for onset of proliferative diabetic retinopathy, diabetic macular edema, and referable retinopathy detected through routine screening were trained and internally validated. Model performance was assessed using area under the curve (AUC) metrics.

RESULTS

The study cohort (N = 276,794) was 51.9% male and 42.1% White. Mean (±SD) age at baseline was 60.0 (±13.1) years. A machine learning XGBoost algorithm was effective in identifying patients who developed proliferative diabetic retinopathy (AUC 0.86; 95% CI, 0.86-0.87), diabetic macular edema (AUC 0.76; 95% CI, 0.75-0.77), and referable retinopathy (AUC 0.78; 95% CI, 0.78-0.79). Similar results were found using a simpler nine-covariate logistic regression model: proliferative diabetic retinopathy (AUC 0.82; 95% CI, 0.80-0.83), diabetic macular edema (AUC 0.73; 95% CI, 0.72-0.74), and referable retinopathy (AUC 0.75; 95% CI, 0.75-0.76).

CONCLUSIONS

Relatively simple logistic regression models using nine readily available clinical variables can be used to rank order patients for onset of diabetic eye disease and thereby more efficiently prioritize and target screening for at risk patients.

A Pilot Study of Implementing Diabetic Retinopathy Screening in the Oslo Region, Norway: Baseline Results

PURPOSE

to gain insight into the baseline parameters of a population with diabetes mellitus (DM) included in a pilot diabetic retinopathy (DR) screening program at Oslo University Hospital (OUH), Norway.

METHODS

This was a cross-sectional study of a cohort of adult patients (≥18 years) with type 1 or 2 DM (T1D and T2D). We measured the best-corrected visual acuity (BCVA), blood pressure (BP), heart rate (HR), intraocular pressure (IOP), height and weight. We also collected HbA1c, total serum cholesterol and urine-albumin, -creatinine and -albumin-to-creatinine ratio (ACR), as well as socio-demographic parameters, medications and previous screening history. We obtained color fundus photographs, which were graded by two experienced ophthalmologists according to the International Clinical Disease Severity Scale for DR.

RESULTS

The study included 180 eyes of 90 patients: 12 patients (13.3%) had T1D and 78 (86.7%) had T2D. In the T1D group, 5 patients (41.7%) had no DR, and 7 (58.3%) had some degree of DR. In the T2D group, 60 patients (76.9%) had no DR, and 18 (23.1%) had some degree of DR. None of the patients had proliferative DR. Of the 43 patients not newly diagnosed (time of diagnosis > 5 years for T1D and >1 years for T2D), 37.5% of the T1D patients and 5.7% of the T2D patients had previously undergone regular screening. Univariate analyses found for the whole cohort significant associations between DR and age, HbA1c, urine albumin-to-creatinine ratio, body mass index (BMI) and duration of DM. For the T2D group alone, there were significant associations between DR and HbA1c, BMI, urine creatinine, urine albumin-to-creatinine ratio and duration of DM. The analysis also showed three times higher odds for DR in the T1D group than the T2D group.

CONCLUSIONS

This study underscores the need for implementing a systematic DR screening program in the Oslo region, Norway, to better reach out to patients with DM and improve their screening adherence. Timely and proper treatment can prevent or mitigate vision loss and improve the prognosis. A considerable number of patients were referred from general practitioners for not being followed by an ophthalmologist.Among patients not newly diagnosed with DM, 62.8% had never had an eye exam, and the duration of DM for these patients was up to 18 years (median: 8 years).

Choriocapillaris Flow Deficit as a Biomarker for Diabetic Retinopathy and Diabetic Macular Edema: 3-Year Longitudinal Cohort

PURPOSE

To investigate the relationship between choriocapillaris flow deficit percentage (CC FD%) by swept-source optical coherence tomography angiography (SS-OCTA) and 3-year risk of diabetic retinopathy (DR) progression and diabetic macular edema (DME) development.

DESIGN

Prospective, observational cohort study.

METHODS

A total of 903 participants with type 2 diabetes mellitus (T2DM) without DR or with mild nonproliferative DR (NPDR) free of DME at baseline were followed up annually for 3 years. All participants underwent standard 7-field fundus photography and spectral-domain OCT. SS-OCTA was used for retinal and choriocapillaris imaging and 3 × 3-mm2 macular CC FD% was quantified. Univariate and multivariate logistic models were used to evaluate the association between CC FD% and 2 or more steps of DR progression and DME development. The additional predictive value of CC FD% for outcome events was assessed using C statistic, net reclassification index (NRI), and integrated discrimination improvement index (IDI).

RESULTS

Over 3 years, 295 of 1805 eyes (16.34%) developed DR progression, and 118 eyes (6.54%) developed DME. A higher average CC FD% was correlated with DR progression (odds ratio [OR], 3.41 per SD increase, 95% CI: 2.65-4.39, P < .001) and DME development (OR, 1.37 per SD increase, 95% CI: 1.06-1.77, P = .016) after adjusting for confounders. In the ETDRS regions, increased CC FD% in all fields was associated with DR progression; however, increased CC FD% in the inferior field was associated with DME development. Compared with the models based on established risk factors, the addition of average CC FD% significantly improved the C statistics for DR progression (0.712 to 0.777, P < .001) and DME occurrence (0.743 to 0.773, P = .044). The estimated NRIs and IDIs (all >0) indicated that the addition of CC FD% led to a significant improvement in the discriminative performance for end points.

CONCLUSION

CC FD% is independently associated with DR progression and DME development in the Chinese T2DM population and provides incremental predictive value beyond traditional risk factors and retinal microvascular parameters. Further inclusion of CC FD% in DR prediction models helps guide population-based screening and personalized management.

Association between Systemic Factors and Vitreous Fluid Cytokines in Proliferative Diabetic Retinopathy

Proliferative diabetic retinopathy (PDR) is a vision-threatening complication of diabetes mellitus (DM). Systemic and intraocular factors are intricately related to PDR, and vitreous fluid (VF) cytokines are representative intraocular biomarkers. However, the associations between systemic factors and VF cytokines and their influence on PDR pathology are unclear. This study aimed to examine the correlation between systemic factors and VF cytokines and analyze their contributions to the pathology of PDR using multivariate analyses. We conducted a retrospective observational study on 26 PDR eyes of 25 patients with type 2 DM, and 30 eyes of 30 patients with idiopathic macular hole or epiretinal membrane as controls. Fifteen systemic and laboratory tests including blood pressure (BP) and body mass index (BMI), and 27 cytokines in VF were analyzed. BP and BMI correlated positively with VF levels of IL-6 and IP-10 in PDR patients, while no significant correlation was found between systemic factors and VF cytokines in controls. MCP-1 and VEGF-A in VF separately clustered with different systemic factors in controls, but these cytokines lost the property similarity with systemic factors and acquired property similarity with each other in PDR. Systemic factors contributed to only 10.4%, whereas VF cytokines contributed to 42.3% out of 52.7% variance of the whole PDR dataset. Our results suggest that intraocular factors play a major role in the pathology of PDR, whereas systemic factors may have limited effects, and that BP and BMI control in PDR could be useful interventions to improve intraocular immune condition.

Secular trends in the prevalence, incidence, and progression of diabetic retinopathy: the Hisayama Study

PURPOSE

To examine the secular trends in the prevalence, incidence, and progression rates of diabetic retinopathy (DR) in a Japanese community.

METHODS

Community-dwelling Japanese residents aged ≥ 40 years with diabetes participated in comprehensive systemic and ophthalmological surveys, including an examination for DR, in 1998 (n = 220), 2007 (n = 511), 2012 (n = 515), and 2017 (n = 560). DR was assessed using colour fundus photographs after pupil dilation according to the modified Airlie House classification system. To compare the frequencies of newly developed or progressed DR between the studied decades, two eye cohorts were established (the 2000s cohort included 145 participants examined in 1998 and 2007; the 2010s cohort included 255 participants examined in 2007, 2012, and 2017). Trends in the prevalence, incidence, and progression rate of DR were tested by logistic regression analysis with a generalised estimating equation.

RESULTS

The age-adjusted prevalence of DR among individuals with diabetes decreased significantly with time from 1998 to 2017 (27.4% in 1998, 22.8% in 2007, 12.8% in 2012, and 6.4% in 2017; p for trend < 0.001). During this period, the prevalence of DR was decreasing in every haemoglobin A_1c category, but it remained constant in the high systolic blood pressure category. In addition, the rates of new-onset of DR were significantly lower in the 2010s compared to the 2000s (p < 0.001).

CONCLUSION

Our findings suggest that the prevalence and incidence of DR among diabetic people significantly decreased with time over the past two decades in a general Japanese population.

Quantification of risk factors for diabetic retinopathy progression

AIMS

To determine the importance of blood sugar control, blood pressure, and other key systemic factors on the risk of progression from no retinopathy to various stages of diabetic retinopathy.

METHODS

Restrospective cohort analysis of patients (N = 99, 280) in the Kaiser Permanente Northern California healthcare system with a baseline retina photographic screening showing no evidence of retinopathy and a minimum follow-up surveillance period of 3 years from 2008 to 2019. We gathered longitudinal data on diabetic retinopathy progression provided by subsequent screening fundus photographs and data captured in the electronic medical record over a mean surveillance of 7.3 ± 2.2 (mean ± SD) years. Progression from an initial state of no diabetic retinopathy to any of four outcomes was determined: (1) any incident retinopathy, (2) referable (moderate or worse) retinopathy, (3) diabetic macular edema, and (4) proliferative diabetic retinopathy. Multiple predictors, including age, race, gender, glycosylated hemoglobin (HbA1c), systolic blood pressure (SBP), cholesterol, chronic renal disease, and type of diabetes were investigated.

RESULTS

Among modifiable risk factors, the average HbA1c had the strongest impact on the progression of diabetic retinopathy, followed by average SBP control and total cholesterol. Patients with an average HbA1c of 10.0% or greater (≥ 97 mmol/mol) had a risk ratio of 5.72 (95% CI 5.44-6.02) for progression to any retinopathy, 18.84 (95% CI 17.25-20.57) for referable retinopathy, 22.85 (95% CI 18.87-27.68) for diabetic macular edema, and 25.96 (95% CI 18.75-36.93) for proliferative diabetic retinopathy compared to those with an average HbA1c of 7.0% (53 mmol/mol) or less. Non-white patients generally had a higher risk of progression to all forms of diabetic retinopathy, while Asian patients were less likely to develop diabetic macular edema (HR 0.76, 95% CI 0.66-0.87).

CONCLUSIONS

We confirm the critical importance of glucose control as measured by HbA1c on the risk of development of diabetic retinopathy.