Risk factors associated with diabetic macular edema

Development and validation of a simple and practical model for early detection of diabetic macular edema in patients with type 2 diabetes mellitus using easily accessible systemic variables

OBJECTIVE

Diabetic macular edema (DME) is the leading cause of visual impairment in patients with diabetes mellitus (DM). The goal of early detection has not yet achieved due to a lack of fast and convenient methods. Therefore, we aim to develop and validate a prediction model to identify DME in patients with type 2 diabetes mellitus (T2DM) using easily accessible systemic variables, which can be applied to an ophthalmologist-independent scenario.

METHODS

In this four-center, observational study, a total of 1994 T2DM patients who underwent routine diabetic retinopathy screening were enrolled, and their information on ophthalmic and systemic conditions was collected. Forward stepwise multivariable logistic regression was performed to identify risk factors of DME. Machine learning and MLR (multivariable logistic regression) were both used to establish prediction models. The prediction models were trained with 1300 patients and prospectively validated with 104 patients from Guangdong Provincial People's Hospital (GDPH). A total of 175 patients from Zhujiang Hospital (ZJH), 115 patients from the First Affiliated Hospital of Kunming Medical University (FAHKMU), and 100 patients from People's Hospital of JiangMen (PHJM) were used as external validation sets. Area under the receiver operating characteristic curve (AUC), accuracy (ACC), sensitivity, and specificity were used to evaluate the performance in DME prediction.

RESULTS

The risk of DME was significantly associated with duration of DM, diastolic blood pressure, hematocrit, glycosylated hemoglobin, and urine albumin-to-creatinine ratio stage. The MLR model using these five risk factors was selected as the final prediction model due to its better performance than the machine learning models using all variables. The AUC, ACC, sensitivity, and specificity were 0.80, 0.69, 0.80, and 0.67 in the internal validation, and 0.82, 0.54, 1.00, and 0.48 in prospective validation, respectively. In external validation, the AUC, ACC, sensitivity and specificity were 0.84, 0.68, 0.90 and 0.60 in ZJH, 0.89, 0.77, 1.00 and 0.72 in FAHKMU, and 0.80, 0.67, 0.75, and 0.65 in PHJM, respectively.

CONCLUSION

The MLR model is a simple, rapid, and reliable tool for early detection of DME in individuals with T2DM without the needs of specialized ophthalmologic examinations.

The Impact of New and Renewed Restrictive State Abortion Laws on Pregnancy-Capable People with Diabetes

PURPOSE OF REVIEW

When the Supreme Court handed down its decision in Dobbs v Jackson Women's Health Organization in June 2022, the constitutional right to abortion was no longer protected by Roe v Wade. Fifteen states now have total or near-total bans on abortion care or no clinics providing abortion services. We review how these restrictions affect the medical care of people with pregestational diabetes.

RECENT FINDINGS

Of the ten states with the highest percent of adult women living with diabetes, eight currently have complete or 6-week abortion bans. People with diabetes are at high risk of diabetes-related pregnancy complications and pregnancy-related diabetes complications and are disproportionately burdened by abortion bans. Abortion is an essential part of comprehensive, evidence-based diabetes care, yet no medical society has published guidelines on pregestational diabetes that explicitly discuss the importance and role of safe abortion care. Medical societies enacting standards for diabetes care and clinicians providing diabetes care must advocate for access to abortion to reduce pregnancy-related morbidity and mortality for pregnant people with diabetes.

Serum apolipoprotein A1 and B are associated with 6-month persistent and incident diabetic macular oedema in type 2 diabetes

AIMS

To investigate the associations of baseline apolipoprotein A1 (ApoA1) and B (ApoB) levels with persistent and incident diabetic macular oedema (DMO) after 6 months of follow-up.

METHODS

This is a prospective cohort study of patients aged ≥30 years with untreated diabetic retinopathy. Examinations, fundus photography and spectral domain optical coherence tomography (SD-OCT) were assessed at baseline, 1, 3 and 6 months. Serum lipids and apolipoproteins were analysed at a pathology laboratory. DMO was confirmed using SD-OCT, classified as (1) incident DMO, (2) persistent DMO and (3) regressed DMO. Eye-specific data were used, controlling for covariates and cluster effect.

RESULTS

We recruited 53 patients but only 38 completed the study [(62 eyes), 20 eyes (32.3%) with DMO]. Higher quartile of ApoA1 was associated with lower risk of persistent/incident DMO (p for trend 0.02), while higher ApoB/A1 was associated with higher risk of persistent/incident DMO (p for trend 0.02). Every 10 mg/dL increase in ApoA1 levels was associated with lower risk of persistent/incident DMO (OR 0.69; 95% CI 0.49 to 0.92; p value 0.016), whereas every 0.2 increase in ApoB/A1 was significantly associated with higher risk of persistent/incident DMO (OR 1.4; 95% CI 1.1 to 1.9; p value 0.013) at the end of the study.

CONCLUSION

Individuals with diabetes with higher ApoA1 had lower risk of persistent/incident DMO and those with higher ApoB/A1 had higher risk of persistent/incident DMO at the end of 6 months. These suggest that serum ApoA1 and ApoB/A1 levels may be important risk factors for DMO and could be predictive of persistent/incident DMO despite anti-vascular endothelial growth factor treatment.

Factors Associated with Fluctuations in Central Subfield Thickness in Patients with Diabetic Macular Edema Using Diabetic Retinopathy Clinical Research Protocols T and V

PURPOSE

To identify baseline ocular and systemic factors associated with central subfield thickness (CST) fluctuations in patients with diabetic macular edema (DME) using data from Diabetic Retinopathy Clinical Research Protocols T and V.

DESIGN

Post hoc analysis of clinical trial databases.

SUBJECTS

Patients in Protocols T and V.

METHODS

The standard deviation (SD) of all recorded CSTs for each patient during each Protocol's study period was calculated. The CST SD (corresponding to CST fluctuations) for each patient was analyzed against baseline ocular and systemic factors using linear regression analyses. Each Protocol was analyzed separately.

MAIN OUTCOME MEASURES

Factors associated with CST fluctuations.

RESULTS

A total of 1197 eyes of 1197 subjects were included. In Protocol T (559 eyes, mean CST SD was 56.4 ± 35.1 microns), using multivariate linear regression analysis, baseline urine albumin/creatine ratio (for every 1000 mg/g, CST point estimate 3.50, 95% confidence interval [CI] 0.58 to 6.43, P = 0.0190), and baseline CST (for every 10 microns, 0.87, 95% CI 0.58 to 1.16, P < 0.0001) were positively associated with CST fluctuations. Baseline visual acuity (for every 10 ETDRS letters, -9.52, 95% CI -11.89 to -7.15, P < 0.0001) was negatively associated with CST fluctuations. In Protocol V (638 eyes, mean CST SD 36.6 ± 28.4 microns), gender (female, 2.18, 95% CI 0.30 to 4.06, P = 0.0227), baseline CST (for every 10 microns, 2.51, 95% CI 2.21 to 2.82, P < 0.0001), systolic blood pressure (for every 1 mm of mercury, 0.11, 95% CI 0.01 to 0.21, P = 0.0261), and observation with deferred anti-VEGF injections (5.04, 95% CI 2.51 to 7.58, P < 0.0001) were positively associated with CST fluctuations. Type 2 diabetes (-7.37, 95% CI -13.64 to -1.11, P = 0.0209) and prompt anti-VEGF injections (-6.51, 95% CI -9.07 to -3.96, P < 0.0001) were negatively associated with CST fluctuations.

CONCLUSIONS

Worse visual acuity at baseline, baseline renal disease, hypertension, female gender, type 1 diabetes, and delayed anti-VEGF treatment may be associated with increased CST fluctuations in patients with DME. Addressing these parameters may limit CST fluctuations and help identify patients requiring more frequent monitoring or treatment.

Diabetic Macular Oedema Guidelines: An Australian Perspective

The number of people living with diabetes is expected to rise to 578 million by 2030 and to 700 million by 2045, exacting a severe socioeconomic burden on healthcare systems around the globe. This is also reflected in the increasing numbers of people with ocular complications of diabetes (namely, diabetic macular oedema (DMO) and diabetic retinopathy (DR)). In one study examining the global prevalence of DR, 35% of people with diabetes had some form of DR, 7% had PDR, 7% had DMO, and 10% were affected by these vision-threatening stages. In many regions of the world (Australia included), DR is one of the top three leading causes of vision loss amongst working age adults (20-74 years). In the management of DMO, the landmark ETDRS study demonstrated that moderate visual loss, defined as doubling of the visual angle, can be reduced by 50% or more by focal/grid laser photocoagulation. However, over the last 20 years, antivascular endothelial growth factor (VEGF) and corticosteroid therapies have emerged as alternative options for the management of DMO and provided patients with choices that have higher chances of improving vision than laser alone. In Australia, since the 2008 NHMRC guidelines, there have been significant developments in both the treatment options and treatment schedules for DMO. This working group was therefore assembled to review and address the current management options available in Australia.

Reduced serum magnesium is associated with the occurrence of diabetic macular edema in patients with diabetic retinopathy: A retrospective study

Serum magnesium levels have been reported to reflect the risk of diabetic retinopathy (DR); however, the effect of serum magnesium level on diabetic macular edema (DME) remains unclear. Here, we investigated the association between the serum magnesium levels and DME in patients with DR. Patients with DR were recruited between January 2018 and June 2021. A total of 519 such patients were included in this study. All patients underwent a standardized clinical ophthalmic examination by an experienced ophthalmologist, and an assay was conducted to determine the serum magnesium concentration. Compared with the non-DME group, the DME group had a higher proportion of insulin use and a higher level of serum ischemia-modified albumin and fasting plasma glucose. The serum magnesium and calcium levels were lower in the DME group than in the non-DME group (P &lt; 0.05). Higher magnesium levels were negatively associated with DME after adjustment for relevant covariates. Compared with the participants in the lowest magnesium quartile, those in the fourth quartile showed a significantly lower risk of DME after adjustment [odds ratio (OR), 0.294; 95% confidence interval, 0.153–0.566; P &lt; 0.0001]. Considering the potentially different effects of serum magnesium on the development of DME in patients with DR based on age, DR staging and insulin use, stratified analysis was performed by considering these factors. Among insulin-using patients with non-proliferative DR who were &lt; 66 years of age, those in the third and fourth quartile of serum magnesium were less likely to develop DME than those in the lowest quartile of serum magnesium [OR (95% CI), 0.095 (0.014–0.620), 0.057 (0.011–0.305); P = 0.014, 0.001]. Overall, a higher serum magnesium level was associated with a lower risk of DME in patients with DR. Furthermore, patients with DR who used insulin were more likely to develop DME. Long-term studies on oral magnesium supplements are needed to determine whether maintaining the serum magnesium levels in a higher physiological range can reduce the risk of DME in patients with DR.

Optical coherence tomography findings in patients with transfusion-dependent β-thalassemia

BACKGROUND

Structural ophthalmologic findings have been reported in patients with β-thalassemia due to chronic anemia, iron overload, and iron chelation therapy toxicity in few previous studies. We aimed to investigate structural ocular findings and their relationship with hematological parameters in patients with transfusion-dependent β-thalassemia (TDT).

METHODS

In this cross-sectional study, from January 2018 to January 2019, 39 patients with TDT over the age of 18 participated. Multicolor fundus imaging, optical coherence tomography (OCT), and blue light fundus autofluorescence imaging were performed for all patients and 27 age- and sex-matched controls.

RESULTS

The mean age of patients was 28.6 ± 6.2 years. The central macular thickness and macular thicknesses in all quadrants were significantly thinner in patients than controls (P<0.05). None of the retinal nerve fiber layer (RNFL) measurements were significantly different between TDT patients and controls. There was a significantly negative correlation between hemoglobin with central macula thickness (r=-0.439, P=0.005). All measurements of macular subfield thickness were insignificantly thinner in patients with diabetes mellitus (DM) compared to the non-DM subgroup.

CONCLUSIONS

Macular thickness was significantly thinner in central macula and entire quadrants in TDT patients compared to healthy individuals; however, all RNFL measurement thicknesses were comparable between the two groups. Close monitoring of TDT patients by periodic ophthalmologic examinations with more focus on diabetic patients, patients with severe anemia and iron overload should be warranted.

Gene Biomarkers Related to Th17 Cells in Macular Edema of Diabetic Retinopathy: Cutting-Edge Comprehensive Bioinformatics Analysis and In Vivo Validation

Background

Previous studies have shown that T-helper 17 (Th17) cell-related cytokines are significantly increased in the vitreous of proliferative diabetic retinopathy (PDR), suggesting that Th17 cells play an important role in the inflammatory response of diabetic retinopathy (DR), but its cell infiltration and gene correlation in the retina of DR, especially in diabetic macular edema (DME), have not been studied.

Methods

The dataset GSE160306 was downloaded from the Gene Expression Omnibus (GEO) database, which contains 9 NPDR samples and 10 DME samples. ImmuCellAI algorithm was used to estimate the abundance of Th17 cells in 24 kinds of infiltrating immune cells. The differentially expressed Th17 related genes (DETh17RGs) between NPDR and DME were documented by difference analysis and correlation analysis. Through aggregate analyses such as gene ontology (GO) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway enrichment analysis, a protein-protein interaction (PPI) network was constructed to analyze the potential function of DETh17RGs. CytoHubba plug-in algorithm, Lasso regression analysis and support vector machine recursive feature elimination (SVM-RFE) were implemented to comprehensively identify Hub DETh17RGs. The expression archetypes of Hub DETh17RGs were further verified in several other independent datasets related to DR. The Th17RG score was defined as the genetic characterization of six Hub DETh17RGs using the GSVA sample score method, which was used to distinguish early and advanced diabetic nephropathy (DN) as well as normal and diabetic nephropathy. Finally, real-time quantitative PCR (qPCR) was implemented to verify the transcription levels of Hub DETh17RGs in the STZ-induced DR model mice (C57BL/6J).

Results

238 DETh17RGs were identified, of which 212 genes were positively correlated while only 26 genes were negatively correlated. Six genes (CD44, CDC42, TIMP1, BMP7, RHOC, FLT1) were identified as Hub DETh17RGs. Because DR and DN have a strong correlation in clinical practice, the verification of multiple independent datasets related to DR and DN proved that Hub DETh17RGs can not only distinguish PDR patients from normal people, but also distinguish DN patients from normal people. It can also identify the initial and advanced stages of the two diseases (NPDR vs DME, Early DN vs Advanced DN). Except for CDC42 and TIMP1, the qPCR transcription levels and trends of other Hub DETh17RGs in STZ-induced DR model mice were consistent with the human transcriptome level in this study.

Conclusion

This study will improve our understanding of Th17 cell-related molecular mechanisms in the progression of DME. At the same time, it also provides an updated basis for the molecular mechanism of Th17 cell crosstalk in the eye and kidney in diabetes.

The effect of insulin on response to intravitreal anti-VEGF injection in diabetic macular edema in type 2 diabetes mellitus

Objectives

To assess whether insulin therapy impacts the effectiveness of anti-vascular endothelial growth factor (anti-VEGF) injection for the treatment of diabetic macular edema (DME) in type 2 diabetes mellitus.

Methods

This was a retrospective multi-center analysis. The best-corrected visual acuity (BCVA) at 12 months, BCVA change, central macular thickness (CMT), CMT change, and cumulative injection number were compared between the insulin and the oral hypoglycemic agent (OHA) groups.

Results

The mean final BCVA and CMT improved in both the insulin (N = 137; p < 0.001; p < 0.001, respectively) and the OHA group (N = 61; p = 0.199; p < 0.001, respectively). The two treatment groups were comparable for final BCVA (p = 0.263), BCVA change (p = 0.184), final CMT (p = 0.741), CMT change (p = 0.458), and the cumulative injections received (p = 0.594). The results were comparable between the two groups when stratified by baseline vision (p > 0.05) and baseline HbA1c (p > 0.05).

Conclusion

Insulin therapy does not alter treatment outcomes for anti-VEGF therapy in DME.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02325-x.

Monoclonal antibodies in diabetic retinopathy

INTRODUCTION

Diabetic retinopathy (DR), as one of the main complications of diabetes, is among the leading causes of blindness and visual impairment worldwide.

AREAS COVERED

Current clinical therapies include photocoagulation, vitrectomy, and anti-vascular endothelial growth factor (VEGF) therapies. Bevacizumab and ranibizumab are two monoclonal antibodies (mAbs) inhibiting angiogenesis. Intravitreal ranibizumab and bevacizumab can decrease the rate of blindness and retinal thickness, and improve visual acuity whether as monotherapy or combined with other treatments. They can increase the efficacy of other treatments and decrease their adverse events. Although administered intravitreally, they also might enter the circulation and cause systemic effects. This study is aimed to review our current knowledge about mAbs, bevacizumab and ranibizumab, in DR including superiorities, challenges, and limitations. Meanwhile, we tried to shed light on new ideas to overcome these limitations. Our latest search was done in April 2021 mainly through PubMed and Google Scholar. Relevant clinical studies were imported.

EXPERT OPINION

Future direction includes detection of more therapeutic targets considering other components of DR pathophysiology and shared pathogenesis of DR and neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, the treat-and-extend regimen, and new ways of drug delivery and other routes of ocular drug administration.

Do serum vitamin D levels correlate with Macular Edema or with Diabetic Retinopathy?

PURPOSE

To compare serum vitamin D (25(OH)D) levels according to the presence of diabetic macular edema (DME) in Diabetes Mellitus (DM) patients with different retinopathy conditions.

METHODS

The files of all DM patients presenting for examination at the ophthalmology clinic between October 2018 and March 2020 were retrospectively examined. Data was collected from the files and included a comprehensive ophthalmological examination, laboratory results from fasting blood tests, and the internal medicine outpatient clinic examination. Patients were divided into two groups according to the presence of DME, they were divided into three groups in terms of retinopathy and DME, and in terms of retinopathy severity and presence of DME, they were divided into five groups.

RESULT

Ninety one (51.1%) of the age-sex matched participants were female and 87 (48.9%) were male. There was a statistically significant difference in vitamin D levels between the group with DME and the group without DME (p ≤ 0.001). In the comparison made according to the presence of retinopathy and DME; a significant difference was found between the DME group and the group with retinopathy but no DME (p ≤ 0.001). When the severity of retinopathy and the presence of DME were evaluated, a significant difference was found between the proliferative diabetic retinopathy (PDR) group with DME and the PDR group without DME in terms of vitamin D levels (p = 0.004).

CONCLUSION

Our study shows that the presence of DME is associated with lower serum 25(OH)D levels.

Serum Levels of Plasmalogens and Fatty Acid Metabolites Associate with Retinal Microangiopathy in Participants from the Finnish Diabetes Prevention Study

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes, and retinal microaneurysms (MA) are one of the first detected abnormalities associated with DR. We recently showed elevated serum triglyceride levels to be associated with the development of MA in the Finnish Diabetes Prevention Study (DPS). The purpose of this metabolomics study was to assess whether serum fatty acid (FA) composition, plasmalogens, and low-grade inflammation may enhance or decrease the risk of MA. Originally, the DPS included 522 individuals (mean 55 years old, range 40-64 years) with impaired glucose tolerance who were randomized into an intervention (n = 265) or control group (n = 257). The intervention lasted for a median of four years (active period), after which annual follow-up visits were conducted. At least five years after stopping the intervention phase of DPS, participants classified as MA negative (n = 115) or MA positive (n = 51) were included in the current study. All these participants were free of diabetes at baseline (WHO 1985) and had high-sensitive C-reactive protein (hs-CRP), serum FA composition, and selected lipid metabolites measured during the active study period. Among the markers associated with MA, the serum plasmalogen dm16:0 (p = 0.006), the saturated odd-chain FA 15.0 (pentadecanoic acid; p = 0.015), and omega-3 very long-chain FAs (p < 0.05) were associated with a decreased occurrence of MA. These associations were independent of study group and other risk factors. The association of high serum triglycerides with the MA occurrence was attenuated when these MA-associated serum lipid markers were considered. Our findings suggest that, in addition to n-3 FAs, odd-chain FA 15:0 and plasmalogen dm16:0 may contribute to a lower risk of MA in individuals with impaired glucose tolerance. These putative novel lipid biomarkers have an association with MA independently of triglyceride levels.

The Determination of Type 2 Diabetes Mellitus's Impact on the Density of Retinal Blood Vessels and the Choriocapillaris: Optical Coherence Tomography Angiography Study

Optical coherence tomography angiography (OCTA) was used to analyze the alterations in the density of retinal blood vessels and the choriocapillaris (VD) in patients suffering from type 2 diabetes mellitus (T2DM). One hundred sixty-six eyes of 83 patients (43 of whom were men and 40 women, with a mean age of 58.59 ± 14.04) with T2DM and without diabetic retinopathy were examined for the purpose of conducting the observational prospective study. The control group (CG) consisted of 66 eyes in 33 healthy subjects (15 male and 18 female, with a mean age of 55.12 ± 12.70). The measurement regions of vessel density (VD) included the deep capillary plexus (DCP), the superficial capillary plexus (SCP), and the choriocapillaris. The results indicate considerable differences in the VD of the DCP and SCP when comparing the control group with the study groups (p < 0.001). In comparison with the control group (p < 0.001), there was a statistically significant reduction in the VD of the choriocapillaris in the study group. Furthermore, patients with T2DM showed a significantly decreased VD concerning the control in different macular regions. Thickness in several macular regions in the study group significantly decreased compared to the ones in the control group. OCTA was used to gather relevant information about the vascular changes which occurred in T2DM patients, assessed through the quantitative analysis of the blood flow in the retina and choriocapillaris.

Impact of systemic parameters before commencing anti-vascular endothelial growth factor therapy for diabetic macular edema - Pan-Indian survey of retina specialists

Purpose:

Intravitreal anti-vascular endothelial growth factor (VEGF) injection therapy has emerged as the mainstay of treatment in the management of diabetic macular edema (DME) today. Various systemic risk factors have to be considered before initiating anti-VEGF therapy. The aim of our study was to form a consensus on various systemic factors to consider before starting anti-VEGF therapy for DME.

Methods:

A questionnaire was created and sent across to various retina specialists across India. A Google™ form with various questions pertaining to what systemic parameters would one consider before giving anti-VEGF therapy for DME was sent to each of them by email/WhatsApp™/direct telephonic interview.

Results:

Of the 650 retina specialists contacted, 322 responded to the questionnaire. There was no difference in responses between private and institutional practitioners. The majority would consider RBS (85%), HbA1c (61%), blood pressure (63%), and renal function (57%) as a routine before administering the anti-VEGF injection, while the majority would not consider hemoglobin (63%) or lipid profile (55%) of the patient as a routine practice prior to administering the injection.

Conclusion:

In our study, most VR specialists prefer to consider RBS, HbA1c, BP, and renal profile (creatinine) routinely prior to anti-VEGF injection. We suggest that it is important to consider blood pressure control, glycemic control, HbA1c, Hb, lipid profile, and renal profile (UACR, eGFR, and creatinine) prior to anti-VEGF therapy in all diabetic patients and to discuss the need for statins in patients with dyslipidemias with the physician.

Updates on the Current Treatments for Diabetic Retinopathy and Possibility of Future Oral Therapy

Diabetic retinopathy (DR) is a complication of diabetes and one of the leading causes of vision loss worldwide. Despite extensive efforts to reduce visual impairment, the prevalence of DR is still increasing. The initial pathophysiology of DR includes damage to vascular endothelial cells and loss of pericytes. Ensuing hypoxic responses trigger the expression of vascular endothelial growth factor (VEGF) and other pro-angiogenic factors. At present, the most effective treatment for DR and diabetic macular edema (DME) is the control of blood glucose levels. More advanced cases require laser, anti-VEGF therapy, steroid, and vitrectomy. Pan-retinal photocoagulation for non-proliferative diabetic retinopathy (NPDR) is well established and has demonstrated promising outcomes for preventing the progressive stage of DR. Furthermore, the efficacy of laser therapies such as grid and subthreshold diode laser micropulse photocoagulation (SDM) for DME has been reported. Vitrectomy has been performed for vitreous hemorrhage and tractional retinal detachment for patients with PDR. In addition, anti-VEGF treatment has been widely used for DME, and recently its potential to prevent the progression of PDR has been remarked. Even with these treatments, many patients with DR lose their vision and suffer from potential side effects. Thus, we need alternative treatments to address these limitations. In recent years, the relationship between DR, lipid metabolism, and inflammation has been featured. Research in diabetic animal models points to peroxisome proliferator-activated receptor alpha (PPARα) activation in cellular metabolism and inflammation by oral fenofibrate and/or pemafibrate as a promising target for DR. In this paper, we review the status of existing therapies, summarize PPARα activation therapies for DR, and discuss their potentials as promising DR treatments.

Diabetic retinopathy and diabetic macular oedema pathways and management: UK Consensus Working Group

The management of diabetic retinopathy (DR) has evolved considerably over the past decade, with the availability of new technologies (diagnostic and therapeutic). As such, the existing Royal College of Ophthalmologists DR Guidelines (2013) are outdated, and to the best of our knowledge are not under revision at present. Furthermore, there are no other UK guidelines covering all available treatments, and there seems to be significant variation around the UK in the management of diabetic macular oedema (DMO). This manuscript provides a summary of reviews the pathogenesis of DR and DMO, including role of vascular endothelial growth factor (VEGF) and non-VEGF cytokines, clinical grading/classification of DMO vis a vis current terminology (of centre-involving [CI-DMO], or non-centre involving [nCI-DMO], systemic risks and their management). The excellent UK DR Screening (DRS) service has continued to evolve and remains world-leading. However, challenges remain, as there are significant variations in equipment used, and reproducible standards of DMO screening nationally. The interphase between DRS and the hospital eye service can only be strengthened with further improvements. The role of modern technology including optical coherence tomography (OCT) and wide-field imaging, and working practices including virtual clinics and their potential in increasing clinic capacity and improving patient experiences and outcomes are discussed. Similarly, potential roles of home monitoring in diabetic eyes in the future are explored. The role of pharmacological (intravitreal injections [IVT] of anti-VEGFs and steroids) and laser therapies are summarised. Generally, IVT anti-VEGF are offered as first line pharmacologic therapy. As requirements of diabetic patients in particular patient groups may vary, including pregnant women, children, and persons with learning difficulties, it is important that DR management is personalised in such particular patient groups. First choice therapy needs to be individualised in these cases and may be intravitreal steroids rather than the standard choice of anti-VEGF agents. Some of these, but not all, are discussed in this document.

Association Between Obstructive Sleep Apnea and Diabetic Macular Edema in Patients with Type 2 Diabetes

PURPOSE

To evaluate the relationship between obstructive sleep apnea (OSA) and diabetic macular edema (DME) and the effect of OSA on refractory DME in patients with type 2 diabetes (T2DM).

DESIGN

Retrospective clinical cohort study.

METHODS

A population-based study was conducted at Chang Gung Memorial Hospital from March 1, 2009, to March 1, 2020. Among 14,152 patients who had undergone polysomnography (PSG) and whose data were registered on the sleep center's PSG database, 121 patients (242 eyes) with T2DM were enrolled according to the International Classification of Diseases, Ninth Revision (ICD-9) code 3620 for diabetic retinopathy (DR). Patients with a secondary cause of macular edema and those lacking medical records were excluded. All patients with T2DM enrolled in our study received both optical coherence tomography (OCT) and PSG. The prevalence of severe (apnea-hypopnea index [AHI] ≥30) and nonsevere (AHI <30) OSA was compared between patients with and without DME and refractory DME.

RESULTS

In total, 102 eyes (54 patients) were divided into groups of 40 eyes with DME or 62 eyes without DME. Severe OSA (odds ratio, 7.36; 95% confidence interval [CI]: 1.32-40.96; P = .023) was significantly associated with DME. Refractory DME was significantly more frequent in patients with severe OSA (27%) than in those with nonsevere OSA (0%; P = .009). Cox proportional hazards regression analysis revealed that OSA (hazard ratio, 2.97; CI, 1.08-8.16; P = .034) independently increased the DME risk after adjustment for age, sex, glycohemoglobin level, hypertension, and hypercholesterolemia.

CONCLUSIONS

Severe OSA is a risk factor for DME and is associated with having refractory DME.

Safety and Efficacy of Ranibizumab and Luseogliflozin Combination Therapy in Patients with Diabetic Macular Edema: Protocol for a Multicenter, Open-Label Randomized Controlled Trial

INTRODUCTION

Diabetic macular edema (DME) threatens daily life activities such as reading and driving and reduces the patients' quality-of-life. Recently, anti-vascular endothelial growth factor (VEGF) agents have become a first-line therapy in DME. However, therapy with anti-VEGF agents has several problems: repeated invasive injections are required; medical costs are high; and a certain proportion of patients with DME are resistant to treatment with anti-VEGF agents. While sodium-glucose co-transporter 2 (SGLT2) inhibitors have been widely used for the treatment of type 2 diabetes mellitus (T2DM), the effects of a combination therapy with anti-VEGF agent and SGLT2 inhibitor on DME are not yet known.

METHODS

This study enrolls subjects with T2DM and DME, randomizes them into either a study agent treatment group (treated with ranibizumab as anti-VEGF agent and luseogliflozin as SGLT2 inhibitor) or a control group (treated with ranibizumab and glimepiride), and observes the subjects for 52 weeks after initiation of treatment. Planned outcomes: The primary endpoint is intergroup difference in the number of intravitreal anti-VEGF injections to the study eye from baseline to week 48. Secondary and exploratory endpoints include safety and ophthalmologic and internal medical clinical parameters.

REGISTRATION

This study is registered at the University Hospital Medical Information Network Clinical Trial Registry (UMIN000033961) and Japan Registry of Clinical Trials (jRCTs031180210).

Systemic and ocular diseases associated with the development of diabetic macular edema among Japanese patients with diabetes mellitus

Background

Diabetic macular edema (DME) causes severe vision loss among patients with diabetes mellitus (DM). We aimed to investigate systemic and ocular diseases associated with the development of DME in a Japanese population.

Methods

A total of 3.11 million Japanese subjects who were registered in the database of the Japan Medical Data Center from 2005 to 2014 were analyzed. Subjects with DM were defined as individuals who had been prescribed any therapeutic medications for DM, and associated diseases were analyzed. The periods assessed were one year before the development of DME among patients with DME and one year before the last visit to an ophthalmic clinic among patients without DME.

Results

A total of 17,403 patients with DM satisfied the inclusion and exclusion criteria, and 420 patients developed DME. Univariate analysis revealed significant associations between 55 diseases, including 39 systemic and 16 ocular diseases, and DME development. Logistic analysis identified 21 systemic diseases and 10 ocular diseases as significant factors associated with DME development.

Conclusion

Various types of systemic and ocular diseases are associated with DME development. Subjects with DM who present these risk factors must be carefully monitored to prevent visual impairment.

Diabetic Macular Edema: State of Art and Intraocular Pharmacological Approaches

Diabetic macular edema (DME) is the main cause of vision loss in diabetic retinopathy (DR). Although it is one of the main complications of diabetes, the pathogenesis of DME is not completely understood. The hyperglycemic state promotes the activation of multiple interlinked pathways leading to DME. Different classifications have been proposed: based on clinical features, on pathogenesis or on diagnostic tests (optical coherence tomography - OCT and fluorescin angiography - FA). The multimodal imaging allows a better analysis of the morphological features of the DME. Indeed, new inflammatory biomarkers have been identified on OCT. Also, several studies are evaluating the role of the morphological features, identified on multimodal imaging, to find new prognostic factors. Over the past decade, great progresses have been made in the management of DME. Therapeutic alternatives include intraocular injection of anti-vascular endothelial grow factor agents (anti-VEGF) and steroid molecules, focal/grid laser photocoagulation and vitreo-retinal surgery. This review is focused on the description and analysis of the current intravitreal therapeutic pharmacological strategies. Current guidelines recommend anti-VEGF as first line therapy in DME. Corticosteroids are becoming increasingly relevant blocking the inflammatory cascade and indirectly reducing VEGF synthesis.

Natural history of diabetic macular edema and factors predicting outcomes in sham-treated patients (MEAD study)

PURPOSE

To describe the natural history of diabetic macular edema (DME) with respect to best-corrected visual acuity (BCVA) and central retinal thickness (CRT) outcomes and to identify baseline patient characteristics and systemic factors associated with improvement or worsening of outcomes in sham-treated patients.

METHODS

The study population was sham-treated patients (n = 350) in the 3-year MEAD registration study of dexamethasone intravitreal implant for treatment of DME. Patients had center-involved DME and received sham intravitreal injections in the study eye at ≥ 6-month intervals. Potential prognostic factors for outcomes were evaluated using multiple linear regression analysis.

RESULTS

Visual and anatomic outcomes were poorer in patients who left the study early (n = 198) than in study completers (n = 152). Mean change in BCVA from baseline at the last visit with available data was + 0.9 letters; 37.5% of patients had no change in BCVA, 23.2% had gained > 10 letters, and 16.0% had lost > 10 letters. Older age and baseline diabetic retinopathy score > 6 were associated with worse BCVA outcomes; thicker baseline CRT and larger number of hypertension medications used were associated with larger reductions in CRT during the study.

CONCLUSIONS

BCVA and CRT outcomes were variable in this population of DME patients with generally good glycemic control. In DME patients without active treatment, older age and baseline diabetic retinopathy score > 6 were associated with less improvement in BCVA; thicker baseline CRT and a larger number of antihypertensive medications used predicted better improvement in CRT.

TRIAL REGISTRATION

The MEAD study trials are registered at ClinicalTrials.gov with the identifiers NCT00168337 and NCT00168389.

Improvement of Recalcitrant Diabetic Macular Edema After Peritoneal Dialysis

Nephropathy may be an independent and contributory risk factor for diabetic macular edema (DME). A 69-year-old man who had previously been treated with panretinal laser photocoagulation for proliferative diabetic retinopathy as well as with steroid and anti-vascular endothelial growth factor injections for DME declined additional treatment for the DME, which was worse in the right eye. The DME was observed without further treatment for the next 36 months. Despite well-controlled blood sugar, blood pressure, and lipid levels, the DME remained unchanged. Peritoneal dialysis was started due to end-stage renal disease. Three months after commencing dialysis, the DME improved significantly. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:834-837.].

Diabetic macular oedema: clinical risk factors and emerging genetic influences

Diabetic macular oedema is the major cause of visual impairment in type 1 and type 2 diabetes. As type 2 diabetes becomes more prevalent worldwide, the prevalence of diabetic macular oedema is also expected to rise. Current management of diabetic macular oedema is challenging, expensive and not optimal in a subset of patients. Therefore, it is important to increase our understanding of the risk factors involved and develop preventative strategies. While clinical risk factors for diabetic macular oedema have been identified, few studies have addressed potential genetic risk factors. Epidemiology and family studies suggest genetic influences are of importance. In this review, we summarise known clinical risk factors, as well as discuss the small number of genetic studies that have been performed for diabetic macular oedema.

Clinical Characteristics of Patients with Newly Diagnosed Diabetic Macular Edema in Turkey: A Real-Life Registry Study-TURK-DEM

Purpose. To evaluate the clinical and diagnostic characteristics of patients with newly diagnosed diabetic macular edema (DME) in Turkey in a real-life setting. Methods. A total of 945 consecutive patients (mean (SD) age: 61.3 (9.9) years, 55.2% male) with newly diagnosed DME were included. Data on patient demographics, comorbidities, ocular history, ophthalmic examination findings including type of DME, central macular thickness (CMT) via time domain (TD) and spectral domain (SD) optical coherence tomography (OCT), and planned treatments were recorded. Results. OCT (98.8%) and fundoscopy (92.9%) were the two most common diagnostic methods. Diffuse and focal DMEs were detected in 39.2% and 36.9% of cases, respectively. Laser photocoagulation (32.1%) and antivascular endothelial growth factors (anti-VEGF; 31.8%) were the most commonly planned treatments. The median CMT in the right eye was significantly greater in untreated than in treated patients [376.5 μm (range: 160–840) versus 342 μm (range: 146–999) (p = 0.002)] and in the left eye [370 μm (range: 201–780) versus 329 μm (range: 148–999) (p < 0.001)]. Conclusions. This study is the first large-scale real-life registry of DME patients in Turkey. SD-OCT and fundoscopy were the most common diagnostic methods. Laser photocoagulation and anti-VEGF therapy were the most common treatments.

Lower Hemoglobin Concentration Is Associated with Retinal Ischemia and the Severity of Diabetic Retinopathy in Type 2 Diabetes

Aims. To assess the association of blood oxygen-transport capacity variables with the prevalence of diabetic retinopathy (DR), retinal ischemia, and macular oedema in patients with type 2 diabetes mellitus (T2DM). Methods. Cross-sectional, case-control study (N = 312) with T2DM: 153 individuals with DR and 159 individuals with no DR. Participants were classified according to the severity of DR and the presence of retinal ischemia or macular oedema. Hematological variables were collected by standardized methods. Three logistic models were adjusted to ascertain the association between hematologic variables with the severity of DR and the presence of retinal ischemia or macular oedema. Results. Individuals with severe DR showed significantly lower hemoglobin, hematocrit, and erythrocyte levels compared with those with mild disease and in individuals with retinal ischemia and macular oedema compared with those without these disorders. Hemoglobin was the only factor that showed a significant inverse association with the severity of DR [beta-coefficient = -0.52, P value = 0.003] and retinal ischemia [beta-coefficient = -0.49, P value = 0.001]. Lower erythrocyte level showed a marginally significant association with macular oedema [beta-coefficient = -0.86, P value = 0.055]. Conclusions. In patients with DR, low blood oxygen-transport capacity was associated with more severe DR and the presence of retinal ischemia. Low hemoglobin levels may have a key role in the development and progression of DR.

Increased serum urea and creatinine levels correlate with decreased retinal nerve fibre layer thickness in diabetic retinopathy

Correlation of increased levels of serum urea and creatinine with retinal nerve fibre layer (RNFL) thinning on spectral domain optical coherence tomography (SD-OCT) was studied in diabetic retinopathy (DR). Sixty consecutive cases and 20 healthy controls were included. Cases were divided into three groups: without DR, non-proliferative DR with macular oedema and proliferative DR with oedema. Serum urea and creatinine were measured using a standard protocol. Average (RNFL) was measured using SD-OCT. Increased severity of DR was associated with decrease in levels of serum urea and serum creatinine levels. RNFL thinning correlated positively with increase in serum urea and creatinine levels.

A classification model for predicting eye disease in newly diagnosed people with type 2 diabetes

Diabetic retinopathy may be present at the time type 2 diabetes is diagnosed, and initial screening encompassing an eye examination performed by an ophthalmologist or optometrist is therefore recommended. However, proper screening for retinopathy may be challenging in many parts of the world. We hypothesized that simple, commonly available patient characteristics can be used to identify patients at high risk for having retinopathy. We investigated data from multiple years extracted from the National Health and Nutrition Examination Survey which holds information about blood glucose and eye examinations. Individuals with hitherto undiagnosed diabetes were classified according to the presence or absence of retinopathy. Linear classification was used to predict which patients had retinopathy at the time of diagnosis. A total of 266 individuals with undiagnosed diabetes were identified from the cohorts. Of these, 222 individuals had no sign of retinopathy, whereas 44 had mild or moderate non-proliferative retinopathy. Using information regarding HbA1c, BMI, waist circumference, age, systolic blood pressure, urinary albumin, and urinary creatinine, we were able to construct a model that predicts the presence of retinopathy with a positive predictive value of 22% and a negative predictive value of 99%. Only one true positive (1/44) with mild non-proliferative retinopathy was falsely classified. A classification model using readily available patient information and routine biochemical measures can be used to identify patients at high risk of having retinopathy at the time their diabetes is diagnosed. The model may be used to identify high-risk patients for retinopathy screening.

Updates in the management of diabetic macular edema

Diabetes mellitus is a chronic disease which has multiple effects on different end-organs, including the retina. In this paper, we discuss updates on diabetic macular edema (DME) and the management options. The underlying pathology of DME is the leakage of exudates from retinal microaneurysms, which trigger subsequent inflammatory reactions. Both clinical and imaging techniques are useful in diagnosing, classifying, and gauging the severity of DME. We performed a comprehensive literature search using the keywords "diabetes," "macula edema," "epidemiology," "pathogenesis," "optical coherence tomography," "intravitreal injections," "systemic treatment," "hypertension," "hyperlipidemia," "anemia," and "renal disease" and collated a total of 47 relevant articles published in English language. The main modalities of treatment currently in use comprise laser photocoagulation, intravitreal pharmacological and selected systemic pharmacological options. In addition, we mention some novel therapies that show promise in treating DME. We also review systemic factors associated with exacerbation or improvement in DME.

Impact of insulin treatment in diabetic macular edema therapy in type 2 diabetes

OBJECTIVE

To evaluate the impact of insulin therapy on the outcomes of diabetic macular edema (DME) treatment with vascular endothelial growth factor (VEGF) inhibitors in people with type 2 diabetes.

METHODS

A retrospective consecutive case series of 95 patients with type 2 diabetes and DME who were treated with anti-VEGF therapy. We examined 2 cohorts: patients taking only oral antidiabetic agents and patients on insulin therapy. The main outcome measures were change in visual acuity and change in central subfield macular thickness measured by spectral-domain optical coherence tomography. The additional variables analyzed included glycated hemoglobin (A1C), creatinine, blood pressure and body mass index and their correlations with clinical findings.

RESULTS

Both groups had a statistically significant improvement in visual acuity (oral antidiabetic agents group: 20/61 to 20/49, p=0.003; insulin therapy group: 20/76 to 20/56, p=0.005). There was no difference between groups at initial or 12-month examination (p=0.239 and p=0.489, respectively). From an anatomic standpoint, central subfield macular thickness also improved significantly in both groups: from 454.7 μm to 354.9 μm (p<0.001) in the oral antidiabetic agents group and from 471.5 μm to 368.4 μm (p<0.001) in the insulin therapy group. Again, there was no significant difference between groups at initial or 12-month follow-up examinations (p=0.586 and p=0.591, respectively). Mean A1C levels remained relatively stable during the follow up in both groups.

CONCLUSION

Anti-VEGF therapy is a useful treatment for DME. This study suggests that chronic insulin therapy, compared with oral antidiabetic agents, does not modify the anatomic or functional effectiveness of DME treatment.