Effects of lipid-lowering agents on diabetic retinopathy: a Meta-analysis and systematic review

Recent Insights into the Etiopathogenesis of Diabetic Retinopathy and Its Management

Purpose: Diabetic retinopathy (DR) is a microvascular retinal disease associated with chronic diabetes mellitus, characterized by the damage of blood vessels in the eye. It is projected to become the leading cause of blindness, given the increasing burden of the diabetic population worldwide. The diagnosis and management of DR pose significant challenges for physicians because of the involvement of multiple biochemical pathways and the complexity of ocular tissues. This review aims to provide a comprehensive understanding of the molecular pathways implicated in the pathogenesis of DR, including the polyo pathway, hexosamine pathway, protein kinase C (PKC), JAK/STAT signaling pathways, and the renin-angiotensin system (RAS). Methods: Academic databases such as PubMed, Scopus, Google Scholar and Web of Science was systematically searched using a carefully constructed search strategy incorporating keywords like "Diabetic Retinopathy," "Molecular Pathways," "Pharmacological Treatments," and "Clinical Trials" to identify relevant literature for the comprehensive review. Results: In addition to activating other inflammatory cascades, these pathways contribute to the generation of oxidative stress within the retina. Furthermore, it aims to explore the existing pharmacotherapy options available for the treatment of DR. In addition to conventional pharmacological therapies such as corticosteroids, antivascular endothelial growth factors, and nonsteroidal anti-inflammatory drugs (NSAIDs), this review highlights the potential of repurposed drugs, phyto-pharmaceuticals, and novel pipeline drugs currently undergoing various stages of clinical trials. Conclusion: Overall, this review serves as a technical exploration of the complex nature of DR, highlighting both established and emerging molecular pathways implicated in its pathogenesis. Furthermore, it delves into the available pharmacological treatments, as well as the promising repurposed drugs, phyto-pharmaceuticals, and novel drugs currently being evaluated in clinical trials, with a focus on their specific mechanisms of action.

Underprescription of Fibrate Among Patients With Diabetic Retinopathy in Perak, Malaysia

Objectives Diabetic retinopathy (DR) is a major cause of blindness and its prevalence is increasing. Fibrate, specifically fenofibrate, has been shown to be efficacious in reducing the progression of DR. This study aims to determine the five-year trend of and factors associated with the prescription of fibrate among patients with DR in Perak. Methods Data on all patients with DR in 76 government health clinics in Perak who were audited between 2018 and 2022 were extracted from the National Diabetes Registry (NDR), excluding those who were lost to follow-up. Multivariable logistic regression was used to identify factors associated with the prescription of fibrates. Results Data from 4028 patients were analysed. Commonly prescribed medications were statins (n = 3466, 86.0%), metformin (n = 3212, 79.7%), and angiotensin-converting enzyme inhibitors (n = 2318, 57.5%). Only 63 (1.6%) patients were prescribed fibrate. Factors associated with the prescription of fibrates were patients from the clinics in northern (adjusted odds ratio (aOR) = 0.33, 95% CI: 0.12-0.65) and southern clusters (aOR = 0.23, 95% CI: 0.08-0.655), triglycerides > 1.7 mmol/L (aOR = 4.85, 95% CI: 1.85-12.70), and prescription of insulin (aOR = 2.77, 95% CI: 1.07-7.18) and statin (aOR = 0.10, 95% CI: 0.04-0.27). Conclusion The prescription of fibrate among patients with DR was low, highlighting a missed opportunity for early treatment and improved outcomes in primary care. The prescription of fibrates to reduce the progression of DR should be expanded to primary care. Clinicians should consider the factors associated with the non-prescription of fibrate identified when prescribing to these patients. Policies, including those at the ministry level, to enhance the availability of these medicines, including financial resources for procurement, are necessary to guarantee easy access for patients in different areas. It is crucial for healthcare providers to be knowledgeable about and follow guidelines. Moreover, improving the overall management of DR in patients with multiple comorbidities can be achieved by addressing worries about the side effects of combination therapies through educational campaigns and providing clear directives. Nevertheless, the study's findings should be interpreted in light of the limitations discussed.

The evolving therapeutic landscape of diabetic retinopathy

INTRODUCTION

Diabetic retinopathy (DR) is a leading cause of blindness worldwide. Recent decades have seen rapid progress in the management of diabetic eye disease, evolving from pituitary ablation to photocoagulation and intravitreal pharmacotherapy. The advent of effective intravitreal drugs inhibiting vascular endothelial growth factor (VEGF) marked a new era in DR therapy. Sustained innovation has since produced several promising biologics targeting angiogenesis, inflammation, oxidative stress, and neurodegeneration.

AREAS COVERED

This review surveys traditional, contemporary, and emerging therapeutics for DR, with an emphasis on anti-VEGF therapies, receptor tyrosine kinase inhibitors, angiopoietin-Tie2 pathway inhibitors, integrin pathway inhibitors, gene therapy 'biofactory' approaches, and novel systemic therapies. Some of these investigational therapies are being delivered intravitreally via sustained release technologies for extended durability. Other investigational agents are being delivered non-invasively via topical and systemic routes. These strategies hold promise for early and long-lasting treatment of DR.

EXPERT OPINION

The evolving therapeutic landscape of DR is rapidly expanding our toolkit for the effective and durable treatment of blinding eye disease. However, further research is required to validate the efficacy of novel therapeutics and characterize real world outcomes.

Ocular conditions and injuries, detection and management in spaceflight

Ocular trauma or other ocular conditions can be significantly debilitating in space. A literature review of over 100 articles and NASA evidence books, queried for eye related trauma, conditions, and exposures was conducted. Ocular trauma and conditions during NASA space missions during the Space Shuttle Program and ISS through Expedition 13 in 2006 were reviewed. There were 70 corneal abrasions, 4 dry eyes, 4 eye debris, 5 complaints of ocular irritation, 6 chemical burns, and 5 ocular infections noted. Unique exposures on spaceflight, such as foreign bodies, including celestial dust, which may infiltrate the habitat and contact the ocular surface, as well as chemical and thermal injuries due to prolonged CO2 and heat exposure were reported. Diagnostic modalities used to evaluate the above conditions in space flight include vision questionnaires, visual acuity and Amsler grid testing, fundoscopy, orbital ultrasound, and ocular coherence tomography. Several types of ocular injuries and conditions, mostly affecting the anterior segment, are reported. Further research is necessary to understand the greatest ocular risks that astronauts face and how better we can prevent, but also diagnose and treat these conditions in space.

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.

Risk factor analysis and clinical decision tree model construction for diabetic retinopathy in Western China

BACKGROUND

Diabetic retinopathy (DR) is the driving force of blindness in patients with type 2 diabetes mellitus (T2DM). DR has a high prevalence and lacks effective therapeutic strategies, underscoring the need for early prevention and treatment. Yunnan province, located in the southwest plateau of China, has a high pre-valence of DR and an underdeveloped economy.

AIM

To build a clinical prediction model that will enable early prevention and treatment of DR.

METHODS

In this cross-sectional study, 1654 Han population with T2DM were divided into groups without (n = 826) and with DR (n = 828) based on fundus photography. The DR group was further subdivided into non-proliferative DR (n = 403) and proliferative DR (n = 425) groups. A univariate analysis and logistic regression analysis were conducted and a clinical decision tree model was constructed.

RESULTS

Diabetes duration ≥ 10 years, female sex, standing- or supine systolic blood pressure (SBP) ≥ 140 mmHg, and cholesterol ≥ 6.22 mmol/L were risk factors for DR in logistic regression analysis (odds ratio = 2.118, 1.520, 1.417, 1.881, and 1.591, respectively). A greater severity of chronic kidney disease (CKD) or hemoglobin A 1c increased the risk of DR in patients with T2DM. In the decision tree model, diabetes duration was the primary risk factor affecting the occurrence of DR in patients with T2DM, followed by CKD stage, supine SBP, standing SBP, and body mass index (BMI). DR classification outcomes were obtained by evaluating standing SBP or BMI according to the CKD stage for diabetes duration < 10 years and by evaluating CKD stage according to the supine SBP for diabetes duration ≥ 10 years.

CONCLUSION

Based on the simple and intuitive decision tree model constructed in this study, DR classification outcomes were easily obtained by evaluating diabetes duration, CKD stage, supine or standing SBP, and BMI.

Management of Diabetic Macular Edema: Guidelines from the Emirates Society of Ophthalmology

In the United Arab Emirates, retinopathy has been shown to be present in 19% of the diabetic population, with diabetes identified in up to 40% of individuals aged over 55 years. Despite the prevalence of diabetic retinal diseases, there are no unified national guidelines on the management of diabetic macular edema (DME). These published guidelines are based on evidence taken from the literature and published trials of therapies, and consensus opinion of a representative expert panel with an interest in this condition, convened by the Emirates Society of Ophthalmology. The aim is to provide evidence-based, clinical guidance for the best management of different aspects of DME, with a special focus on vision-threatening diabetic retinopathy. Treatment should be initiated in patients with best-corrected visual acuity 20/30 or worse, and/or features of DME as seen on optical coherence tomography (OCT) with central retinal thickness (CRT) of at least 300 μm or in symptomatic patients with vision better than 20/25, and/or CRT less than 300 μm where there are OCT features consistent with center-involving macular edema. The treatment of DME is effective irrespective of glycated hemoglobin (HbA1c) level, and treatment must not be denied or delayed in order to optimize systemic parameters. All ophthalmic treatment options should be discussed with the patient for better compliance and expectations. Non-center-involving DME can be initially observed until progression toward the center is documented. Macular laser no longer has a primary role in center-involving DME, and anti-vascular endothelial growth factor (anti-VEGF) therapy should be considered as first-line treatment for all patients, unless contraindicated. If anti-VEGF is contraindicated, a steroid dexamethasone implant can be considered for first-line treatment. Recommendations for the treatment of DME in special circumstances and in relapsing and refractory DME are also discussed.

Aggravation of retinal hard exudates after intravitreal anti-vascular endothelial growth factor therapy for cystoid macular edema and the risk factors: a retrospective study

Background/aims

To evaluate retinal hard exudates (HEs) progression in patients with cystoid macular edema (CME) secondary to diabetic retinopathy (DR) or branch retinal vascular occlusion (BRVO) after intravitreal injections of ranibizumab (IVR) treatment and identify the risk factors for the deterioration of HEs.

Methods

This retrospective study enrolled 288 eyes with center-involving CME secondary to DR or BRVO from 288 patients (one eye per patient). All patients were treated with three loading doses of ranibizumab intravitreally at a monthly interval. The morphologic features of HEs were observed, and the HEs areas were quantified using a semi-automatic method at baseline, 1 month after the first dose of IVR and 1 month after the third dose of IVR therapy. HEs progression was defined as having a > =2-grade increase in the HEs severity scale. The best-corrected vision acuity (BCVA) and alterations in HEs areas were compared between DR and BRVO groups. And logistic regression analyses were used to identify the risk factors for HEs exacerbation.

Results

Morphological changes of retinal HEs occurred in all eyes after IVR therapy, although HEs area was not significantly changed in some eyes. DR group has a higher percentage of eyes with progressed HEs area than the BRVO groups (34.9% vs. 21.8%, P = 0.019) 1 month after the first dose of IVR. Both DR and BRVO groups had a decreased percentage of enlarged HEs 1 month after the third injection, but the DR group is still higher than the BRVO group (17.1% vs. 8.4%, P = 0.027). At baseline, there was no correlation between VA and HEs areas. After the first and third doses of IVR, there still was no consistent correlation between HEs severity and change in VA over time. Furthermore, CME with subretinal fluid (SRF) is associated with a higher risk of HEs progression (P = 0.001). Long CME duration and high serum low-density lipoprotein cholesterol (LDL-C) level were identified as risk factors for HEs progression following IVR treatment in both univariable and multivariable regression analyses (Odds ratio (OR) = 1.88, P = 0.012 and OR = 1.14, P = 0.021, respectively).

Conclusions

Alterations in the area of retinal HEs are widely observed after IVR treatment for CME. The eyes with CME secondary to DR have a higher percentage of progressed HEs than the BRVO eyes. DME with SRF, extended duration of CME, and high LDL-C level are potential risk factors of deteriorated HEs after IVR treatment.

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.

Vamos E, Molina G, Sivaprasad S. Associations between attainment of incentivized primary care indicators and incident sight-threatening diabetic retinopathy in England: A population-based historical cohort study

AIM

To examine the impact of attainment of primary care diabetes clinical indicators on progression to sight-threatening diabetic retinopathy (STDR) among those with mild non-proliferative diabetic retinopathy (NPDR).

MATERIALS AND METHODS

An historical cohort study of 18,978 adults (43.63% female) diagnosed with type 2 diabetes before 1 April 2010 and mild NPDR before 1 April 2011 was conducted. The data were obtained from the UK Clinical Practice Research Datalink during 2010-2017, provided by 330 primary care practices in England. Exposures included attainment of the Quality and Outcomes Framework HbA1c (≤59 mmol/mol [≤7.5%]), blood pressure (≤140/80 mmHg) and cholesterol (≤5 mmol/L) indicators in the financial year 2010-2011, as well as the number of National Diabetes Audit processes completed in 2010-2011. The outcome was time to incident STDR. Nearest neighbour propensity score matching was undertaken, and univariable and multivariable Cox proportional hazards models were then fitted using the matched samples. Concordance statistics were calculated for each model.

RESULTS

A total of 1037 (5.5%) STDR diagnoses were observed over a mean follow-up of 3.6 (SD 2.0) years. HbA1c, blood pressure and cholesterol indicator attainment were associated with lower rates of STDR (adjusted hazard ratios [95% CI] 0.64 [0.55-0.74; p < .001], 0.83 [0.72-0.94; p = .005] and 0.80 [0.66-0.96; p = .015], respectively).

CONCLUSIONS

Our findings provide support for meeting appropriate indicators for the management of type 2 diabetes in primary care to bring a range of benefits, including improved health outcomes-such as a reduction in the risk of STDR-for people with type 2 diabetes.

Association of Bone Metabolism Indices and Bone Mineral Density with Diabetic Retinopathy in Elderly Patients with Type 2 Diabetes Mellitus: A Cross-Sectional Inpatient Study in China

OBJECTIVE

This study is aimed at analyzing the association between bone metabolism indices and diabetic retinopathy (DR) in elderly patients with type 2 diabetes mellitus.

METHODS

Data of 352 men and 284 postmenopausal women, aged more than 50 years, with type 2 diabetes mellitus were retrospectively analyzed. Patients were divided into three groups based on the degree of DR: nondiabetic retinopathy (NDR) group, background diabetic retinopathy (BDR) group, and proliferative diabetic retinopathy (PDR) group.

RESULTS

(1) The diabetic duration and urinary albumin to creatinine ratio (UACR) were significantly higher in the PDR and BDR groups than in the NDR group (P < 0.05). The level of beta-C-terminal telopeptide (β-CTX) in male patients was lower in the PDR and BDR groups than in the NDR group (P < 0.05). In addition, the level of procollagen 1 intact N-terminal (P1NP) in female patients was higher in the PDR and BDR groups than in the NDR group (P < 0.05). (2) For men and postmenopausal women, the proportion of vitamin deficiency was higher in the PDR and BDR groups than in the NDR group (P < 0.05). (3) The logistic regression analysis in men and postmenopausal women showed that the diabetic duration and lower levels of UACR and 25(OH)D were independent risk factors for DR (P < 0.05). (4) The diabetic duration was also an independent risk factor for PDR (P < 0.05); however, no independent correlation was found between the level of 25(OH)D and PDR (P > 0.05).

CONCLUSIONS

A close association was observed between 25(OH)D level and DR in the elderly male patients and postmenopausal women with type 2 diabetes mellitus. P1NP and β-CTX levels might be closely related to DR in elderly male patients and postmenopausal women with type 2 diabetes mellitus.

Emerging insights into the relationship between hyperlipidemia and the risk of diabetic retinopathy

Hyperlipidemia is correlated with a series of health problems. Notably, aside from its established role in promoting cardiovascular morbidity and mortality, hyperlipidemia has also been considered for modulating the risk and the severity of multiple metabolic disorders. According to the results of epidemiologic investigations, several certain circulating lipoprotein species are correlated with the prevalence of diabetic retinopathy, suggesting that the physiological and pathological role of these lipoproteins is analogous to that observed in cardiovascular diseases. Furthermore, the lipid-lowering treatments, particularly using statin and fibrate, have been demonstrated to ameliorate diabetic retinopathy. Thereby, current focus is shifting towards implementing the protective strategies of diabetic retinopathy and elucidating the potential underlying mechanisms. However, it is worth noting that the relationship between major serum cholesterol species and the development of diabetic retinopathy, published by other studies, was inconsistent and overall modest, revealing the relationship is still not clarified. In this review, the current understanding of hyperlipidemia in pathogenesis of diabetic retinopathy was summarized and the novel insights into the potential mechanisms whereby hyperlipidemia modulates diabetic retinopathy were put forward.

Predictors for diabetic retinopathy progression-findings from nominal group technique and Evidence review

Objectives

Risk stratification is needed for patients referred to hospital eye services by Diabetic Eye Screening Programme UK. This requires a set of candidate predictors. The literature contains a large number of predictors. The objective of this research was to arrive at a small set of clinically important predictors for the outcome of the progression of diabetic retinopathy (DR). They need to be evidence based and readily available during the clinical consultation.

Methods and analysis

Initial list of predictors was obtained from a systematic review of prediction models. We sought the clinical expert opinion using a formal qualitative study design. A series of nominal group technique meetings to shorten the list and to rank the predictors for importance by voting were held with National Health Service hospital-based clinicians involved in caring for patients with DR in the UK. We then evaluated the evidence base for the selected predictors by critically appraising the evidence.

Results

The source list was presented at nominal group meetings (n=4), attended by 44 clinicians. Twenty-five predictors from the original list were ranked as important predictors and eight new predictors were proposed. Two additional predictors were retained after evidence check. Of these 35, 21 had robust supporting evidence in the literature condensed into a set of 19 predictors by categorising DR.

Conclusion

We identified a set of 19 clinically meaningful predictors of DR progression that can help stratify higher-risk patients referred to hospital eye services and should be considered in the development of an individual risk stratification model.

Study design

A qualitative study and evidence review.

Setting

Secondary eye care centres in North East, Midlands and South of England.

The Evolving Treatment of Diabetic Retinopathy

Purpose

To review the current therapeutic options for the management of diabetic retinopathy (DR) and diabetic macular edema (DME) and examine the evidence for integration of laser and pharmacotherapy.

Methods

A review of the PubMed database was performed using the search terms diabetic retinopathy, diabetic macular edema, neovascularization, laser photocoagulation, intravitreal injection, vascular endothelial growth factor (VEGF), vitrectomy, pars plana vitreous surgery, antiangiogenic therapy. With additional cross-referencing, this yielded 835 publications of which 301 were selected based on content and relevance.

Results

Many recent studies have evaluated the pharmacological, laser and surgical therapeutic strategies for the treatment and prevention of DR and DME. Several newer diagnostic systems such as optical coherence tomography (OCT), microperimetry, and multifocal electroretinography (mfERG) are also assisting in further refinements in the staging and classification of DR and DME. Pharmacological therapies for both DR and DME include both systemic and ocular agents. Systemic agents that promote intensive glycemic control, control of dyslipidemia and antagonists of the renin-angiotensin system demonstrate beneficial effects for both DR and DME. Ocular therapies include anti-VEGF agents, corticosteroids and nonsteroidal anti-inflammatory drugs. Laser therapy, both as panretinal and focal or grid applications continue to be employed in management of DR and DME. Refinements in laser devices have yielded more tissue-sparing (subthreshold) modes in which many of the benefits of conventional continuous wave (CW) lasers can be obtained without the adverse side effects. Recent attempts to lessen the burden of anti-VEGF injections by integrating laser therapy have met with mixed results. Increasingly, vitreoretinal surgical techniques are employed for less advanced stages of DR and DME. The development and use of smaller gauge instrumentation and advanced anesthesia agents have been associated with a trend toward earlier surgical intervention for diabetic retinopathy. Several novel drug delivery strategies are currently being examined with the goal of decreasing the therapeutic burden of monthly intravitreal injections. These fall into one of the five categories: non-biodegradable polymeric drug delivery systems, biodegradable polymeric drug delivery systems, nanoparticle-based drug delivery systems, ocular injection devices and with sustained release refillable devices. At present, there remains no one single strategy for the management of the particular stages of DR and DME as there are many options that have not been rigorously tested through large, randomized, controlled clinical trials.

Conclusion

Pharmacotherapy, both ocular and systemic, will be the primary mode of intervention in the management of DR and DME in many cases when cost and treatment burden are less constrained. Conventional laser therapy has become a secondary intervention in these instances, but remains a first-line option when cost and treatment burden are more constrained. Results with subthreshold laser appear promising but will require more rigorous study to establish its role as adjunctive therapy. Evidence to support an optimal integration of the various treatment options is lacking. Central to the widespread adoption of any therapeutic regimen for DR and DME is substantiation of safety, efficacy, and cost-effectiveness by a body of sound clinical trials.

Comparison of Coronary Heart Disease and Stroke in Association with Diabetic Retinopathy in Adults with Diabetes Using a National Survey

OBJECTIVE

Diabetic retinopathy (DR) was reported to have higher prevalence of coronary heart disease (CHD) and stroke compared with people without DR. However, whether DR had similar effects on CHD and stroke in US adults with diabetes was not well known. This study was to compare the association between DR, CHD and stroke in US adults with diabetes using the 2015 Behavioral Risk Factor Surveillance System (BRFSS).

METHODS

Respondents with diabetes aged over 18 years and undergone a fundus examination over the past 2 years were included in this study. DR, CHD and stroke were self-reported. A weighted hierarchical logistic regression was used to examine the association of DR with CHD and stroke.

RESULTS

A total of 21,049 respondents with diabetes aged over 18 years having undergone a fundus examination over the past 2 years were included in the analysis. There were 4690 people reported having CHD, accounting for the weighted prevalence 22.1%. The weighted prevalence of stroke was 9.6%. There was 28.3% of CHD people who had DR which was higher than that in people without CHD. Differences in weighted frequency distributions of gender, age category (over 45 years or not), current smoking, hypercholesterolemia, hypertension and insulin treatment were significantly different between the CHD and without CHD groups (p<0.001). Similar results were found in people with stroke. Logistic analysis showed that DR was related to CHD and stroke (crude OR =1.876, 2.263, respectively, p all <0.001). After adjusting other variables, these associations persisted (Adjusted OR=1.632 (95% CI=1.625-1.639), 1.846 (95% CI=1.836-1.856), respectively, p all<0.001).

CONCLUSION

The BRFSS 2015 data indicated that DR was not only associated with CHD but also associated with stroke in US adults with diabetes, independently of other risk factor. DR might be more strongly associated with stroke than with CHD.

Protective potential of klotho protein on diabetic retinopathy: Evidence from clinical and in vitro studies

AIMS/INTRODUCTION

The purpose of the present study was to observe the relationship between serum α-klotho (KL) protein level and diabetic retinopathy (DR), and to further examine the effects of KL protein on apoptosis induced by palmitic acid (PA) in human retinal endothelial cells.

MATERIALS AND METHODS

A total of 17 healthy people and 60 type 2 diabetes patients were included. According to the results from fundus fluorescein angiography, the diabetes patients were divided into three subgroups: without DR, non-proliferative DR and proliferative DR. Serum KL level was measured by enzyme-linked immunosorbent assay. In vitro, human retinal endothelial cells were exposed to PA with or without KL protein. Apoptosis rates were analyzed by flow cytometry analysis. Apoptotic-related protein expressions were detected by western blotting analysis.

RESULTS

Serum KL level was lower in diabetes patients than that in healthy participants (P = 0.007), and was gradually decreased among the without DR, non-proliferative DR and proliferative DR subgroups (P = 0.045). A logistic regression analysis showed that after adjusting for the other confounding factors, serum KL level was independently and negatively related with DR (P = 0.049). Furthermore, the increased apoptosis rates induced by PA were inhibited with the addition of KL protein. Consistently, KL protein reversed the expression levels of the increased pro-apoptotic protein Bax and the decreased anti-apoptotic protein Bcl-2 induced by PA. However, the anti-apoptotic effect of KL protein was attenuated by LY294002 through the phosphatidylinositol 3 kinase-serine∕threonine kinase pathway.

CONCLUSIONS

The data suggested that KL protein was probably a potential protective factor against retinopathy in type 2 diabetes patients.

Carbamazepine Alleviates Retinal and Optic Nerve Neural Degeneration in Diabetic Mice via Nerve Growth Factor-Induced PI3K/Akt/mTOR Activation

Aim: Diabetic retinopathy causes loss of vision in adults at working-age. Few therapeutic options are available for treatment of diabetic retinopathy. Carbamazepine (CARB), a widely used antiepileptic drug, was recently accounted for its neuroprotective effect. Nerve growth factor (NGF) activates various cascades among which, PI3K/Akt/mTOR pathway has a vital action in NGF-mediated neuronal differentiation and survival. This study evaluated the effect of CARB in the treatment of diabetic retina and unveiled some of the underlying molecular mechanisms. Main Methods: Alloxan diabetes model was induced in 36 albino well-acclimatized mice. After establishment of the diabetic model in 9 weeks, mice were assigned to treatment groups: (1) saline, (2) alloxan-diabetic, (3 and 4) alloxan+CARB (25 or 50 mg per kg p.o) for 4 weeks. After completion of the therapeutic period, mice were sacrificed and eyeballs were enucleated. Retinal levels of NGF and PI3K/Akt were assessed using real-time polymerase chain reaction. Further, total and phosphorylated TrKA, PI3K, Akt, mTOR as well as Caspase-3 were measured by Western blot analysis. Key Findings: Histopathological examination demonstrated that CARB attenuated vacuolization and restored normal thickness and organization of retinal cell layers. In addition, CARB increased pTrKA/TrKA ratio and ameliorated diabetes-induced reduction of NGF mRNA and immunostaining in retina. Additionally, it augmented the mRNA expression of PI3K and Akt, as well as the protein level of the phosphorylated PI3/Akt/mTOR. Significance: Results highlighted, for the first time, the neuronal protective effect for CARB in diabetic retina, which is mediated, at least in part, by activation of the NGF/PI3K/Akt/mTOR pathway.

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.

The relationship of blood cell-associated inflammatory indices and diabetic retinopathy: a Meta-analysis and systematic review

AIM

To explore the correlation between several blood cell-associated inflammatory indices including mean platelet volume (MPV), platelet distribution width (PDW), neutrophil to lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), and the presence and severity of diabetic retinopathy (DR).

METHODS

We searched for eligible studies from PubMed, EMBASE, Web of Science and CNKI up to December 13, 2017. Standardized mean difference (SMD) calculated with confidence interval (CI) of 95% was used to estimate the values of those indices.

RESULTS

A total of 31 studies were included in the present Meta-analysis. As compared with type 2 diabetes mellitus (T2DM) patients without DR, the values of MPV, PDW, NLR, and PLR were higher in patients with DR (SMD=0.67; 95%CI: 0.36 to 0.98; SMD=0.51; 95%CI: 0.27 to 0.75; SMD=0.77; 95%CI: 0.49 to 1.05 and SMD=1.18; 95%CI: 0.07 to 2.28). Additionally, it was also observed that MPV was closely correlated with the severity of DR.

CONCLUSION

MPV, PDW, NLR, and PLR could be recommended as diagnostic biomarkers for DR, and MPV could be applied to assess the severity of DR.

Statins and/or fibrates for diabetic retinopathy: a systematic review and meta-analysis

Evidence from observational studies have found a relationship between serum cholesterol and diabetic retinopathy (DR). Apart of the assumption that cholesterolemic control has benefits for patients with diabetes with or without retinopathy, the effects of lipid-lowering drugs have not been properly mapped and critically assessed so far. The objective of this study was to evaluate the effects of statins and/or fibrates on prevention and progression of DR. We conducted a Systematic review of randomized controlled trials (RCTs) following the Cochrane Handbook for Systematic Reviews of Interventions and reported in accordance to PRISMA Statement. GRADE approach was used to summarize the certainty of the evidence. Eight RCTs that fulfilled our eligibility criteria were included, assessing the effects of fibrates (n = 4), statins (n = 3) and fibrate plus statins (n = 1) for therapy (n = 8) or prevention (n = 4) of DR. Overall, the main concern regarding risk of bias assessment was due to incomplete outcome data because high rate of losses in five RCTs. Furthermore, the risk of reporting bias was rated unclear due the lack of previously published protocol in seven RCTs. Fibrates seemed to be associated with a 45% risk reduction of macular edema incidence (Relative Risk 0.55, 95% confidence interval of 0.38 to 0.81, 1309 participants, 2 RCTs, I² = 0%, low certainty of the evidence). The certainty of evidence for other outcomes was also very low or low, and we are uncertain regarding the effects of fibrates for DR. Overall, adverse events seemed to be similar between fibrate and placebo, but again based on the width of the confidence intervals, an important increase of adverse events cannot be rule out. The combination statin/fibrate did not seem to have benefit for visual acuity but is likely that further studies can modify this estimate since the current evidence is limited. Adverse events and quality of life were not measured or reported. Concluding, this study found eight RCTs, with limited methodological quality, that assessed the effects of fibrates and/or statins for DR. Based on these findings, we are uncertain about the effects of statins for DR. Fibrates seemed to reduce the incidence of macular edema (low certainty evidence) without increase adverse events (low to very low certainty evidence). Number of Protocol registration PROSPERO CRD42016029746.