Vision-Related Functional Burden of Diabetic Retinopathy Across Severity Levels in the United States

A critical review: Psychophysical assessments of diabetic retinopathy

Diabetic retinal disease remains a leading cause of vision loss despite currently available screening methods, ocular treatments, and efforts to control metabolic dysfunction. It is now understood that diabetes damages the entire retina and the cellular components of the neurovascular unit. Multiple studies have demonstrated impairment of various aspects of retinal function across the spectrum of retinopathy severity. Here we review these tests, the principles underlying their use, clinical data from multiple publications, the strengths and limitations of the studies, and prospects for their application to understand the pathophysiology of diabetic retinal disease and monitor its response to therapy. We focus on visual acuity, contrast sensitivity, color vision, visual field, and dark adaptation and their use to understand the pathophysiology of diabetic retinopathy and as potential endpoints for clinical trials.

THREE-YEAR OUTCOMES IN A RANDOMIZED SINGLE-BLIND CONTROLLED TRIAL OF INTRAVITREAL RANIBIZUMAB AND ORAL SUPPLEMENTATION WITH DOCOSAHEXAENOIC ACID AND ANTIOXIDANTS FOR DIABETIC MACULAR EDEMA

The decrease in macular thickness observed at 24 months was maintained at Month 36 in patients with diabetic macular edema treated with a combination of intravitreal ranibizumab and oral supplementation with high-dose docosahexaenoic acid and antioxidants.

Purpose:

To report 3-year results of a randomized single-blind controlled trial of intravitreal ranibizumab combined with oral docosahexaenoic acid (DHA) supplementation versus ranibizumab alone in patients with diabetic macular edema.

Methods:

There were 26 patients (31 eyes) in the DHA group and 29 (38 eyes) in the control group. Ranibizumab (0.5 mg) was administered monthly for the first 4 months followed by a pro re nata (PRN) regimen. In the experimental group, patients received oral DHA supplementation (1,050 mg/day) (Brudyretina 1.5 g).

Results:

At 36 months, mean decrease of central subfield macular thickness was higher in the DHA-supplementation group than in controls (275 ± 50 μm vs. 310 ± 97 μm) with significant differences at Months 25, 30, 33, and 34. Between-group differences in best-corrected visual acuity were not found, but the percentages of ETRDS gains >5 and >10 letters were higher in the DHA-supplementation group. Differences serum HbA1c, plasma total antioxidant capacity values, erythrocyte DHA content, and serum IL-6 levels were all significant in favor of the DHA-supplementation group.

Conclusion:

The addition of a high-rich DHA dietary supplement to intravitreal ranibizumab was effective to achieve better sustained improvement of central subfield macular thickness outcomes after 3 years of follow-up as compared with intravitreal ranibizumab alone.

MicroRNA-199a-3p inhibits angiogenesis by targeting the VEGF/PI3K/AKT signalling pathway in an in vitro model of diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) is a major inducer of blindness and visual impairment. As a critical cause for DR, hyperglycaemia is able to trigger multiple biochemical alterations. MiRNAs, which contain various functions, can effectively regulate blood glucose levels. This research aims to confirm the roles of miRNA-199a-3p in the progression of angiogenesis in an in vitro model of DR.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was carried to determine the expression levels of miR-199a-3p and VEGF in both hRMECs and APRE-19 cells. The luciferase reporter assay was used to study the interaction between miR-199a-3p and VEGF. Western blot assay was conducted to examine the expression levels of VEGF and the PI3K/AKT signalling pathway. The cell proliferation capacity was detected via the CCK-8 test. The impact of miR-199a-3p on migration was determined using Transwell and wound healing assays. A Matrigel tube formation assay was employed to determine the vascular formation of hRMECs. Flow cytometry was used to determine cell apoptosis in the presence of LY294002 as a PI3K inhibitor.

RESULTS

Our results showed that high glucose (HG) decreased the relative expression level of miR-199a-3p but increased VEGF expression in hRMECs and APRE-19 cells. MiR-199a-3p inhibitor augmented cell growth, migration and angiogenesis of hRMECs. Moreover, upregulation of miR-199a-3p evidently alleviated the increases in cell proliferation, migration and angiogenesis caused by HG. In addition, the luciferase reporter assay indicated that miR-199a-3p directly targeted VEGF. The overexpression of miR-199a-3p obviously restrained the HG-stimulated PI3K/AKT signalling pathway and angiogenesis, which could be further inhibited by LY294002. Moreover, LY294002 could slightly ameliorate the miR-199a-3p inhibitor-stimulated PI3K/AKT signalling pathway and angiogenesis.

CONCLUSION

MiR-199a-3p upregulation ameliorated HG-stimulated angiogenesis of hRMECs by modulating the PI3K/AKT pathway through inhibiting VEGF. Although retinal neovascularization in vivo has not been studied, these in vitro findings provide more evidence for the role of miR-199a-3p upregulation against HG-induced angiogenesis.

Psychological, social and everyday visual impact of diabetic macular oedema and diabetic retinopathy: a systematic review

AIMS

To synthesize the evidence on the impact of diabetic retinopathy and diabetic macular oedema from the patient perspective.

METHODS

A systematic literature review was conducted using MEDLINE Complete, PsycINFO, EMBASE and AMED. We included articles investigating the impact of the condition on quality of life, symptoms, visual functioning, activities of daily living, well-being, social functioning, and financial status. The studies evaluated were observational, including cross-sectional, prospective cohort and retrospective cohort designs. Outcome data were extracted and synthesized.

RESULTS

Searches yielded 5114 publications. After screening, 85 studies were included, measuring the following outcomes: visual functioning (n=46); quality of life (n=22); well-being (n=16); functional status (n=5); work (n=4); and visual task performance (n=2). Diabetic retinopathy has a considerable impact on visual functioning and this is greater in people with greater disease severity. Diabetic retinopathy significantly limits activities including working, driving, walking and reading, and has the potential to have a negative impact on psychological well-being.

CONCLUSIONS

Diabetic retinopathy is associated with poor self-reported visual functioning, well-being, and health-related quality of life. Ability to perform basic everyday tasks appears to diminish with disease severity. Some studies suggest impaired mobility and problems with work, but there are gaps in this evidence.

n-3 Fatty Acid and Its Metabolite 18-HEPE Ameliorate Retinal Neuronal Cell Dysfunction by Enhancing Müller BDNF in Diabetic Retinopathy

Diabetic retinopathy (DR) is a widespread vision-threatening disease, and neuroretinal abnormality should be considered as an important problem. Brain-derived neurotrophic factor (BDNF) has recently been considered as a possible treatment to prevent DR-induced neuroretinal damage, but how BDNF is upregulated in DR remains unclear. We found an increase in hydrogen peroxide (H₂O₂) in the vitreous of patients with DR. We confirmed that human retinal endothelial cells secreted H₂O₂ by high glucose, and H₂O₂ reduced cell viability of MIO-M1, Müller glia cell line, PC12D, and the neuronal cell line and lowered BDNF expression in MIO-M1, whereas BDNF administration recovered PC12D cell viability. Streptozocin-induced diabetic rats showed reduced BDNF, which is mainly expressed in the Müller glia cell. Oral intake of eicosapentaenoic acid ethyl ester (EPA-E) ameliorated BDNF reduction and oscillatory potentials (OPs) in electroretinography (ERG) in DR. Mass spectrometry revealed an increase in several EPA metabolites in the eyes of EPA-E-fed rats. In particular, an EPA metabolite, 18-hydroxyeicosapentaenoic acid (18-HEPE), induced BDNF upregulation in Müller glia cells and recovery of OPs in ERG. Our results indicated diabetes-induced oxidative stress attenuates neuroretinal function, but oral EPA-E intake prevents retinal neurodegeneration via BDNF in Müller glia cells by increasing 18-HEPE in the early stages of DR.

American Society of Retina Specialists Clinical Practice Guidelines on the Management of Nonproliferative and Proliferative Diabetic Retinopathy without Diabetic Macular Edema

Purpose

Nonproliferative (NPDR) and proliferative diabetic retinopathy (PDR) without diabetic macular edema (DME) affect millions of individuals living with diabetes throughout the world. There is increasing data on various management strategies for such patients, but there is limited consensus on how the data should be adopted into clinical practice.

Methods

This literature review and editorial presents and synthesizes the current evidence for various management paradigms for NPDR and PDR without DME.

Results

Retina specialists are an integral member of the diabetes management team, and should encourage patients on the importance of glycemic and cardiovascular optimization for both systemic and retinopathy risk factor reduction. The diabetic retinopathy severity scale (DRSS) is now an approvable endpoint for clinical trials in the United States, therefore becoming more clinically relevant. For PDR without DME, the Diabetic Retinopathy Study (DRS) and the Early Treatment Diabetic Retinopathy Study (ETDRS) established the standard of care with panretinal photocoagulation (PRP). Laser parameters have since evolved to include less intense and earlier intervention. Studies have recently demonstrated that anti-vascular endothelial growth factor (VEGF) treatment of PDR is effective at regressing neovascularization and improving DRSS levels in many patients. Further evidence is required to determine optimal treatment frequency, duration, and retreatment criteria, in the real world. There are concerns for adverse events in patients being lost to follow up during anti-VEGF treatment. For NPDR without DME, the standard of care has been a wait-and-watch approach. Data within the DRS and the ETDRS suggest that PRP for severe NPDR can be an option for select patients as well. Multiple clinical trials have now demonstrated that anti-VEGF treatment can improve the DRSS score in NPDR. Further studies are required to assess whether this positively affects long-term visual outcomes, and whether the benefits outweigh the risks in the real world for routine use.

Conclusions

There is cumulative evidence demonstrating the efficacy of various treatment options for NPDR and PDR without DME. Currently, patients would most likely benefit from thoughtful management strategies that are tailored to the individual patient.

microRNA Expression Profiling Based on Microarray Approach in Human Diabetic Retinopathy: A Systematic Review and Meta-Analysis

Diabetes mellitus (DM) is one of the growing public health threats globally and as one of the common serious microvascular complications of DM, diabetic retinopathy (DR) is the leading cause of irreversible visual impairments and blindness. There is growing concern about the role of microRNAs (miRNAs) in the pathogenesis of DR. This meta-analysis was designed to collect those published miRNA expression profiling studies that compared the miRNA expression profiles in the biological samples of DR patients with those in the control group. Eight publications were finally included in the meta-analysis, and a total of 93 differentially expressed miRNAs were reported. Although six miRNAs were reported in at least two studies and with the consistent direction, after stratification by the type of biological samples, miR-320a was consistently reported to be upregulated in two serum sample-based studies and miR-423-5p was consistently reported to be upregulated in two vitreous humor sample-based studies. miR-27b was consistently reported to be downregulated in two serum sample-based studies. In conclusion, the results of this meta-analysis of human DR miRNAs' expression profiling studies might provide some clues of the potential biomarkers of DR. Further investigation of the mechanisms of miRNAs and more external validation studies are warranted with the aim of developing new diagnostic markers for preventing or reversing DR.

Survival Time of Visual Gains after Diabetic Vitrectomy and Its Relationship with Ischemic Heart Disease

Vitrectomy surgery in proliferative diabetic retinopathy improves the vision-related quality of life. However, there is lack of data on the duration of maintenance of visual gains post vitrectomy. This study thus aimed to determine the survival time of visual gains and the prognostic factors of vision loss after vitrectomy surgery for complications of proliferative diabetic retinopathy. A retrospective cohort study was conducted in an ophthalmology clinic in Malaysia. We included 134 patients with type 2 diabetes mellitus on follow-up after vitrectomy for proliferative diabetic retinopathy. Visual acuity was measured using the log of minimum angle of resolution (LogMar). A gain of ≥0.3 LogMar sustained on two subsequent visits was considered evidence of visual improvement post vitrectomy. Subjects were considered to have vision loss when their post-operative visual acuity subsequently dropped by ≥0.3 LogMar. Kaplan–Meier analysis was used to determine the survival time of visual gains. Cox Proportional Hazard regression was used to determine the prognostic factors of vision loss. The median age of patients was 56.00 years (IQR ± 10.00). The median duration of diabetes mellitus was 14.00 years (IQR ± 10.00). Approximately 50% of patients with initial improvement post vitrectomy subsequently experienced vision loss. The survival time, i.e., the median time from surgery until the number of patients with vision loss formed half of the original cohort, was 14.63 months (95% CI: 9.95, 19.32). Ischemic heart disease was a significant prognostic factor of vision loss. Patients with underlying ischemic heart disease (adjusted HR: 1.97, 95% CI: 1.18, 3.33) had a higher risk of vision loss post vitrectomy, after adjusting for other factors. Approximately half the patients with initial visual gains post vitrectomy maintained their vision for at least one year. Ischemic heart disease was a poor prognostic factor for preservation of visual gains post vitrectomy.

Association of Age-Related Macular Degeneration With Risk of All-Cause and Specific-Cause Mortality in the National Health and Nutrition Examination Survey, 2005 to 2008

Question

What is the association of age-related macular degeneration with mortality outcomes among older adults?

Findings

In this cohort study of 5603 participants 40 years or older, only late age-related macular degeneration was associated with more than a doubling of all-cause mortality and more than 3-fold higher risk of mortality not due to cardiovascular disease and cancer.

Meaning

The association of late age-related macular degeneration and poor survival may shed light on mechanisms underlying the disease, indicating that late age-related macular degeneration may be a marker of frailty and aging or may be due to residual confounding factors indicative of aging.

Importance

Age-related macular degeneration (AMD) is the leading cause of irreversible visual impairment and blindness in the United States if subretinal neovascularization is left untreated. Knowledge of the association between AMD and survival is informative for underlying mechanisms of AMD.

Objective

To examine the association between AMD and risk of all-cause and specific-cause mortality in a representative US sample.

Design, Setting, and Participants

This population-based prospective cohort study included 5603 participants 40 years or older who responded to the National Health and Nutrition Examination Survey (NHANES) in the 2005-2008 phase. Retinal photographs were graded as early, late, or no AMD. All analyses accounted for the complex and stratified design of NHANES with weighted data. Risks of all-cause mortality were assessed with Cox proportional hazards regression models; risks of specific-cause mortality, with Fine and Gray competing risks regression models. Time to death was counted from baseline to date of death or December 31, 2011, whichever came first. Data analysis was conducted from April 1 through 30, 2018.

Exposures

Age-related macular degeneration status as determined by digital fundus images.

Main Outcomes and Measures

Mortality resulting from all causes and specific causes until December 31, 2011.

Results

Among the 5603 participants (52.6% female [n = 2793] and 77.1% white [n = 3017]; mean [SE] age, 56.4 [0.4] years), weighted prevalence of any AMD was 6.6%, with 386 (5.8%) having early AMD and 55 (0.8%) having late AMD. After a median follow-up of 4.5 years (interquartile range, 3.6-5.6 years), 433 (5.3%) died of all causes, of whom 361 (83.1%) had no AMD, 54 (11.5%) had signs of early AMD, 18 (5.4%) had signs of late AMD, and 72 (16.9%) had any AMD at baseline. Overall, unadjusted all-cause and specific-cause mortality rates were higher for those participants who had early, late, or any AMD compared with no AMD. However, after adjusting confounding factors, only late AMD was associated with more than a doubling of all-cause mortality (hazard ratio [HR], 2.01; 95% CI, 1.00-4.03) and more than a 3-fold higher risk of mortality due to causes other than cardiovascular disease and cancer (HR, 3.42; 95% CI, 1.38-8.49). No association was identified between AMD presence or early AMD and all-cause or specific-cause mortality.

Conclusions and Relevance

In this study’s findings, only late AMD was independently associated with all-cause mortality and mortality due to causes other than cardiovascular disease and cancer, indicating that late AMD may be a marker of biological aging. Alternatively, this association may be due to unmeasured or inadequately assessed confounding factors for late AMD.

[On classification of diabetic retinopathy]

The article analyses current state of the problem of diabetic retinopathy classifications based on the data from Russian and foreign literature on pathogenesis, clinical manifestations, results of multicenter studies on treatment and prognosis of the disease. Every existing classification was found to be limited in applications; attempts had been made to unify and complement them with the aim of achieving more complete and better-detailed description of the processes of diagnostics and determination of treatment algorithms. In conclusion, none of the existing classifications can be considered consistent in both clinical and practical aspects with respect to diabetic retinopathy.

Novel anti-angiogenic PEDF-derived small peptides mitigate choroidal neovascularization

Abnormal migration and proliferation of endothelial cells (EC) drive neovascular retinopathies. While anti-VEGF treatment slows progression, pathology is often supported by decrease in intraocular pigment epithelium-derived factor (PEDF), an endogenous inhibitor of angiogenesis. A surface helical 34-mer peptide of PEDF, comprising this activity, is efficacious in animal models of neovascular retina disease but remains impractically large for therapeutic use. We sought smaller fragments within this sequence that mitigate choroidal neovascularization (CNV). Expecting rapid intravitreal (IVT) clearance, we also developed a method to reversibly attach peptides to nano-carriers for extended delivery. Synthetic fragments of 34-mer yielded smaller anti-angiogenic peptides, and N-terminal capping with dicarboxylic acids did not diminish activity. Charge restoration via substitution of an internal aspartate by asparagine improved potency, achieving low nM apoptotic response in VEGF-activated EC. Two optimized peptides (PEDF 335, 8-mer and PEDF 336, 9-mer) were tested in a mouse model of laser-induced CNV. IVT injection of either peptide, 2-5 days before laser treatment, gave significant CNV decrease at day +14 post laser treatment. The 8-mer also decreased CNV, when administered as eye drops. Also examined was a nanoparticle-conjugate (NPC) prodrug of the 9-mer, having positive zeta potential, expected to display longer intraocular residence. This NPC showed extended efficacy, even when injected 14 days before laser treatment. Neither inflammatory cells nor other histopathologic abnormalities were seen in rabbit eyes harvested 14 days following IVT injection of PEDF 336 (>200 μg). No rabbit or mouse eye irritation was observed over 12-17 days of PEDF 335 eye drops (10 mM). Viability was unaffected in 3 retinal and 2 choroidal cell types by PEDF 335 up to 100 μM, PEDF 336 (100 μM) gave slight growth inhibition only in choroidal EC. A small anti-angiogenic PEDF epitope (G-Y-D-L-Y-R-V) was identified, variants (adipic-Sar-Y-N-L-Y-R-V) mitigate CNV, with clinical potential in treating neovascular retinopathy. Their shared active motif, Y - - - R, is found in laminin (Ln) peptide YIGSR, which binds Ln receptor 67LR, a known high-affinity ligand of PEDF 34-mer.

Protective factors for diabetic retinopathy in Type 2 diabetes mellitus patients: Long duration of no less than 10 years

AIM

To study the factors protecting against diabetic retinopathy (DR) in patients with over a decade-long history of type 2 diabetes mellitus.

METHODS

A total of 490 patients with type 2 diabetes mellitus lasting for ≥10 years were divided into DR and no diabetic retinopathy (no DR) groups. Their basic information was collected, including age, sex, and duration of diabetes mellitus, as well as pertinent laboratory data. Potential correlations between these factors and DR were evaluated using multivariate analysis.

RESULTS

Overall, 208 patients met the diagnostic criteria for DR. Multivariate logistic regression was used to evaluate factors with P < 0.10 after univariate analysis. Age, total bilirubin, and total cholesterol were found to be protective factors against DR. Presence of diabetic kidney disease and diabetic peripheral neuropathy, duration of diabetes mellitus, apolipoprotein B, blood urea nitrogen, and prothrombin time were found to be risk factors for DR.

CONCLUSIONS

We conclude that total cholesterol is a protective factor against DR. Specifically, it was confirmed that high levels of total cholesterol reduce the risk of DR. These findings may provide a basis for new diet and lifestyle guidelines for patients with diabetes mellitus.

Deep learning algorithm predicts diabetic retinopathy progression in individual patients

The global burden of diabetic retinopathy (DR) continues to worsen and DR remains a leading cause of vision loss worldwide. Here, we describe an algorithm to predict DR progression by means of deep learning (DL), using as input color fundus photographs (CFPs) acquired at a single visit from a patient with DR. The proposed DL models were designed to predict future DR progression, defined as 2-step worsening on the Early Treatment Diabetic Retinopathy Diabetic Retinopathy Severity Scale, and were trained against DR severity scores assessed after 6, 12, and 24 months from the baseline visit by masked, well-trained, human reading center graders. The performance of one of these models (prediction at month 12) resulted in an area under the curve equal to 0.79. Interestingly, our results highlight the importance of the predictive signal located in the peripheral retinal fields, not routinely collected for DR assessments, and the importance of microvascular abnormalities. Our findings show the feasibility of predicting future DR progression by leveraging CFPs of a patient acquired at a single visit. Upon further development on larger and more diverse datasets, such an algorithm could enable early diagnosis and referral to a retina specialist for more frequent monitoring and even consideration of early intervention. Moreover, it could also improve patient recruitment for clinical trials targeting DR.

Surgical Innovations in the Treatment of Diabetic Macular Edema and Diabetic Retinopathy

PURPOSE OF REVIEW

Diabetic macular edema (DME) and complications of proliferative diabetic retinopathy (PDR) are the primary causes of vision loss in patients with diabetic retinopathy. As the incidence of diabetes increases worldwide, new, cost-effective treatments for DME and PDR will become paramount. Currently, anti-vascular endothelial growth factor (anti-VEGF) medications are considered first-line treatment. However, multiple visits for injections and the economic and time burden they entail make this treatment modality less than ideal. Early vitrectomy as well as depot delivery systems for medications could potentially reduce the treatment burden of patients with diabetes, prevent visual loss, and provide long-term stabilization of retinopathy in patients with diabetes. Newer port delivery systems for anti-VEGF medications could one day make this treatment modality better suited for patients across the globe.

RECENT FINDINGS

Real-world data shows poor compliance with treatment among patients with diabetes. Recent publications show catastrophic results when anti-VEGF treatments are stopped abruptly. The port delivery system for ranibizumab shows maintenance of adequate anti-VEGF levels in the vitreous cavity for many months. Early vitrectomy can provide cost-effective long-term stabilization in eyes with diabetic retinopathy. Microincisional vitrectomy as a treatment for DME and PDR remains controversial and larger trials are needed to definitively prove its superiority over other modalities; however, small-scale data point towards its usefulness in specific populations. Newer port delivery systems of anti-VEGF show promise in decreasing the number of office visits in patients with diabetic retinopathy.

Erianin alleviates diabetic retinopathy by reducing retinal inflammation initiated by microglial cells via inhibiting hyperglycemia-mediated ERK1/2-NF-κB signaling pathway

Blood-retinal barrier (BRB) breakdown is a typical event in the early stage of diabetic retinopathy (DR). This study aims to elucidate the protection of erianin, a natural compound isolated from Dendrobium chrysotoxum Lindl, against DR development. Erianin alleviated BRB breakdown and rescued the reduced claudin1 and occludin expression in retinas from streptozotocin-induced diabetic mice. Erianin reduced microglial activation, ERK1/2 phosphorylation, NF-κB transcriptional activation, and the elevated TNF-α expression both in vitro and in vivo. ERK1/2 inhibitor U0126 abrogated NF-κB activation in d-glucose-treated BV2 cells. Erianin reduced cellular glucose uptake, and molecular docking analysis indicated the potential interaction of erianin with glucose transporter (GLUT)1. GLUT1 inhibitor (STF31) reduced the activation of the ERK1/2-NF-κB signaling pathway. Coculture with d-glucose-stimulated microglial BV2 cells and with TNF-α stimulation both induced inner BRB and outer BRB damage in human retinal endothelial cells and APRE19 cells, but erianin improved all these damages. In summary, erianin attenuated BRB breakdown during DR development by inhibiting microglia-triggered retinal inflammation via reducing cellular glucose uptake and abrogating the subsequent activation of the downstream ERK1/2-NF-κB pathway. Moreover, erianin also alleviated BRB damage induced by TNF-α released from the activated microglia.-Zhang, T., Ouyang, H., Mei, X., Lu, B., Yu, Z., Chen, K., Wang, Z., Ji, L. Erianin alleviates diabetic retinopathy by reducing retinal inflammation initiated by microglial cells via inhibiting hyperglycemia-mediated ERK1/2-NF-κB signaling pathway.

Characteristics Associated with Adherence to Annual Dilated Eye Examinations among US Patients with Diagnosed Diabetes

PURPOSE

To identify the characteristics that are associated with adherence to annual diabetic eye exams and patient awareness of retinopathy using a nationally representative sample from the United States.

DESIGN

Cross-sectional, secondary analysis.

PARTICIPANTS

National Health and Nutrition Examination Survey (NHANES) participants from 2005 to 2016 aged 20 years and older with diabetes mellitus.

METHODS

The NHANES collected surveys every 2 years from 2005 to 2016, which contained demographic information, clinical information, and time to last dilated eye exam. From 2005 to 2008, retinal photographs were taken of all participants older than 40 years of age. We used univariate and multivariable logistic regression to determine the demographic and clinical factors associated with adherence to annual diabetic eye examinations and those associated with correctly reporting their retinopathy status.

MAIN OUTCOME MEASURE

Factors associated with adherence defined as having an eye exam within the preceding 12 or 24 months.

RESULTS

From 2005 to 2016, NHANES surveyed 4072 individuals who represent 20 million Americans aged 20 years and older with self-report of diabetes. By using the adherence definitions of 12 and 24 months, 63.4% and 78.7%, respectively, were adherent to diabetic eye examinations. The nonadherence rates of 36.6% and 21.3% for this national estimate did not change from 2005 to 2016 (P = 0.7, logistic regression). Insurance status, age, education, income, cholesterol levels, duration of diabetes, and self-reported retinopathy were all significantly associated with adherence with both definitions (all P < 0.05, logistic regression). Insurance status had the highest predictive value, with 76% of Americans on combination private-public insurance adherent compared with 36% of uninsured. Most Americans with retinopathy incorrectly denied having the diagnosis (2 727 144/3 896 093 or 70%).

CONCLUSIONS

Multiple variables were associated with nonadherence to eye exams, with insurance status having the strongest association. Adherence with annual eye exams has not improved over the past decade. The majority of patients with retinopathy are unaware of this diagnosis, including the majority of those with a dilated funduscopic examination in the past year. Further improvements in education and adherence may reduce the visual morbidity caused by diabetes.

Extended Intravitreal Rabbit Eye Residence of Nanoparticles Conjugated With Cationic Arginine Peptides for Intraocular Drug Delivery: In Vivo Imaging

Purpose

Drug delivery by intravitreal injection remains problematic, small agents and macromolecules both clearing rapidly. Typical carriers use microparticles (>2 μm), with size-related liabilities, to slow diffusion. We recently described cationic nanoparticles (NP) where conjugated Arg peptides prolonged residence in rat eyes, through ionic interaction with vitreal poly-anions. Here we extended this strategy to in vivo tracking of NP-conjugate (NPC) clearance from rabbit eyes. Relating t_1/2 to zeta potential, and varied dose, we estimated the limits of this charge-based delivery system.

Methods

NPC carried covalently attached PEG₈-2Arg or PEG₈-3Arg pentapeptides, having known sequences from human eye proteins. Peptides were conjugated (61–64 per NPC); each NP/NPC also carried a cyanine7 tag (<0.5 dye/particle). In vivo imaging system (IVIS), after intravitreal injection, estimated NPC loss by 800-nm photon emission (745-nm excitation) at 1 to 3-week intervals following initial scan at day 10.

Results

NPC of 2Arg-peptides or 3Arg-peptides showed clearance t_1/2 of 7 days and 17 days respectively, unconjugated NP t_1/2 was <<5 days. Doses of 90, 180, and 360 μg of PEG₈-2Arg NPC were compared. The lower doses showed dose-proportional day-10 concentration, and similar clearance. Higher early loss was seen with a 360-μg dose, exceeding rabbit vitreal binding capacity. No inflammation was observed.

Conclusions

This type of cationic NPC can safely increase residence t_1/2 in a 1 to 3-week range, with dose <100 μg per mL vitreous. Human drug load may then range from 10 to 100 μg/eye, usefulness depending on individual drug potency and release rate, superimposed on extended intravitreal residence.

Durability of Diabetic Retinopathy Improvement with As-Needed Ranibizumab: Open-Label Extension of RIDE and RISE Studies

PURPOSE

To evaluate the durability of diabetic retinopathy (DR) improvements after a change in ranibizumab dosing from monthly to individualized pro re nata (PRN) therapy.

DESIGN

Pooled analysis of the open-label extension (OLE) of RIDE and RISE (clinicaltrials.gov identifiers, NCT00473382 and NCT00473330) patients with DR and diabetic macular edema (DME).

PARTICIPANTS

Patients who completed 36-month participation in RIDE and RISE and entered the OLE.

METHODS

In RIDE and RISE, patients (n = 759) were randomized 1:1:1 to ranibizumab 0.3 mg monthly, 0.5 mg monthly, or monthly sham injections with rescue macular laser available after 6 months, per protocol-specified criteria. After 24 months, sham patients crossed over to ranibizumab 0.5 mg monthly. After 36 months in the core studies, patients in the OLE (n = 500) could receive ranibizumab 0.5 mg PRN based on predefined DME re-treatment criteria. Diabetic retinopathy severity was evaluated photographically using the Early Treatment Diabetic Retinopathy Study DR severity scale.

MAIN OUTCOME MEASURES

Change in DR severity from months 36 to 48 by re-treatment status.

RESULTS

Among patients who entered the OLE, 121 of 500 (24%) did not require additional ranibizumab injections. Overall, 367 patients had evaluable DR at months 36 and 48. Among patients not requiring ranibizumab re-treatment from months 36 to 48 (88/367), 57% to 78%, 0% to 7%, and 22% to 36% experienced DR severity stability, 2-step or more improvement, and 2-step or more worsening, respectively. Among patients requiring ranibizumab re-treatment (279/367), 84% to 94%, 2%, and 3% to 14% experienced DR severity stability, 2-step or more improvement, and 2-step or more worsening, respectively. On average, vision improvements were maintained during the OLE regardless of change in DR severity.

CONCLUSIONS

Diabetic retinopathy severity improvements with ranibizumab were maintained in over 70% of OLE patients after switching from ranibizumab monthly to an individualized ranibizumab 0.5 mg PRN dosing regimen. Because approximately one third of OLE patients experienced DR worsening, careful monitoring should be part of the long-term management of patients with DR.

Pharm-MD; an open-label, randomized controlled, phase II study to evaluate the efficacy of a pharmacist-managed diabetes clinic in high-risk diabetes patients - study protocol for a randomized controlled trial

Background

Millions of Americans are currently living with diabetes and approximately 1.5 million cases are being diagnosed each year. Diabetes is now the seventh leading cause of death in the United States. In addition, the economic burden of the disease has resulted in billions of dollars in health care costs. In spite of these investments, the United States lags behind other developed countries on diabetes life expectancy and disease-related deaths. The purpose of this study is to assess the impact of a pharmacist-managed diabetes clinic (PMDC) model on diabetes core measures. Our hypothesis is that a PMDC would have a significant positive impact on the diabetes measures and will result in higher-quality care at a lower price.

Methods

This study is a randomized, open-label, controlled, parallel-group trial which will be conducted in the outpatient clinic at Beaumont Hospital, Royal Oak, Michigan. Patients will be randomly assigned to one of two groups: standard of care (SOC) or standard of care plus PMDC (SOC + PMDC). Included in the study will be patients older than 18 years of age with a diagnosis of type 2 diabetes mellitus and a hemoglobin A1c ≥ 9%, who are established with a primary care resident and who have not been seen in the PMDC within the last 3 months. The primary outcome is the change in hemoglobin A1c, measured at 6 and 12 months. Secondary outcomes include the impact on all diabetes core measures, patient quality of life, harms, and cost impact related to the intervention.

Discussion

If the results of this trial are consistent with the previous retrospective analysis that a pharmacy clinic has a significant impact in controlling hemoglobin A1c levels as well as other diabetes core measures to improve clinical outcomes, it will constitute a scaffold for a future multicenter, randomized controlled trial. In addition, these results may influence future diabetes guidelines, leading to the inclusion of a PMDC as the standard of care. The impact of these results on the economic burden, life expectancy, and diabetes-related deaths are needed and have yet to be studied.

Trial registration

ClinicalTrials.gov, ID: NCT03377127.

Protocol version: registered on 10 February 2018; version #1.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2836-8) contains supplementary material, which is available to authorized users.