Diabetic Retinopathy: Focus on Minority Populations

A Systematic Review and Meta-Analysis Assessing Diversity and Representation in Diabetic Retinopathy Clinical Trials in the U.S

PURPOSE

To perform a systematic review and meta-analysis assessing the diversity and representation of diabetic retinopathy (DR) patients in clinical trials conducted in the United States from January 1, 2018, to December 31, 2023.

METHODS

A comprehensive search strategy was conducted on May 28th, 2024 using MEDLINE (PubMed) and Embase (Elsevier) to identify relevant clinical trials. Inclusion criteria included trials published between January 1, 2018 and December 31, 2023, focusing on interventions for DR that were conducted in the United States. Screening and data extraction were independently performed by three reviewers.

RESULTS

Eleven clinical trials met the inclusion criteria and were analyzed for participant representation based on sex, age, and race/ethnicity. Sex representation was rated as good in 9 of the 11 studies. However, age representation was rarely reported (only 1/11 studies) and race/ethnicity representation was poor in 6 of the 11 studies. The findings highlight significant underrepresentation of Asian and Black populations.

CONCLUSION

This study reveals substantial disparities in the demographic representation within DR clinical trials in the United States, emphasizing the critical need for improved inclusion strategies. Enhancing diversity in these trials is essential for producing research findings that are more applicable to the broader population affected by DR, ultimately contributing to more equitable healthcare outcomes and advancing the effectiveness of treatments across diverse demographic groups.

How intravitreal anti-vascular endothelial growth factor initial dosing impacts patient outcomes in diabetic macular oedema

BACKGROUND

Intravitreal anti-vascular endothelial growth factor (VEGF) treatment for diabetic macular oedema (DME) may begin with several initial monthly doses. Characteristics, treatment patterns and outcomes were compared for eyes with DME that did and did not receive such initial doses.

METHODS

This was a retrospective database study using American Academy of Ophthalmology Intelligent Research in Sight® Registry data (01/01/15-31/12/20; index period). Eligible adults had documented DME within 2 months of first anti-VEGF treatment (index date), data available for 12 months beforehand, and ≥ 1 visual acuity (VA) recording ≤ 60 days before index date. Eyes must have received intravitreal anti-VEGF injections during the index period, but none in the prior 12 months. Characteristics and outcomes for eyes with initial doses (three injections within 100 days of index date) were compared with those without. Multivariate Cox Proportional Hazards modelling estimated predictors for treatment discontinuation, re-initiation, or switch; Generalized Estimating Equations-adjusted modelling estimated characteristics associated with receiving initial doses. Demographics and characteristics were summarised. Injection frequency and number, and VA were determined annually for ≤ 6 years. Discontinuations, reinitiations and switches were compared.

RESULTS

Included were 217,696 eyes (n = 77,769 initial; n = 139,927 non-initial) from 166,868 patients. Mean (SD) baseline VA was numerically higher for eyes with versus without initial doses (63.0 [18.1] vs. 62.5 [19.8] letters); this remained during follow-up. Based on modelling results, Eyes with initial doses received more injections (mean [standard deviation (SD)] 11.6 [8.9] vs. 6.1 [6.8] injections) more frequently (interval 7.6 [2.8] vs. 12.6 [7.7] weeks) than eyes without. These differences occurred across follow-up years. Discontinuation (45.7% vs. 63.8%), re-initiation (17.2% vs. 25.0%), and switch (24.5% vs. 31.5%) were less common with initial doses. Asian, Black, and patients of other/unknown race were less likely (P < 0.01) to receive initial doses than White patients, as were Medicare/Medicaid-insured patients versus commercially insured patients (P < 0.01).

CONCLUSIONS

Various sociodemographic factors associate with initial anti-VEGF doses, including race, ethnicity and insurance. Although eyes with frequent initial doses maintained higher VA than those without, they also receive more injections over time. Further research may elucidate the impact of frequent initial doses versus total injection number on DME outcomes.

Diabetic Disease of the Eye in Canada: Consensus Statements from a Retina Specialist Working Group

Despite advances in systemic care, diabetic disease of the eye (DDE) remains the leading cause of blindness worldwide. There is a critical gap of up-to-date, evidence-based guidance for ophthalmologists in Canada that includes evidence from recent randomized controlled trials. Previous guidance has not always given special consideration to applying treatments and managing DDE in the context of the healthcare system. This consensus statement aims to assist practitioners in the field by providing a spectrum of acceptable opinions on DDE treatment and management from recognized experts in the field. In compiling evidence and generating consensus, a working group of retinal specialists in Canada addressed clinical questions surrounding the four themes of disease, patient, management, and collaboration. The working group reviewed literature representing the highest level of evidence on DDE and shared their opinions on topics surrounding the epidemiology and pathophysiology of diabetic retinopathy and diabetic macular edema; diagnosis and monitoring; considerations around diabetes medication use; strategic considerations for management given systemic comorbidities, ocular comorbidities, and pregnancy; treatment goals and modalities for diabetic macular edema, non-proliferative and proliferative diabetic retinopathy, and retinal detachment; and interdisciplinary collaboration. Ultimately, this work highlighted that the retinal examination in DDE not only informs the treating ophthalmologist but can serve as a global index for disease progression across many tissues of the body. It highlighted further that DDE can be treated regardless of diabetic control, that a systemic approach to patient care will result in the best health outcomes, and prevention of visual complications requires a multidisciplinary management approach. Ophthalmologists must tailor their clinical approach to the needs and circumstances of individual patients and work within the realities of their healthcare setting.

Corneal Sensitivity Is Inversely Correlated With Severity of Diabetic Retinopathy in a Predominantly Underrepresented Population

PURPOSE

To assess the relationship between diabetic retinopathy (DR) and corneal sensitivity.

METHODS

In this prospective study, 100 eyes of 50 patients from primarily underrepresented racial and ethnic backgrounds with DR underwent assessment of corneal sensitivity using a Cochet-Bonnet esthesiometer. Severity of DR was graded by a masked reading center. Corneal sensitivity was compared in eyes with current or regressed proliferative DR (PDR) (n=35) and eyes with nonproliferative DR (NPDR) with no history of PDR (n=65). Corneal sensitivity in eyes that regressed from PDR to NPDR with anti-vascular endothelial growth factor (anti-VEGF) therapy (n=7) was compared to treatment-naïve eyes with no current or prior PDR (n=55) and to eyes with newly diagnosed, treatment-naïve PDR (n=12).

RESULTS

In eyes with current or prior PDR, the median corneal sensitivity (average of 4 quadrants) was 0.5 cm (interquartile range [IQR] 0-3.375), whereas in eyes with no current or prior PDR, the median corneal sensitivity was 4.75 cm (IQR 2.0-6.0, P < .0001). The median corneal sensitivity in eyes with regressed PDR was 0 cm (IQR 0-0.875), significantly lower than eyes with no current or prior PDR (4.5 cm, IQR 4.0, P = .0076) and no different than eyes with untreated PDR (0 cm, IQR 1.25). The odds of eyes with DR severity scale score ≥60 having complete corneal sensitivity loss was 3.6 times that of eyes with NPDR.

CONCLUSIONS

Corneal sensitivity is impaired in eyes with PDR compared to NPDR and is not rescued by anti-VEGF therapy. Assessment of corneal sensitivity in eyes with DR may identify patients at risk for additional complications, including neurotrophic keratopathy. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Deep learning innovations in diagnosing diabetic retinopathy: The potential of transfer learning and the DiaCNN model

Diabetic retinopathy (DR) is a significant cause of vision impairment, emphasizing the critical need for early detection and timely intervention to avert visual deterioration. Diagnosing DR is inherently complex, as it necessitates the meticulous examination of intricate retinal images by experienced specialists. This makes the early diagnosis of DR essential for effective treatment and prevention of eventual blindness. Traditional diagnostic methods, relying on human interpretation of medical images, face challenges in terms of accuracy and efficiency. In the present research, we introduce a novel method that offers superior precision in DR diagnosis, compared to traditional methods, by employing advanced deep learning techniques. Central to this approach is the concept of transfer learning. This entails the utilization of pre-existing, well-established models, specifically InceptionResNetv2 and Inceptionv3, to extract features and fine-tune selected layers to cater to the unique requirements of this specific diagnostic task. Concurrently, we also present a newly devised model, DiaCNN, which is tailored for the classification of eye diseases. To prove the efficacy of the proposed methodology, we leveraged the Ocular Disease Intelligent Recognition (ODIR) dataset, which comprises eight different eye disease categories. The results are promising. The InceptionResNetv2 model, incorporating transfer learning, registered an impressive 97.5% accuracy in both the training and testing phases. Its counterpart, the Inceptionv3 model, achieved an even more commendable 99.7% accuracy during training, and 97.5% during testing. Remarkably, the DiaCNN model showcased unparalleled precision, achieving 100% accuracy in training and 98.3% in testing. These figures represent a significant leap in classification accuracy when juxtaposed with existing state-of-the-art diagnostic methods. Such advancements hold immense promise for the future, emphasizing the potential of our proposed technique to revolutionize the accuracy of DR and other eye disease diagnoses. By facilitating earlier detection and more timely interventions, this approach stands poised to significantly reduce the incidence of blindness associated with DR, thus heralding a new era of improved patient outcomes. Therefore, this work, through its novel approach and stellar results, not only pushes the boundaries of DR diagnostic accuracy but also promises a transformative impact in early detection and intervention, aiming to substantially diminish DR-induced blindness and champion enhanced patient care.

A Comparison of Black and Non-Black Patients in the Presentation and Treatment of Keratoconus

Purpose

Patients with advanced keratoconus (KCN) are less likely to benefit from corneal cross-linking and may require a partial or full thickness keratoplasty. This study aimed to determine whether racial disparities exist in the clinical presentation and initial treatment recommendations for patients evaluated for KCN.

Methods

A single-center retrospective review was conducted on all patients who presented to the cornea department for initial evaluation of KCN between 2018 and 2020. Patients who had undergone prior corneal procedures or surgeries were excluded. Baseline sociodemographic and clinical information was collected and stratified according to black versus non-black race. Generalized estimating equations were used to examine the association between black race and presenting corrected distance visual acuity (CDVA), presence of corneal scarring, keratometry values, Belin ABCD score, and treatment recommendations. Multivariate models were adjusted for patient demographics.

Results

A total of 128 patients (251 eyes) were included in this study. In fully adjusted models, black individuals presented with significantly worse CDVA (p < 0.0001) and worse tomographic KCN staging according to the Belin ABCD criteria (p = 0.002) compared to non-blacks. Blacks were also more than four times as likely to present with a thinnest pachymetry <400 µm (p < 0.0001) and more than three times as likely to have corneal scarring (p = 0.001). Blacks were more than seven times more likely to have keratoplasty recommended as treatment than conservative management such as corneal cross-linking or contact lenses (p = 0.004).

Conclusion

Compared with their non-black counterparts, blacks presented with significantly more advanced KCN, which placed them at risk of requiring more invasive treatment plans. Future studies should investigate reasons for such late presentations and aim to mitigate disparities in the presentation and management of KCN.

Silicone oil as a corneal lubricant to reduce corneal edema and improve visualization during vitrectomy

AIM

To evaluate the efficacy and safety of silicone oil (SO) as a corneal lubricant to improve visualization during vitrectomy.

METHODS

Patients who underwent vitreoretinal surgery were divided into two groups. Group 1 was operated on with initial SO (Oxane 5700) as a corneal lubricant. Group 2 was operated on with initial lactated ringer's solution (LRS) and then replaced with SO as required. Fundus clarity was scored during the surgery. Fluorescein staining was performed to determine the damage to corneal epithelium.

RESULTS

Totally 114 eyes of 114 patients were included. Single SO use maintained a clear cornea and provided excellent visualization of surgical image. In group 1, the fundus clarity was grade 3 in 41/45 eyes and grade 2 in 4/45 eyes. In group 2, corneal edema frequently occurred after initial LRS use. The fundus clarity was grade 3 in 19/69 eyes, 2 in 37/69 eyes and 1 in 13/69 eyes (P<0.05). SO was applied in 29 eyes of initial LRS use with subsequent corneal edema, which eliminated the corneal edema in 26 eyes. Corneal fluorescein staining score in group 1 was 0 in 28 eyes, 1 in 11 eyes and 2 in 6 eyes, and 40, 20 and 9, respectively, in group 2 (all P>0.05).

CONCLUSION

The use of SO as a corneal lubricant is effective and safe for preserving and improving corneal clarity and providing clear surgical field during vitrectomy.

Clinical Utility of Spectral-Domain Optical Coherence Tomography Marker Disorganization of Retinal Inner Layers in Diabetic Retinopathy

BACKGROUND AND OBJECTIVE

Disorganization of retinal inner layers (DRIL) is a potential spectral-domain optical coherence tomography (SD-OCT) imaging biomarker with clinical utility in diabetic retinopathy (DR).

PATIENTS AND METHODS

A cross-sectional study was conducted at a large academic center. The cohort was composed of 1,175 patients with type 2 diabetes with and without retinopathy on initial examination between September 2009 and January 2019 (n = 2,083 eyes). DR risk and progression factors were obtained from the medical record. Trained graders masked to patients' clinical histories evaluated SD-OCT scans for DRIL.

RESULTS

Of 2,083 eyes, 28.1% (n = 585) demonstrated presence of DRIL with high interrater reliability (K = 0.88, 95% CI 0.86-0.90). DRIL was associated with worse visual acuity (VA) (P < 0.001) and DR severity (P < 0.0001). Insulin users had more severe DR (P < 0.0001). DR-related factors, race (Black, White) and sex (male) were significantly associated with DRIL (P < 0.05).

CONCLUSIONS

DRIL was strongly associated with DR severity and worse VA, supporting its utility as an unfavorable prognostic indicator. [Ophthalmic Surg Lasers Imaging Retina 2023;54:692-700.].

Racial and Ethnic Distribution in Diabetic Macular Edema Clinical Trials in the United States (2002-2021)

PURPOSE

Diabetic macular edema (DME), the leading cause of vision loss among patients with diabetes mellitus, disproportionately affects Black and Hispanic patients. Currently, non-White racial and ethnic subgroups are frequently underrepresented in clinical trials, limiting the application of results to the most pertinent patient populations. Thus, we aimed to characterize the trajectory of racial reporting as well as changes and disparities in racial and ethnic distribution among participants of DME clinical trials.

DESIGN

This is a cross-sectional retrospective study.

SUBJECTS

Patients enrolled in United States (US)-based clinical trials for DME.

METHODS

We examined the racial and ethnic demographic distribution of participants in clinical trials related to DME across a 20-year period from 2002 to 2021. Clinical trials were screened from ClinicalTrials.gov for DME, US trial location, study completion, and > 50 patient enrollment. Descriptive statistics, proportions, odds ratios (ORs), and chi-square tests were reported and compared with 2021 US Census demographic data and diagnosed patients with diabetes demographic data.

MAIN OUTCOME MEASURES

Change in racial reporting and race/ethnicity across 2 decades and comparison of racial/ethnic distribution with 2021 US Census demographics and diagnosed patients with diabetes.

RESULTS

There was an increase in race reporting from January 2002 to December 2011 (8 trials [40%]) versus January 2012 to December 2021 (20 trials [87%]; OR, 10.00; 95% confidence interval [CI], 2.21-45.16; P = 0.0032). Across the 2 decades, the proportion of Asian patients enrolled increased from 2.4% to 8.0% (OR, 3.47; 95% CI, 2.64-4.56; P < 0.0001). Similarly, the proportion of enrolled Hispanic patients increased from 13.4% to 19.5% (OR, 1.56; 95% CI, 1.37-1.78; P < 0.0001). Compared with diabetes prevalence, many minority groups are underrepresented in the total enrollment of DME clinical trial patients (Black [z = -18.51, P < 0.001]; Asian [z = -5.11, P < 0.0001]; Hispanic [chi-square = 274.7, df = 1, P < 0.0001]).

CONCLUSIONS

In the past 2 decades, there has been a trend of increased racial reporting and minority patient enrollment in DME clinical trials. However, Black, Asian, and Hispanic patients remain significantly underrepresented among the DME clinical trial patient population based on diabetes prevalence.

FINANCIAL DISCLOSURE(S)

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

Impact of Dyslipidemia Medications on the Prevalence of Diabetic Retinopathy Among a Large US Cohort

BACKGROUND AND OBJECTIVE

Dyslipidemia medications such as statins and fibrates may be associated with a reduction in diabetic retinopathy (DR) progression, but real-world data is lacking. This study evaluates cholesterol-lowering medications and their association with the prevalence of DR and advanced DR complications.

PATIENTS AND METHODS

Data was collected using codes from the International Classification of Diseases on TriNetX, a cross-sectional database of over 79 million Americans, between June and August 2022. Prevalence and prevalence odds ratios (POR) were calculated.

RESULTS

Patients taking pitavastatin (OR 0.64, 95% CI 0.49, 0.84), fenofibrate (OR 0.83, CI 0.79, 0.87), or evolocumab (OR 0.80, CI 0.68, 0.95) had lower POR of proliferative DR compared to nonproliferative DR. Patients taking any cholesterol medication had a lower POR of vitreous hemorrhage. Patients taking fibrates also had lower POR of neovascular glaucoma.

CONCLUSION

This exploratory study highlights positive associations between DR and dyslipidemia and medications that may have fewer worsening events in DR patients. [Ophthalmic Surg Lasers Imaging Retina 2023;54:626-633.].

Effect of Accessible Nonmydriatic Retinal Imaging on Diabetic Retinopathy Surveillance Rates

Purpose: To evaluate the impact on surveillance rates for diabetic retinopathy (DR) by providing nonmydriatic retinal imaging as part of comprehensive diabetes care at no cost to patients or insurers. Methods: A retrospective comparative cohort study was designed. Patients were imaged from April 1, 2016 to March 31, 2017 at a tertiary diabetes-specific academic medical center. Retinal imaging was provided without additional cost beginning October 16, 2016. Images were evaluated for DR and diabetic macular edema using standard protocol at a centralized reading center. Diabetes surveillance rates before and after no-cost imaging were compared. Results: A total of 759 and 2,080 patients respectively were imaged before and after offering no-cost retinal imaging. The difference represents a 274% increase in the number of patients screened. Furthermore, there was a 292% and 261% increase in the number of eyes with mild DR and referable DR, respectively. In the comparative 6-month period, 92 additional cases of proliferative DR were identified, estimated to prevent 6.7 cases of severe visual loss with annual cost savings of $180,230 (estimated yearly cost of severe vision loss per person: $26,900). In patients with referable DR, self-awareness was low, with no significant difference in the before and after groups (39.4% vs. 43.8%, p = 0.3725). Conclusions: Providing retinal imaging as part of comprehensive diabetes care substantially increased the number of patients identified by nearly threefold. The data suggest that the removal of out-of-pocket costs substantially increased patient surveillance rates, which may translate to improved long-term patient outcomes.

Disparities in diabetes prevalence and management by race and ethnicity in the USA: defining a path forward

Type 2 diabetes disparities in the USA persist in both the prevalence of disease and diabetes-related complications. We conducted a literature review related to diabetes prevention, management, and complications across racial and ethnic groups in the USA. The objective of this review is to summarise the current understanding of diabetes disparities by examining differences between and within racial and ethnic groups and among young people (aged <18 years). We also examine the pathophysiology of diabetes as it relates to race and ethnic differences. We use a conceptual framework built on the socioecological model to categorise the causes of diabetes disparities across the lifespan looking at factors in five domains of health behaviours and social norms, public awareness, structural racism, economic development, and access to high-quality care. The range of disparities in diabetes prevalence and management in the USA calls for a community-engaged and multidisciplinary approach that must involve community partners, researchers, practitioners, health system administrators, and policy makers. We offer recommendations for each of these groups to help to promote equity in diabetes prevention and care in the USA.

The co-development of a linguistic and culturally tailored tele-retinopathy screening intervention for immigrants living with diabetes from China and African-Caribbean countries in Ottawa, Canada

BACKGROUND

Diabetic retinopathy is a sight-threatening ocular complication of diabetes. Screening is an effective way to reduce severe complications, but screening attendance rates are often low, particularly for newcomers and immigrants to Canada and people from cultural and linguistic minority groups. Building on previous work, in partnership with patient and health system stakeholders, we co-developed a linguistically and culturally tailored tele-retinopathy screening intervention for people living with diabetes who recently immigrated to Canada from either China or African-Caribbean countries.

METHODS

Following an environmental scan of diabetes eye care pathways in Ottawa, we conducted co-development workshops using a nominal group technique to create and prioritize personas of individuals requiring screening and identify barriers to screening that each persona may face. Next, we used the Theoretical Domains Framework to categorize the barriers/enablers and then mapped these categories to potential evidence-informed behaviour change techniques. Finally with these techniques in mind, participants prioritized strategies and channels of delivery, developed intervention content, and clarified actions required by different actors to overcome anticipated intervention delivery barriers.

RESULTS

We carried out iterative co-development workshops with Mandarin and French-speaking individuals living with diabetes (i.e., patients in the community) who immigrated to Canada from China and African-Caribbean countries (n = 13), patient partners (n = 7), and health system partners (n = 6) recruited from community health centres in Ottawa. Patients in the community co-development workshops were conducted in Mandarin or French. Together, we prioritized five barriers to attending diabetic retinopathy screening: language (TDF Domains: skills, social influences), retinopathy familiarity (knowledge, beliefs about consequences), physician barriers regarding communication for screening (social influences), lack of publicity about screening (knowledge, environmental context and resources), and fitting screening around other activities (environmental context and resources). The resulting intervention included the following behaviour change techniques to address prioritized local barriers: information about health consequence, providing instructions on how to attend screening, prompts/cues, adding objects to the environment, social support, and restructuring the social environment. Operationalized delivery channels incorporated language support, pre-booking screening and sending reminders, social support via social media and community champions, and providing using flyers and videos as delivery channels.

CONCLUSION

Working with intervention users and stakeholders, we co-developed a culturally and linguistically relevant tele-retinopathy intervention to address barriers to attending diabetic retinopathy screening and increase uptake among two under-served groups.

Findings from a Statewide Teleretina Diabetic Retinopathy Screening Program in Arkansas

Introduction

A significant proportion of diabetic patients in the United States do not present for annual dilated eye exams to monitor for signs of diabetic retinopathy (DR). The purpose of this study was to analyze the results of a statewide, multiclinic teleretina program designed to screen rural Arkansans for this sight-debilitating disease.

Methods

Patients with diabetes seen at 10 primary care clinics across Arkansas were offered teleretinal-imaging services. Images were transmitted to the University of Arkansas for Medical Sciences' (UAMS) Harvey and Bernice Jones Eye Institute (JEI) for grading and recommendations for further treatment.

Results

From February 2019 to May 2022, 668 patients underwent imaging; 645 images were deemed of sufficient quality to generate an interpretation. 541 patients had no evidence of DR, while 104 patients had some evidence of DR. 587 patients had no evidence of maculopathy, while 58 patients had some evidence of maculopathy on imaging. 246 patients had other pathology evident on imaging, with the most common being hypertensive retinopathy, glaucoma suspects, and cataracts. Discussion. In a rural, primary care setting, the JEI teleretina program identifies DR and other nondiabetic ocular pathologies, allowing for an appropriate triage for eye care for patients in a predominantly rural state.

Impact of COVID-19 on the Delivery of Eye Care to Uninsured Diabetic Patients at a Student-Run Free Clinic: A Comprehensive Evaluation of Eye Clinic Performance

Background

Diabetic retinopathy is the leading cause of blindness among working-age adults in the United States and requires timely screening and management. This study evaluates the impact of the coronavirus disease 2019 (COVID-19) pandemic on diabetic retinopathy screening (DRS) for uninsured, predominantly Latino patients at the University of California San Diego Student-Run Free Clinic Project (SRFCP).

Methods

A retrospective chart review was conducted of all living diabetic patients at SRFCP who were seen in 2019 (n=196), 2020 (n=183), and 2021 (n=178). Ophthalmology clinic referrals, scheduled patient visits, and visit outcomes were analyzed longitudinally to determine the impact of the pandemic on screening patterns.

Results

The study population was 92.1% Latino, 69.5% female, with a mean age of 58.7 years. The distribution of patients seen (p<0.001), referred (p=0.012), and scheduled (p<0.001) in 2020 and 2021 significantly differed from 2019. In 2019, 50.5% of 196 patients eligible for DRS were referred, 49.5% were scheduled, and 45.4% were seen. In 2020, 41.5% of 183 eligible patients were referred, but only 20.2% were scheduled and 11.4% were seen. In 2021, there was a rebound: 63.5% of 178 patients were referred, 56.2% scheduled and 46.1% seen. No shows and cancellations represented 12.4% and 6.2% of the 97 encounters scheduled in 2019, but were markedly higher (10.8% and 40.5% respectively) for the 37 encounters scheduled in 2020.

Conclusions

The COVID-19 pandemic significantly impacted the delivery of eye care at SRFCP. The need for annual DRS exceeded the capacity of the ophthalmology clinic in all years studied, but the difference was especially pronounced with more stringent COVID-19 restrictions in 2020. SRFCP patients could benefit from telemedicine DRS programs to improve screening capacity.

MicroRNA-150 (miR-150) and Diabetic Retinopathy: Is miR-150 Only a Biomarker or Does It Contribute to Disease Progression?

Diabetic retinopathy (DR) is a chronic disease associated with diabetes mellitus and is a leading cause of visual impairment among the working population in the US. Clinically, DR has been diagnosed and treated as a vascular complication, but it adversely impacts both neural retina and retinal vasculature. Degeneration of retinal neurons and microvasculature manifests in the diabetic retina and early stages of DR. Retinal photoreceptors undergo apoptosis shortly after the onset of diabetes, which contributes to the retinal dysfunction and microvascular complications leading to vision impairment. Chronic inflammation is a hallmark of diabetes and a contributor to cell apoptosis, and retinal photoreceptors are a major source of intraocular inflammation that contributes to vascular abnormalities in diabetes. As the levels of microRNAs (miRs) are changed in the plasma and vitreous of diabetic patients, miRs have been suggested as biomarkers to determine the progression of diabetic ocular diseases, including DR. However, few miRs have been thoroughly investigated as contributors to the pathogenesis of DR. Among these miRs, miR-150 is downregulated in diabetic patients and is an endogenous suppressor of inflammation, apoptosis, and pathological angiogenesis. In this review, how miR-150 and its downstream targets contribute to diabetes-associated retinal degeneration and pathological angiogenesis in DR are discussed. Currently, there is no effective treatment to stop or reverse diabetes-caused neural and vascular degeneration in the retina. Understanding the molecular mechanism of the pathogenesis of DR may shed light for the future development of more effective treatments for DR and other diabetes-associated ocular diseases.

Disparities in Eye Care Utilization During the COVID-19 Pandemic

PURPOSE

To assess the relationship between telemedicine utilization and sociodemographic factors among patients seeking eye care.

DESIGN

Comparative utilization analysis.

METHODS

We reviewed the eye care utilization patterns of a stratified random sample of 1720 patients who were seen at the University of Michigan Kellogg Eye Center during the height of the COVID-19 pandemic (April 30 to May 25, 2020) and their odds of having a video, phone, or in-person visit compared with having a deferred visit. Associations between independent variables and visit type were determined using a multinomial logistic regression model.

RESULTS

Older patients had lower odds of having a video visit (P = .007) and higher odds of having an in-person visit (P = .023) compared with being deferred, and in the nonretina clinic sample, older patients still had lower odds of a video visit (P = .02). Non-White patients had lower odds of having an in-person visit (P < .02) in the overall sample compared with being deferred, with a similar trend seen in the retina clinic. The mean neighborhood median household income was $76,200 (±$33,500) and varied significantly (P < .0001) by race with Blacks having the lowest estimated mean income.

CONCLUSION

Disparities exist in how patients accessed eye care during the COVID-19 pandemic with older patients-those for whom COVID-19 posed a higher risk of mortality-being more likely to be seen for in-person care. In our affluent participant sample, there was a trend toward non-White patients being less likely to access care. Reimbursing telemedicine solely through broadband internet connection may further exacerbate disparities in eye care.

Decreased MicroRNA-150 Exacerbates Neuronal Apoptosis in the Diabetic Retina

Diabetic retinopathy (DR) is a chronic complication associated with diabetes and the number one cause of blindness in working adults in the US. More than 90% of diabetic patients have obesity-associated type 2 diabetes (T2D), and 60% of T2D patients will develop DR. Photoreceptors undergo apoptosis shortly after the onset of diabetes, which contributes to the retinal dysfunction and microvascular complications leading to vision impairment. However, how diabetic insults cause photoreceptor apoptosis remains unclear. In this study, obesity-associated T2D mice and cultured photoreceptors were used to investigate how decreased microRNA-150 (miR-150) and its downstream target were involved in photoreceptor apoptosis. In the T2D retina, miR-150 was decreased with its target ETS-domain transcription factor (ELK1) and phosphorylated ELK1 at threonine 417 (pELK1_T417) upregulated. In cultured photoreceptors, treatments with palmitic acid (PA), to mimic a high-fat environment, decreased miR-150 but upregulated ELK1, pELK1_T417, and the translocation of pELK1_T417 from the cytoplasm to the cell nucleus. Deletion of miR-150 (miR-150^-/-) exacerbates T2D- or PA-induced photoreceptor apoptosis. Blocking the expression of ELK1 with small interfering RNA (siRNA) for Elk1 did not rescue PA-induced photoreceptor apoptosis. Translocation of pELK1_T417 from cytoplasm-to-nucleus appears to be the key step of diabetic insult-elicited photoreceptor apoptosis.

Clinical and Demographic Factors Associated With Diabetic Retinopathy Among Young Patients With Diabetes

IMPORTANCE

Diabetic retinopathy (DR) is a leading cause of vision loss worldwide. As the incidence of both type 1 and type 2 diabetes among youths continues to increase around the world, understanding the factors associated with the development of DR in this age group is important.

OBJECTIVE

To identify factors associated with DR among children, adolescents, and young adults with type 1 or type 2 diabetes in the US.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study pooled data from 2 large academic pediatric centers in the US (Baylor College of Medicine/Texas Children's Hospital [BCM/TCH] Diabetes and Endocrine Care Center and Johns Hopkins University [JHU] Pediatric Diabetes Center) to form a diverse population for analysis. Data were collected prospectively at the JHU center (via point-of-care screening using fundus photography) from December 3, 2018, to November 1, 2019, and retrospectively at the BCM/TCH center (via electronic health records of patients who received point-of-care screening using retinal cameras between June 1, 2016, and May 31, 2019). A total of 1640 individuals aged 5 to 21 years with type 1 or type 2 diabetes (308 participants from the JHU center and 1332 participants from the BCM/TCH center) completed DR screening and had gradable images.

MAIN OUTCOME AND MEASURES

Prevalence of DR, as identified on fundus photography, and factors associated with DR.

RESULTS

Among 1640 participants (mean [SD] age, 15.7 [3.6] years; 867 female individuals [52.9%]), 1216 (74.1%) had type 1 diabetes, and 416 (25.4%) had type 2 diabetes. A total of 506 participants (30.9%) were Hispanic, 384 (23.4%) were non-Hispanic Black or African American, 647 (39.5%) were non-Hispanic White, and 103 (6.3%) were of other races or ethnicities (1 was American Indian or Alaska Native, 50 were Asian, 1 was Native Hawaiian or Pacific Islander, and 51 did not specify race or ethnicity, specified other race or ethnicity, or had unavailable data on race or ethnicity). Overall, 558 of 1216 patients (45.9%) with type 1 diabetes used an insulin pump, and 5 of 416 patients (1.2%) with type 2 diabetes used an insulin pump. Diabetic retinopathy was found in 57 of 1640 patients (3.5%). Patients with DR vs without DR had a greater duration of diabetes (mean [SD], 9.4 [4.4] years vs 6.6 [4.4] years; P < .001) and higher hemoglobin A1c (HbA1c) levels (mean [SD], 10.3% [2.4%] vs 9.2% [2.1%]; P < .001). Among those with type 1 diabetes, insulin pump use was associated with a lower likelihood of DR after adjusting for race and ethnicity, insurance status, diabetes duration, and HbA1c level (odds ratio [OR], 0.43; 95% CI, 0.20-0.93; P = .03). The likelihood of having DR was 2.1 times higher among Black or African American participants compared with White participants (OR, 2.12; 95% CI, 1.12-4.01; P = .02); this difference was no longer significant after adjusting for duration of diabetes, insurance status, insulin pump use (among patients with type 1 diabetes only), and mean HbA1c level (type 1 diabetes: OR, 1.79; 95% CI, 0.83-3.89; P = .14; type 2 diabetes: OR, 1.08; 95% CI, 0.30-3.85; P = .91).

CONCLUSIONS AND RELEVANCE

This study found that although the duration of diabetes and suboptimal glycemic control have long been associated with DR, insulin pump use (among those with type 1 diabetes) was independently associated with a lower likelihood of DR, which is likely owing to decreased glycemic variability and increased time in range (ie, the percentage of time blood glucose levels remain within the 70-180 mg/dL range). Black or African American race was found to be associated with DR in the univariable analysis but not in the multivariable analysis, which may represent disparities in access to diabetes technologies and care.

Association between diabetic retinopathy and polymorphisms of cytokine genes: a systematic review and meta-analysis

INTRODUCTION

Diabetic retinopathy (DR) is a medical condition caused by damage to the blood vessels of retina tissue due to diabetes mellitus. DR leads to injury in neural and vascular structures and is reported to be significantly influenced by inflammation and inflammatory mediators like cytokines. In this study, a systematic review and meta-analysis were performed to analyze the association between cytokine gene polymorphisms and DR.

METHODS

We identified relevant studies from Scopus, PubMed, and Google scholar databases. Allele and genotype frequencies were pooled. Heterogeneity and publication bias were explored. The odds ratio (OR) and corresponding 95% confidence intervals (CIs) were calculated to estimate the relation.

RESULTS

A total of 3337 cases and 4945 controls in 19 eligible studies were included in the meta-analysis. Overall, results indicated the negative association between the cytokine gene polymorphisms and DR susceptibility in the allelic model (IFN-γ (rs2430561): OR 0.64, [CI]: 0.5 to 0.82; and TGF-β (rs1800471): [OR] = 0.15, [CI]: 0.03 to 0.79); and also, in the dominant model (IFN-γ (rs2430561): OR = 0.4, [CI]: 0.22 to 0.75; and TGF-β (rs1800471): OR = 0.14, [CI]: 0.05 to 0.4).

CONCLUSION

The present study suggests that IFN-γ (rs2430561) and TGF-β (rs1800471) polymorphisms are associated with decreased susceptibility to DR.

Improving Timely Annual Ocular Examinations for Patients With Diabetes Mellitus in a Primary Care Office

BACKGROUND

A common complication of diabetes mellitus (DM) is diabetic retinopathy (DR).

LOCAL PROBLEM

An audit in a primary care office found that fewer than 50% of patients with DM received an annual ocular examination. The aim of this project was to increase timely annual ocular examinations among patients with type 2 DM to 85% within 90 days.

METHODS

The model for improvement with 4 Plan-Do-Study-Act (PDSA) cycles was implemented in a rapid cycle format as well as changes in an electronic medical record (EMR) checklist and referral processes.

INTERVENTIONS

Interventions included team huddles and trainings, the Association of Diabetes Care and Education Specialists checklist with additional information about DR, an EMR checklist, and a logbook referral tracking process changes.

RESULTS

Of the patients referred during the project, 87% completed the ocular appointment, and the rate for patients with DM having annual ocular examinations increased from 48% to 86% meeting the current guideline of the American Diabetes Association.

CONCLUSIONS

Timely annual ocular examinations increased to 86% in 90 days, thus improving current DM treatment guidelines in primary care.

Nimbolide ameliorates the streptozotocin-induced diabetic retinopathy in rats through the inhibition of TLR4/NF-κB signaling pathway

BACKGROUND

Diabetic retinopathy (DR) is a common problem in the diabetic patients due to the high blood glucose level. DR affects more number of diabetic patients worldwide with irreversible vision loss.

OBJECTIVE

The current investigation was focused to reveal the therapeutic actions of nimbolide against the streptozotocin (STZ)-provoked DR in rats through inhibition of TLR4/NF-κB pathway.

METHODOLOGY

DR was provoked to the rats through administering a single dose of STZ (60 mg/kg) intraperitoneally. The DR rats were then supplemented with the 50 mg/kg of nimbolide for 60 days. The bodyweight and blood glucose level was measured using standard methods. The lipid profiles (cholesterol, TG, LDL, and HDL), inflammatory markers, and antioxidants level was detected using respective kits. The level of MCP-1, VEGF, and MMP-9 was quantified using kits. The morphometric analysis of retinal tissues were done. The mRNA expressions of target genes were studied using RT-PCR assay.

RESULTS

Nimbolide treatment effective decreased the food intake and blood glucose, and improved the bodyweight of STZ-provoked animals. The levels of pro-inflammatory mediators, cholesterol, TG, LDL, and HDL, MCP-1, VEGF, and MMP-9 was remarkably suppressed by the nimbolide treatment. Nimbolide also improved the antioxidants, retinal thickness and cell numbers. The TLR4/NF-κB pathway was appreciably inhibited by the nimbolide.

CONCLUSION

Overall, our findings demonstrated that the nimbolide attenuated the STZ-provoked DR in rats through inhibiting the TLR4/NF-κB pathway.

Genome-wide polygenic risk score for retinopathy of type 2 diabetes

Diabetic retinopathy (DR) is a common consequence in type 2 diabetes (T2D) and a leading cause of blindness in working-age adults. Yet, its genetic predisposition is largely unknown. Here, we examined the polygenic architecture underlying DR by deriving and assessing a genome-wide polygenic risk score (PRS) for DR. We evaluated the PRS in 6079 individuals with T2D of European, Hispanic, African and other ancestries from a large-scale multi-ethnic biobank. Main outcomes were PRS association with DR diagnosis, symptoms and complications, and time to diagnosis, and transferability to non-European ancestries. We observed that PRS was significantly associated with DR. A standard deviation increase in PRS was accompanied by an adjusted odds ratio (OR) of 1.12 [95% confidence interval (CI) 1.04-1.20; P = 0.001] for DR diagnosis. When stratified by ancestry, PRS was associated with the highest OR in European ancestry (OR = 1.22, 95% CI 1.02-1.41; P = 0.049), followed by African (OR = 1.15, 95% CI 1.03-1.28; P = 0.028) and Hispanic ancestries (OR = 1.10, 95% CI 1.00-1.10; P = 0.050). Individuals in the top PRS decile had a 1.8-fold elevated risk for DR versus the bottom decile (P = 0.002). Among individuals without DR diagnosis, the top PRS decile had more DR symptoms than the bottom decile (P = 0.008). The PRS was associated with retinal hemorrhage (OR = 1.44, 95% CI 1.03-2.02; P = 0.03) and earlier DR presentation (10% probability of DR by 4 years in the top PRS decile versus 8 years in the bottom decile). These results establish the significant polygenic underpinnings of DR and indicate the need for more diverse ancestries in biobanks to develop multi-ancestral PRS.

Geographic Access Disparities to Clinical Trials in Diabetic Eye Disease in the United States

PURPOSE

To identify geographic and socioeconomic variables predictive of residential proximity to diabetic eye disease clinical trial locations.

DESIGN

Cross-sectional, retrospective study.

PARTICIPANTS

De-identified census tract-level data from public datasets and trial-level data from ClinicalTrials.gov.

METHODS

Using public data from ClinicalTrials.gov, we identified all active interventional clinical trials in diabetic eye disease since 2017. After geolocating every trial site, we used an origin-destination cost-matrix to calculate the driving distance and travel time from the population-weighted United States census tract centroid to the nearest site. We then used public databases to identify census tract-level socioeconomic factors predictive of driving distance and time.

MAIN OUTCOME MEASURES

Driving distance > 60 miles and time traveled > 60 minutes to the nearest clinical trial site.

RESULTS

In a multivariate model, driving distance of more than 60 miles had a significant association with rural versus urban location (adjusted odds ratio, 5.22; 95% confidence interval [CI], 3.75-7.26; P < 0.001), percentage of population at less than 200% of federal poverty level compared with the fourth quartile (first quartile: adjusted odds ratio, 0.40 [95% CI, 0.29-0.55]; second quartile: adjusted odds ratio, 0.60 [95% CI, 0.47-0.77]; third quartile: adjusted odds ratio, 0.76 [95% CI, 0.63-0.91]; P < 0.001) and the Midwest (adjusted odds ratio, 2.15; 95% CI, 1.13-4.07; P = 0.02), South (adjusted odds ratio, 2.71; 95% CI, 1.23-5.99; P = 0.01), and West (adjusted odds ratio, 3.01; 95% CI, 1.21-7.54; P = 0.02) regions as compared with the Northeast. Driving distance was associated with county-level prevalence of diabetes in the univariate model (odds ratio, 1.12; 95% CI, 1.06-1.19; P < 0.001), although it was nonsignificant in the multivariate model. Similar predictors were found for time traveled in minutes.

CONCLUSIONS

Geographic maldistributions of clinical trial sites exist for diabetic eye disease in the United States. Those with higher travel burden are more likely to reside in a census tract that is rural, low income, and from areas outside the Northeast.

[Current trends in the screening for diabetic retinopathy]

The incidence of diabetes in the world is steadily increasing, and so is growing the number of cases of vision loss and blindness resulting from diabetic retinopathy (DR). This pathology is asymptomatic in the initial stages, but only the early treatment can be effective. In this regard, DR screening is an important and actual problem. This article reviews the principles, criteria, and problems of the currently run DR screening programs that are based on digital photography of the fundus. Special attention is paid to the displayed biomarkers and their role in DR screening. Various research methods are described, such as fluorescence angiography, optical coherence tomography, optical coherence tomography agniography, laser scanning ophthalmoscopy, which can be used to visualize pathological changes in the retina associated with DR. These changes were considered as potential screening biomarkers for DR. The review also describes new areas of screening based on telemedicine, artificial intelligence, and mobile photo-registering devices.

Functional imaging of mitochondria in retinal diseases using flavoprotein fluorescence

Mitochondria are critical for cellular energy production and homeostasis. Oxidative stress and associated mitochondrial dysfunction are integral components of the pathophysiology of retinal diseases, including diabetic retinopathy (DR), age-related macular degeneration, and glaucoma. Within mitochondria, flavoproteins are oxidized and reduced and emit a green autofluorescence when oxidized following blue light excitation. Recently, a noninvasive imaging device was developed to measure retinal flavoprotein fluorescence (FPF). Thus, oxidized FPF can act as a biomarker of mitochondrial dysfunction. This review article describes the literature surrounding mitochondrial FPF imaging in retinal disease. The authors describe the role of mitochondrial dysfunction in retinal diseases, experiments using FPF as a marker of mitochondrial dysfunction in vitro, the three generations of retinal FPF imaging devices, and the peer-reviewed publications that have examined FPF imaging in patients. Finally, the authors report their own study findings. Goals were to establish normative reference levels for FPF intensity and heterogeneity in healthy eyes, to compare between healthy eyes and eyes with diabetes and DR, and to compare across stages of DR. The authors present methods to calculate a patient's expected FPF values using baseline characteristics. FPF intensity and heterogeneity were elevated in diabetic eyes compared to age-matched control eyes, and in proliferative DR compared to diabetic eyes without retinopathy. In diabetic eyes, higher FPF heterogeneity was associated with poorer visual acuity. In conclusion, while current retinal imaging modalities frequently focus on structural features, functional mitochondrial imaging shows promise as a metabolically targeted tool to evaluate retinal disease.

Review of methods for detecting glycemic disorders

Prediabetes (intermediate hyperglycemia) consists of two abnormalities, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) detected by a standardized 75-gram oral glucose tolerance test (OGTT). Individuals with isolated IGT or combined IFG and IGT have increased risk for developing type 2 diabetes (T2D) and cardiovascular disease (CVD). Diagnosing prediabetes early and accurately is critical in order to refer high-risk individuals for intensive lifestyle modification. However, there is currently no international consensus for diagnosing prediabetes with HbA1c or glucose measurements based upon American Diabetes Association (ADA) and the World Health Organization (WHO) criteria that identify different populations at risk for progressing to diabetes. Various caveats affecting the accuracy of interpreting the HbA1c including genetics complicate this further. This review describes established methods for detecting glucose disorders based upon glucose and HbA1c parameters as well as novel approaches including the 1-hour plasma glucose (1-h PG), glucose challenge test (GCT), shape of the glucose curve, genetics, continuous glucose monitoring (CGM), measures of insulin secretion and sensitivity, metabolomics, and ancillary tools such as fructosamine, glycated albumin (GA), 1,5- anhydroglucitol (1,5-AG). Of the approaches considered, the 1-h PG has considerable potential as a biomarker for detecting glucose disorders if confirmed by additional data including health economic analysis. Whether the 1-h OGTT is superior to genetics and omics in providing greater precision for individualized treatment requires further investigation. These methods will need to demonstrate substantially superiority to simpler tools for detecting glucose disorders to justify their cost and complexity.

Vasant Kusmakar Ras, an ayurvedic herbo-mineral formulation prevents the development of diabetic retinopathy in rats

BACKGROUND

Diabetic retinopathy is a slow progressing complication of diabetes mellitus with multifactorial aetiology affecting approximately 80% of diabetics worldwide. Chronic hyperglycemic milieu of Diabetes induces biochemical changes which contribute to the pathogenesis of Diabetic retinopathy.

OBJECTIVE

The present study examined the protective effect of Vasant Kusumakar Ras, an Ayurvedic herbo-mineral formulation, in diabetic retinopathy.

MATERIALS AND METHODS

Diabetes was induced in rats by intraperitoneal injection of streptozotocin (45 mg/kg). Rats were kept without any treatment for period of three weeks for induction of Diabetic retinopathy followed by treatment with Vasant Kusumakar Ras (11.25 mg/kg, p.o) for further 5 weeks. Fasting blood glucose levels, lipid profile and HbA1c were determined. Eye tissue homogenates were subjected to biochemical analysis to determine the levels of oxidative stress parameters (superoxide dismutase, catalase, reduced glutathione, lipid peroxidation), vascular endothelial growth factor and aldose reductase activity. Histopathological analysis of retinal tissue was conducted using Hematoxylin and Eosin staining.

RESULTS

Vasant Kusumakar Ras treatment restored serum lipid profile which was altered in diabetic rats. Treatment with Vasant Kusumakar Ras significantly ameliorated the oxidative stress in eye tissue resulting in decreased lipid peroxidation and increase in endogenous antioxidant levels. Levels of aldose reductase and vascular endothelial growth factor in eye tissue were significantly decreased in Vasant Kusumakar Ras treated rats. Hematoxylin and Eosin staining indicated that the Vasant Kusumakar Ras treatment significantly restored the normal architecture of the retinal tissue.

CONCLUSION

Vasant Kusumakar Ras exhibits protective effect and prevents the development of Diabetic retinopathy through its effects on multiple biochemical pathways implicated in pathogenesis of Diabetic retinopathy.

Diabetic Retinopathy Screening Using a Gold Nanoparticle-Based Paper Strip Assay for the At-Home Detection of the Urinary Biomarker 8-Hydroxy-2'-Deoxyguanosine

PURPOSE

We sought to assess a smartphone-based, gold nanoparticle-based colorimetric lateral flow immunoassay paper sensor for quantifying urine 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker for diabetic retinopathy (DR) screening.

METHODS

Paper strips incorporate gold nanoparticle-8-OHdG antibody conjugates that produce color changes that are proportional to urine 8-OHdG and that are discernible on a smartphone camera photograph. Paper strip accuracy, precision, and stability studies were performed with 8-OHdG solutions of varying concentrations. Urine was collected from 97 patients with diabetes who were receiving DR screening examinations, including 7-field fundus photographs. DR was graded by standard methods as either low risk (no or mild DR) or high risk (moderate or severe DR). Paper sensor assays were performed on urine samples from patients and 8-OHdG values were correlated with DR grades. The differences in 8-OHdG values between the low- and high-risk groups were analyzed for outliers to identify the threshold 8-OHdG value that would minimize false-negative results.

RESULTS

Lateral flow immunoassay paper strips quantitatively measure 8-OHdG and were found to be accurate, precise, and stable. Average urine 8-OHdG concentrations in study patients were 22 ± 10 ng/mg of creatinine in the low-risk group and 55 ± 11 ng/mg of creatinine in the high-risk group. Screening cutoff values of 8-OHdG >50 ng/mg of creatinine or urine creatinine >1.5 mg minimized screen failures, with 91% sensitivity and 81% specificity.

CONCLUSIONS

Urinary 8-OHdG is a useful biomarker to screen DR. Quantitative 8-OHdG detection with the lateral flow immunoassay paper sensor and smartphone camera demonstrates its potential in DR screening. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.