Comparison between binocular indirect ophthalmoscopy and digital retinography for diabetic retinopathy screening: the multicenter Brazilian Type 1 Diabetes Study

Automated Identification of Different Severity Levels of Diabetic Retinopathy Using a Handheld Fundus Camera and Single-Image Protocol

Purpose

To evaluate the performance of artificial intelligence (AI) systems embedded in a mobile, handheld retinal camera, with a single retinal image protocol, in detecting both diabetic retinopathy (DR) and more-than-mild diabetic retinopathy (mtmDR).

Design

Multicenter cross-sectional diagnostic study, conducted at 3 diabetes care and eye care facilities.

Participants

A total of 327 individuals with diabetes mellitus (type 1 or type 2) underwent a retinal imaging protocol enabling expert reading and automated analysis.

Methods

Participants underwent fundus photographs using a portable retinal camera (Phelcom Eyer). The captured images were automatically analyzed by deep learning algorithms retinal alteration score (RAS) and diabetic retinopathy alteration score (DRAS), consisting of convolutional neural networks trained on EyePACS data sets and fine-tuned using data sets of portable device fundus images. The ground truth was the classification of DR corresponding to adjudicated expert reading, performed by 3 certified ophthalmologists.

Main Outcome Measures

Primary outcome measures included the sensitivity and specificity of the AI system in detecting DR and/or mtmDR using a single-field, macula-centered fundus photograph for each eye, compared with a rigorous clinical reference standard comprising the reading center grading of 2-field imaging protocol using the International Classification of Diabetic Retinopathy severity scale.

Results

Of 327 analyzed patients (mean age, 57.0 ± 16.8 years; mean diabetes duration, 16.3 ± 9.7 years), 307 completed the study protocol. Sensitivity and specificity of the AI system were high in detecting any DR with DRAS (sensitivity, 90.48% [95% confidence interval (CI), 84.99%-94.46%]; specificity, 90.65% [95% CI, 84.54%-94.93%]) and mtmDR with the combination of RAS and DRAS (sensitivity, 90.23% [95% CI, 83.87%-94.69%]; specificity, 85.06% [95% CI, 78.88%-90.00%]). The area under the receiver operating characteristic curve was 0.95 for any DR and 0.89 for mtmDR.

Conclusions

This study showed a high accuracy for the detection of DR in different levels of severity with a single retinal photo per eye in an all-in-one solution, composed of a portable retinal camera powered by AI. Such a strategy holds great potential for increasing coverage rates of screening programs, contributing to prevention of avoidable blindness.

Financial Disclosures

F.K.M. is a medical consultant for Phelcom Technologies. J.A.S. is Chief Executive Officer and proprietary of Phelcom Technologies. D.L. is Chief Technology Officer and proprietary of Phelcom Technologies. P.V.P. is an employee at Phelcom Technologies.

Prevalence and incidence of diabetic retinopathy in patients with diabetes of Latin America and the Caribbean: A systematic review and meta-analysis

OBJECTIVES

This systematic review aimed to assess the prevalence and incidence of diabetic retinopathy in patients with diabetes of Latin America and the Caribbean.

METHODS

We searched Web of Science (WoS)/Core Collection, WoS/MEDLINE, WoS/Scielo, Scopus, PubMed/Medline and Embase databases until January 16, 2023. We meta-analyzed prevalences according to type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM).

RESULTS

Forty-three prevalence studies (47 585 participants) and one incidence study (436 participants) were included. The overall prevalence of retinopathy in patients with T1DM was 40.6% (95% CI: 34.7 to 46.6; I2: 92.1%) and in T2DM was 37.3% (95% CI: 31.0 to 43.8; I2: 97.7), but the evidence is very uncertain (very low certainty of evidence). In meta-regression, we found that age (T1DM) and time in diabetes (T2DM) were factors associated with the prevalence. On the other hand, one study found a cumulative incidence of diabetic retinopathy of 39.6% at 9 years of follow-up.

CONCLUSIONS

Two out of five patients with T1DM or T2DM may present diabetic retinopathy in Latin America and the Caribbean, but the evidence is very uncertain. This is a major public health problem, and policies and strategies for early detection and opportunely treatment should be proposed.

Image quality assessment of retinal fundus photographs for diabetic retinopathy in the machine learning era: a review

This study aimed to evaluate the image quality assessment (IQA) and quality criteria employed in publicly available datasets for diabetic retinopathy (DR). A literature search strategy was used to identify relevant datasets, and 20 datasets were included in the analysis. Out of these, 12 datasets mentioned performing IQA, but only eight specified the quality criteria used. The reported quality criteria varied widely across datasets, and accessing the information was often challenging. The findings highlight the importance of IQA for AI model development while emphasizing the need for clear and accessible reporting of IQA information. The study suggests that automated quality assessments can be a valid alternative to manual labeling and emphasizes the importance of establishing quality standards based on population characteristics, clinical use, and research purposes. In conclusion, image quality assessment is important for AI model development; however, strict data quality standards must not limit data sharing. Given the importance of IQA for developing, validating, and implementing deep learning (DL) algorithms, it's recommended that this information be reported in a clear, specific, and accessible way whenever possible. Automated quality assessments are a valid alternative to the traditional manual labeling process, and quality standards should be determined according to population characteristics, clinical use, and research purpose.

Potency of teleophthalmology as a detection tool for diabetic retinopathy

In China, the prevalence of diabetic retinopathy (DR) is increasing, so it is necessary to provide convenient and effective community outreach screening programs for DR, especially in rural and remote areas. The purpose of this study was to use the results of ophthalmologists as the gold standard to evaluate the accuracy of community general practitioners' judgement and grading of DR to find a feasible and convenient DR screening method to reduce the risk of visual impairment and blindness in known diabetes patients. Retinal images of 1646 diabetic patients who underwent DR screening through teleophthalmology at Nanchang First Hospital were collected for 30 months (January 2020 to June 2022). Retinal images were collected without medication for mydriasis, stored by community general practitioner, and diagnosed by both community general practitioner and ophthalmologist of our hospital through teleophthalmology. The grading of ophthalmologist was used as a reference or gold standard for comparison with that of community general practitioner. A total of 1646 patients and 3185 eyes were examined, including 2310 eyes with DR. The evaluation by the community general practitioner had a Kappa value of 0.578, sensitivity of 80.58%, specificity of 89.94%, and accuracy of 83.38%% in 2020; a Kappa value of 0.685, sensitivity of 95.43%, specificity of 78.55%, and accuracy of 90.77% in 2021; and a Kappa value of 0.744, sensitivity of 93.99%, specificity of 88.97%, and accuracy of 92.86% in 2022. Teleophthalmology helped with large-scale screening of DR and made it possible for community general practitioner to grade images with high accuracy after appropriate training. It is possible to solve the current shortage of eye care personnel, promote the early recognition of disease and reduce the impact of diabetes-associated blindness.

Use of digital retinography to detect vascular changes in pre-diabetic patients: a cross-sectional study

BACKGROUND

Diabetic retinopathy (DR) is a common complication of DM and may go unnoticed until irreversible damage occurs. Its screening can contribute to the early detection. Although, there are no studies which investigate the ability of digital retinography to detect vascular changes in pre-diabetic patients.

OBJECTIVE

Identify the prevalence and severity of RD in patients with pre-diabetes.

METHODS

Cross-sectionalstudy carried out in a sample of patients with pre-diabetes and weight excess characterized from January 2020 to April 2023. Sociodemographic and clinical variables were collected, in addition to lifestyle habits. Retinographic evaluation was also performed using a Digital Retinography. For the analysis of all variables, the adopted significance level was 5%. The software used for the analysis was SPSS version 25.0.

RESULTS

Of 108 patients selected 7.1% have alteration in the exam indicating DR. Among the participants with diabetic retinopathy, four had the moderate form (50%), three the moderate form (37%) and only one participant had the severe form (13%).

CONCLUSIONS

Our findings highlight the importance of preventive measures and adequate control of these conditions in pre-diabetic patients, in order to prevent or delay the progression of diabetic retinopathy and, consequently, reduce the risk of blindness and other ocular complications.

A Systematic Review of Digital Ophthalmoscopes in Medicine

Purpose

Recent advances in telemedicine have led to increased use of digital ophthalmoscopes (DO) in clinical settings. This review aims to assess commercially available DOs, including smartphone (SP), desktop, and handheld ophthalmoscopes, and evaluate their applications.

Methods

A literature review was performed by searching PubMed (pubmed.ncbi.nlm.nih.gov), Web of Science (webofknowledge.com), and Science Direct (sciencedirect.com). All English-language papers that resulted from the search terms "digital ophthalmoscope", "screening tool", "glaucoma screening", "diabetic retinopathy screening", "cataract screening", and "papilledema screening" were reviewed. Studies that contained randomized clinical trials with human participants between January 2010 and December 2020 were included. The Risk of Bias in Systematic Reviews (ROBIS) tool was used to assess the methodological quality of each included paper.

Results

Of the 1307 studies identified, 35 met inclusion and exclusion criteria. The ROBIS tool determined that 29/35 studies (82.8%) had a low risk of bias, 3/35 (8.5%) had a moderate risk of bias, and 3/35 (8.5%) had a high risk of bias.

Conclusion

The continued adoption of DOs remains uncertain because of concerns about the image quality for non-mydriatic eyes and the confidence in data captured from the device. Likewise, there is a lack of guidelines for the use of DOs, which makes it difficult for providers to determine the best device for their practice and to ensure appropriate use. Even so, DOs continue to gain acceptance as technology and practice integration improve, especially in underserved areas with limited access to ophthalmologists.

Single retinal image for diabetic retinopathy screening: performance of a handheld device with embedded artificial intelligence

BACKGROUND

Diabetic retinopathy (DR) is a leading cause of blindness. Our objective was to evaluate the performance of an artificial intelligence (AI) system integrated into a handheld smartphone-based retinal camera for DR screening using a single retinal image per eye.

METHODS

Images were obtained from individuals with diabetes during a mass screening program for DR in Blumenau, Southern Brazil, conducted by trained operators. Automatic analysis was conducted using an AI system (EyerMaps™, Phelcom Technologies LLC, Boston, USA) with one macula-centered, 45-degree field of view retinal image per eye. The results were compared to the assessment by a retinal specialist, considered as the ground truth, using two images per eye. Patients with ungradable images were excluded from the analysis.

RESULTS

A total of 686 individuals (average age 59.2 ± 13.3 years, 56.7% women, diabetes duration 12.1 ± 9.4 years) were included in the analysis. The rates of insulin use, daily glycemic monitoring, and systemic hypertension treatment were 68.4%, 70.2%, and 70.2%, respectively. Although 97.3% of patients were aware of the risk of blindness associated with diabetes, more than half of them underwent their first retinal examination during the event. The majority (82.5%) relied exclusively on the public health system. Approximately 43.4% of individuals were either illiterate or had not completed elementary school. DR classification based on the ground truth was as follows: absent or nonproliferative mild DR 86.9%, more than mild (mtm) DR 13.1%. The AI system achieved sensitivity, specificity, positive predictive value, and negative predictive value percentages (95% CI) for mtmDR as follows: 93.6% (87.8-97.2), 71.7% (67.8-75.4), 42.7% (39.3-46.2), and 98.0% (96.2-98.9), respectively. The area under the ROC curve was 86.4%.

CONCLUSION

The portable retinal camera combined with AI demonstrated high sensitivity for DR screening using only one image per eye, offering a simpler protocol compared to the traditional approach of two images per eye. Simplifying the DR screening process could enhance adherence rates and overall program coverage.

Clinical validation of a smartphone-based retinal camera for diabetic retinopathy screening

AIMS

This study aims to compare the performance of a handheld fundus camera (Eyer) and standard tabletop fundus cameras (Visucam 500, Visucam 540, and Canon CR-2) for diabetic retinopathy and diabetic macular edema screening.

METHODS

This was a multicenter, cross-sectional study that included images from 327 individuals with diabetes. The participants underwent pharmacological mydriasis and fundus photography in two fields (macula and optic disk centered) with both strategies. All images were acquired by trained healthcare professionals, de-identified, and graded independently by two masked ophthalmologists, with a third senior ophthalmologist adjudicating in discordant cases. The International Classification of Diabetic Retinopathy was used for grading, and demographic data, diabetic retinopathy classification, artifacts, and image quality were compared between devices. The tabletop senior ophthalmologist adjudication label was used as the ground truth for comparative analysis. A univariate and stepwise multivariate logistic regression was performed to determine the relationship of each independent factor in referable diabetic retinopathy.

RESULTS

The mean age of participants was 57.03 years (SD 16.82, 9-90 years), and the mean duration of diabetes was 16.35 years (SD 9.69, 1-60 years). Age (P = .005), diabetes duration (P = .004), body mass index (P = .005), and hypertension (P < .001) were statistically different between referable and non-referable patients. Multivariate logistic regression analysis revealed a positive association between male sex (OR 1.687) and hypertension (OR 3.603) with referable diabetic retinopathy. The agreement between devices for diabetic retinopathy classification was 73.18%, with a weighted kappa of 0.808 (almost perfect). The agreement for macular edema was 88.48%, with a kappa of 0.809 (almost perfect). For referable diabetic retinopathy, the agreement was 85.88%, with a kappa of 0.716 (substantial), sensitivity of 0.906, and specificity of 0.808. As for image quality, 84.02% of tabletop fundus camera images were gradable and 85.31% of the Eyer images were gradable.

CONCLUSIONS

Our study shows that the handheld retinal camera Eyer performed comparably to standard tabletop fundus cameras for diabetic retinopathy and macular edema screening. The high agreement with tabletop devices, portability, and low costs makes the handheld retinal camera a promising tool for increasing coverage of diabetic retinopathy screening programs, particularly in low-income countries. Early diagnosis and treatment have the potential to prevent avoidable blindness, and the present validation study brings evidence that supports its contribution to diabetic retinopathy early diagnosis and treatment.

Diabetic Retinopathy Screening Using Artificial Intelligence and Handheld Smartphone-Based Retinal Camera

BACKGROUND

Portable retinal cameras and deep learning (DL) algorithms are novel tools adopted by diabetic retinopathy (DR) screening programs. Our objective is to evaluate the diagnostic accuracy of a DL algorithm and the performance of portable handheld retinal cameras in the detection of DR in a large and heterogenous type 2 diabetes population in a real-world, high burden setting.

METHOD

Participants underwent fundus photographs of both eyes with a portable retinal camera (Phelcom Eyer). Classification of DR was performed by human reading and a DL algorithm (PhelcomNet), consisting of a convolutional neural network trained on a dataset of fundus images captured exclusively with the portable device; both methods were compared. We calculated the area under the curve (AUC), sensitivity, and specificity for more than mild DR.

RESULTS

A total of 824 individuals with type 2 diabetes were enrolled at Itabuna Diabetes Campaign, a subset of 679 (82.4%) of whom could be fully assessed. The algorithm sensitivity/specificity was 97.8 % (95% CI 96.7-98.9)/61.4 % (95% CI 57.7-65.1); AUC was 0·89. All false negative cases were classified as moderate non-proliferative diabetic retinopathy (NPDR) by human grading.

CONCLUSIONS

The DL algorithm reached a good diagnostic accuracy for more than mild DR in a real-world, high burden setting. The performance of the handheld portable retinal camera was adequate, with over 80% of individuals presenting with images of sufficient quality. Portable devices and artificial intelligence tools may increase coverage of DR screening programs.

Non-mydriatic fundus photography as an alternative to indirect ophthalmoscopy for screening of diabetic retinopathy in community settings: a comparative pilot study in rural and tribal India

OBJECTIVES

The impending and increasing prevalence of diabetic retinopathy (DR) in India has necessitated a need for affordable and valid community outreach screening programme for DR, especially in rural and far to reach indigenous local communities. The present study is a pilot study aimed to compare non-mydriatic fundus photography with indirect ophthalmoscopy for its utilisation as a feasible and logistically convenient screening modality for DR in an older age, rural, tribal population in Western India.

DESIGN AND SETTING

This community-based, cross-sectional, prospective population study was a part of a module using Rapid Assessment of Avoidable Blindness and DR methodology in 8340 sampled participants with ≥50 years age. In this study, the diabetics identified were screened for DR using two methods: non-mydriatic fundus photography on the field by trained professionals, that were then graded by a retina specialist at the base hospital and indirect ophthalmoscopy by expert ophthalmologists in the field with masking of each other's findings for its utility and comparison.

RESULTS

The prevalence of DR, sight threatening DR and maculopathy using indirect ophthalmoscopy was found to be 12.1%, 2.1% and 6.6%, respectively. A fair agreement (κ=0.48 for DR and 0.59 for maculopathy) was observed between both the detection methods. The sensitivity and specificity of fundus photographic evaluation compared with indirect ophthalmoscopy were found to be 54.8% and 92.1% (for DR), 60.7% and 90.8% (for any DR) and 84.2% and 94.8% (for only maculopathy), respectively.

CONCLUSION

Non-mydriatic fundus photography has the potential to identify DR (any retinopathy or maculopathy) in community settings in Indian population. Its utility as an affordable and logistically convenient cum practical modality is demonstrable. The sensitivity of this screening modality can be further increased by investing in better resolution cameras, capturing quality images and training and validation of imagers.

TRIAL REGISTRATION NUMBER

CTRI/2020/01/023025; Clinical Trial Registry, India (CTRI).

Human Leukocyte Antigens class II (HLA II) gene profile from an admixed population of patients with type 1 diabetes with severe diabetic retinopathy: a nested case-control study in Brazil

BACKGROUND

Although the well-established role of the HLA genes on the predisposition of type 1 diabetes (T1D), its contribution to the development and progression of diabetic retinopathy is still unclear, especially in admixed populations. We aimed to study the relationship between HLA alleles and severe diabetic retinopathy in a highly admixed population of T1D patients.

METHODS

This was a nested case-control study based on a cross-sectional, nationwide survey conducted in Brazil. We included 117 patients with severe diabetic retinopathy and 117 random controls composed of T1D patients without retinopathy, matched for diabetes duration. HLA-class II genes (HLA-DRB1, -DQA1, and -DQB1) were genotyped using the SSO and NGS methods.

RESULTS

Haplotypes HLA-DRB1*04:05 ~ DQA1*03:01 g ~ DQB1*03:02 (OR 1.75, CI 0.97-3.16, p value 0.058) and HLA-DRB1*13:02 ~ DQA1*01:02 ~ DQB1*06:04 (OR 5.18, CI 1.12-23.09, p value 0.019) were more prevalent on the severe DR group but they did not present statistically difference after Bonferroni correction. The most frequent haplotype on both groups was HLA-DRB1*03:01 ~ DQA1*05:01 g ~ DQB1*02:01 (29.6% on severe DR and 33.33% on the control group).

CONCLUSIONS

Our study showed no influence of HLA genes on the development of DR. Further longitudinal data is needed to better understand the role of genetic factors on this multifactorial significant microvascular complication.

Diabetic retinopathy screening in urban primary care setting with a handheld smartphone-based retinal camera

AIMS

To evaluate diabetic retinopathy (DR) screening with a portable handheld smartphone-based retinal camera and telemedicine in an urban primary healthcare setting and to evaluate the learning curve for image acquisition, performed by healthcare personnel without previous experience in retinal imaging.

METHODS

This was a prospective study that enrolled patients with type 2 diabetes mellitus (T2DM) followed at a primary healthcare unit in São Paulo, Brazil. After a brief training in image acquisition, there was further continuous feedback given by a retina specialist during the remote image reading process. Each patient underwent two fundus and one anterior ocular segment images per eye, after mydriasis. Patients were classified according to the need of referral.

RESULTS

A total of 627 adult individuals with T2DM underwent retinal evaluation. The population was composed by 63.2% female individuals, age median of 66 years, diabetes duration 10.7 ± 8.2 years and HbA1c 7.7 ± 1.9% (61 + 20.8 mmol/mol). The most prevalent associated comorbidities were arterial hypertension (80.3%) and dyslipidemia (50.2%). Referral decision was possible in 81.2% patients. Most patients had absent or non-referable DR; the main ocular media opacity detected was cataract. After the 7th day of image acquisition, the daily rate of patients whose images allowed clinical decision was maintained above 80%. A higher HbA1c was associated with referable DR.

CONCLUSIONS

A low-cost DR screening strategy with a handheld device and telemedicine is feasible and has the potential to increase coverage of DR screening in underserved areas; the possibility of mobile units is relevant for DR screening in the context of COVID-19 pandemic. Daily rate of patients whose examinations allowed clinical decision. X-axis: day of examination; Y-axis: rate (%) of patients whose examinations allowed a clinical decision.

The feasibility of smartphone based retinal photography for diabetic retinopathy screening among Brazilian Xavante Indians

AIMS

To evaluate the feasibility of smartphone based retinal photography for diabetic retinopathy (DR) screening among Brazilian Xavante Indians and the yield of retinal images.

METHODS

A non-probabilistic cluster sample of 170 individuals with and without diabetes was enrolled for ocular examination with a portable retinal camera during DR screening at two Xavante Reservations. Due to operational conditions and to optimize the field work, only the larger Xavante villages were included. Images were obtained after pupil dilation; image analysis included assessment of quality, presence of media opacities and diabetic retinopathy grading whenever possible for individuals with diabetes.

RESULTS

A total of 157 individuals underwent the complete ocular imaging protocol, 95 with diabetes (60.5%). Among those with diabetes, 23 (24.2%) could not have DR graded because of media opacities. For those with gradable images, the frequency of DR was 22.2%; sight-threatening DR was present in 9.7%. The main causes for ungradable images were cataracts and asteroid hyalosis.

CONCLUSIONS

The presence of DR was higher than in previous studies, calling attention for its prevention in this vulnerable population. The screening model with a smartphone-based portable retinal camera is feasible and could increase screening coverage if associated with telemedicine.

Genomic ancestry as a risk factor for diabetic retinopathy in patients with type 1 diabetes from an admixed population: a nested case-control study in Brazil

AIMS

The influence of genetic factors on the development and progression of diabetic retinopathy is still unclear. Previous studies showed controversial results. We aimed to characterize the relationship between genomic ancestry and self-reported color/race with severe diabetic retinopathy in patients with type 1 diabetes belonging to a highly admixed population.

METHODS

This study was a nested case-control based on data collected from a large cross-sectional, nationwide survey conducted in clinics from all five geographic regions of Brazil. For the present study, we included 414 individuals. Cases (n = 176) were considered if they had severe non-proliferative or proliferative diabetic retinopathy, and controls (n = 238) were type 1 diabetes patients without retinopathy, matched for diabetes duration by a range of 5 years. Indirect ophthalmoscopy was performed, and individual genomic ancestry was inferred using a panel of 46 ancestry informative markers.

RESULTS

The backward stepwise logistic regression analysis showed that African genomic ancestry (OR 3.9, p = 0.045), HbA1c (OR 1.24, p = 0.001), glomerular filtration rate (OR 0.98, p < 0.001) and hypertension (OR 2.52, p < 0.001) were associated with severe diabetic retinopathy after adjusting for clinical and demographic data. Self-reported color/race was not statistically associated with diabetic retinopathy.

CONCLUSIONS

Genomic ancestry, as well as clinical variables such as hypertension, impaired glomerular filtration rate and poor diabetes control (HbA1c), was important risk factor for the development of severe diabetic retinopathy. Further studies are needed, especially in highly admixed populations, to better understand the role of genomic ancestry and possible genes that might be associated with the development and/or progression of diabetic retinopathy.

Cost-utility Analysis of Opportunistic and Systematic Diabetic Retinopathy Screening Strategies from the Perspective of the Brazilian Public Healthcare System

OBJECTIVE

To perform a cost-utility analysis of diabetic retinopathy (DR) screening strategies from the perspective of the Brazilian Public Healthcare System.

METHODS

A model-based economic evaluation was performed to estimate the incremental costs per quality-adjusted life-year (QALY) gained between three DR screening strategies: (1) the opportunistic ophthalmology referral-based (usual practice), (2) the systematic ophthalmology referral-based, and (3) the systematic teleophthalmology-based. The target population included individuals with type 2 diabetes (T2D) aged 40 years, without retinopathy, followed over a 40-year time horizon. A Markov model was developed with five health states and a 1-year cycle. Model parameters were based on literature and country databases. One-way and probabilistic sensitivity analyses were performed to assess model parameters' uncertainty. WHO willingness-to-pay (WHO-WTP) thresholds were used as reference (i.e. one and three times the Brazilian per capita Gross Domestic Product of R$32747 in 2018).

RESULTS

Compared to usual practice, the systematic teleophthalmology-based screening was associated with an incremental cost of R$21445/QALY gained ($9792/QALY gained). The systematic ophthalmology referral-based screening was more expensive (incremental costs = R$4) and less effective (incremental QALY = -0.012) compared to the systematic teleophthalmology-based screening. The probability of systematic teleophthalmology-based screening being cost-effective compared to usual practice was 0.46 and 0.67 at the minimum and the maximum WHO-WTP thresholds, respectively.

CONCLUSION

Systematic teleophthalmology-based DR screening for the Brazilian population with T2D would be considered very cost effective compared to the opportunistic ophthalmology referral-based screening according to the WHO-WTP threshold. However, there is still a considerable amount of uncertainty around the results.

Retinal exams requested at Primary Care Unit: indications, results and alternative strategies of evaluation

Objective

To evaluate indications, results and strategy of retinal exams requested at Primary Care Units.

Methods

A retrospective study that analyzed the indications and results of retinal exams, in the modalities clinical dilated fundus exams and color fundus photographs. In the following situations, patients were considered eligible for color fundus photographs if visual acuity was normal and ocular symptoms were absent: diabetes mellitus and/or hypertension, in use of drugs with potential retinal toxicity, diagnosis or suspicion of glaucoma, stable and asymptomatic retinopathies, except myopia greater than -3.00 diopters.

Results

A total of 1,729 patients were evaluated (66% female, age 63.5±15.5 years), and 1,190 underwent clinical dilated fundus exam and 539 underwent color fundus photographs. Diabetes was present in 32.2%. The main indications were diabetes (23.7%) and glaucoma evaluation (23.5%). In 3.4% of patients there was no apparent indication. The main results were a large cup/disc ratio (30.7%) and diabetic retinopathy (13.2%). Exam was normal in 9.6%, detected peripheral changes in 7% and could not be performed in 1%. Considering patients eligible for fundus photographs (22.4%), more than half underwent clinical dilated fundus exams.

Conclusion

Regarding exam modality, there were no important differences in the distribution of indications or diagnosis. Color fundus photograph is compatible with telemedicine and more cost-effective, and could be considered the strategy of choice in some scenarios. Since there are no clear guidelines for retinal exams indications or the modality of choice, this study may contribute to such standardization, in order to optimize public health resources.

Relationship between health care insurance status, social determinants and prevalence of diabetes-related microvascular complications in patients with type 1 diabetes: a nationwide survey in Brazil

AIMS

To evaluate the relationship between social determinants, health care insurance status and occurrence of diabetes-related chronic complications (DRCC) in Brazilian patients with type 1 diabetes.

METHODS

A multicenter cross-sectional study conducted between August 2011 and August 2014 in 14 public clinics in 10 Brazilian cities. Data were obtained from 1760 patients, aged 29.9 ± 11.9 years, with diabetes duration of 15.5 ± 9.3 years; 55.9% female, 54.5% Caucasians, 69.7% were attended exclusively by the public Brazilian National Health Care System (BNHCS) and 30.3% had also private health care insurance. Patients' information was obtained through a questionnaire and a chart review form.

RESULTS

The social determinants associated with having both private and public health care insurance were being employed, belonging to medium or high socioeconomic status, having more years of school attendance and having younger age. Regarding DRCC, patients that had private and public health care had lower rates of diabetic retinopathy and of any other DRCC. Chronic kidney disease was not associated with health care coverage status after adjusting for classical clinical risk factors.

CONCLUSIONS

Brazilian patients with type 1 diabetes had better clinical control and lower rates of DRCC, mainly retinopathy, when also having private health care insurance. These patients presented less frequently predictors of chronic complications such as high levels of HbA1c and blood pressure. BNHCS should change the approach for screening DRCC such as diabetic retinopathy, using methods such as telemedicine that would lead to earlier diagnosis, better outcomes and will be cost-effective sometime after its implementation.

Teleophthalmology Screening for Diabetic Retinopathy in Brazil: Applicability and Economic Assessment

Introduction: Early diagnosis and prompt therapy of diabetic retinopathy (DR) are essential to prevent visual loss, but access of the diabetic population to regular fundus examination by an ophthalmologist remains a challenge. Methods: This prospective comparative study, including two referral health centers in the state of Minas Gerais, Southeastern Brazil, assesses applicability and economic viability of fundus photography-based teleophthalmology screening for DR. Results: A total of 2,662 eyes of 1,331 patients were examined at both health centers. Mean age was 57 years, with 836 (62.8%) females. Quality of fundus photographs was acceptable for 2,398 eyes (90.1%). The presence of DR was disclosed in 394 patients (29.6%), with 28 patients (2.1%) presenting evidence of advanced disease (severe nonproliferative or proliferative DR). Economic assessment revealed cost reduction of 28.76 US$ per patient, with a calculated break-even point of 112 exams/month or 1,344 exams/year. Conclusions: For the situation studied under the perspective of public health service, teleophthalmology was viable and cost effective when compared with ordinary ophthalmology examination. In addition, teleophthalmology allowed rapid resolution of repressed demand for fundus examination of diabetic patients locally at the two sites, with early DR diagnoses and referrals. Fundus photography-based teleophthalmology was a viable, effective, and significantly cheaper strategy for the screening of DR.

Diabetic Retinopathy May Indicate an Increased Risk of Cardiovascular Disease in Patients With Type 1 Diabetes-A Nested Case-Control Study in Brazil

Objective: Cardiovascular disease, the leading cause of death worldwide, and diabetic retinopathy, the main cause of blindness in economically active populations, share clinical risk factors, and pathophysiological features. The aim of this study is to examine the association between diabetic retinopathy, cardiovascular disease, and common risk factors in patients with type 1 diabetes. Design and Methods: This nested case-control study was performed in patients from the Brazilian Type 1 Diabetes Study Group, a nationwide survey that was conducted in Brazil and enrolled 1,760 patients with type 1 diabetes. A total of 342 patients were selected (57 cases with macrovascular disease and 285 controls who were matched for duration of diabetes and gender). Results: In the exploratory analysis, stratified by cardiovascular disease, the following variables were statistically significant: age (p=0.037), hypertension (p=0.035), high BMI (p = 0.046), diabetic retinopathy (p = 0.003), and chronic kidney disease (p = 0.026). By multivariate logistic regression, patients with diabetic retinopathy were more likely to develop cardiovascular disease (OR 2.16, 95% CI 1.16-4.02, p = 0.015). Although to a lesser extent than diabetic retinopathy, higher BMI levels were also related to an increase in the risk of cardiovascular disease of 1.08 (95% CI 1.01-1.15, p = 0.024). Conclusion: The presence of diabetic retinopathy indicates a greater risk for cardiovascular disease in Brazilian patients with type 1 diabetes. Further studies are warranted to determine whether a noninvasive exam, such as fundoscopy, could help identify patients who show an increased risk for cardiovascular disease.

Current epidemiology of diabetic retinopathy in patients with type 1 diabetes: a national multicenter study in Brazil

BACKGROUND

Diabetic retinopathy is the leading cause of blindness in economically active populations. The aims of this study were to estimate the prevalence and to identify risk factors for diabetic retinopathy in patients with type 1 diabetes in Brazil.

METHODS

This was a nationwide, cross-sectional study conducted between August 2010 and August 2014. The study included 1760 patients with type 1 diabetes. Patients underwent a standard questionnaire, clinical and laboratory analyses and were screened for diabetic retinopathy. To analyze the risk factors related to diabetic retinopathy, two models of logistic regression models were performed, one considering vision-threatening cases and the other with any diabetic retinopathy cases as dependent variables. The group with vision-threatening included patients with severe non-proliferative diabetic retinopathy, proliferative diabetic retinopathy and macular edema.

RESULTS

In total, 1644 patients (mean age, 30.1± 12.0 years; duration of diabetes, 15.3 ± 9.3 years; female, 55.8%) were studied. 35.7% presented diabetic retinopathy and 12% presented vision-threatening diabetic retinopathy. Three risk factors associated with diabetic retinopathy were in common to both groups: longer diabetes duration (OR 1.07; 95% CI, 1.05-1.09), higher levels of HbA1c (OR 1.24; CI, 1.17-1.32) and higher levels of serum uric acid (OR 1.22; CI, 1.13-1.31) (p < 0.001 for all comparisons).

CONCLUSION

The higher rate of vision-threatening retinopathy found in our study highlights the need to improve access to eye care and screening programs for diabetic retinopathy in Brazil. In addition to traditional risk factors, we found an association between serum uric acid levels and diabetic retinopathy. Further studies are needed to address this association.

Teleophthalmology Support for Primary Care Diagnosis and Management

This study was performed to evaluate a healthcare strategy based on teleophthalmology for diagnosis and management of primary healthcare users. A descriptive cross-sectional study was conducted to review the medical records of patients from January 2013 to December 2014 from primary care units in the city of São Paulo. The units referred patients, who had diabetes or high blood pressure, and were users of chloroquine compounds, for a fundus examination. The images were sent to a reading center for review, diagnosis, and patient referrals. From 9173 analyzed patients, 570 (6.2%) were excluded because of poor image quality. Of the remaining patients, 4933 (57.3%) had diabetes, 7242 (84,2%) systemic hypertension, and 113 (1.3%) used chloroquine. Of these, 989 (11.5%) patients needed ophthalmologic treatment. The most frequently prescribed treatments were cataract extraction in 692 (70%) of 989 and photocoagulation in 245 (24.8%) of 989 cases. Overall, cataract extraction was indicated in 692 (8%) of 8603 cases and photocoagulation in 245 (2.8%) of 8603 cases. When only patients with diabetes were considered, the indication for photocoagulation increased to 4.5%.The results showed that non-medical professionals could produce good-quality ocular images for screening of ocular diseases in most cases; only 6.2% of ocular images did not meet quality requirements. Most patients referred for fundus examination did not need a specific treatment, indicating that this system could be an inexpensive and reliable tool for use in developing countries.

Non-Mydriatic Fundus Retinography in Screening for Diabetic Retinopathy: Agreement Between Family Physicians, General Ophthalmologists, and a Retinal Specialist

PURPOSE

To determine the level of agreement between trained family physicians (FPs), general ophthalmologists (GOs), and a retinal specialist (RS) in the assessment of non-mydriatic fundus retinography in screening for diabetic retinopathy (DR) in the primary health-care setting.

METHODS

200 Diabetic patients were submitted to two-field non-mydriatic digital fundus camera. The images were examined by four trained FPs, two GOs, and one RS with regard to the diagnosis and severity of DR and the diagnosis of macular edema. The RS served as gold standard. Reliability and accuracy were determined with the kappa test and diagnostic measures.

RESULTS

A total of 397 eyes of 200 patients were included. The mean age was 55.1 (±11.7) years, and 182 (91%) had type 2 diabetes. The mean levels of serum glucose and glycosylated hemoglobin A1c were 195.6 (±87.3) mg/dL and 8.9% (±2.1), respectively. DR was diagnosed in 166 eyes by the RS and in 114 and 182 eyes by GO₁ and GO₂, respectively. For severity, DR was graded as proliferative in 8 eyes by the RS vs. 15 and 9 eyes by GO₁ and GO₂, respectively. The agreement between the RS and the GOs was substantial for both DR diagnosis (GO₁k = 0.65; GO₂k = 0.74) and severity (GO₁k = 0.60; GO₂k = 0.71), and fair or moderate for macular edema (GO₁k = 0.27; GO₂k = 0.43). FP₁, FP₂, FP₃, and FP₄ diagnosed DR in 108, 119, 163, and 117 eyes, respectively. The agreement between the RS and the FPs with regard to DR diagnosis was substantial (FP₂k = 0.69; FP₃k = 0.73; FP₄k = 0.71) or moderate (FP₁k = 0.56). As for DR severity, the agreement between the FPs and the RS was substantial (FP₂k = 0.66; FP₃k = 069; FP₄k = 0.64) or moderate (FP₁k = 0.51). Agreement between the FPs and the RS with regard to macular edema was fair (FP₁k = 0.33; FP₂k = 0.39; FP₃k = 0.37) or moderate (FP₄k = 0.51).

CONCLUSION

Non-mydriatic fundus retinography was shown to be useful in DR screening in the primary health-care setting. FPs made assessments with good levels of agreement with an RS. Non-mydriatic fundus retinography associated with appropriate general physicians training is essential for the DR screening.

Telemedicine for diabetic retinopathy screening using an ultra-widefield fundus camera

OBJECTIVE

Telemedicine reporting of diabetic retinopathy (DR) screening using ultra-widefield (UWF) fundus camera.

MATERIALS AND METHODS

Cross-sectional study of diabetic patients who visited the endocrinology department of a private multi-specialty hospital in United Arab Emirates between April 2015 and January 2017 who underwent UWF fundus imaging. Fundus pictures are then accessed at the Retina Clinic in the Department of Ophthalmology. Primary outcome measure was incidence of any form of DR detected. The secondary outcome measure was failure to take good image and inability to grade.

RESULTS

A total of 1,024 diabetic individuals were screened for DR from April 2015 to January 2017 in the department of Endocrinology. Rate of DR was 9.27%; 165 eyes of 95 individuals were diagnosed to have some form of DR. Mild non-proliferative DR (NPDR) was seen in 114 of 165 eyes (69.09%), moderate NPDR in 32 eyes (19.39%), severe NPDR in six eyes (3.64%), and proliferative DR (PDR) in 13 eyes (7.88%). The secondary outcome measure of poor image acquisition was seen in one individual who had an image acquired in one eye that could not be graded due to bad picture quality.

CONCLUSIONS

The present study has shown the effectiveness of DR screening using UWF fundus camera. It has shown the effectiveness of trained nursing personnel taking fundus images. This model can be replicated in any private multi-specialty hospital and reduce the burden of DR screening in the retina clinic and enhance early detection of treatable DR.

Clinical Components of Telemedicine Programs for Diabetic Retinopathy

Diabetic retinopathy is a leading cause of new-onset vision loss worldwide. Treatments supported by large clinical trials are effective in preserving vision, but many persons do not receive timely diagnosis and treatment of diabetic retinopathy, which is typically asymptomatic when most treatable. Telemedicine evaluation to identify diabetic retinopathy has the potential to improve access to care, but there are no universal standards regarding camera choice or protocol for ocular telemedicine. We review the literature regarding the impact of imaging device, number and size of retinal images, pupil dilation, type of image grader, and diagnostic accuracy on telemedicine assessment for diabetic retinopathy. Telemedicine assessment of diabetic retinopathy has the potential to preserve vision, but further development of telemedicine specific technology and standardization of operations are needed to better realize its potential.