Changes in the Epidemiology of Diabetic Retinopathy in Spain: A Systematic Review and Meta-Analysis

Validation of artificial intelligence algorithm LuxIA for screening of diabetic retinopathy from a single 45° retinal colour fundus images: the CARDS study

OBJECTIVE

This study validated the artificial intelligence (AI)-based algorithm LuxIA for screening more-than-mild diabetic retinopathy (mtmDR) from a single 45° colour fundus image of patients with diabetes mellitus (DM, type 1 or type 2) in Spain. Secondary objectives included validating LuxIA according to the International Clinical Diabetic Retinopathy (ICDR) classification and comparing its performance between different devices.

METHODS

In this multicentre, cross-sectional study, retinal colour fundus images of adults (≥18 years) with DM were collected from five hospitals in Spain (December 2021-December 2022). 45° colour fundus photographs were captured using non-mydriatic Topcon and ZEISS cameras. The Discovery platform (RetinAI) was used to collect images. LuxIA output was an ordinal score (1-5), indicating a classification as mtmDR based on an ICDR severity score.

RESULTS

945 patients with DM were included; the mean (SD) age was 64.6 (13.5) years. The LuxIA algorithm detected mtmDR with a sensitivity and specificity of 97.1% and 94.8%, respectively. The area under the receiver-operating characteristic curve was 0.96, indicating a high test accuracy. The 95% CI data for overall accuracy (94.8% to 95.6%), sensitivity (96.8% to 98.2%) and specificity (94.3% to 95.1%) indicated robust estimations by LuxIA, which maintained a concordance of classification (N=829, kappa=0.837, p=0.001) when used to classify Topcon images. LuxIA validation on ZEISS-obtained images demonstrated high accuracy (90.6%), specificity (92.3%) and lower sensitivity (83.3%) as compared with Topcon-obtained images.

CONCLUSIONS

AI algorithms such as LuxIA are increasing testing feasibility for healthcare professionals in DR screening. This study validates the real-world utility of LuxIA for mtmDR screening.

Cost-Effectiveness of a Telemedicine Optometric-Based Assessment for Screening Diabetic Retinopathy in a Country with a Universal Public Health System

Objective: To determine the cost-effectiveness of a new telemedicine optometric-based screening program of diabetic retinopathy (DR) compared with traditional models' assessments in a universal European public health system. Methods: A new teleophthalmology program for DR based on the assessment of retinographies (3-field Joslin Vision Network by a certified optometrist and a reading center [IOBA-RC]) was designed. This program was first conducted in a rural area 40 km from the referral hospital (Medina de Rioseco, Valladolid, Spain). The cost-effectiveness was compared with telemedicine based on evaluations by primary care physicians and general ophthalmologists, and to face-to-face examinations conducted by ophthalmologists. A decision tree model was developed to simulate the cost-effectiveness of both models, considering public and private costs. The effectiveness was measured in terms of quality of life. Results: A total of 261 patients with type 2 diabetes were included (42 had significant DR and required specific surveillance by the RC; 219 were undiagnosed). The sensitivity and specificity of the detection of DR were 100% and 74.1%, respectively. The telemedicine-based DR optometric screening model demonstrated similar utility to models based on physicians and general ophthalmologists and traditional face-to-face evaluations (0.845) at a lower cost/patient (€51.23, €71.65, and €86.46, respectively). Conclusions: The telemedicine-based optometric screening program for DR in a RC demonstrated cost savings even in a developed country with a universal health care system. These results support the expansion of this kind of teleophthalmology program not only for screening but also for the follow-up of diabetic patients.

Incidence of Diabetic Retinopathy in Individuals with Type 2 Diabetes: A Study Using Real-World Data

Background/Objectives: This study aimed to assess the incidence of diabetic retinopathy (DR) in patients with type 2 diabetes (T2DM) treated in primary-care settings in Catalonia, Spain, and identify key risk factors associated with DR development. Methods: A retrospective cohort study was conducted using the SIDIAP (System for Research and Development in Primary Care) database. Patients aged 30-90 with T2DM who underwent retinal screening between 2010 and 2015 were included. Multivariable Cox regression analysis was used to assess the impact of clinical variables, including HbA1c levels, diabetes duration, and comorbidities, on DR incidence. Results: This study included 146,506 patients, with a mean follow-up time of 6.96 years. During this period, 4.7% of the patients developed DR, resulting in an incidence rate of 6.99 per 1000 person-years. Higher HbA1c levels were strongly associated with an increased DR risk, with patients with HbA1c > 10% having more than four times the risk compared to those with HbA1c levels < 7% (hazard ratio: 4.23; 95% CI: 3.90-4.58). Other significant risk factors for DR included greater diabetes duration, male sex, ex-smoker status, macrovascular disease, and chronic kidney disease. In contrast, obesity appeared to be a protective factor against DR, with an HR of 0.93 (95% CI: 0.89-0.98). Conclusions: In our real-world setting, the incidence rate of DR was 6.99 per 1000 person-years. Poor glycemic control, especially HbA1c > 10%, and prolonged diabetes duration were key risk factors. Effective management of these factors is crucial in preventing DR progression. Regular retinal screenings in primary care play a vital role in early detection and reducing the DR burden for T2DM patients.

Two Handheld Retinograph Devices Evaluated by Ophthalmologists and an Artificial Intelligence Algorithm

Background/Objectives: Telemedicine in diabetic retinopathy (RD) screening is effective but does not reach the entire diabetes population. The use of portable cameras and artificial intelligence (AI) can help in screening diabetes. Methods: We evaluated the ability of two handheld cameras, one based on a smartphone and the other on a smartscope, to obtain images for comparison with OCT. Evaluation was carried out in two stages: the first by two retina specialists and the second using an artificial intelligence algorithm that we developed. Results: The retina specialists reported that the smartphone images required mydriasis in all cases, compared to 73.05% of the smartscope images and 71.11% of the OCT images. Images were ungradable in 27.98% of the retinographs with the smartphone and in 7.98% with the smartscope. The detection of any DR using the AI algorithm showed that the smartphone obtained lower recall values (0.89) and F1 scores (0.89) than the smartscope, with 0.99. Low results were also obtained using the smartphone to detect mild DR (146 retinographs), compared to using the smartscope (218 retinographs). Conclusions: we consider that the use of handheld devices together with AI algorithms for reading retinographs can be useful for DR screening, although the ease of image acquisition through small pupils with these devices needs to be improved.

[Evaluation of the management and follow-up of diabetic patients in the prevention of diabetic retinopathy]

OBJECTIVE

Diabetes mellitus is a chronic disease with high morbidity and mortality, affecting 537 million adults worldwide. Spain is the second European country in prevalence, with 14.8% in the population aged twenty/seventy-nine years; with 11.6 cases per 1,000 people/year. Diabetic retinopathy (DR) is the fifth cause of vision loss worldwide and the seventh cause of blindness/visual impairment among members of the National Organization of the Blind in Spain (ONCE). Early detection of DR prevents blindness in diabetics and is conditioned by glycosylated hemoglobin. The aim of this paper was to analyze the management of diabetic patients in Aljarafe region (Seville) and identify opportunities for improvement in the coordination of their follow-up between the Primary Care physician and the ophthalmologist.

METHODS

A retrospective observational study (2016-2019) was carried out, with patients registered in the diabetic census of the twenty-eight municipalities of Aljarafe. The primary care and hospital health history, and telemedicine program were consulted. About statistical analysis, for qualitative variables, totals and percentages were calculated; for quantitative variables, mean and standard deviation (if normally distributed) and median and quartiles (if non-normally distributed).

RESULTS

There were 17,175 diabetics registered in Aljarafe (5.7% of the population); 14,440 patients (84.1%) had some determination of hemoglobin during the period, 9,228 (63.9%) had all of them in the appropriate range. Fundoscopic control was performed on 12,040 diabetics (70.1%), and of those who did not, 346 (10.6%) had all of them out of range. There were 1,878 (10.9%) patients without fundoscopic or metabolic control, 1,019 (54.3%) were women, 1,219 (64.9%) were under sixty-five years of age, 1,019 (54.3%) had severe comorbidity.

CONCLUSIONS

Most patients have adequate screening, and more than half have determinations within range. However, a significant percentage with no glycated hemoglobin within range lack fundoscopic control, and another smaller group lack fundoscopic or metabolic control, with inter-municipal variability. We propose to improve communication channels between levels.

Present and future screening programs for diabetic retinopathy: a narrative review

Diabetes is a prevalent global concern, with an estimated 12% of the global adult population affected by 2045. Diabetic retinopathy (DR), a sight-threatening complication, has spurred diverse screening approaches worldwide due to advances in DR knowledge, rapid technological developments in retinal imaging and variations in healthcare resources.Many high income countries have fully implemented or are on the verge of completing a national Diabetic Eye Screening Programme (DESP). Although there have been some improvements in DR screening in Africa, Asia, and American countries further progress is needed. In low-income countries, only one out of 29, partially implemented a DESP, while 21 out of 50 lower-middle-income countries have started the DR policy cycle. Among upper-middle-income countries, a third of 59 nations have advanced in DR agenda-setting, with five having a comprehensive national DESP and 11 in the early stages of implementation.Many nations use 2-4 fields fundus images, proven effective with 80-98% sensitivity and 86-100% specificity compared to the traditional seven-field evaluation for DR. A cell phone based screening with a hand held retinal camera presents a potential low-cost alternative as imaging device. While this method in low-resource settings may not entirely match the sensitivity and specificity of seven-field stereoscopic photography, positive outcomes are observed.Individualized DR screening intervals are the standard in many high-resource nations. In countries that lacks a national DESP and resources, screening are more sporadic, i.e. screening intervals are not evidence-based and often less frequently, which can lead to late recognition of treatment required DR.The rising global prevalence of DR poses an economic challenge to nationwide screening programs AI-algorithms have showed high sensitivity and specificity for detection of DR and could provide a promising solution for the future screening burden.In summary, this narrative review enlightens on the epidemiology of DR and the necessity for effective DR screening programs. Worldwide evolution in existing approaches for DR screening has showed promising results but has also revealed limitations. Technological advancements, such as handheld imaging devices, tele ophthalmology and artificial intelligence enhance cost-effectiveness, but also the accessibility of DR screening in countries with low resources or where distance to or a shortage of ophthalmologists exists.

[Teleophthalmology-based diabetic retinopathy screening in a rural health basic area]

OBJECTIVE

To investigate the prevalence of diabetic retinopathy in a rural health basic area, and to establish the type, the severity degree and the relationship with sex and with another cardiovascular risk factors.

DESIGN

Cross-sectional or prevalence descriptive study.

LOCATION

Rural health basic area in Spain. Primary health care level.

PARTICIPANTS

500 patients over 18 years old with diabetes.

MAIN MEASUREMENTS

Study of the retina through retinography under mydriasis, according to the Joslin Vision Network protocol, with the incorporation of a diagnostic reading center. Correlation of the existence and severity of the retinopathy with the cardiovascular risk factors -smoking, hypertension and hyperlipidemia- and the characteristics of the diabetes -type, evolution time, treatment, metabolic control and renal function-.

RESULTS

The findings showed a 16.4% prevalence, with no significant differences between both sexes. The variables smoking and high blood pressure were related to the existence of retinopathy, and the variable years of diabetes evolution was correlated to both the existence and the severity of the retinopathy. In the study, 9.6% of the affected people were preferentially referred to the ophthalmologists because of sight-threatening retinopathy, and 6.8% of the people studied were referred due to other ophthalmological pathologies.

CONCLUSIONS

It is possible to do the ophthalmological follow-up of 82% of the population with diabetes in primary health care, involving its professionals and team-working with the ophthalmologists. It is paramount to consider diabetic retinopathy within the global context of the person with diabetes, relating diabetic retinopathy with the other microvascular complications and cardiovascular diseases.