Screening for diabetic retinopathy by ophthalmologists and endocrinologists with pupillary dilation and a nonmydriatic digital camera

Risk Factors for Nondiagnostic Imaging in a Real-World Deployment of Artificial Intelligence Diabetic Retinal Examinations in an Integrated Healthcare System: Maximizing Workflow Efficiency Through Predictive Dilation

OBJECTIVE

In the pivotal clinical trial that led to Food and Drug Administration De Novo "approval" of the first fully autonomous artificial intelligence (AI) diabetic retinal disease diagnostic system, a reflexive dilation protocol was used. Using real-world deployment data before implementation of reflexive dilation, we identified factors associated with nondiagnostic results. These factors allow a novel predictive dilation workflow, where patients most likely to benefit from pharmacologic dilation are dilated a priori to maximize efficiency and patient satisfaction.

METHODS

Retrospective review of patients who were assessed with autonomous AI at Johns Hopkins Medicine (8/2020 to 5/2021). We constructed a multivariable logistic regression model for nondiagnostic results to compare characteristics of patients with and without diagnostic results, using adjusted odds ratio (aOR). P < .05 was considered statistically significant.

RESULTS

Of 241 patients (59% female; median age = 59), 123 (51%) had nondiagnostic results. In multivariable analysis, type 1 diabetes (T1D, aOR = 5.82, 95% confidence interval [CI]: 1.45-23.40, P = .01), smoking (aOR = 2.86, 95% CI: 1.36-5.99, P = .005), and age (every 10-year increase, aOR = 2.12, 95% CI: 1.62-2.77, P < .001) were associated with nondiagnostic results. Following feature elimination, a predictive model was created using T1D, smoking, age, race, sex, and hypertension as inputs. The model showed an area under the receiver-operator characteristics curve of 0.76 in five-fold cross-validation.

CONCLUSIONS

We used factors associated with nondiagnostic results to design a novel, predictive dilation workflow, where patients most likely to benefit from pharmacologic dilation are dilated a priori. This new workflow has the potential to be more efficient than reflexive dilation, thus maximizing the number of at-risk patients receiving their diabetic retinal examinations.

Diabetic Retinopathy Screening at the Point of Care (DR SPOC): detecting undiagnosed and vision-threatening retinopathy by integrating portable technologies within existing services

INTRODUCTION

The aim of this study was to determine the prevalence of diabetic retinopathy (DR) in a low socioeconomic region of a high-income country, as well as determine the diagnostic utility of point-of-care screening for high-risk populations in tertiary care settings.

RESEARCH DESIGN AND METHODS

This was a cross-sectional study of patients with diabetes attending foot ulcer or integrated care diabetes clinics at two Western Sydney hospitals (n=273). DR was assessed using portable, two-field, non-mydriatic fundus photography and combined electroretinogram/ pupillometry (ERG). With mydriatic photographs used as the reference standard, sensitivity and specificity of the devices were determined. Prevalence of DR and vision-threatening diabetic retinopathy (VTDR) were reported, with multivariate logistic regression used to identify predictors of DR.

RESULTS

Among 273 patients, 39.6% had any DR, while 15.8% had VTDR, of whom 59.3% and 62.8% were previously undiagnosed, respectively. Non-mydriatic photography demonstrated 20.2% sensitivity and 99.5% specificity for any DR, with a 56.7% screening failure rate. Meanwhile, mydriatic photography produced high-quality images with a 7.6% failure rate. ERG demonstrated 72.5% sensitivity and 70.1% specificity, with a 15.0% failure rate. The RETeval ERG was noted to have an optimal DR cut-off score at 22. Multivariate logistic regression identified an eGFR of ≤29 mL/min/1.73 m2, HbA1c of ≥7.0%, pupil size of <4 mm diameter, diabetes duration of 5-24 years and RETeval score of ≥22 as strong predictors of DR.

CONCLUSION

There is a high prevalence of vision-threatening and undiagnosed DR among patients attending high-risk tertiary clinics in Western Sydney. Point-of-care DR screening using portable, mydriatic photography demonstrates potential as a model of care which is easily accessible, targeted for high-risk populations and substantially enhances DR detection.

[Performance of ultra-wide field retinophotography for screening of diabetic retinopathy]

INTRODUCTION

Early diagnosis of diabetic retinopathy is a public health issue. Fundus retinophotography (FRP) is widely used for the detection of the disease. Recently, ultra-wide field retinophotography (WFRP) device allows imaging of approximately 80% of the retinal surface in a single image. The goal of the present study was to evaluate the efficacy of WFRP in the diagnosis and gradation of diabetic retinopathy compared to the gold standard of FRP.

METHODS

The non-mydriatic Optos P200Tx was used for WFRP imaging. FRP in the 9 positions of gaze was then acquired with the Topcon TRC-NW6S after pupillary dilation. The processing time for each imaging modality was recorded.

RESULTS

One hundred and sixteen eyes of 58 patients were included in this study. Fourteen eyes were excluded from the analysis due to insufficient imaging quality. WFRP sensitivity was 96% and specificity was 92%. Only 6 eyes received a higher severity grade of diabetic retinopathy by WFRP compared to FRP. In these cases, when the WFRP was analyzed in the same field as the FRP, the severity grade was similar for 5 of the 6 eyes. The mean time of acquisition was significantly lower for WFRP compared to FRP.

CONCLUSION

WFRP is fast and effective in screening for diabetic retinopathy. The severity grade of the disease was similar to the gold standard of FRP in most cases. WFRP could thus be used in mass screening for diabetic retinopathy.

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.

Tele-ophthalmology for diabetic retinopathy screening: 8 years of experience

PURPOSE

To describe the results of a diabetic retinopathy screening program implemented in a primary care area.

METHODS

A retrospective study was conducted using data automatically collected since the program began on 1 January 2007 until 31 December 2015.

RESULTS

The number of screened diabetic patients has progressively increased, from 7,173 patients in 2007 to 42,339 diabetic patients in 2015. Furthermore, the ability of family doctors to correctly interpret retinographies has improved, with the proportion of retinal images classified as normal having increased from 55% in 2007 to 68% at the end of the study period. The proportion of non-evaluable retinographies decreased to 7% in 2015, having peaked at 15% during the program. This was partly due to a change in the screening program policy that allowed the use of tropicamide. The number of severe cases detected has declined, from 14% with severe non-proliferative and proliferativediabetic retinopathy in the initial phase of the program to 3% in 2015.

CONCLUSIONS

Diabetic eye disease screening by tele-ophthalmology has shown to be a valuable method in a growing population of diabetics. It leads to a regular medical examination of patients, helps ease the workload of specialised care services and favours the early detection of treatable cases. However, the results of implementing a program of this type are not immediate, achieving only modest results in the early years of the project that have improved over subsequent years.

Effectiveness of a mobile diabetic retinopathy screening campaign to encourage diabetics to undergo regular ophthalmic follow-up

AIM

To evaluate the effectiveness of a mobile diabetic retinopathy (DR) screening campaign with a non-mydriatic camera to encourage diabetics to undergo a subsequent ophthalmic follow-up.

METHODS

Diabetic patients who underwent free DR screening with a non-mydriatic fundus camera were given the recommendation to have an ophthalmic visit, in a time frame suited to the DR stage or in case abnormalities in the macula, the optic nerve or intra-ocular pressure were detected. The photographs were performed by a trained orthoptist. The date of the visit to their ophthalmologist and the report of this consultation were recorded.

RESULTS

During 5 annual campaigns, 4,699 diabetics were screened. Of the 1,573 ophthalmic examinations recommended at the screening, 1,241 (79%) were actually conducted. A total of 623 new cases of DR were found in the course of this screening campaign, with a fair concordance between the diagnosis suggested at screening and the examination by the ophthalmologist (κ = 0.48).

CONCLUSION

Information and recommendations given during DR screening helped to reintroduce patients to a regular ophthalmic follow-up, at least in the short term.

Rodent Hyperglycemia-Induced Inner Retinal Deficits are Mirrored in Human Diabetes

PURPOSE

To evaluate the utility of low luminance stimuli to functionally probe inner retinal rod pathways in the context of diabetes mellitus in both rat and human subjects.

METHODS

Inner retinal dysfunction was assessed using oscillatory potential (OP) delays in diabetic rats. Scotopic electroretinograms (ERGs) in response to a series of increasing flash luminances were recorded from streptozotocin (STZ)-treated and control Sprague-Dawley rats after 7, 14, 20, and 29 weeks of hyperglycemia. We then evaluated OP delays in human diabetic subjects with (DR) and without (DM) diabetic retinopathy using the International Society for Clinical Electrophysiology in Vision (ISCEV) standard scotopic protocol and two additional dim test flashes.

RESULTS

Beginning 7 weeks after STZ, OP implicit times in diabetic rats were progressively delayed in response to dim, but not bright stimuli. In many diabetic subjects the standard ISCEV dim flash failed to illicit measureable OPs. However, OPs became measurable using a brighter, nonstandard dim flash (Test Flash 1, -1.43 log cd s/m²), and exhibited prolonged implicit times in the DM group compared with control subjects (CTRL).

CONCLUSIONS

Delays in scotopic OP implicit times are an early response to hyperglycemia in diabetic rats. A similar, inner retinal, rod-driven response was detected in diabetic human subjects without diabetic retinopathy, only when a nonstandard ISCEV flash intensity was employed during ERG testing.

TRANSLATIONAL RELEVANCE

The addition of a dim stimulus to standard ISCEV flashes with assessment of OP latency during ERG testing may provide a detection method for early retinal dysfunction in diabetic patients.

Screening for diabetic retinopathy: review of current methods

OBJECTIVE

To review the current screening methods for diabetic retinopathy, with a focus on nonmydriatic digital fundus photography.

METHODS

Articles from Medline were reviewed from 1976 to November 2011 for different combinations of the words "diabetic retinopathy," "screening," "fundus photography," and "nonmydriasis."

RESULTS

Because of its ease of use and cost-effectiveness, digital fundus photography is becoming the preferred method for diagnosing diabetic retinopathy. Current research has proven that pupillary dilation is not a necessary step in the fundus examination, although it reduces the number of unnecessary referrals to ophthalmologists. Automated grading systems, while saving time and reducing human error, still need refinement before they can replace manual grading by trained ophthalmologists.

CONCLUSION

Nonmydriatic digital fundus photography with manual grading by a trained technician is an acceptable method of screening for diabetic retinopathy.

No loss of chance of diabetic retinopathy screening by endocrinologists with a digital fundus camera

OBJECTIVE

To compare the efficacy of the diabetic retinopathy (DR) screening with digital camera by endocrinologists with that by specialist and resident ophthalmologists in terms of sensitivity, specificity, and level of "loss of chance."

RESEARCH DESIGN AND METHODS

In a cross-sectional study, 500 adult diabetic patients (1,000 eyes) underwent three-field retinal photography with a digital fundus camera following pupillary dilatation. Five endocrinologists and two ophthalmology residents underwent 40 h of training on screening and grading of DR and detection of associated retinal findings. A κ test compared the accuracy of endocrinologist and ophthalmology resident screening with that performed by experienced ophthalmologists. Screening efficiency of endocrinologists was evaluated in terms of "loss of chance," i.e., missed diagnoses that required ophthalmologist referrals.

RESULTS

The mean weighted κ of DR screening performed by endocronologists was similar to that of ophthalmology residents (0.65 vs. 0.73). Out of 456 DR eyes, both endocrinologists and ophthalmology residents misdiagnosed only stage 1 DR (36 and 14, respectively), which did not require ophthalmologist referral. There were no significant differences between endocrinologists and ophthalmology residents in terms of diabetic maculopathy and incidental findings except for papillary cupping and choroidal lesions, which were not the main purpose of the study or of the training.

CONCLUSIONS

The endocrinologist with specific training for DR detection using a three-field digital fundus camera with pupillary dilatation can perform a reliable DR screening without any loss of chance for the patients when compared with identical evaluation performed by experienced ophthalmologists.

Reliability of stereoscopic nonmydriatic retinography for assessment of diabetic macular edema when performed by endocrinologists

BACKGROUND

Diabetic macular edema (DME) is the main cause of moderate vision loss in type 2 diabetes. Diagnosis is achieved by dilated fundus examination or by measuring retinal thickness. However, it can be identified in nonmydriatic retinography (NMR) with hard exudates as a surrogate marker or macular thickness under stereoscopic vision. To date, few studies have focused on interobserver reliability for DME with this technique.

METHODS

Fity-three type 2 diabetes patients with known diabetic retinopathy were studied. We obtained 182 pairs of stereoscopic retinographs with a nonmydriatic camera. Photographic options were 30 degrees or 45 degrees macula-centered retinal field and spontaneous or pharmacological dilation using tropicamide. An endocrinologist with a minimum of training and another with no specific training in this kind of examination diagnosed the images. DME was assumed if retinal thickness was identified within one disc diameter around the fovea.

RESULTS

The kappa index agreement between both endocrinologists for all the data was 0.16 (P = 0.02). Depending on the photographic options, all the kappa indices were below 0.25, except for the 45 degrees retinal field under spontaneous mydriasis (0.58) where the number of samples analyzed was reduced to 22.

CONCLUSIONS

In our study, endocrinologists with a low level of training did not reach a suitable level of agreement regarding the reliability of stereoscopic NMR as a technique for diagnosing DME. We feel that, as NMR can be performed by various different health providers, it would be advisable to establish generally agreed upon criteria for training staff in this technique.

Mobile digital fundus screening of type 2 diabetes patients in the Finnish county of South-Ostrobothnia

In 1999 we introduced a digital, mobile eye fundus camera for screening type 2 diabetes mellitus patients (adult onset diabetes) in the Finnish county of South-Ostrobothnia. Prior to this, eye fundus examinations were only available in the regional central hospital, and no systematic screening of type 2 (adult onset) diabetes patients was possible. The total number of screenings carried out with the mobile equipment from 1999 to 2006 was 17,471 cases. There were significant benefits, most important from improved coverage of type 2 diabetes patients. Because the mobile system made eye fundus examinations available to patients in their nearest health centre, approximately 85% of all patients with diabetes in the region are now screened. On average this means that each patient is screened once every 2.5 years, which is in line with national recommendations. As a result, more of the earlier stage retinopathy cases have been diagnosed. There have also been changes in the frequency and type of procedures at the eye department of the regional central hospital. The number of cases referred to the eye department for follow-up studies has decreased from 49 in 2000 to 19 in 2005. The screening system adopted in South-Ostrobothnia has had beneficial effects for both patients and health-care providers.

A comparative cost analysis of digital fundus imaging and direct fundus examination for assessment of diabetic retinopathy

The objective of this study was to compare the cost between two procedures for fundus examination in patients with diabetes. In our setting, two alternatives for fundus examination are available for patients with diabetes. In the first alternative, a digital image is taken with a nonmydriatic fundus camera when the patient is at the endocrinology consultation, and the image is then examined by an ophthalmologist. In the second alternative, a direct fundus examination is made by an ophthalmologist. We calculated the costs of both procedures from both Public Healthcare System (PHS) and patient perspectives using the official scales to compute personnel, consumables, capital cost of equipment, travel expenses, and time loss of the patient caused by attending the consultation. The first alternative (digital fundus image) required 2.69, 0.03, and 1.62 Euros per patient for personnel, consumables, and capital cost of the equipment, respectively. A direct fundus examination was needed in 31% of patients that had an additional cost of 0.97 Euros per patient for the PHS plus 14.97 Euros per patient because of travel cost and loss of income. The second alternative (direct fundus examination) required 2.69, 0.11, and 0.33 Euros per patient for personnel, consumables, and capital cost, respectively. All patients in this second alternative had to attend a consultation that implied travel and loss of income costs. Attending a consultation represented a cost of 48.29 Euros per patient. From the PHS perspective, direct fundus examination is less costly than using digital fundus images. The higher cost of the digital fundus option is a consequence of the higher capital costs required by the equipment needed to obtain the digital image. However, from a global perspective, the digital image alternative is more convenient because the travel cost and loss of income of the patient are lower.

Interobserver and intraobserver reliability of detecting age-related macular degeneration using a nonmydriatic digital camera

PURPOSE

To evaluate the interobserver and intraobserver reliability of detecting early and late age-related macular degeneration (AMD) using a nonmydriatic digital camera in two distinct groups of older people.

DESIGN

Prospective study.

METHODS

The two groups consisted of a series of patients older than 70 years hospitalized in a geriatric unit and a younger series of people older than 55 years. In both groups, nonmydriatic color fundus photographs were obtained and graded independently by two ophthalmologists (V.L. and M.S.). No ophthalmic examination was performed. Main outcome measures were frequencies of early and late AMD and interobserver and intraobserver agreement.

RESULTS

Among 233 patients in group 1 (mean age, 84.6 years), only 119 patients (51%) could undergo photography because of associated multiple morbidities. Mean age of group 2 was 63.8 years. In group 1, 35 (14.5%) of 238 pictures were ungradable. In series 2, 65 (9.1%) of 716 pictures were ungradable. Frequencies of early and late AMD were 30.3% and 5.9% vs 12.6% and 2.6% in series 1 and 2, respectively. Interobserver and intraobserver agreement was good or excellent (kappa > 0.6) in both groups.

CONCLUSIONS

In the entire geriatric cohort, 43% of the patients had gradable pictures allowing a diagnosis. These patients would otherwise have had no access to any form of funduscopy. In the younger population, nonmydriatic pictures permitted a diagnosis in 90% of the individuals. Detection of AMD with a nonmydriatic digital camera may lead to large-scale screening and specific management.

[Screening diabetic retinopathy in Burgundy with an itinerant nonmydriatic camera]

INTRODUCTION

The aim of this study was to assess the suitability of screening diabetic retinopathy (DR) with an itinerant nonmydriatic camera.

METHODS

This program required collaboration between ophthalmologists and general practitioners. Three professional organizations gave their support: L'union Professionnelle des Médecins Libéraux de Bourgogne (UPMLB), le Fonds d'Aide à la Qualité des Soins de Ville (FAQSV), et la Fédération des Associations des Diabétiques de Bourgogne (FADB). The screening programm took place from November 2004 to June 2005 throughout the Burgundy region. General practitioners, health professionals (pharmacists, nurses), local media, and health insurance offices informed patients of the DR screening. An orthoptist took photographs with a nonmydriatic digital camera. Each patient had four fundus photographs without pupillary dilatation. Photographs were analyzed in the Department of Ophthalmology of Dijon's General Hospital.

RESULTS

In this study, 676 diabetic patients were screened. Among these patients, 58 had DR, exclusively nonproliferative retinopathies. Nine percent of the photographs were ungradable. The mean age of patients with DR was 65 years. The mean onset of diabetes was 18 years before the study. Insulin therapy was followed by 27 patients (46.6%). Hemoglobin A1c was known in 26 patients (44.8%), with a mean value of 8.14%. Nearly 60% of patients with DR did not have their recommended annual consultation. After screening, 84% of patients consulted an ophthalmologist.

CONCLUSION

Screening DR with an itinerant nonmydriatic camera can improve ophthalmologic follow-up of diabetics in rural areas. This screening program has continued in 2006 with an adapted vehicle.

Systematic screening for diabetic retinopathy with a digital fundus camera following pupillary dilatation in a university diabetes department

AIMS

Screening for diabetic retinopathy (DR) is highly inadequate in France because of insufficient infrastructure and increasing disease prevalence. We describe the results of the first systematic DR screening programme established in a university diabetes department.

METHODS

In this cross-sectional study conducted over 1 year, consecutive adult patients underwent three-field retinal photography with the Topcon TRC NW6S digital fundus camera following pupillary dilatation with Tropicamide 1%. A questionnaire provided information on patients' systemic and ocular history. Glycated haemoglobin (HbA1c) was measured at the screening visit. Two ophthalmologists graded the retinal photographs in a masked fashion.

RESULTS

Of 1157 patients attending the diabetes department, 1153 (99.7%)underwent photographic screening. Images were gradable in 96% patients. Diabetic retinopathy was detected in 522 (45%) patients and sight-threatening DR in 167 (14%). Of 704 (61%) patients previously believed to have no DR,254 (34%) screened positive. The presence of DR was associated with age,insulin use and non-Caucasian ethnicity in Type 2 patients, and with duration of diabetes and HbA1c in Type 1 and Type 2 patients. Associated ocular pathologies were diagnosed in 612 (53%) patients.

CONCLUSIONS

Our photographic screening programme using pharmacological mydriasis provided a high screening coverage feasible in a hospital setting. We obtained information regarding prevalence and associated risk factors of DR inpatients attending a tertiary care centre. Screening was well accepted by patients and met with no protest from city ophthalmologists. It generated considerable interest among endocrinologists and feedback of results is expected to improve optimization of glycaemic control.