Effectiveness of Multimodal imaging for the Evaluation of Retinal oedema And new vesseLs in Diabetic retinopathy (EMERALD)

Standard threshold laser versus subthreshold micropulse laser for adults with diabetic macular oedema: the DIAMONDS non-inferiority RCT

BACKGROUND

The National Institute for Health and Care Excellence recommends macular laser to treat diabetic macular oedema with a central retinal subfield thickness of < 400 µm on optical coherence tomography. The DIAMONDS (DIAbetic Macular Oedema aNd Diode Subthreshold micropulse laser) trial compared standard threshold macular laser with subthreshold micropulse laser to treat diabetic macular oedema suitable for macular laser.

OBJECTIVES

Determining the clinical effectiveness, safety and cost-effectiveness of subthreshold micropulse laser compared with standard threshold macular laser to treat diabetic macular oedema with a central retinal subfield thickness of < 400 µm.

DESIGN

A pragmatic, multicentre, allocation-concealed, double-masked, randomised, non-inferiority, clinical trial.

SETTING

Hospital eye services in the UK.

PARTICIPANTS

Adults with diabetes and centre-involving diabetic macular oedema with a central retinal subfield thickness of < 400 µm, and a visual acuity of > 24 Early Treatment Diabetic Retinopathy Study letters (Snellen equivalent > 20/320) in one/both eyes.

INTERVENTIONS

Participants were randomised 1 : 1 to receive 577 nm subthreshold micropulse laser or standard threshold macular laser (e.g. argon laser, frequency-doubled neodymium-doped yttrium aluminium garnet 532 nm laser); laser treatments could be repeated as needed. Rescue therapy with intravitreal anti-vascular endothelial growth factor therapies or steroids was allowed if a loss of ≥ 10 Early Treatment Diabetic Retinopathy Study letters between visits occurred and/or central retinal subfield thickness increased to > 400 µm.

MAIN OUTCOME MEASURES

The primary outcome was the mean change in best-corrected visual acuity in the study eye at 24 months (non-inferiority margin 5 Early Treatment Diabetic Retinopathy Study letters). Secondary outcomes included the mean change from baseline to 24 months in the following: binocular best-corrected visual acuity; central retinal subfield thickness; the mean deviation of the Humphrey 10-2 visual field in the study eye; the percentage of people meeting driving standards; and the EuroQol-5 Dimensions, five-level version, National Eye Institute Visual Function Questionnaire - 25 and Vision and Quality of Life Index scores. Other secondary outcomes were the cost per quality-adjusted life-years gained, adverse effects, number of laser treatments and additional rescue treatments.

RESULTS

The DIAMONDS trial recruited fully (n = 266); 87% of participants in the subthreshold micropulse laser group and 86% of participants in the standard threshold macular laser group had primary outcome data. Groups were balanced regarding baseline characteristics. Mean best-corrected visual acuity change in the study eye from baseline to month 24 was -2.43 letters (standard deviation 8.20 letters) in the subthreshold micropulse laser group and -0.45 letters (standard deviation 6.72 letters) in the standard threshold macular laser group. Subthreshold micropulse laser was deemed to be not only non-inferior but also equivalent to standard threshold macular laser as the 95% confidence interval (-3.9 to -0.04 letters) lay wholly within both the upper and lower margins of the permitted maximum difference (5 Early Treatment Diabetic Retinopathy Study letters). There was no statistically significant difference between groups in any of the secondary outcomes investigated with the exception of the number of laser treatments performed, which was slightly higher in the subthreshold micropulse laser group (mean difference 0.48, 95% confidence interval 0.18 to 0.79; p = 0.002). Base-case analysis indicated no significant difference in the cost per quality-adjusted life-years between groups.

FUTURE WORK

A trial in people with ≥ 400 µm diabetic macular oedema comparing anti-vascular endothelial growth factor therapy alone with anti-vascular endothelial growth factor therapy and macular laser applied at the time when central retinal subfield thickness has decreased to < 400 µm following anti-vascular endothelial growth factor injections would be of value because it could reduce the number of injections and, subsequently, costs and risks and inconvenience to patients.

LIMITATIONS

The majority of participants enrolled had poorly controlled diabetes.

CONCLUSIONS

Subthreshold micropulse laser was equivalent to standard threshold macular laser but required a slightly higher number of laser treatments.

TRIAL REGISTRATION

This trial is registered as EudraCT 2015-001940-12, ISRCTN17742985 and NCT03690050.

FUNDING

This project was funded by the National Institute for Health and Care Research ( NIHR ) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 50. See the NIHR Journals Library website for further project information.

Patients views on a new surveillance pathway involving allied non-medical staff for people with treated diabetic macular oedema and proliferative diabetic retinopathy

BACKGROUND/OBJECTIVE

To explore acceptability by patients and health care professionals of a new surveillance pathway for people with previously treated and stable diabetic macular oedema (DMO) and/or proliferative diabetic retinopathy (PDR).

SUBJECT/METHODS

Structured discussions in 10 focus groups with patients; two with ophthalmic photographers/graders, and one with ophthalmologists, held across the UK as part of a large diagnostic accuracy study (EMERALD).

RESULTS

The most prominent issues raised by patients concerned (i) expertise of the various professionals within clinic, (ii) quality of interactions with clinic professionals, especially the flow of information from professionals to patients, and (iii) wish to be treated holistically. Ophthalmologists suggested such issues could be best dealt with via a programme of patient education and tended to overlook deeper implications of patient concerns for the organisation of services.

CONCLUSION

For patients, the clinical service should not only include the identification and treatment of disease but also exchange of information, reassurance, and mitigation of anxiety. Alterations in the standard care pathway need to take account of such concerns and their implications, in addition to any assessments of 'efficiency' that may flow from changes in diagnostic technology, or the division of professional labour.

Surveillance of people with previously successfully treated diabetic macular oedema and proliferative diabetic retinopathy by trained ophthalmic graders: cost analysis from the EMERALD study

Background/aims

Surveillance of people with previously successfully treated diabetic macular oedema (DMO) and proliferative diabetic retinopathy (PDR) adds pressure on ophthalmology services. This study evaluated a new surveillance pathway entailing multimodal imaging reviewed by trained ophthalmic graders and compared it with the current standard care (face-to-face evaluation by an ophthalmologist).

Methods

Cost analysis of the new ophthalmic grader pathway, compared with the standard of care, from the perspective of the UK National Health Service, based on evidence from the Effectiveness of Multimodal imaging for the Evaluation of Retinal oedema And new vesseLs in Diabetic retinopathy study. Resource use data were prospectively obtained including times to undertake each procedure. Effectiveness was assessed in terms of sensitivity and specificity of referral decisions in the grader pathway. Costs (SDs) were analysed per 100 patients separately for DMO and PDR at 2018/2019 costs.

Results

For DMO, where sensitivity was very high (97%), the cost difference (savings) for the grader’s pathway would be £1390 per 100 patients. For PDR, the cost would be reduced by £461 for seven-field Early Treatment for Diabetic Retinopathy Study (ETDRS) images and by £1889 for ultrawide field images, per 100 patients. Ultrawide images required less time to be obtained and read than seven-field ETDRS. The real savings would be in ophthalmologist time, which could be then redirected to the evaluation of people at high risk of visual loss.

Conclusions

Surveillance of people with previously successfully treated DMO and PDR by trained ophthalmic graders can achieve satisfactory results and release ophthalmologist time.

Trial registration numbers

NCT03490318, ISRCTN10856638.

Multimodal imaging interpreted by graders to detect re-activation of diabetic eye disease in previously treated patients: the EMERALD diagnostic accuracy study

BACKGROUND

Owing to the increasing prevalence of diabetes, the workload related to diabetic macular oedema and proliferative diabetic retinopathy is rising, making it difficult for hospital eye services to meet demands.

OBJECTIVE

The objective was to evaluate the diagnostic performance, cost-effectiveness and acceptability of a new pathway using multimodal imaging interpreted by ophthalmic graders to detect reactivation of diabetic macular oedema/proliferative diabetic retinopathy in previously treated patients.

DESIGN

This was a prospective, case-referent, cross-sectional diagnostic study.

SETTING

The setting was ophthalmic clinics in 13 NHS hospitals.

PARTICIPANTS

Adults with type 1 or type 2 diabetes with previously successfully treated diabetic macular oedema/proliferative diabetic retinopathy in one/both eyes in whom, at the time of enrolment, diabetic macular oedema/proliferative diabetic retinopathy could be active or inactive.

METHODS

For the ophthalmic grader pathway, review of the spectral domain optical coherence tomography scans to detect diabetic macular oedema, and seven-field Early Treatment Diabetic Retinopathy Study/ultra-wide field fundus images to detect proliferative diabetic retinopathy, by trained ophthalmic graders. For the current standard care pathway (reference standard), ophthalmologists examined patients face to face by slit-lamp biomicroscopy for proliferative diabetic retinopathy and, in addition, spectral domain optical coherence tomography imaging for diabetic macular oedema.

OUTCOME MEASURES

The primary outcome measure was sensitivity of the ophthalmic grader pathway to detect active diabetic macular oedema/proliferative diabetic retinopathy. The secondary outcomes were specificity, agreement between pathways, cost-consequences, acceptability and the proportion of patients requiring subsequent ophthalmologist assessment, unable to undergo imaging and with inadequate quality images/indeterminate findings. It was assumed for the main analysis that all patients in whom graders diagnosed active disease or were 'unsure' or images were 'ungradable' required examination by an ophthalmologist.

RESULTS

Eligible participants with active and inactive diabetic macular oedema (152 and 120 participants, respectively) and active and inactive proliferative diabetic retinopathy (111 and 170 participants, respectively) were recruited. Under the main analysis, graders had a sensitivity of 97% (142/147) (95% confidence interval 92% to 99%) and specificity of 31% (35/113) (95% confidence interval 23% to 40%) to detect diabetic macular oedema. For proliferative diabetic retinopathy, graders had a similar sensitivity and specificity using seven-field Early Treatment Diabetic Retinopathy Study [sensitivity 85% (87/102), 95% confidence interval 77% to 91%; specificity 48% (77/160), 95% confidence interval 41% to 56%] or ultra-wide field imaging [sensitivity 83% (87/105), 95% confidence interval 75% to 89%; specificity 54% (86/160), 95% confidence interval 46% to 61%]. Participants attending focus groups expressed preference for face-to-face evaluations by ophthalmologists. In the ophthalmologists' absence, patients voiced the need for immediate feedback following grader's assessments, maintaining periodic evaluations by ophthalmologists. Graders and ophthalmologists were supportive of the new pathway. When compared with the reference standard (current standard pathway), the new grader pathway could save £1390 per 100 patients in the review of people with diabetic macular oedema and, depending on the imaging modality used, between £461 and £1189 per 100 patients in the review of people with proliferative diabetic retinopathy.

CONCLUSIONS

For people with diabetic macular oedema, the ophthalmic grader pathway appears safe and cost saving. The sensitivity of the new pathway to detect active proliferative diabetic retinopathy was lower, but may still be considered acceptable for patients with proliferative diabetic retinopathy previously treated with laser. Suggestions from focus group discussions should be taken into consideration if the new pathway is introduced to ensure its acceptability to users.

LIMITATIONS

Lack of fundus fluorescein angiography to confirm diagnosis of active proliferative diabetic retinopathy.

FUTURE WORK

Could refinement of the new pathway increase its sensitivity to detect proliferative diabetic retinopathy? Could artificial intelligence be used for automated reading of images in this previously treated population?

TRIAL REGISTRATION

Current Controlled Trials ISRCTN10856638 and ClinicalTrials.gov NCT03490318.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology AssessmentVol. 25, No. 32. See the NIHR Journals Library website for further project information.

Accuracy of Diabetic Retinopathy Staging with a Deep Convolutional Neural Network Using Ultra-Wide-Field Fundus Ophthalmoscopy and Optical Coherence Tomography Angiography

PURPOSE

The present study aimed to compare the accuracy of diabetic retinopathy (DR) staging with a deep convolutional neural network (DCNN) using two different types of fundus cameras and composite images.

METHOD

The study included 491 ultra-wide-field fundus ophthalmoscopy and optical coherence tomography angiography (OCTA) images that passed an image-quality review and were graded as no apparent DR (NDR; 169 images), mild nonproliferative DR (NPDR; 76 images), moderate NPDR (54 images), severe NPDR (90 images), and proliferative DR (PDR; 102 images) by three retinal experts by the International Clinical Diabetic Retinopathy Severity Scale. The findings of tests 1 and 2 to identify no apparent diabetic retinopathy (NDR) and PDR, respectively, were then assessed. For each verification, Optos, OCTA, and Optos OCTA imaging scans with DCNN were performed.

RESULT

The Optos, OCTA, and Optos OCTA imaging test results for comparison between NDR and DR showed mean areas under the curve (AUC) of 0.79, 0.883, and 0.847; sensitivity rates of 80.9%, 83.9%, and 78.6%; and specificity rates of 55%, 71.6%, and 69.8%, respectively. Meanwhile, the Optos, OCTA, and Optos OCTA imaging test results for comparison between NDR and PDR showed mean AUC of 0.981, 0.928, and 0.964; sensitivity rates of 90.2%, 74.5%, and 80.4%; and specificity rates of 97%, 97%, and 96.4%, respectively.

CONCLUSION

The combination of Optos and OCTA imaging with DCNN could detect DR at desirable levels of accuracy and may be useful in clinical practice and retinal screening. Although the combination of multiple imaging techniques might overcome their individual weaknesses and provide comprehensive imaging, artificial intelligence in classifying multimodal images has not always produced accurate results.

Evaluation of a New Model of Care for People with Complications of Diabetic Retinopathy: The EMERALD Study

Purpose

The increasing diabetes prevalence and advent of new treatments for its major visual-threatening complications (diabetic macular edema [DME] and proliferative diabetic retinopathy [PDR]), which require frequent life-long follow-up, have increased hospital demands markedly. Subsequent delays in patient's evaluation and treatment are causing sight loss. Strategies to increase capacity are needed urgently. The retinopathy (EMERALD) study tested diagnostic accuracy, acceptability, and costs of a new health care pathway for people with previously treated DME or PDR.

Design

Prospective, multicenter, case-referent, cross-sectional, diagnostic accuracy study undertaken in 13 hospitals in the United Kingdom.

Participants

Adults with type 1 or 2 diabetes previously successfully treated DME or PDR who, at the time of enrollment, had active or inactive disease.

Methods

A new health care pathway entailing multimodal imaging (spectral-domain OCT for DME, and 7-field Early Treatment Diabetic Retinopathy Study [ETDRS] and ultra-widefield [UWF] fundus images for PDR) interpreted by trained nonmedical staff (ophthalmic graders) to detect reactivation of disease was compared with the current standard care (face-to-face examination by ophthalmologists).

Main Outcome Measures

Primary outcome: sensitivity of the new pathway. Secondary outcomes: specificity; agreement between pathways; costs; acceptability; proportions requiring subsequent ophthalmologist assessment, unable to undergo imaging, and with inadequate images or indeterminate findings.

Results

The new pathway showed sensitivity of 97% (95% confidence interval [CI], 92%–99%) and specificity of 31% (95% CI, 23%–40%) to detect DME. For PDR, sensitivity and specificity using 7-field ETDRS images (85% [95% CI, 77%–91%] and 48% [95% CI, 41%–56%], respectively) or UWF images (83% [95% CI, 75%–89%] and 54% [95% CI, 46%–61%], respectively) were comparable. For detection of high-risk PDR, sensitivity and specificity were higher when using UWF images (87% [95% CI, 78%–93%] and 49% [95% CI, 42%–56%], respectively, for UWF versus 80% [95% CI, 69–88%] and 40% [95% CI, 34%–47%], respectively, for 7-field ETDRS images). Participants preferred ophthalmologists’ assessments; in their absence, they preferred immediate feedback by graders, maintaining periodic ophthalmologist evaluations. When compared with the current standard of care, the new pathway could save £1390 per 100 DME visits and between £461 and £1189 per 100 PDR visits.

Conclusions

The new pathway has acceptable sensitivity and would release resources. Users’ suggestions should guide implementation.

Health economic evaluation in ophthalmology

Health economic evaluation is the application of economic theories, tools and concepts to healthcare. In the setting of limited resources, increasing demand and a growing array of intervention options, economic evaluation provides a framework for measuring, valuing and comparing the costs and benefits of different healthcare interventions. This review provides an overview of the concepts and methods of economic evaluation, illustrated with examples in ophthalmology. Types of economic evaluation include cost-minimisation, cost-benefit, cost-effectiveness, cost-utility and economic modelling. Topics including utility measures, the quality-adjusted lifeyear, discounting, perspective and timeframe are discussed. Health economic evaluation is important to understand the costs and value of interventions in ophthalmology and to inform health policy as well as guide clinical decision-making.