The Role of Retinal Imaging and Portable Screening Devices in Tele-ophthalmology Applications for Diabetic Retinopathy Management

Development of 3D-printed universal adapter in enhancing retinal imaging accessibility

BACKGROUND

The revolutionary technology of smartphone-based retinal imaging has been consistently improving over the years. Smartphone-based retinal image acquisition devices are designed to be portable, easy to use, and cost-efficient, which enables eye care to be more widely accessible especially in geographically remote areas. This enables early disease detection for those who are in low- and middle- income population or just in general has very limited access to eye care. This study investigates the limitation of smartphone compatibility of existing smartphone-based retinal image acquisition devices. Additionally, this study aims to propose a universal adapter design that is usable with an existing smartphone-based retinal image acquisition device known as the PanOptic ophthalmoscope. This study also aims to simulate the reliability, validity, and performance overall of the developed prototype.

METHODS

A literature review has been conducted that identifies the limitation of smartphone compatibility among existing smartphone-based retinal image acquisition devices. Designing and modeling of proposed adapter were performed using the software AutoCAD 3D. For the proposed performance evaluation, finite element analysis (FEA) in the software Autodesk Inventor and 5-point scale method were demonstrated.

RESULTS

Published studies demonstrate that most of the existing smartphone-based retinal imaging devices have compatibility limited to specific older smartphone models. This highlights the benefit of a universal adapter in broadening the usability of existing smartphone-based retinal image acquisition devices. A functional universal adapter design has been developed that demonstrates its compatibility with a variety of smartphones regardless of the smartphone dimension or the position of the smartphone's camera lens. The proposed performance evaluation method generates an efficient stress analysis of the proposed adapter design. The end-user survey results show a positive overall performance of the developed universal adapter. However, a significant difference between the expert's views on the developed adapter and the quality of images is observed.

CONCLUSION

The compatibility of existing smartphone-based retinal imaging devices is still mostly limited to specific smartphone models. Besides this, the concept of a universal and suitable adapter for retinal imaging using the PanOptic ophthalmoscope was presented and validated in this paper. This work provides a platform for future development of smartphone-based ophthalmoscope that is universal.

Accuracy of Integrated Artificial Intelligence Grading Using Handheld Retinal Imaging in a Community Diabetic Eye Screening Program

Purpose

To evaluate mydriatic handheld retinal imaging performance assessed by point-of-care (POC) artificial intelligence (AI) as compared with retinal image graders at a centralized reading center (RC) in identifying diabetic retinopathy (DR) and diabetic macular edema (DME).

Design

Prospective, comparative study.

Subjects

Five thousand five hundred eighty-five eyes from 2793 adult patients with diabetes.

Methods

Point-of-care AI assessment of disc and macular handheld retinal images was compared with RC evaluation of validated 5-field handheld retinal images (disc, macula, superior, inferior, and temporal) in identifying referable DR (refDR; defined as moderate nonproliferative DR [NPDR], or worse, or any level of DME) and vision-threatening DR (vtDR; defined as severe NPDR or worse, or any level of center-involving DME [ciDME]). Reading center evaluation of the 5-field images followed the international DR/DME classification. Sensitivity (SN) and specificity (SP) for ungradable images, refDR, and vtDR were calculated.

Main Outcome Measures

Agreement for DR and DME; SN and SP for refDR, vtDR, and ungradable images.

Results

Diabetic retinopathy severity by RC evaluation: no DR, 67.3%; mild NPDR, 9.7%; moderate NPDR, 8.6%; severe NPDR, 4.8%; proliferative DR, 3.8%; and ungradable, 5.8%. Diabetic macular edema severity by RC evaluation was as follows: no DME (80.4%), non-ciDME (7.7%), ciDME (4.4%), and ungradable (7.5%). Referable DR was present in 25.3% and vtDR was present in 17.5% of eyes. Images were ungradable for DR or DME in 7.5% by RC evaluation and 15.4% by AI. There was substantial agreement between AI and RC for refDR (κ = 0.66) and moderate agreement for vtDR (κ = 0.54). The SN/SP of AI grading compared with RC evaluation was 0.86/0.86 for refDR and 0.92/0.80 for vtDR.

Conclusions

This study demonstrates that POC AI following a defined handheld retinal imaging protocol at the time of imaging has SN and SP for refDR that meets the current United States Food and Drug Administration thresholds of 85% and 82.5%, but not for vtDR. Integrating AI at the POC could substantially reduce centralized RC burden and speed information delivery to the patient, allowing more prompt eye care referral.

Financial Disclosures

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

Portable devices for diagnosis and monitoring of glaucoma: a scoping review protocol

INTRODUCTION

Glaucoma is the leading cause of irreversible blindness in the world. The need to diagnose glaucoma early in its natural history before extensive sight loss occurs cannot be overemphasised. However, glaucoma is largely asymptomatic in the early stages of the disease making it complex to diagnose clinically and requires the support of technology. The objective of this scoping review is to determine the nature and extent of the evidence for use of portable devices in the diagnosis of glaucoma.

METHODS

We will consider studies conducted in all healthcare settings using portable devices for the detection of all type of adult glaucoma. We will also include any systematic reviews or scoping reviews, which relate to this topic. Searches will be conducted in MEDLINE, Embase, CENTRAL on the Cochrane Library and Global Health databases, from their inception to the present. Reference lists from publications identified in the searches will also be reviewed. Two authors will independently screen titles and abstracts, followed by full-text screening to assess studies for inclusion. Any disagreements will be discussed and resolved with a third author. Tables accompanied by narrative descriptions will be employed to discuss results and show how it relates to review questions.

ETHICS AND DISSEMINATION

Ethical approval is not required in this review. Only published and publicly accessible data will be used. We will publish our findings in an open-access, peer-reviewed journal and develop an accessible summary of results and recommendations.

Monocular Painless Vision Loss in the Emergency Department: Multipurpose Utility of Point-of-Care Ultrasound

BACKGROUND

Eye-related symptoms are a common presentation in the emergency department (ED). The cases range from simple viral conjunctivitis to trauma-related eye injuries. One pathological condition that could lead to vision loss is retinal artery occlusion (RAO). Evaluating a patient with an eye symptom requires thorough eye examination and advanced imaging in certain instances. Consultation with an ophthalmologist is also necessary for cases that require treatment recommendations and further testing. In the ED, point-of-care ultrasound (POCUS) is a commonly used diagnostic tool that can be used for ocular examination.

CASE REPORT

We reported a case of a 60-year-old man who presented with painless partial right-eye vision loss. POCUS showed decreased flow in the right central retinal artery with an area of the pale retina seen on the image from the retinal camera, suggesting a possible branch RAO. Further examination with POCUS showed plaque formation at the carotid bifurcation, a potential cause of the patient's symptoms. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians and other providers should be encouraged to use POCUS to diagnose eye symptoms accurately and promptly. Abnormal findings will prompt immediate specialty consult and early appropriate management. Our case and other reported cases highlight POCUS's reliability and rapid diagnostic ability.

Teleophthalmology and retina: a review of current tools, pathways and services

Telemedicine, the use of telecommunication and information technology to deliver healthcare remotely, has evolved beyond recognition since its inception in the 1970s. Advances in telecommunication infrastructure, the advent of the Internet, exponential growth in computing power and associated computer-aided diagnosis, and medical imaging developments have created an environment where telemedicine is more accessible and capable than ever before, particularly in the field of ophthalmology. Ever-increasing global demand for ophthalmic services due to population growth and ageing together with insufficient supply of ophthalmologists requires new models of healthcare provision integrating telemedicine to meet present day challenges, with the recent COVID-19 pandemic providing the catalyst for the widespread adoption and acceptance of teleophthalmology. In this review we discuss the history, present and future application of telemedicine within the field of ophthalmology, and specifically retinal disease. We consider the strengths and limitations of teleophthalmology, its role in screening, community and hospital management of retinal disease, patient and clinician attitudes, and barriers to its adoption.

Comparison of two ultra-widefield color-fundus imaging devices for visualization of retinal periphery and microvascular lesions in patients with early diabetic retinopathy

Comparison of two ultra-widefield (UWF) color-fundus (CF) imaging devices in diabetic patients for visualization of retinal periphery and detection of early microvascular lesions. The total gradable areas (TGA) seen on non-mydriatic CF-images of two UWF-imaging devices (Optos Daytona P200T; Zeiss Clarus 700) were compared and differences in projected area measured. Retinal periphery outside the 7 standard fields (7SF) was divided into: F3 temporal, F4 superotemporal, F5 inferotemporal, F6 superonasal, F7 inferonasal. DR stage was evaluated in the 7SF and the TGA on images of both devices and compared using Cohens κ. 67 eyes of 67 patients (52.5 ± 15.3 years) were analysed. DR stages in the 7SF were no (n = 36 Optos, n = 35 Clarus), mild (n = 16 Optos, n = 17 Clarus), and moderate DR (n = 15). Optos depicted significantly more area in F3 (median [interquartile range]; 2.41% [1.06-4.11] vs 0% [0-0], P < 0.001) and Clarus in F7 (3.29% [0-7.69] vs 0% [0-3.27], P = 0.002). In 4 eyes DR-stage was higher using Optos due to peripheral lesions not seen on the Clarus. Interrater reliability of DR-stage on both devices was almost perfect in the 7SF (κ = 0.975) and the TGA (κ = 0.855). Reliability in detecting signs of early DR is high on both devices. Clarus allowed for better visualization of the inferonasal field, Optos of the temporal field.

Comparison of Handheld Retinal Imaging with ETDRS 7-Standard Field Photography for Diabetic Retinopathy and Diabetic Macular Edema

PURPOSE

To compare nonmydriatic (NM) and mydriatic (MD) handheld retinal imaging with standard ETDRS 7-field color fundus photography (ETDRS photographs) for the assessment of diabetic retinopathy (DR) and diabetic macular edema (DME).

DESIGN

Prospective, comparative, instrument validation study.

SUBJECTS

A total of 225 eyes from 116 patients with diabetes mellitus.

METHODS

Following a standardized protocol, NM and MD images were acquired using handheld retinal cameras (NM images: Aurora, Smartscope, and RetinaVue-700; MD images: Aurora, Smartscope, RetinaVue-700, and iNview) and dilated ETDRS photographs. Grading was performed at a centralized reading center using the International Clinical Classification for DR and DME. Kappa statistics (simple [K], weighted [Kw]) assessed the level of agreement for DR and DME. Sensitivity and specificity were calculated for any DR, referable DR (refDR), and vision-threatening DR (vtDR).

MAIN OUTCOME MEASURES

Agreement for DR and DME; sensitivity and specificity for any DR, refDR, and vtDR; ungradable rates.

RESULTS

Severity by ETDRS photographs: no DR, 33.3%; mild nonproliferative DR, 20.4%; moderate DR, 14.2%; severe DR, 11.6%; proliferative DR, 20.4%; no DME, 68.0%; DME, 9.3%; non-center involving clinically significant DME, 4.9%; center-involving clinically significant DME, 12.4%; and ungradable, 5.3%. For NM handheld retinal imaging, Kw was 0.70 to 0.73 for DR and 0.76 to 0.83 for DME. For MD handheld retinal imaging, Kw was 0.68 to 0.75 for DR and 0.77 to 0.91 for DME. Thresholds for sensitivity (0.80) and specificity (0.95) were met by NM images acquired using Smartscope and MD images acquired using Aurora and RetinaVue-700 cameras for any DR and by MD images acquired using Aurora and RetinaVue-700 cameras for refDR. Thresholds for sensitivity and specificity were met by MD images acquired using Aurora and RetinaVue-700 for DME. Nonmydriatic and MD ungradable rates for DR were 15.1% to 38.3% and 0% to 33.8%, respectively.

CONCLUSIONS

Following standardized protocols, NM and MD handheld retinal imaging devices have substantial agreement levels for DR and DME. With mydriasis, not all handheld retinal imaging devices meet standards for sensitivity and specificity in identifying any DR and refDR. None of the handheld devices met the established 95% specificity for vtDR, suggesting that lower referral thresholds should be used if handheld devices must be utilized. When using handheld devices, the ungradable rate is significantly reduced with mydriasis and DME sensitivity thresholds are only achieved following dilation.

Urgent Virtual Eye Assessments During the COVID-19 Pandemic

Purpose

We aimed to evaluate the effectiveness and safety of a virtual eye assessment triage system implemented in response to COVID-19.

Patients and Methods

We conducted a retrospective cross-sectional study using a consecutive sample of all virtual assessments conducted from March 24 to June 7, 2020 at a single ophthalmology center in Toronto, ON, Canada. Visual acuity and smartphone photographs were uploaded to an electronic assessment website. All patients were virtually triaged to an email or phone consult. Patient outcomes and satisfaction were assessed with a quality assurance survey. Primary outcome measures were the incidence of unplanned additional in-person visits and changes in treatment.

Results

We performed 1535 virtual assessments. Of the triage pathways, 15% received an email consult only and 85% received a phone consult. Subsequently, 15% required an in-person assessment, 3% were referred elsewhere, and 0.1% were sent to the emergency. Presentations were most commonly cornea (52%) and retina (25%). They were non-urgent in 68% of cases and no pharmacologic treatment was required for 49%. Of 397 patients that responded out of 653 patients surveyed, 4% had an unplanned additional visit to the emergency, after which two patients underwent urgent retinal surgery and one patient underwent urgent glaucoma surgery. Two patients (0.5%) had a minor change in treatment.

Conclusion

As routine regular in-person visits were not possible during the COVID-19 lockdown, virtual eye assessments provided an opportunity to triage patients. Virtual assessments have the potential to reduce in-person visits, but caution must be exercised to not miss vision-threatening conditions.

The Cost-Effectiveness of a Telemedicine Screening Program for Diabetic Retinopathy in New York City

Background

A telemedicine screening initiative was implemented by the Montefiore Health System to improve access to eyecare for a multi-ethnic, at-risk population of diabetic patients in a largely underserved urban community in the Bronx, New York. This retrospective, cross-sectional analysis evaluates the societal benefit and financial sustainability of this program by analyzing both cost and revenue generation based on current standard Medicare reimbursement rates.

Methods

Non-mydriatic fundus cameras were placed in collaboration with a vendor in eight outpatient primary care sites throughout the Montefiore Health Care System, and data was collected between June 2014 and July 2016. Fundus photos were electronically transmitted to a central reading center to be systematically reviewed and coded by faculty ophthalmologists, and patients were subsequently scheduled for ophthalmic evaluation based upon a predetermined treatment algorithm. A retrospective chart review of 2251 patients was performed utilizing our electronic medical record system (Epic Systems, Verona WI). Revenue was projected utilizing standard Medicare rates for our region while societal benefit was calculated using quality adjusted life years (QALY).

Results

Of the 2251 patient charts reviewed, 791 patients (35.1%) were seen by Montefiore ophthalmologists within a year of the original screening date. Estimated revenue generated by these visits was $276,800, with the majority from the treatment of retinal disease ($208,535), and the remainder from other ophthalmic conditions detected in the fundus photos ($68,265). There was a societal benefit of 14.66 quality adjusted life years (QALYs) with an estimated value of $35,471/QALY.

Conclusion

This telemedicine initiative was successful in identifying many patients with diabetic retinopathy and other ophthalmic conditions who may otherwise not have been formally evaluated. Our analysis demonstrates the program to generate a downstream revenue of nearly $280K with a cost benefit below <50% of the threshold of $100,000/QALY, and therefore cost-effective in marginalized communities.

Update on Current and Future Management for Diabetic Maculopathy

Diabetic macular edema (DME) remains the major cause of preventable blindness in the working-age population in developed countries, and screening programs are extremely important in the management of this complication of diabetic retinopathy. The introduction of modern imaging modalities and technological advances have facilitated both the early detection and the follow-up of patients with DME, particularly optical coherence tomography angiography and artificial intelligence. Intravitreal therapy is the gold standard treatment for DME, but not all patients respond equally to this therapy, and sometimes it is not easy to apply treatment protocols correctly; for these reasons, clinical practice results may differ from those of clinical trials in terms of vision gain. One approach has been to implement new treatment regimens, such as treat and extend, and new molecules and therapeutic targets are constantly being developed. The main goal of this review paper is to describe the current treatment options and management strategies for DME in Europe and to provide a brief oversight of the novel therapeutic options on the horizon.

Toward a New Staging System for Diabetic Retinopathy Using Wide Field Swept-Source Optical Coherence Tomography Angiography

PURPOSE OF REVIEW

For over 50 years, diabetic retinopathy (DR) has been classified by pathologic features seen on clinical examination and conventional retinal photographs. However, newer technology such as optical coherence tomography angiography (OCTA) now enables rapid acquisition of retinal structural and vascular information in a reliable, non-invasive, high-resolution fashion. Here, we highlight recent studies that have explored wide field swept-source OCTA (WF SS-OCTA) for the diagnosis and management of DR.

RECENT FINDINGS

Multiple studies have demonstrated the utility of WF SS-OCTA for detection of all clinically relevant features of DR. An updated DR staging system is proposed that leverages the advantages of WF SS-OCTA, including the ability to correlate detailed vascular and structural pathology over time with longitudinal imaging. WF SS-OCTA has tremendous potential for evaluating patients with DR. A new WF SS-OCTA-based staging system may be useful in routine clinical practice and for clinical trials.

Teleophthalmology and Artificial Intelligence As Game Changers in Ophthalmic Care After the COVID-19 Pandemic

The current COVID-19 pandemic has boosted a sudden demand for telemedicine due to quarantine and travel restrictions. The exponential increase in the use of telemedicine is expected to affect ophthalmology drastically. The aim of this review is to discuss the utility, effectiveness and challenges of teleophthalmological new tools for eyecare delivery as well as its implementation and possible facilitation with artificial intelligence. We used the terms: “teleophthalmology,” “telemedicine and COVID-19,” “retinal diseases and telemedicine,” “virtual ophthalmology,” “cost effectiveness of teleophthalmology,” “pediatric teleophthalmology,” “Artificial intelligence and ophthalmology,” “Glaucoma and teleophthalmology” and “teleophthalmology limitations” in the database of PubMed and selected the articles being published in the course of 2015-2020. After the initial search, 321 articles returned as relevant. A meticulous screening followed and eventually 103 published manuscripts were included and used as our references. Emerging in the market, teleophthalmology is showing great potential for the future of ophthalmological care, benefiting both patients and ophthalmologists in times of pandemics. The spectrum of eye diseases that could benefit from teleophthalmology is wide, including mostly retinal diseases such as diabetic retinopathy, retinopathy of prematurity, age-related macular degeneration but also glaucoma and anterior segment conditions. Simultaneously, artificial intelligence provides ways of implementing teleophthalmology easier and with better outcomes, contributing as significant changing factors for ophthalmology practice after the COVID-19 pandemic.

Remote Screening for Optic Nerve Cupping Using Smartphone-based Nonmydriatic Fundus Photography

PRECIS

Evaluation of nonmydriatic fundus photographs captured with a low-cost, smartphone-based camera facilitated remote screening of patients for enlarged optic nerve cup-to-disc ratio in the Independent Nation of Samoa, an underserved setting with one full-time ophthalmologist in the entire country.

PURPOSE

To investigate factors that impact inter-rater agreement of glaucoma suspect optic disc status using a low-cost, handheld nonmydriatic fundus camera.

METHODS

Color fundus photographs were obtained using the PanOptic iExaminer attached to an iPhone 6S by a lay examiner on 206 participants in the Independent Nation of Samoa. Images were remotely graded by an ophthalmologist and optometrist, and images from participants identified as at-risk for glaucoma were escalated to a glaucoma subspecialist for review. Fundus photo brightness, contrast, and focus were measured using the cup, rim, and temporal regions of the disc. Stereoscopic image pairs were subsequently generated from a subset of individual nonmydriatic photographs.

RESULTS

Features suggestive of glaucoma based on optic disc cupping were identified in 16.0% (33/206) of participants. There was moderately strong agreement between graders (90.3%) with κ=0.53 [95% confidence interval (CI)=0.33-0.73]. The intraclass correlation coefficients for the cup-to-disc ratio (CDR) and its difference were 0.84 (95% CI=0.81-0.87) and 0.68 (95% CI=0.59-0.75). Of the 33 participants identified, 94% had clinical risk criteria for potential glaucoma when reviewed by a subspecialist. Color fundus photograph cup brightness was significantly associated with cup-to-disc (CDR) grade, R2=0.36 (P<0.001), in which a brighter disc yielded a higher CDR.

CONCLUSIONS

Smartphone-based screening is a simple, low-cost method capable of measuring the CDR of the optic nerve. When combined with testing for other glaucoma risk factors such as intraocular pressure, this method of measuring CDR may help identify those patients who should be referred for further ophthalmologic assessment. We are currently conducting studies to assess the sensitivity and specificity of smart phone-based remote screening.

ANATOMICAL AND FUNCTIONAL TESTING IN DIABETIC PATIENTS WITHOUT RETINOPATHY: Results of Optical Coherence Tomography Angiography and Visual Acuity Under Varying Contrast and Luminance Conditions

PURPOSE

To assess early retinal microvascular and functional changes in diabetic patients without clinical evidence of diabetic retinopathy with optical coherence tomography angiography and central visual analyzer.

METHODS

This was an observational case-control study of diabetic patients without diabetic retinopathy and nondiabetic controls. Patients underwent optical coherence tomography angiography imaging and visual acuity testing using the central visual analyzer. The foveal avascular zone area and the capillary density in the superficial and deep capillary plexuses were measured manually by a masked grader.

RESULTS

Sixty eyes from 35 diabetic patients were included in the study group, and 45 eyes from 31 nondiabetic patients were included in the control group. The foveal avascular zone area was not significantly different between the diabetic group and controls (both P > 0.05). The mean capillary density in the deep capillary plexus was significantly lower in diabetic eyes compared with control eyes (P = 0.04). The mean visual acuity in all central visual analyzer modules was significantly decreased in diabetic patients compared with controls (all P < 0.05).

CONCLUSION

Optical coherence tomography angiography was able to detect retinal microvascular changes in the deep capillary plexus, and the central visual analyzer showed signs of decreased visual acuity under conditions simulating suboptimal contrast and glare in diabetic patients without diabetic retinopathy.

Foveal avascular zone analysis by optical coherence tomography angiography in patients with type 1 and 2 diabetes and without clinical signs of diabetic retinopathy

PURPOSE

To analyze the early macular microvascular alterations in patients with type 1 and 2 diabetes mellitus (DM) without diabetic retinopathy (DR), using optical coherence tomography angiography (OCT-A), and compare these with nondiabetic patients.

METHODS

This prospective study involved 93 patients with type 1 diabetes (DM1), 104 patients with type 2 diabetes (DM2) without signs of DR, and 71 healthy subjects for the control group. The foveal avascular zone (FAZ) area and the vessel density (VD) at the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were evaluated.

RESULTS

The SCP and DCP FAZ areas were significantly larger in the DM1 group in comparison with the controls (p = .001), while no significant differences were observed between the DM2 group and the healthy control group (p = .12). Additionally, no significant differences in FAZ area were found between the DM1 and DM2 groups (p = .26). The VD was significantly reduced in DM1 and DM2 groups compared to controls. A direct correlation was found between the duration of diabetes and SCP FAZ area (r = 0.44; R² = 0.19; p = .0001). Statistically significant differences in the FAZ area at SCP and DCP were observed when comparing patients with a diabetes duration > 10 years and < 10 years in the DM2 group (p = .0001, respectively) and only in the FAZ area at the DCP in the DM1 group (p = .0001).

CONCLUSION

Diabetic patients without DR demonstrate early microvascular alteration in the macular area on OCT-A, which is more pronounced in type I DM, and correlates with the duration of the disease.

Impact of the COVID-19 Pandemic on Essential Vitreoretinal Care with Three Epicenters in the United States

Purpose

To report the impact of COVID-19 on retina practices in three different “hot spot” cities in the United States.

Patients and Methods

The authors assessed data of encounters and intravitreal injections from March 16th to May 8th 2020, at different offices specializing in retina in the United States. All three practices are located in COVID-19 hot spot zones. One practice was in an academic setting, one practice was in a private multispecialty setting, and one practice was a solo private vitreo-retina practice. All practices were focused on emergent/urgent care, and the results were compared to preCOVID-19 weekly averages.

Results

A significant decrease in the number of encounters and injections was revealed in all three centers involved in this review. There was a decrease of 87% in encounters (156 patients were seen only) and a decrease of 58% (126 patients) in intravitreal injections in Weill Cornell Medical College in NYC and a decline of 59% (569 patients) in encounters and a decrease of 64% (280 patients) of intravitreal injections at the Ophthalmic Consultants of Boston and Tufts University School of Medicine in Boston. The decline at Miami Ocular Oncology & Retina in Miami was 37% (1198 patients) in the encounters and 30% (867 patients) in the injections.

Conclusion

This manuscript documents a specific example illustrating that COVID-19 has led to a significant decrease in specialized health services. The degree of infection and mortality rate at each hot spot had a direct impact on the practice volume; however, the type of practice setting also played a role.

A Novel Device for Smartphone-Based Fundus Imaging and Documentation in Clinical Practice: Comparative Image Analysis Study

Background

Smartphone-based fundus imaging allows for mobile and inexpensive fundus examination with the potential to revolutionize eye care, particularly in lower-resource settings. However, most smartphone-based fundus imaging adapters convey image quality not comparable to conventional fundus imaging.

Objective

The purpose of this study was to evaluate a novel smartphone-based fundus imaging device for documentation of a variety of retinal/vitreous pathologies in a patient sample with wide refraction and age ranges.

Methods

Participants’ eyes were dilated and imaged with the iC2 funduscope (HEINE Optotechnik) using an Apple iPhone 6 in single-image acquisition (image resolution of 2448 × 3264 pixels) or video mode (1248 × 1664 pixels) and a subgroup of participants was also examined by conventional fundus imaging (Zeiss VISUCAM 500). Smartphone-based image quality was compared to conventional fundus imaging in terms of sharpness (focus), reflex artifacts, contrast, and illumination on semiquantitative scales.

Results

A total of 47 eyes from 32 participants (age: mean 62.3, SD 19.8 years; range 7-93; spherical equivalent: mean –0.78, SD 3.21 D; range: –7.88 to +7.0 D) were included in the study. Mean (SD) visual acuity (logMAR) was 0.48 (0.66; range 0-2.3); 30% (14/47) of the eyes were pseudophakic. Image quality was sufficient in all eyes irrespective of refraction. Images acquired with conventional fundus imaging were sharper and had less reflex artifacts, and there was no significant difference in contrast and illumination (P<.001, P=.03, and P=.10, respectively). When comparing image quality at the posterior pole, the mid periphery, and the far periphery, glare increased as images were acquired from a more peripheral part of the retina. Reflex artifacts were more frequent in pseudophakic eyes. Image acquisition was also possible in children. Documentation of deep optic nerve cups in video mode conveyed a mock 3D impression.

Conclusions

Image quality of conventional fundus imaging was superior to that of smartphone-based fundus imaging, although this novel smartphone-based fundus imaging device achieved image quality high enough to document various fundus pathologies including only subtle findings. High-quality smartphone-based fundus imaging might represent a mobile alternative for fundus documentation in clinical practice.

Smartphone-Based Fundus Imaging-Where Are We Now?

With the advent of smartphone-based fundus imaging (SBFI), a low-cost alternative to conventional digital fundus photography has become available. SBFI allows for a mobile fundus examination, is applicable both with and without pupil dilation, comes with built-in connectivity and post-processing capabilities, and is relatively easy to master. Furthermore, it is delegable to paramedical staff/technicians and, hence, suitable for telemedicine. Against this background a variety of SBFI applications have become available including screening for diabetic retinopathy, glaucoma, and retinopathy of prematurity and its applications in emergency medicine and pediatrics. In addition, SBFI is convenient for teaching purposes and might serve as a surrogate for direct ophthalmoscopy. First wide-field montage techniques are available and the combination of SBFI with machine learning algorithms for image analyses is promising. In conclusion, SBFI has the potential to make fundus examinations and screenings for patients particularly in low- and middle-income settings more accessible and, therefore, aid tackling the burden of diabetic retinopathy, glaucoma, and retinopathy of prematurity screening. However, image quality for SBFI varies substantially and a reference standard for grading appears prudent. In addition, there is a strong need for comparison of different SBFI approaches in terms of applicability to disease screening and cost-effectiveness.

Comparison of automated and expert human grading of diabetic retinopathy using smartphone-based retinal photography

PURPOSE

The aim of this study is to investigate the efficacy of a mobile platform that combines smartphone-based retinal imaging with automated grading for determining the presence of referral-warranted diabetic retinopathy (RWDR).

METHODS

A smartphone-based camera (RetinaScope) was used by non-ophthalmic personnel to image the retina of patients with diabetes. Images were analyzed with the Eyenuk EyeArt® system, which generated referral recommendations based on presence of diabetic retinopathy (DR) and/or markers for clinically significant macular oedema. Images were independently evaluated by two masked readers and categorized as refer/no refer. The accuracies of the graders and automated interpretation were determined by comparing results to gold standard clinical diagnoses.

RESULTS

A total of 119 eyes from 69 patients were included. RWDR was present in 88 eyes (73.9%) and in 54 patients (78.3%). At the patient-level, automated interpretation had a sensitivity of 87.0% and specificity of 78.6%; grader 1 had a sensitivity of 96.3% and specificity of 42.9%; grader 2 had a sensitivity of 92.5% and specificity of 50.0%. At the eye-level, automated interpretation had a sensitivity of 77.8% and specificity of 71.5%; grader 1 had a sensitivity of 94.0% and specificity of 52.2%; grader 2 had a sensitivity of 89.5% and specificity of 66.9%.

DISCUSSION

Retinal photography with RetinaScope combined with automated interpretation by EyeArt achieved a lower sensitivity but higher specificity than trained expert graders. Feasibility testing was performed using non-ophthalmic personnel in a retina clinic with high disease burden. Additional studies are needed to assess efficacy of screening diabetic patients from general population.

Cost-effectiveness of diabetic retinopathy screening programs using telemedicine: a systematic review

Background

Diabetic retinopathy (DR) is a significant global public health and economic burden. DR accounts for approximately 15–17% of all cases of total blindness in the USA and Europe. Telemedicine is a new intervention for DR screening, however, there is not enough evidence to support its cost-effectiveness. The aim of this study is to review the most recent published literature on economic evaluations of telemedicine in DR screening and summarize the evidence on the cost-effectiveness of this technology.

Methods

A systematic search of PubMed, Embase and Google Scholar for relevant articles published between January 2010 and January 2020. Studies were included if they met the following criteria: (1) recruited subjects with either type 1, type 2 diabetes (2) evaluated telemedicine technology (3) patients underwent primary screening for DR (4) compared a telemedicine-based intervention with standard care (5) performed an economic evaluation or provided sufficient data for evaluating the cost-effectiveness of the technology used.

Results

Of 2238 articles screened, seven studies were included. Four of the studies were conducted in developed countries: The United States, Singapore and two studies in Canada. Three studies were conducted in developing countries: India, Brazil and South Africa. The patient populations in all studies were diabetic patients over the age of 18, previously not screened for DR. All seven studies used a telemedicine program which included capturing a retinal image and subsequently transmitting it to an ocular imaging center to assess the severity of DR. All studies compared telemedicine to a standard screening method for DR, including the option of no screening as standard of care. Although telemedicine requires initial and maintenance costs, it has the potential to provide significant cost savings by increasing patients’ working ability, increasing independent living ability, increasing quality of life and reducing travel costs.

Conclusions

Diabetic retinopathy telemedicine technology has the potential to provide significant cost savings, especially in low-income populations and rural patients with high transportation costs.

Scaling Up Teleophthalmology for Diabetic Eye Screening: Opportunities for Widespread Implementation in the USA

PURPOSE OF REVIEW

We discuss opportunities to address key barriers to widespread implementation of teleophthalmology programs for diabetic eye screening in the United States (U.S.).

RECENT FINDINGS

Teleophthalmology is an evidence-based form of diabetic eye screening. This technology has been proven to substantially increase diabetic eye screening rates and decrease blindness. However, teleophthalmology implementation remains limited among U.S. health systems. Major barriers include financial concerns as well as limited utilization by providers, clinical staff, and patients. Possible interventions include increasingly affordable camera technology, demonstration of financially sustainable billing models, and engaging key stakeholders. Significant opportunities exist to overcome barriers to scale up and promote widespread implementation of teleophthalmology in the USA. Further development of methods to sustain effective increases in diabetic eye screening rates using this technology is needed. In addition, the demonstration of cost-effectiveness in a variety of billing models should be investigated to facilitate widespread implementation of teleophthalmology in U.S. health systems.

Light-Induced Pupillary Responses in Alzheimer's Disease

The impact of Alzheimer's disease (AD) on the pupillary light response (PLR) is controversial, being dependent on the stage of the disease and on the experimental pupillometric protocols. The main hypothesis driving pupillometry research in AD is based on the concept that the AD-related neurodegeneration affects both the parasympathetic and the sympathetic arms of the PLR (cholinergic and noradrenergic theory), combined with additional alterations of the afferent limb, involving the melanopsin expressing retinal ganglion cells (mRGCs), subserving the PLR. Only a few studies have evaluated the value of pupillometry as a potential biomarker in AD, providing various results compatible with parasympathetic dysfunction, displaying increased latency of pupillary constriction to light, decreased constriction amplitude, faster redilation after light offset, decreased maximum velocity of constriction (MCV) and maximum constriction acceleration (MCA) compared to controls. Decreased MCV and MCA appeared to be the most accurate of all PLR parameters allowing differentiation between AD and healthy controls while increased post-illumination pupillary response was the most consistent feature, however, these results could not be replicated by more recent studies, focusing on early and pre-clinical stages of the disease. Whether static or dynamic pupillometry yields useful biomarkers for AD screening or diagnosis remains unclear. In this review, we synopsize the current knowledge on pupillometric features in AD and other neurodegenerative diseases, and discuss potential roles of pupillometry in AD detection, diagnosis and monitoring, alone or in combination with additional biomarkers.

Implementation of a diabetic retinopathy referral network, Peru

Objective

To describe the implementation of a diabetic retinopathy referral network incorporating all levels of health care in La Libertad region, Peru.

Method

The nongovernmental organization Orbis International and the Regional Institute of Ophthalmology established a network of primary, secondary and tertiary health-care facilities for diabetic retinopathy screening and treatment. The programme included the provision of three non-mydriatic retinal cameras for patient examination, the development of a flowchart to guide patient referrals, training of health personnel, investment in laser technology for treatment and the delivery of public awareness activities for blindness prevention and the need for timely screening.

Findings

From 2014-2017, 11 849 patients with diabetes were screened within the diabetic retinopathy referral network. In primary-care centres, 6012 patients with diabetes mellitus were identified and 5632 patients were referred for diabetic retinopathy screening. A further 4036 patients directly attended two secondary-level hospitals and 2181 attended the tertiary-level hospital for screening. This represented a 138.1% increase in diabetic retinopathy screenings from a baseline of 4977 patients screened at the regional institute of ophthalmology over 2010-2013. A total of 2922 patients (24.7%) were found to have diabetic retinopathy and 923 (31.6%) were treated: 508 with laser photocoagulation, 345 with intravitreal bevacizumab and 70 with vitreoretinal surgery.

Conclusion

Effective and timely treatment for diabetic retinopathy is possible when patient education, screening and care are fully integrated into the general health-care system across primary-, secondary- and tertiary-level facilities. This requires the integration of professionals at all levels and all relevant specialties.

Robotic Remote Controlled Stereo Slit Lamp

Purpose

Our purpose was to develop a robotic remotely operated stereo slit lamp system allowing three-dimensional stereo viewing and recording of the patient's examination via local area network, Internet, and satellite.

Methods

A commercial slit lamp was modified to accept motors and servos to permit control of all optical and mechanical components of the device. The custom graphical user interface with dual high-resolution real-time stereoscopic imaging, control/position indicators, overview video, and audio were transmitted via local area network, Internet, and satellite. Under University of Miami Institutional Review Board authorization, Internet connectivity enabled multiple examiners to simultaneously view and control the slit lamp and to collaboratively discuss diagnosis and treatment options. The remote clinicians used a tablet, laptop, or desktop computer to view and control the slit lamp.

Results

The network, Internet, satellite-connected system was controllable from the United States, Europe, and Canada while acquiring high-resolution, real-time video in all subjects. Control of the slit lamp through Ethernet, WiFi, and 4G exhibited total system latencies of 464 ± 58, 483 ± 64, and 870 ± 66 milliseconds when transmitting within the continent, and Ethernet control exhibited a latency of 606 ± 130 milliseconds when transmitting between continents. High- and low-magnification images of healthy volunteers were acquired by a remote clinician.

Conclusions

The robotic remotely operated stereo slit lamp system allows three-dimensional stereo viewing and recording of the patient's examination via local area network, Internet, and satellite.

Translational Relevance

The robotic remotely controlled stereo slit lamp system enables remote examination of human subjects.

Analysis of yield of retinal imaging in a rural diabetes eye care model

Purpose:

The aim of this study is to analyze the yield of retinal images obtained in a rural diabetes eye care model.

Methods:

An analysis of a sample of nonmydriatic fundus photography (NMFP) of posterior segment ophthalmic images, obtained by an indigenous equipment (3 nethra-Forus Royal), was done in a district-wide rural diabetic retinopathy (DR) screening program; a trained optometrist did the initial image grading. DR and diabetic macular edema (DME) were classified based on international DR and DME severity scale. The agreement between the optometrist and retina specialist was very good (κ = 0.932; standard error = 0.030; 95% confidence interval = 0.874–0.991).

Results:

Posterior segment images of 2000 eyes of 1000 people with diabetes mellitus (DM) were graded. The mean age of the participants was 55.7 ± 11.5 standard deviation years. Nearly 42% of the screened participants (n = 420/1000) needed referral. The most common referable posterior segment abnormality was DR (8.2%). The proportion of people with any form of DR was seen in 110/1225 eyes, and sight-threatening DR was seen in 35/1225 eyes. About 62% of posterior segment images were gradable. The reasons for ungradable posterior segment images (34%) were small pupil, unfocused/partially available field of images, and cataract.

Conclusion:

A NMFP model was able to detect referable posterior segment abnormalities in a rural diabetes eye care program. Reasons found for ungradability of images in the present study can be addressed while designing future DR screening programs in the rural areas.

Screening for Diabetic Eye Disease among Samoan Adults: A Pilot Study

Introduction

The purpose of this study was to determine the prevalence of diabetic retinopathy in Samoa by piloting a retinal photography screening programme.

Methods

We performed a cross-sectional study of patients with diabetes who presented to the Tupua Tamasese Meaole eye clinic in Apia, Samoa, between May 2011 and September 2011. Study approval was granted by the National Health Service Board of Samoa, the Monash University Human Research Ethics Committee, and the study adhered to the Tenets of the Declaration of Helsinki. Following informed consent, data collection included patient demographics [age, area of residence (rural or urban)], type of diabetes, length of time since diagnosis, most recent random blood sugar and blood pressure levels. The subjects had three 45-degree retinal photographs taken in each eye with the Canon CR6-45NM camera. All gradable photographs were assessed for the presence of diabetic retinopathy or macular oedema using the International Clinical Diabetic Retinopathy Severity Scale and the International Clinical Diabetic Macular Oedema Severity scale, respectively.

Results

Two hundred and fourteen eyes from 107 subjects were examined during the study period, all of whom had type 2 diabetes mellitus. Diabetic retinopathy was present in 53.3% (114/214) of eyes, with 14.5% having proliferative retinopathy and 7.5% with severe non-proliferative retinopathy. Also, 25.2% (54/214) had some evidence of macular oedema with 11.7% (25/214) requiring treatment. A statistically significant relationship existed between the length of time since diagnosis and the severity of both retinopathy (p < 0.001) and macular oedema (p = 0.031). Blood pressure more than 150/85 mmHg was associated with higher levels of diabetic retinopathy (p = 0.03) and macular oedema (p = 0.02).

Conclusion

A comprehensive diabetic retinopathy screening programme is much needed in Samoa given the high prevalence of diabetic eye disease.