Validated System for Centralized Grading of Retinopathy of Prematurity: Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) Study

Retinopathy of prematurity: from oxygen management to molecular manipulation

INTRODUCTION

Retinopathy of prematurity (ROP) is a vasoproliferative disorder of the premature retina with the potential to progress to extraretinal neovascularisation. This review serves as an introduction to retinopathy of prematurity (ROP), outlining key parts of ROP pathophysiology, diagnosis and treatment. ROP is traditionally diagnosed by indirect ophthalmoscopy and classified using anatomical zones, stages of disease, and the presence or absence of "plus disease" (dilation and tortuosity of the major retinal arterioles and venules). ROP has a bi-phasic pathophysiology: initial hyperoxia causes reduced retinal vascularisation, followed by pathological vaso-proliferation resulting from subsequent hypoxia and driven by vascular endothelial growth factor (VEGF).

ADVANCEMENTS IN MANAGEMENT

This review summarises previous trials to establish optimum oxygen exposure levels in newborns and more recently the development of anti-VEGF agents locally delivered to block pathological neovascularisation, which is technically easier to administer and less destructive than laser treatment.

FUTURE DIRECTIONS

There remains an ongoing concern regarding the potential unwanted systemic effects of intravitreally administered anti-VEGF on the overall development of the premature baby. Ongoing dosing studies may lessen these fears by identifying the minimally effective dose required to block extraretinal neovascularisation.

Efficacy of Smartphone-Based Telescreening for Retinopathy of Prematurity With and Without Artificial Intelligence in India

Importance

Retinopathy of prematurity (ROP) telemedicine screening programs have been found to be effective, but they rely on widefield digital fundus imaging (WDFI) cameras, which are expensive, making them less accessible in low- to middle-income countries. Cheaper, smartphone-based fundus imaging (SBFI) systems have been described, but these have a narrower field of view (FOV) and have not been tested in a real-world, operational telemedicine setting.

Objective

To assess the efficacy of SBFI systems compared with WDFI when used by technicians for ROP screening with both artificial intelligence (AI) and human graders.

Design, Setting, and Participants

This prospective cross-sectional comparison study took place as a single-center ROP teleophthalmology program in India from January 2021 to April 2022. Premature infants who met normal ROP screening criteria and enrolled in the teleophthalmology screening program were included. Those who had already been treated for ROP were excluded.

Exposures

All participants had WDFI images and from 1 of 2 SBFI devices, the Make-In-India (MII) Retcam or Keeler Monocular Indirect Ophthalmoscope (MIO) devices. Two masked readers evaluated zone, stage, plus, and vascular severity scores (VSS, from 1-9) in all images. Smartphone images were then stratified by patient into training (70%), validation (10%), and test (20%) data sets and used to train a ResNet18 deep learning architecture for binary classification of normal vs preplus or plus disease, which was then used for patient-level predictions of referral warranted (RW)- and treatment requiring (TR)-ROP.

Main Outcome and Measures

Sensitivity and specificity of detection of RW-ROP, and TR-ROP by both human graders and an AI system and area under the receiver operating characteristic curve (AUC) of grader-assigned VSS. Sensitivity and specificity were compared between the 2 SBFI systems using Pearson χ2testing.

Results

A total of 156 infants (312 eyes; mean [SD] gestational age, 33.0 [3.0] weeks; 75 [48%] female) were included with paired examinations. Sensitivity and specificity were not found to be statistically different between the 2 SBFI systems. Human graders were effective with SBFI at detecting TR-ROP with a sensitivity of 100% and specificity of 83.49%. The AUCs with grader-assigned VSS only were 0.95 (95% CI, 0.91-0.99) and 0.96 (95% CI, 0.93-0.99) for RW-ROP and TR-ROP, respectively. For the AI system, the sensitivity of detecting TR-ROP sensitivity was 100% with specificity of 58.6%, and RW-ROP sensitivity was 80.0% with specificity of 59.3%.

Conclusions and Relevance

In this cross-sectional study, 2 different SBFI systems used by technicians in an ROP screening program were highly sensitive for TR-ROP. SBFI systems with AI may be a cost-effective method to improve the global capacity for ROP screening.

Effectiveness of a telemedicine program for triage and diagnosis of emergent ophthalmic conditions

BACKGROUND

To study the utility of a teleophthalmology program to diagnose and triage common ophthalmic complaints presenting to an ophthalmic emergency room.

METHODS

Prospective, observational study of 258 eyes of 129 patients presenting to the Massachusetts Eye and Ear Infirmary Emergency Ward (MEE EW) who completed a questionnaire to gather chief complaint (CC), history of present illness, and medical history. Anterior and posterior segment photographs were collected via iPhone 5 C camera and a Canon non-mydriatic fundus camera, respectively. Ophthalmic vital signs were collected. All information was reviewed remotely by three ophthalmologists; a diagnosis and urgency designation were recorded. The remote assessment was compared to gold standard in-person assessment.

RESULTS

The 129 recruited patients collectively contributed 220 visual complaints, of which 121 (55%) were from females with mean age 56.5 years (range 24-89). Sensitivities and specificities for telemedical triage were as follows: eye pain (n = 56; sensitivity: 0.58, CI [0.41, 0.74]; specificity: 0.91, CI [0.80, 1]), eye redness (n = 54; 0.68, CI [0.50, 0.86]; 0.93, CI [0.84, 1]), blurry vision (n = 68; 0.73, CI [0.60, 0.86]; 0.91, CI [0.80, 1]), and eyelid complaints (n = 42; 0.67, CI [0.43, 0.91]; 0.96, CI [0.89, 1]). The remote diagnostic accuracies, as stratified by CC, were eye pain (27/56; 48.21%), eye redness: (32/54; 59.26%), blurry vision: (30/68; 44.11%), eyelid (24/42; 57.14%).

CONCLUSIONS

Telemedical examination of emergent ophthalmic complaints consisting of a patient questionnaire, anterior segment and fundus photos, and ophthalmic vital signs, may be useful to reliably triage eye disease based on presenting complaint.

Teleophthalmology Using Remote Retinal Imaging During the COVID-19 Pandemic

Introduction: Lower insurance reimbursements have limited the financial sustainability of remote eye screening programs. Greater utilization and insurance coverage for teleophthalmology screening during the coronavirus disease 2019 (COVID-19) pandemic in 2020 may enhance awareness and expand remote retinal imaging services. This retrospective cross-sectional study evaluates utilization and insurance coverage for remote retinal imaging in the United States in 2020. Methods: We analyzed teleretinal imaging utilization and insurance payments from January 1 to December 31, 2020, using the Optum Labs Data Warehouse, a comprehensive national database of deidentified administrative claims for commercial and Medicare Advantage enrollees in the United States. We evaluated frequency of claims and insurance payment for services using the Current Procedural Terminology codes 92227 and 92228 for remote eye imaging by any provider, and 92250 for fundus photography by non-eye care providers. Results: The use of remote retinal imaging in the United States declined rapidly during the initial COVID-19 lockdown from 3,627 claims in February 2020 to 1,414 claims in April 2020, but returned to 3,133 claims by December 2020, similar to mean prepandemic levels in 2019 (2,841 ± 174.8 claims). The proportion of insurance payments for remote imaging increased temporarily from 47.4% in February to 56.7% in April, and then returned to 45.9% in December of 2020. Discussion: Utilization of remote retinal imaging declined steeply, while the insurance coverage increased during the initial COVID-19 lockdown in 2020, but returned to prepandemic levels by end of the year. Changes in utilization and relaxed restrictions on insurance reimbursements for teleophthalmology during the COVID-19 pandemic were not sustained.

Latest Trends in Retinopathy of Prematurity: Research on Risk Factors, Diagnostic Methods and Therapies

Retinopathy of prematurity (ROP) is a vasoproliferative disorder with an imminent risk of blindness, in cases where early diagnosis and treatment are not performed. The doctors' constant motivation to give these fragile beings a chance at life with optimal visual acuity has never stopped, since Terry first described this condition. Thus, throughout time, several specific advancements have been made in the management of ROP. Apart from the most known risk factors, this narrative review brings to light the latest research about new potential risk factors, such as: proteinuria, insulin-like growth factor 1 (IGF-1) and blood transfusions. Digital imaging has revolutionized the management of retinal pathologies, and it is more and more used in identifying and staging ROP, particularly in the disadvantaged regions by the means of telescreening. Moreover, optical coherence tomography (OCT) and automated diagnostic tools based on deep learning offer new perspectives on the ROP diagnosis. The new therapeutical trend based on the use of anti-VEGF agents is increasingly used in the treatment of ROP patients, and recent research sustains the theory according to which these agents do not interfere with the neurodevelopment of premature babies.

Operationalization of Retinopathy of Prematurity Screening by the Application of the Essential Public Health Services Framework

Retinopathy of prematurity (ROP) is one of the leading causes of preventable pediatric blindness worldwide. ROP screening programs have been previously implemented in multiple low- and middle-income countries. On a global scale, it is crucial that evidence-based, standardized screening criteria are utilized in the early detection and treatment of ROP. In this review article, we utilize the National Public Health Performance Standards (NPHPS) Ten Essential Public Health Services Model organized by the core functions of assessment, policy development, and assurance to evaluate the barriers and successes of existing ROP screening programs. This framework can be applied to countries facing the third epidemic of ROP and can be used to establish a generalized model for eye care and screening worldwide.

The state of ocular arterial blood flow in active retinopathy of prematurity

Purpose: to study the state of blood flow in the ocular arteries of patients with various forms, stages and course types of active retinopathy of prematurity (ROP). Material and methods. Colour duplex scanning was performed by colour Doppler mapping and pulsed Doppler sonography for 55 premature babies (55 eyes) with active ROP and 8 premature babies (8 eyes) without ROP signs. The children’s gestation age was 25 to 32 weeks, and the body weight at birth was 680 to1760 g. Blood flow was examined in the ophthalmic artery (OA), the central retinal artery (CRA) and the medial and lateral posterior short ciliary arteries (PSCA). Results. The ophthalmic artery revealed no significant differences between the children with ROP and without ROP, except for a significant increase in the peak systolic velocity (Vsyst) in an unfavorable course of stage III of ROP. The development of aggressive posterior ROP is accompanied by a statistically insignificant decrease in blood flow velocity of OA. Hemodynamic parameters of CRA indicate an increase in peripheral vascular resistance in children with an unfavorable course of ROP. A significant increase of Vsyst in the posterior short ciliary arteries was revealed in children with an unfavorable course of stages I–III of ROP and Vsyst, and Vdiast (diastolic blood flow velocity) in children with aggressive posterior ROP as compared with children without ROP. A pronounced impact of the ROP course (favorable or unfavorable) on the Vsyst, Vdiast, and PI indicators in the posterior short ciliary arteries was revealed. The most informative hemodynamic parameters in predicting the course of active ROP are Vsyst and Vdiast values in the ophthalmic artery and Vsyst in the posterior short ciliary arteries. The least informative were the hemodynamic parameters of the central retinal artery. Conclusion. The assessment of hemodynamic changes in eye arteries may be used as an additional diagnostic criterion in the early diagnosis of ROP.

Use of artificial intelligence in ophthalmology: a narrative review

BACKGROUND

Artificial intelligence (AI) deals with development of algorithms that seek to perceive one's environment and perform actions that maximize one's chance of successfully reaching one's predetermined goals.

OBJECTIVE

To provide an overview of the basic principles of AI and its main studies in the fields of glaucoma, retinopathy of prematurity, age-related macular degeneration and diabetic retinopathy. From this perspective, the limitations and potential challenges that have accompanied the implementation and development of this new technology within ophthalmology are presented.

DESIGN AND SETTING

Narrative review developed by a research group at the Universidade Federal de São Paulo (UNIFESP), São Paulo (SP), Brazil.

METHODS

We searched the literature on the main applications of AI within ophthalmology, using the keywords "artificial intelligence", "diabetic retinopathy", "macular degeneration age-related", "glaucoma" and "retinopathy of prematurity," covering the period from January 1, 2007, to May 3, 2021. We used the MEDLINE database (via PubMed) and the LILACS database (via Virtual Health Library) to identify relevant articles.

RESULTS

We retrieved 457 references, of which 47 were considered eligible for intensive review and critical analysis.

CONCLUSION

Use of technology, as embodied in AI algorithms, is a way of providing an increasingly accurate service and enhancing scientific research. This forms a source of complement and innovation in relation to the daily skills of ophthalmologists. Thus, AI adds technology to human expertise.

Applications and Current Medico-Legal Challenges of Telemedicine in Ophthalmology

BACKGROUND

The digital revolution is redesigning the healthcare model, and telemedicine offers a good example of the best cost-effectiveness ratio. The COVID-19 pandemic has catalysed the use of the telemedicine. The aim of this review is to describe and discuss the role and the main applications of telemedicine in the ophthalmic clinical practice as well as the related medico-legal aspects.

METHODS

45 original articles and 5 reviews focused on this topic and published in English language from 1997 and 2021 were searched on the online databases of Pubmed, Scopus, Web of Sciences and Embase, by using the following key words: "telemedicine", "privacy", "ophthalmology", "COVID-19" and "informed consent".

RESULTS

Telemedicine is able to guarantee patient care using information and communication technologies. Technology creates an opportunity to link doctors with the aim of assessing clinical cases and maintaining high standards of care while performing and saving time as well. Ophthalmology is one of the fields in which telemedicine is most commonly used for patient management.

CONCLUSIONS

Telemedicine offers benefits to patients in terms of saving time and costs and avoiding physical contact; however, it is necessary to point out significant limitations such as the absence of physical examinations, the possibility of transmission failure and potential violations of privacy and confidentiality.

Comparison of RetCam and Smartphone-Based Photography for Retinopathy of Prematurity Screening

This study aimed to compare the clinical performance between a smartphone-based fundus photography device and a contact imaging device for retinopathy of prematurity (ROP) screening. All patients were first examined with binocular indirect ophthalmoscopy (BIO), which served as the reference standard. The patients were then assessed by two devices. Imaging quality, ability to judge the zone and stage of ROP, agreement with the BIO results, vital signs, and pain scores were compared between these two devices. In total, 142 eyes of 71 infants were included. For the smartphone-based fundus photography, image quality was graded excellent or acceptable in 91.4% of examinations, although it was still significantly inferior to that of the contact imaging device (p < 0.001). The smartphone-based fundus photography images had moderate agreement with the BIO results regarding the presence or absence of plus disease (Cohen’s κ = 0.619), but evaluating the zone (p < 0.001) and stage (p < 0.001) of ROP was difficult. Systemic parameters, except for heart rate, were similar between the two imaging devices (all p > 0.05). In conclusion, although the smartphone-based fundus photography showed moderate agreement for determining the presence or absence of plus disease, it failed to identify the zone and stage of ROP.

Automated vs. human evaluation of corneal staining

BACKGROUND AND PURPOSE

Corneal fluorescein staining is one of the most important diagnostic tests in dry eye disease (DED). Nevertheless, the result of this examination is depending on the grader. So far, there is no method for an automated quantification of corneal staining commercially available. Aim of this study was to develop a software-assisted grading algorithm and to compare it with a group of human graders with variable clinical experience in patients with DED.

METHODS

Fifty images of eyes stained with 2 µl of 2% fluorescein presenting different severity of superficial punctate keratopathy in patients with DED were taken under standardized conditions. An algorithm for detecting and counting superficial punctate keratitis was developed using ImageJ with a training dataset of 20 randomly picked images. Then, the test dataset of 30 images was analyzed (1) by the ImageJ algorithm and (2) by 22 graders, all ophthalmologists with different levels of experience. All graders evaluated the images using the Oxford grading scheme for corneal staining at baseline and after 6-8 weeks. Intrarater agreement was also evaluated by adding a mirrored version of all original images into the set of images during the 2nd grading.

RESULTS

The count of particles detected by the algorithm correlated significantly (n = 30; p < 0.01) with the estimated true Oxford grade (Sr = 0,91). Overall human graders showed only moderate intrarater agreement (K = 0,426), while software-assisted grading was always the same (K = 1,0). Little difference was found between specialists and non-specialists in terms of intrarater agreement (K = 0,436 specialists; K = 0,417 non-specialists). The highest interrater agreement was seen with 75,6% in the most experienced grader, a cornea specialist with 29 years of experience, and the lowest was seen in a resident with 25,6% who had only 2 years of experience.

CONCLUSION

The variance in human grading of corneal staining - if only small - is likely to have only little impact on clinical management and thus seems to be acceptable. While human graders give results sufficient for clinical application, software-assisted grading of corneal staining ensures higher consistency and thus is preferrable for re-evaluating patients, e.g., in clinical trials.

Use of Telemedicine for subspecialty support in the NICU setting

The regionalization of neonatal care was implemented with an overarching goal to improve neonatal outcomes.¹ This led to centralized neonatal care in urban settings that jeopardized the sustainability of the community level 2 and level 3 Neonatal Intensive Care Units (NICU) in medically underserved areas.² Coupled with pediatric subspecialist and allied health professional workforce shortages, regionalization resulted in disparate and limited access to subspecialty care.^3-6 Innovative telemedicine technologies may offer an alternative and powerful care model for infants in geographically isolated and underserved areas. This chapter describes how telemedicine offerings of remote pediatric subspecialty and specialized programs may bridge gaps of access to specialized care and maintain the clinical services in community NICUs.

Key factors in a rigorous longitudinal image-based assessment of retinopathy of prematurity

To describe a database of longitudinally graded telemedicine retinal images to be used as a comparator for future studies assessing grader recall bias and ability to detect typical progression (e.g. International Classification of Retinopathy of Prematurity (ICROP) stages) as well as incremental changes in retinopathy of prematurity (ROP). Cohort comprised of retinal images from 84 eyes of 42 patients who were sequentially screened for ROP over 6 consecutive weeks in a telemedicine program and then followed to vascular maturation or treatment, and then disease stabilization. De-identified retinal images across the 6 weekly exams (2520 total images) were graded by an ROP expert based on whether ROP had improved, worsened, or stayed the same compared to the prior week’s images, corresponding to an overall clinical “gestalt” score. Subsequently, we examined which parameters might have influenced the examiner’s ability to detect longitudinal change; images were graded by the same ROP expert by image view (central, inferior, nasal, superior, temporal) and by retinal components (vascular tortuosity, vascular dilation, stage, hemorrhage, vessel growth), again determining if each particular retinal component or ROP in each image view had improved, worsened, or stayed the same compared to the prior week’s images. Agreement between gestalt scores and view, component, and component by view scores was assessed using percent agreement, absolute agreement, and Cohen’s weighted kappa statistic to determine if any of the hypothesized image features correlated with the ability to predict ROP disease trajectory in patients. The central view showed substantial agreement with gestalt scores (κ = 0.63), with moderate agreement in the remaining views. Of retinal components, vascular tortuosity showed the most overall agreement with gestalt (κ = 0.42–0.61), with only slight to fair agreement for all other components. This is a well-defined ROP database graded by one expert in a real-world setting in a masked fashion that correlated with the actual (remote in time) exams and known outcomes. This provides a foundation for subsequent study of telemedicine’s ability to longitudinally assess ROP disease trajectory, as well as for potential artificial intelligence approaches to retinal image grading, in order to expand patient access to timely, accurate ROP screening.

The Serine Protease HTRA-1 Is a Biomarker for ROP and Mediates Retinal Neovascularization

Retinopathy of prematurity (ROP) is a blinding aberrancy of retinal vascular maturation in preterm infants. Despite delayed onset after preterm birth, representing a window for therapeutic intervention, we cannot prevent or cure ROP blindness. A natural form of ROP protection exists in the setting of early-onset maternal preeclampsia, though is not well characterized. As ischemia is a central feature in both ROP and preeclampsia, we hypothesized that angiogenesis mediators may underlie this protection. To test our hypothesis we analyzed peripheral blood expression of candidate proteins with suggested roles in preeclamptic and ROP pathophysiology and with a proposed angiogenesis function (HTRA-1, IGF-1, TGFβ-1, and VEGF-A). Analysis in a discovery cohort of 40 maternal-infant pairs found that elevated HTRA-1 (high-temperature requirement-A serine peptidase-1) was significantly associated with increased risk of ROP and the absence of preeclampsia, thus fitting a model of preeclampsia-mediated ROP protection. We validated these findings and further demonstrated a dose-response between systemic infant HTRA-1 expression and risk for ROP development in a larger and more diverse validation cohort consisting of preterm infants recruited from two institutions. Functional analysis in the oxygen-induced retinopathy (OIR) murine model of ROP supported our systemic human findings at the local tissue level, demonstrating that HtrA-1 expression is elevated in both the neurosensory retina and retinal pigment epithelium by RT-PCR in the ROP disease state. Finally, transgenic mice over-expressing HtrA-1 demonstrate greater ROP disease severity in this model. Thus, HTRA-1 may underlie ROP protection in preeclampsia and represent an avenue for disease prevention, which does not currently exist.

Progression from preplus to plus disease in the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) Study: incidence, timing, and predictors

PURPOSE

To determine the incidence of and timing and predictors for progression from pre-plus to plus disease, based on evaluation of images.

METHODS

Two trained readers independently evaluated posterior pole images of infants from 13 North American centers for pre-plus/plus disease, stage, and zone of retinopathy of prematurity (ROP). Discrepancies between readers were adjudicated. To be eligible for analysis, eyes had to have at least two imaging sessions, the earlier one with pre-plus disease.

RESULTS

Of 681 eyes of 444 infants with pre-plus first detected at mean postmenstrual age (PMA) of 35.5 ± 2.1 weeks, 54 (7.9%) progressed to plus disease at a mean PMA of 37.6 ± 2.4 weeks with the mean interval for progression of 2.7 weeks (range, 0.4-8.9 weeks). Progression rate was higher for eyes with larger number of quadrants of pre-plus (44% for eyes with four quadrants vs 4% with one quadrant [P < 0.0001]), earlier PMA with pre-plus (18% for 32 weeks' PMA vs 3% for PMA of >37 weeks [P = 0.02]), higher ROP stage (12% for stage 3, 2.5% for no ROP [P < 0.0001]), lower ROP zone (24% for zone I, 6% for zone II or no ROP [P < 0.0001]) at the time of first pre-plus detection.

CONCLUSIONS

Based on image evaluation, 8% of eyes progressed from pre-plus to plus disease at a mean interval of 3 weeks. Pre-plus in multiple quadrants, higher stages of ROP, and lower zones of ROP were associated with higher risk of progression. Image evaluation for pre-plus may help in the identification of high-risk eyes for developing plus disease.

[Retinopathy of prematurity: from prevention to treatment]

Retinopathy of prematurity (ROP) is one of the leading cause of preventable blindness in children. Its incidence increases with increasing survival of extremely preterm babies. ROP results from a multifactorial impairment of retinal development, the retinal vascular network, involving both oxygen-dependent and nutritional factors. The numerous factors involved in ROP development suggest that preventive strategies should be synergistic and complementary, including tight control of oxygen therapy, optimized nutritional intakes and postnatal growth, breastfeeding, adequate ω-3 PUFAs supply and control of hyperglycemic episodes associated with prematurity. ROP requires a multidisciplinary management, which includes systematic screening, appropriate treatment and long-term follow-up. Current screening modalities are based on wide-field digital retinal imaging systems, which also allow screening by telemedicine. The gold-standard treatment for ROP remains laser photocoagulation. It may be combined with intravitreal anti-VEGF administration, which is currently being evaluated, or surgery for advanced stages.

Application of Artificial Intelligence in Targeting Retinal Diseases

Retinal diseases affect an increasing number of patients worldwide because of the aging population. Request for diagnostic imaging in ophthalmology is ramping up, while the number of specialists keeps shrinking. Cutting-edge technology embedding artificial intelligence (AI) algorithms are thus advocated to help ophthalmologists perform their clinical tasks as well as to provide a source for the advancement of novel biomarkers. In particular, optical coherence tomography (OCT) evaluation of the retina can be augmented by algorithms based on machine learning and deep learning to early detect, qualitatively localize and quantitatively measure epi/intra/subretinal abnormalities or pathological features of macular or neural diseases. In this paper, we discuss the use of AI to facilitate efficacy and accuracy of retinal imaging in those diseases increasingly treated by intravitreal vascular endothelial growth factor (VEGF) inhibitors (i.e. anti-VEGF drugs), also including integration and interpretation features in the process. We review recent advances by AI in diabetic retinopathy, age-related macular degeneration, and retinopathy of prematurity that envision a potentially key role of highly automated systems in screening, early diagnosis, grading and individualized therapy. We discuss benefits and critical aspects of automating the evaluation of disease activity, recurrences, the timing of retreatment and therapeutically potential novel targets in ophthalmology. The impact of massive employment of AI to optimize clinical assistance and encourage tailored therapies for distinct patterns of retinal diseases is also discussed.

Ophthalmology practice during the COVID-19 pandemic

OBJECTIVE

To present an established practice protocol for safe and effective hospital-setting ophthalmic practice during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS AND ANALYSIS

Literature was reviewed to identify articles relevant to COVID-19 pandemic and ophthalmology. The following keywords were used: COVID-19, SARS-CoV-2 and telemedicine, combined with eye, ophthalmology, conjunctivitis and tears. Data were extracted from the identified manuscripts and discussed among subspecialists to obtain consensus evidence-based practice.

RESULTS

A protocol for ophthalmic practice in the era of COVID-19 pandemic was established. The protocol covered patient screening, clinic flow, required personal protective equipment and modifications of ophthalmic equipment for improved safety.

CONCLUSION

Important literature emerged with respect to the practice of ophthalmology in the era of COVID-19. An evidence-based ophthalmic practice protocol was established and should be modified in the future to accommodate new insights on the COVID-19 pandemic.

Proposed measures to be taken by ophthalmologists during the coronavirus disease 2019 pandemic: Experience from Chang Gung Memorial Hospital, Linkou, Taiwan

PURPOSE

Although Taiwan was one of the first countries to develop coronavirus disease 2019 (COVID-19), with effective antiepidemic measures, Taiwan has effectively controlled the spread of the disease. The purpose of this article is to provide useful safety strategies for ophthalmologists in daily practice during the COVID-19 pandemic.

MATERIALS AND METHODS

Infection control strategies in the hospital and Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, are discussed.

RESULTS

Ophthalmologists are at high risk of contracting COVID-19 infection, as they have close contact with patients during ocular examinations, and are also facing high patient volume in outpatient clinics as well as emergency consultations. Furthermore, ocular symptoms, such as conjunctivitis, may be the presenting signs of COVID-19 infection. We provide our strategies, which include hospital's gate control with triage station, patient volume control, proper personal protective equipment, and consultation with telemedicine technology, to decrease the risk of cross-infection between medical staffs and patients.

CONCLUSION

To achieve the goal of preventing viral spread and maximizing patient and medical staffs' safety, besides providing proper protective equipment, it is also crucial for staffs and patients to strictly follow antiepidemic measures. We hope that our experience can help ophthalmologists and health-care workers to have a safer working environment when facing COVID-19 pandemic.

Practice Guidelines for Ocular Telehealth-Diabetic Retinopathy, Third Edition

Contributors The following document and appendices represent the third edition of the Practice Guidelines for Ocular Telehealth-Diabetic Retinopathy. These guidelines were developed by the Diabetic Retinopathy Telehealth Practice Guidelines Working Group. This working group consisted of a large number of subject matter experts in clinical applications for telehealth in ophthalmology. The editorial committee consisted of Mark B. Horton, OD, MD, who served as working group chair and Christopher J. Brady, MD, MHS, and Jerry Cavallerano, OD, PhD, who served as cochairs. The writing committees were separated into seven different categories. They are as follows: 1.Clinical/operational: Jerry Cavallerano, OD, PhD (Chair), Gail Barker, PhD, MBA, Christopher J. Brady, MD, MHS, Yao Liu, MD, MS, Siddarth Rathi, MD, MBA, Veeral Sheth, MD, MBA, Paolo Silva, MD, and Ingrid Zimmer-Galler, MD. 2.Equipment: Veeral Sheth, MD (Chair), Mark B. Horton, OD, MD, Siddarth Rathi, MD, MBA, Paolo Silva, MD, and Kristen Stebbins, MSPH. 3.Quality assurance: Mark B. Horton, OD, MD (Chair), Seema Garg, MD, PhD, Yao Liu, MD, MS, and Ingrid Zimmer-Galler, MD. 4.Glaucoma: Yao Liu, MD, MS (Chair) and Siddarth Rathi, MD, MBA. 5.Retinopathy of prematurity: Christopher J. Brady, MD, MHS (Chair) and Ingrid Zimmer-Galler, MD. 6.Age-related macular degeneration: Christopher J. Brady, MD, MHS (Chair) and Ingrid Zimmer-Galler, MD. 7.Autonomous and computer assisted detection, classification and diagnosis of diabetic retinopathy: Michael Abramoff, MD, PhD (Chair), Michael F. Chiang, MD, and Paolo Silva, MD.

Telemedicine for Retinopathy of Prematurity

Background: Retinopathy of prematurity (ROP) is a disease of the retinal vasculature that remains a leading cause of childhood blindness worldwide despite improvements in the systemic care of premature newborns. Screening for ROP is effective and cost-effective, but in many areas, access to skilled examiners to conduct dilated examinations is poor. Remote screening with retinal photography is an alternative strategy that may allow for improved ROP care. Methods: The current literature was reviewed to find clinical trials and expert consensus documents on the state-of-the-art of telemedicine for ROP. Results: Several studies have confirmed the utility of telemedicine for ROP. In addition, several clinical studies have reported favorable long-term results. Many investigators have reinforced the need for detailed protocols on image acquisition and image interpretation. Conclusions: Telemedicine for ROP appears to be a viable alternative to live ophthalmoscopic examinations in many circumstances. Standardization and documentation afforded by telemedicine may provide additional benefits to providers and their patients. With continued improvements in image quality and affordability of imaging systems as well as improved automated image interpretation tools anticipated in the near future, telemedicine for ROP is expected to play an expanding role for a uniquely vulnerable patient population.

Accuracy and Reliability of Eye-Based vs Quadrant-Based Diagnosis of Plus Disease in Retinopathy of Prematurity

Importance

Presence of plus disease in retinopathy of prematurity is the most critical element in identifying treatment-requiring disease. However, there is significant variability in plus disease diagnosis. In particular, plus disease has been defined as 2 or more quadrants of vascular abnormality, and it is not clear whether it is more reliably and accurately diagnosed by eye-based assessment of overall retinal appearance or by quadrant-based assessment combining grades of 4 individual quadrants.

Objective

To compare eye-based vs quadrant-based diagnosis of plus disease and to provide insight for ophthalmologists about the diagnostic process.

Design, Setting, and Participants

In this multicenter cohort study, we developed a database of 197 wide-angle retinal images from 141 preterm infants from neonatal intensive care units at 9 academic institutions (enrolled from July 2011 to December 2016). Each image was assigned a reference standard diagnosis based on consensus image-based and clinical diagnosis. Data analysis was performed from February 2017 to September 2017.

Interventions

Six graders independently diagnosed each of the 4 quadrants (cropped images) of the 197 eyes (quadrant-based diagnosis) as well as the entire image (eye-based diagnosis). Images were displayed individually, in random order. Quadrant-based diagnosis of plus disease was made when 2 or more quadrants were diagnosed as indicating plus disease by combining grades of individual quadrants post hoc.

Main Outcomes and Measures

Intragrader and intergrader reliability (absolute agreement and κ statistic) and accuracy compared with the reference standard diagnosis.

Results

Of the 141 included preterm infants, 65 (46.1%) were female and 116 (82.3%) white, and the mean (SD) gestational age was 27.0 (2.6) weeks. There was variable agreement between eye-based and quadrant-based diagnosis among the 6 graders (Cohen κ range, 0.32-0.75). Four graders showed underdiagnosis of plus disease with quadrant-based diagnosis compared with eye-based diagnosis (by McNemar test). Intergrader agreement of quadrant-based diagnosis was lower than that of eye-based diagnosis (Fleiss κ, 0.75 [95% CI, 0.71-0.78] vs 0.55 [95% CI, 0.51-0.59]). The accuracy of eye-based diagnosis compared with the reference standard diagnosis was substantial to near-perfect, whereas that of quadrant-based plus disease diagnosis was only moderate to substantial for each grader.

Conclusions and Relevance

Graders had lower reliability and accuracy using quadrant-based diagnosis combining grades of individual quadrants than with eye-based diagnosis, suggesting that eye-based diagnosis has advantages over quadrant-based diagnosis. This has implications for more precise definitions of plus disease regarding the criterion of 2 or more quadrants, clinical care, computer-based image analysis, and education for all ophthalmologists who manage retinopathy of prematurity.

The role of retinal photography and telemedicine in ROP screening

Until advances in retinal imaging over recent decades, detection of retinopathy of prematurity requiring treatment depended largely on indirect ophthalmoscopy by ophthalmologists with experience in examination of low birth weight, often fragile infants. Recent studies have added to our understanding of the pros and cons of using this technology to provide timely care for the increasing number of infants at risk for ROP blindness worldwide.

Auckland regional telemedicine retinopathy of prematurity screening network: A 10-year review

IMPORTANCE

Retinopathy of prematurity (ROP) is a potentially blinding condition affecting the retinae of premature infants. Effective screening is necessary for timely treatment.

BACKGROUND

The Auckland Regional Telemedicine ROP (ART-ROP) network, utilizes wide-field digital imaging for ROP screening. This study reviews the ART-ROP network.

DESIGN

Retrospective analysis of the ART-ROP database.

PARTICIPANTS

Files of infants in ART-ROP from 2006 to 2015.

METHODS

Data on infant demographics, ROP stage, treatment and outcome was collected.

MAIN OUTCOME MEASURES

The efficacy of ART-ROP in the management of ROP.

RESULTS

A review of 1181 infants across three neonatal intensive care units, was completed. Infants had a mean of four screening sessions with no infants who met ROP screening criteria being missed. Type 1 ROP was present in 83 infants, who had significantly lower average birth weight 786 ± 191 g compared to 1077 ± 285 g (P < .001), and gestational age 25.3 ± 1.7 weeks compared to 27.8 ± 2.2 weeks (P < .001) than the screened cohort. The number of infants requiring screening increased (R² = .7993), yet treatment rates decreased (R² = .9205) across the time period. Out-patient clinic follow-up was attended by 75.10% of infants screened and there was no missed ROP in those infants seen.

CONCLUSIONS AND RELEVANCE

ART-ROP solely uses wide-field digital imaging for ROP diagnosis, and management, including discharge, of infants. This detailed review of ART-ROP indicates an increase in screening demand, but a decrease in the rate of type 1 ROP. The ART-ROP telemedicine model demonstrates real potential to address workforce shortage in ROP screening.

Novel Use of Telemedicine for Corneal Tissue Evaluation in Eye Banking: Establishing a Standardized Approach for the Remote Evaluation of Donor Corneas for Transplantation

PURPOSE

To determine the feasibility of using telemedicine consultations in the evaluation of recovered donor corneas for transplant suitability.

METHODS

This study aims to establish and test the minimum imaging requirements for telemedical consultations of corneal tissue by remote eye bank medical directors. Digital images from the slit lamp, optical coherence tomography, and/or specular microscope were assembled into telemedical consults and emailed to 4 eye bank medical directors (M.A.T., J.W., C.S.S., N.K.R.). Feedback on the minimum image requirements for each corneal finding was collected. After establishing a standardized imaging and presentation protocol, test cases were presented to the medical directors to examine the validity of these remote consults. To establish a benchmark for the study's parameters, one medical director (J.W.) examined each case in person after his initial remote review. Examiners were masked to each other's responses.

RESULTS

Minimum image requirements for determination of corneal findings were defined and were specific to each anatomic layer of the cornea (epithelial, stromal, or endothelial). Using a defined set of digital images for a set of common corneal findings, the rate of agreement between remote evaluators, eye bank staff, and the in-person evaluator was 100% (11 of 11 examples). For ambiguous test cases, remote evaluators agreed on 80% of the cases (4 of 5).

CONCLUSIONS

Results from this pilot study suggest that telemedical review of corneal tissue using high-quality digital images may be adequate for accurate identification of specific corneal findings commonly encountered by eye banks.

Artificial intelligence and deep learning in ophthalmology

Artificial intelligence (AI) based on deep learning (DL) has sparked tremendous global interest in recent years. DL has been widely adopted in image recognition, speech recognition and natural language processing, but is only beginning to impact on healthcare. In ophthalmology, DL has been applied to fundus photographs, optical coherence tomography and visual fields, achieving robust classification performance in the detection of diabetic retinopathy and retinopathy of prematurity, the glaucoma-like disc, macular oedema and age-related macular degeneration. DL in ocular imaging may be used in conjunction with telemedicine as a possible solution to screen, diagnose and monitor major eye diseases for patients in primary care and community settings. Nonetheless, there are also potential challenges with DL application in ophthalmology, including clinical and technical challenges, explainability of the algorithm results, medicolegal issues, and physician and patient acceptance of the AI 'black-box' algorithms. DL could potentially revolutionise how ophthalmology is practised in the future. This review provides a summary of the state-of-the-art DL systems described for ophthalmic applications, potential challenges in clinical deployment and the path forward.

A new scale for the assessment of conjunctival bulbar redness

PURPOSE

Current scales for assessment of bulbar conjunctival redness have limitations for evaluating digital images. We developed a scale suited for evaluating digital images and compared it to the Validated Bulbar Redness (VBR) scale.

METHODS

From a digital image database of 4889 color corrected bulbar conjunctival images, we identified 20 images with varied degrees of redness. These images, ten each of nasal and temporal views, constitute the Digital Bulbar Redness (DBR) scale. The chromaticity of these images was assessed with an established image processing algorithm. Using 100 unique, randomly selected images from the database, three trained, non-physician graders applied the DBR scale and printed VBR scale. Agreement was assessed with weighted Kappa statistics (Kw).

RESULTS

The DBR scale scores provide linear increments of 10 from 10-100 when redness is measured objectively with an established image processing algorithm. Exact agreement of all graders was 38% and agreement with no more than a difference of ten units between graders was 91%. Kw for agreement between any two graders ranged from 0.57 to 0.73 for the DBR scale and from 0.38 to 0.66 for the VBR scale. The DBR scale allowed direct comparison of digital to digital images, could be used in dim lighting, had both temporal and nasal conjunctival reference images, and permitted viewing reference and test images at the same magnification.

CONCLUSION

The novel DBR scale, with its objective linear chromatic steps, demonstrated improved reproducibility, fewer visualization artifacts and improved ease of use over the VBR scale for assessing conjunctival redness.

Automated Diagnosis of Plus Disease in Retinopathy of Prematurity Using Deep Convolutional Neural Networks

Importance

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness worldwide. The decision to treat is primarily based on the presence of plus disease, defined as dilation and tortuosity of retinal vessels. However, clinical diagnosis of plus disease is highly subjective and variable.

Objective

To implement and validate an algorithm based on deep learning to automatically diagnose plus disease from retinal photographs.

Design, Setting, and Participants

A deep convolutional neural network was trained using a data set of 5511 retinal photographs. Each image was previously assigned a reference standard diagnosis (RSD) based on consensus of image grading by 3 experts and clinical diagnosis by 1 expert (ie, normal, pre-plus disease, or plus disease). The algorithm was evaluated by 5-fold cross-validation and tested on an independent set of 100 images. Images were collected from 8 academic institutions participating in the Imaging and Informatics in ROP (i-ROP) cohort study. The deep learning algorithm was tested against 8 ROP experts, each of whom had more than 10 years of clinical experience and more than 5 peer-reviewed publications about ROP. Data were collected from July 2011 to December 2016. Data were analyzed from December 2016 to September 2017.

Exposures

A deep learning algorithm trained on retinal photographs.

Main Outcomes and Measures

Receiver operating characteristic analysis was performed to evaluate performance of the algorithm against the RSD. Quadratic-weighted κ coefficients were calculated for ternary classification (ie, normal, pre-plus disease, and plus disease) to measure agreement with the RSD and 8 independent experts.

Results

Of the 5511 included retinal photographs, 4535 (82.3%) were graded as normal, 805 (14.6%) as pre-plus disease, and 172 (3.1%) as plus disease, based on the RSD. Mean (SD) area under the receiver operating characteristic curve statistics were 0.94 (0.01) for the diagnosis of normal (vs pre-plus disease or plus disease) and 0.98 (0.01) for the diagnosis of plus disease (vs normal or pre-plus disease). For diagnosis of plus disease in an independent test set of 100 retinal images, the algorithm achieved a sensitivity of 93% with 94% specificity. For detection of pre-plus disease or worse, the sensitivity and specificity were 100% and 94%, respectively. On the same test set, the algorithm achieved a quadratic-weighted κ coefficient of 0.92 compared with the RSD, outperforming 6 of 8 ROP experts.

Conclusions and Relevance

This fully automated algorithm diagnosed plus disease in ROP with comparable or better accuracy than human experts. This has potential applications in disease detection, monitoring, and prognosis in infants at risk of ROP.

A national telemedicine network for retinopathy of prematurity screening

PURPOSE

To report the results of retinopathy of prematurity (ROP) screening by a telemedicine system in Chile and evaluate its usefulness for referring patients who require treatment.

METHODS

Premature infants at risk of developing ROP from 11 neonatal intensive care units were included. Screening was performed on all infants born at a gestational age of <32 weeks and/or birth weight of <1500 g. A trained nonphysician operator used an imaging system to capture retinal images, which were reviewed by two independent ROP experts. All infants that required treatment were referred for further evaluation.

RESULTS

The study included 2,048 eyes of 1,024 premature infants. Mean gestational age was 28.8 ± 2.2 weeks, and mean birth weight was 1128 ± 279 g. A total of 5,263 telemedicine examinations were performed and reported. The average number of image sets per patient was 2.6 ± 2.5. Of the 5,263 images, 4,903 (93%) were recorded to at least the end of zone II; 5,172 (98%) were graded as having good quality, allowing for staging of ROP disease. Forty-two infants (4%) were referred for treatment. Discharged patients with ROP type 2 that regressed did not present with any complications or adverse effects during 6 months' follow-up.

CONCLUSIONS

Our study demonstrates the utility of telemedicine screening for ROP with ophthalmologist readers in a developing country. Telemedicine screening was able to detect treatment-requiring ROP. Most of the images had good quality and showed the end of zone II, two variables sufficient to discharge patients.

Single grading vs double grading with adjudication in the telemedicine approaches to evaluating acute-phase retinopathy of prematurity (e-ROP) study

PURPOSE

To evaluate the sensitivity and specificity of single, independent, nonphysician trained reader (TR) gradings in the Telemedicine Approaches to Evaluating Acute-phase Retinopathy of Prematurity (e-ROP) study.

METHODS

Secondary analyses of image grading results from 1,235 infants of birth weights <1251 g. Two of three TRs independently graded image sets; discrepancies were adjudicated by the reading center director (an ophthalmologist) to reach final grading. Sensitivity and specificity of each TR grading and final grading was calculated by comparing gradings to clinical examination results.

RESULTS

Of 7,808 double graded image sets, TR1 graded 5,165; TR2, 3,787; and TR3, 6,664. Compared to final grading for referral warranted retinopathy of prematurity (RW-ROP), two TRs had relatively lower sensitivity (TR1, 75% vs 79% [P = 0.03]; TR2, 73% vs 77% [P = 0.02]) and specificity (TR1, 80% vs 83% [P < 0.001]; TR2, 82% vs 83% [P = 0.09]). TR3 had similar sensitivity (83% vs 83% [P = 0.78]) and specificity (83% vs 84% [P = 0.02]). Compared to final grading, TR1 had lower sensitivity for zone I ROP (47% vs 56% [P = 0.04]) and stage ≥3 ROP (71% vs 77% [P = 0.002]); TR2 had lower sensitivity for stage ≥3 ROP (69% vs 77% [P < 0.001]) and lower specificity for all three components (P < 0.001); TR3 had lower sensitivity for detecting plus disease (23% vs 35% [P < 0.001]) and similar sensitivity for zone I ROP and stage ≥3 ROP.

CONCLUSIONS

There is a small but significant decrease in the sensitivity and specificity for RW-ROP when single-reader grading is compared to double adjudicated grading.

Vision in former very low birthweight young adults with and without retinopathy of prematurity compared with term born controls: the NZ 1986 VLBW follow-up study

Objective

There are few data on visual outcomes in adulthood of former very low birthweight (VLBW; <1500 g) infants. We aimed to assess vision at 27–29 years in a national cohort of VLBW infants born in 1986 and assessed for retinopathy of prematurity (ROP) when no treatment was available, compared with term born controls.

Methods

The cohort and controls attended a 2-day assessment in Christchurch as part of a larger study. Visual assessment included glasses prescription measured by focimeter, logarithm of the minimum angle of resolution (logMAR) distance visual acuity (VA), contrast sensitivity, autorefraction, retinal photographs and a questionnaire on vision-related everyday activities. Rates of reduced VA and myopia in the VLBW cohort at 27–29 were compared with the results of vision testing at 7–8 years.

Results

250 VLBW adults (77% those alive) gave study consent and 229 (45 with a history of ROP) were assessed in Christchurch, plus 100 term born controls. VLBW adults with ROP had reduced VA compared with no ROP and controls (mean logMAR score (SD); 0.003 (0.19), –0.021 (0.16), –0.078 (0.09), P=0.001). There were no differences in myopia (>2 D) between the groups but high myopia (>5 D) was confined to those with ROP. VLBW adults with ROP drove a car less often and had higher difficulties with everyday activities scores due to eyesight. Between 7–8 and 27–29 years rates of reduced VA were stable but myopia increased.

Conclusion

Former VLBW young adults with ROP have ongoing problems with vision affecting daily living and should continue in regular ophthalmological review.

Trial registration number

ACTRN12612000995875, Pre-results .

The Current State of Teleophthalmology in the United States

Telemedicine services facilitate the evaluation, diagnosis, and management of the remote patient. Telemedicine has rapidly flourished in the United States and has improved access to care, outcomes, and patient satisfaction. However, the use of telemedicine in ophthalmology is currently in its infancy and has yet to gain wide acceptance. Current models of telemedicine in ophthalmology are largely performed via "store and forward" methods, but remote monitoring and interactive modalities exist. Although studies have examined the effects of telemedicine, few reports have characterized its current status. We perform a descriptive analysis of the current state of teleophthalmology in the United States. We describe the use of teleophthalmology in the hospital and outpatient settings. We also review the applications to retinopathy of prematurity, diabetic retinopathy, age-related macular degeneration, and glaucoma, as well as anticipated barriers and hurdles for the future adoption of teleophthalmology. With ongoing advances in teleophthalmology, these models may provide earlier detection and more reliable monitoring of vision-threatening diseases.

Accuracy and Reliability of a Handheld, Nonmydriatic Fundus Camera for the Remote Detection of Optic Disc Edema

BACKGROUND

Optic disc edema can be an important indicator of serious neurological disease, but is poorly detected using the direct ophthalmoscope. Portable fundus photography may overcome this difficulty.

INTRODUCTION

The purpose of this study was to determine the sensitivity and specificity of a handheld, nonmydriatic fundus camera for the detection of optic disc edema.

MATERIALS AND METHODS

Retrospective review of nonmydriatic optic disc photographs taken with a portable fundus camera (Pictor Plus; Volk Optical, Mentor, OH) from the University of Michigan Neuro-Ophthalmology Clinics. We included 103 consecutive eyes with optic disc edema and 103 consecutive eyes without optic disc edema of 109 patients. Four masked neuro-ophthalmologists graded a single photograph of each optic disc presented in randomized order and documented the presence of optic disc edema. Sensitivity and specificity of graders' photographic interpretation was compared with clinical examinations. Reliability of assessments within and between graders was determined using kappa statistics.

RESULTS

The sensitivity and specificity for detection of optic disc edema were 71.8-92.2% and 81.6-95.2%, respectively. Photos were found to be ungradable in 0-8.3% of cases. The intergrader reliabilities ranged from 0.60 [95% confidence interval (CI): 0.52-0.67] to 0.72 (95% CI: 0.66-0.77). Intragrader reliability ranged from 0.76 (95% CI: 0.63-0.92) to 0.82 (95% CI: 0.69-0.95).

DISCUSSION

Photographs taken with portable, nonmydriatic technology met threshold sensitivity and specificity for remote screening for optic disc edema when performed by most, but not all graders. Reliability between graders was moderate-strong and strong within individual providers.

CONCLUSIONS

Portable photography holds promise for use in remote screening of optic disc edema.

Pathophysiology, screening and treatment of ROP: A multi-disciplinary perspective

The population of infants at risk for retinopathy of prematurity (ROP) varies by world region; in countries with well developed neonatal intensive care services, the highest risk infants are those born at less than 28 weeks gestational age (GA) and less than 1 kg at birth, while, in regions where many aspects of neonatal intensive and ophthalmological care are not routinely available, more mature infants up to 2000 g at birth and 37 weeks GA are also at risk for severe ROP. Treatment options for both groups of patients include standard retinal laser photocoagulation or, more recently, intravitreal anti-VEGF drugs. In addition to detection and treatment of ROP, this review highlights new opportunities created by telemedicine, where screening and diagnosis of ROP in remote locations can be undertaken by non-ophthalmologists using digital fundus cameras. The ophthalmological care of the ROP infant is undertaken in the wider context of neonatal care and general wellbeing of the infant. Because of this context, this review takes a multi-disciplinary perspective with contributions from retinal vascular biologists, pediatric ophthalmologists, an epidemiologist and a neonatologist. This review highlights the latest insights regarding cellular and molecular mechanisms in the formation of the retinal vasculature in the human infant, pathogenesis of ROP, detection and treatment of severe ROP, the risks and benefits of anti-VEGF therapy, the identification of new therapies over the horizon, and the optimal neonatal care regimen for best ROP outcomes, and the benefits and pitfalls of telemedicine in the remote screening and diagnosis of ROP, all of which have the potential to improve ROP outcomes.

Detection of Potentially Severe Retinopathy of Prematurity by Remote Image Grading

Importance

Telemedicine in retinopathy of prematurity (ROP) has the potential for delivering timely care to premature infants at risk for serious ROP.

Objective

To describe the characteristics of eyes at risk for ROP to provide insights into what types of ROP are most easily detected early by image grading.

Design, Setting, and Participants

Secondary analysis of eyes with referral-warranted (RW) ROP (stage 3 ROP, zone I ROP, plus disease) on diagnostic examination from the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) study was conducted from May 1, 2011, to October 31, 2013, in 1257 premature infants with birth weights less than 1251 g in 13 neonatal units in North America. Data analysis was performed between February 1, 2016, and June 5, 2017.

Interventions

Serial imaging sessions with concurrent diagnostic examinations for ROP.

Main Outcomes and Measures

Time of detecting RW-ROP on image evaluation compared with clinical examination.

Results

In the e-ROP study, 246 infants (492 eyes) were included in the analysis; 138 (56.1%) were male. A total of 447 eyes had RW-ROP on diagnostic examination. Image grading in 123 infants (mean [SD] gestational age, 24.8 [1.4] weeks) detected RW-ROP earlier than diagnostic examination (early) in 191 (42.7%) eyes by about 15 days and detected RW-ROP in 123 infants (mean [SD] gestational age, 24.6 [1.5] weeks) at the same time (same) in 200 (44.7%) eyes. Most of the early eyes (153 [80.1%]) interpreted as being RW-ROP positive on imaging evaluation agreed with examination findings when the examination subsequently documented RW-ROP. At the sessions in which RW-ROP was first found by examination, stage 3 or more in 123 infants (mean [SD] gestational age, 24.8 [1.4] weeks) ROP was noted earlier on image evaluation in 151 of 191 early eyes (79.1%) and in 172 of 200 of same eyes (86.0%) (P = .08); the presence of zone I ROP was detected in 57 of 191 (29.8%) early eyes vs 64 of 200 (32.0%) same eyes (P = .90); and plus disease was noted in 30 of 191 (15.7%) early eyes and 45 of 200 (22.5%) same eyes (P = .08).

Conclusions and Relevance

In both early and same eyes, zone I and/or stage 3 ROP determined a significant proportion of RW-ROP; plus disease played a relatively minor role. In most early RW-ROP eyes, the findings were consistent with clinical examination and/or image grading at the next session. Because ROP telemedicine is used more widely, development of standard approaches and protocols is essential.

An international comparison of retinopathy of prematurity grading performance within the Benefits of Oxygen Saturation Targeting II trials

Purpose

To investigate whether the observed international differences in retinopathy of prematurity (ROP) treatment rates within the Benefits of Oxygen Saturation Targeting (BOOST) II trials might have been caused by international variation in ROP disease grading.

Methods

Groups of BOOST II trial ophthalmologists in UK, Australia, and New Zealand (ANZ), and an international reference group (INT) used a web based system to grade a selection of RetCam images of ROP acquired during the BOOST II UK trial. Rates of decisions to treat, plus disease grading, ROP stage grading, ROP zone grading, inter-observer variation within groups and intra-observer variation within groups were measured.

Results

Forty-two eye examinations were graded. UK ophthalmologists diagnosed treat-requiring ROP more frequently than ANZ ophthalmologists, 13.9 (3.49) compared to 9.4 (4.46) eye examinations, P=0.038. UK ophthalmologists diagnosed plus disease more frequently than ANZ ophthalmologists, 14.1 (6.23) compared to 8.5 (3.24) eye examinations, P=0.021. ANZ ophthalmologists diagnosed stage 2 ROP more frequently than UK ophthalmologists, 20.2 (5.8) compared to 12.7 (7.1) eye examinations, P=0.026. There were no other significant differences in the grading of ROP stage or zone. Inter-observer variation was higher within the UK group than within the ANZ group. Intra-observer variation was low in both groups.

Conclusions

We have found evidence of international variation in the diagnosis of treatment-requiring ROP. Improved standardisation of the diagnosis of treatment-requiring ROP is required. Measures might include improved training in the grading of ROP, using an international approach, and further development of ROP image analysis software.

Intereye Agreement of Retinopathy of Prematurity from Image Evaluation in the Telemedicine Approaches to Evaluating of Acute-Phase ROP (e-ROP) Study

PURPOSE

To determine the symmetry on retinal image grading of fellow eyes for retinopathy of prematurity (ROP) features (stage, zone and plus disease) and severity, to provide the basis for the within subject comparison for ROP trials.

DESIGN

Secondary analyses of data from the Telemedicine Approaches to Evaluating of Acute-Phase ROP (e-ROP) Study.

SUBJECTS

Infants with birth weight less than 1251g.

METHODS

Infants underwent serial retinal imaging sessions in both eyes by certified imagers starting at 32-weeks postmenstrual age (PMA). Two trained non-physician readers graded each eye independently for ROP features in a 5 retinal-image set from each session. Discrepancies were adjudicated by a reading center supervisor. Readers were masked to all eye examination results, previous gradings of both eyes, current grading of the fellow eye, and demographic data.

MAIN OUTCOME MEASURES

The inter-eye agreement assessed using percent exact agreement and weighted kappa (K_w ) for stage, zone, plus, referral-warranted ROP (RW-ROP, defined as presence of stage 3 or above, plus disease, or zone I ROP), and severity of ROP.

RESULTS

Among 3918 image sessions in 1235 infants, the percent agreement (K_w ) between paired eyes was 75.3% (0.65) for stage of ROP, 82.3% (0.68) for zone of ROP, 78.7% (0.51) for plus disease, 84.7% (0.56) for RW-ROP, and 72.7% (0.63) for severity of ROP. Similar inter-eye agreements were found when considering ROP features at the first image session, at the last image session, at any image session. Based on image evaluations from all sessions, 412 (33.4%) infants had ROP stage 3 or above, 148 (12.0%) had zone I ROP, 70 (5.7%) had plus disease, and 419 (33.9%) had RW-ROP in one or both eyes; symmetrical findings were present in 71.4% for ROP stage 3 or above, 56.8% for zone I ROP, 50.0% for plus disease, and 73.7% for RW-ROP.

CONCLUSIONS

Masked image evaluations by trained readers showed good inter-eye agreement in ROP characteristics, consistent with the high inter-eye agreement in ROP from clinical examinations by ophthalmologists in other studies. These data confirm that acute ROP is typically symmetrical and supports within subject comparison in ROP trials.

Analysis of Discrepancy Between Diagnostic Clinical Examination Findings and Corresponding Evaluation of Digital Images in the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity Study

Importance

As effective treatments for potentially blinding retinopathy of prematurity (ROP) have been introduced, the importance of consistency in findings has increased, especially with the shift toward retinal imaging in infants at risk of ROP.

Objective

To characterize discrepancies in findings of ROP between digital retinal image grading and examination results from the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity study, conducted from May 2011 to October 2013.

Design, Setting, and Participants

A poststudy consensus review of images was conducted by 4 experts, who examined discrepancies in findings between image grades by trained nonphysician readers and physician examination results in infants with referral-warranted ROP (RW-ROP). Images were obtained from 13 North American neonatal intensive care units from eyes of infants with birth weights less than 1251 g. For discrepancy categories with more than 100 cases, 40 were randomly selected; in total, 188 image sets were reviewed.

Main Outcomes and Measures

Consensus evaluation of discrepant image and examination findings for RW-ROP components.

Results

Among 5350 image set pairs, there were 161 instances in which image grading did not detect RW-ROP noted on clinical examination (G-/E+) and 854 instances in which grading noted RW-ROP when the examination did not (G+/E-). Among the sample of G-/E+ cases, 18 of 32 reviews (56.3%) agreed with clinical examination findings that ROP was present in zone I and 18 of 40 (45.0%) agreed stage 3 ROP was present, but only 1 of 20 (5.0%) agreed plus disease was present. Among the sample of G+/E- cases, 36 of 40 reviews (90.0%) agreed with readers that zone I ROP was present, 23 of 40 (57.5%) agreed with readers that stage 3 ROP was present, and 4 of 16 (25.0%) agreed that plus disease was present. Based on the consensus review results of the sampled cases, we estimated that review would agree with clinical examination findings in 46.5% of the 161 G-/E+ cases (95% CI, 41.6-51.6) and agree with trained reader grading in 70.0% of the 854 G+/E- cases (95% CI, 67.3-72.8) for the presence of RW-ROP.

Conclusions and Relevance

This report highlights limitations and strengths of both the remote evaluation of fundus images and bedside clinical examination of infants at risk for ROP. These findings highlight the need for standardized approaches as ROP telemedicine becomes more widespread.

Advances in understanding and management of retinopathy of prematurity

The understanding, diagnosis, and treatment of retinopathy of prematurity have changed in the 70 years since the original description of retrolental fibroplasia associated with high oxygenation. It is now recognized that retinopathy of prematurity differs in appearance worldwide and as ever smaller and younger premature infants survive. New methods are being evaluated to image the retina, diagnose severe retinopathy of prematurity, and determine windows of time for treatment to save eyes and improve visual and neural outcomes. New treatments to promote physiologic retinal vascular development, vascular repair, and inhibit vasoproliferation by regulating proteins involved in vascular endothelial growth factor, insulin-like growth factor, or erythropoietin signaling. Reducing excessive oxidative/nitrosative stress and understanding progenitor cells and neurovascular and glial vascular interactions are being studied.

Comparison of strategies for grading retinal images of premature infants for referral warranted retinopathy of prematurity

PURPOSE

To determine the accuracy of identifying referral-warranted retinopathy of prematurity (RW-ROP, defined as any zone I ROP, stage 3 or worse, or plus disease) from retinal image sets using three grading protocols: a single optic disk-centered image, a set of 3 horizontal images, and a 5-image set.

METHODS

In this secondary analysis of images from the e-ROP study, a weighted sample of 250 image sets from 250 infants (125 with RW-ROP and 125 without RW-ROP) was randomly selected. The sensitivities and specificities for detecting RW-ROP and its components from a single disk center image, along with nasal and temporal retinal images, were calculated and compared with the e-ROP grading of RW-ROP of all 5 retinal images (disk center and nasal, temporal, superior, and inferior retinal images).

RESULTS

RW-ROP was identified with a sensitivity of 11.2% (95% CI, 6.79%-17.9%) using a single disk center image, with a sensitivity of 70.4% (95% CI, 61.9%-77.9%) using 3 horizontal images, and a statistically higher sensitivity of 82.4% (95% CI, 75.0%-89.0%) using all 5 images (P = 0.002). The specificities were 100%, 86.4%, and 90.4%, respectively. For grading using 3 horizontal images, sensitivity was 14.3% for plus disease, 25% for zone I ROP, and 71.2% for stage 3 or worse compared to 40.8%, 50%, and 79.8% for grading using 5-image sets, respectively.

CONCLUSIONS

Both a single, disk-centered, posterior pole image and 3 horizontal images were less effective than a 5-image set in determining the presence of RW-ROP on qualitative grading by trained readers.

Intraocular Hemorrhages and Retinopathy of Prematurity in the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) Study

PURPOSE

To describe the clinical characteristics of intraocular hemorrhages (IOHs) in infants in the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) Study and to evaluate their potential use for prediction of disease severity.

DESIGN

Secondary data analysis from a prospective study.

PARTICIPANTS

Preterm infants with birth weight (BW) ≤1250 g.

METHODS

Infants underwent serial digital retinal imaging in both eyes starting at 32 weeks' postmenstrual age. Nonphysician trained readers (TRs) evaluated all image sets from eyes that ever had IOHs documented on image evaluation or eye examination for the presence, location, type, area, and relation of the IOH to the junction between vascularized and avascular retina. Associations of IOH with demographic and neonatal factors, and with the presence and severity of retinopathy of prematurity (ROP) were investigated by univariate and multivariate analyses. Sensitivity and specificity of the telemedicine system for detecting referral-warranted ROP (RW-ROP) were calculated with and without incorporating hemorrhage into the standardized grading protocol.

MAIN OUTCOME MEASURES

Retinal and vitreous hemorrhage.

RESULTS

Among 1239 infants (mean [standard deviation] BW = 864 [212] g; gestational age [GA] = 27 [2.2] weeks) who underwent an average of 3.2 imaging sessions, 22% had an IOH in an eye on at least 1 of the e-ROP visits. Classification of IOH was preretinal (57%), blot (57%), dot (38%), flame-shaped (16%), and vitreous (8%); most IOHs were unilateral (70%). The IOH resolved in 35% of eyes by the next imaging session and in the majority (76%) of cases by 8 weeks after initial detection. Presence of IOH was inversely associated with BW and GA and significantly associated (P < 0.0001) with the presence and severity of ROP (BW and GA adjusted odds ratios [ORs] of 2.46 for any ROP, 2.88 for stage 3, and 3.19 for RW-ROP). Incorporating IOH into the grading protocol minimally altered the sensitivity of the system (94% vs. 95%).

CONCLUSIONS

Approximately 1 in 5 preterm infants examined had IOHs, generally unilateral. The presence of hemorrhage was directly correlated with both presence and severity of ROP and inversely correlated with BW and GA, although including hemorrhage in the grading algorithm only minimally improved the sensitivity of the telemedicine system to detect RW-ROP.

Impact of number and quality of retinal images in a telemedicine screening program for ROP: results from the e-ROP study

BACKGROUND

Telemedicine for the detection of retinopathy of prematurity (ROP) is becoming increasingly common; however, obtaining the required multiple retinal images from an infant can be challenging. This secondary analysis from the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) study evaluated the detection of referral-warranted ROP (RW-ROP) by trained readers when a full set of 5 retinal images could not be obtained.

METHODS

A total of 7,905 image sets from 1,257 infants in the study were evaluated. Retinal location of images and image quality were recorded. Sensitivity and specificity of RW-ROP detection by trained readers were calculated by comparing findings in incomplete image sets to the findings on standard eye examination.

RESULTS

The majority of image sets contained all 5 retinal images (92.8%). The disk center view was the image most likely to be present and to be of acceptable image quality (96.8%). The nasal retina was the most difficult to obtain with acceptable image quality (83.4%). Sensitivity of detection of RW-ROP was 82.1% when 5 retinal images of acceptable quality were submitted for grading, 67.2% when 4 acceptable images were submitted, and 66.7% for 3 or fewer acceptable images (P = 0.02), with corresponding specificity of 82.2%, 89.0%, and 81.7% respectively (P < 0.0001). When images of any quality were evaluated, sensitivity was not increased (P = 0.74).

CONCLUSIONS

The likelihood of detecting RW-ROP by telemedicine screening is decreased when a full set of retinal images is not obtained.

Timely implementation of a retinopathy of prematurity telemedicine system

PURPOSE

To examine the feasibility of a retinopathy of prematurity (ROP) telemedicine evaluation system of providing timely feedback to a neonatal intensive care unit (NICU) with at-risk premature infants.

METHODS

This was a prospective observational study of premature infants with birth weights of <1251 g in five NICUs in the United States. Infants scheduled for clinically indicated ROP evaluations underwent indirect ophthalmoscopic examinations and digital imaging on the same day. Imaging was performed by nonphysician retinal imagers. Times required were determined from obtaining digital images of both eyes to submission via web-based system to a secure server for grading by trained readers at a central reading center to sending back grading results to the clinical center.

RESULTS

A total of 1,642 image sets of eyes of 292 infants were obtained, from 823 imaging sessions. The mean turnaround time from submission of image sets of both eyes to return of the grading results to the clinical center was 10.1 ± 11.3 hours (standard deviation), with a median of 12.0 hours (1st quartile, 0.9 hours; 3rd quartile, 16 hours). Overall, 95.5% of gradings (95% CI, 93.9%-96.7%) were returned within 24 hours. Subgroup analyses found, for image sets submitted to the reading center before 2 p.m. Eastern Standard Time, median time to report was 1.7 hours (1st quartile, 0.7 hours; 3rd quartile, 15.5 hours) compared with those submitted after 2pm (median, 14.1 hours; 1st quartile, 11.2, hours; 3rd quartile, 16.3 hours).

CONCLUSIONS

An ROP telemedicine approach can provide timely feedback to the NICU regarding the detection of potentially serious ROP and thus referral to an ophthalmologist for examination and consideration of treatment.

Risk Score for Predicting Treatment-Requiring Retinopathy of Prematurity (ROP) in the Telemedicine Approaches to Evaluating Acute-Phase ROP Study

PURPOSE

To develop a risk score for predicting treatment-requiring retinopathy of prematurity (TR-ROP) in the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) study.

DESIGN

Second analyses of an observational cohort study.

PARTICIPANTS

Infants with birth weight (BW) <1251 g who had ≥1 imaging session by 34 weeks of postmenstrual age (PMA) and ≥1 subsequent retinopathy of prematurity (ROP) examination for determining TR-ROP by study-certified ophthalmologists.

METHODS

Nonphysician trained readers evaluated wide-field retinal image sets for characteristics of ROP, pre-plus/plus disease, and retinal hemorrhage. Risk score points for predicting TR-ROP were derived from the regression coefficients of significant predictors in a multivariate logistic regression model.

MAIN OUTCOME MEASURES

TR-ROP.

RESULTS

Eighty-five of 771 infants (11.0%) developed TR-ROP. In a multivariate model, significant predictors for TR-ROP were gestational age (GA) (odds ratio [OR], 5.7; 95% confidence interval [CI], 1.7-18.9 for ≤25 vs. ≥28 weeks), need for respiratory support (OR, 7.0; 95% CI, 1.3-37.1 for high-frequency oscillatory ventilation vs. no respiratory support), slow weight gain (OR, 2.4; 95% CI, 1.2-4.6 for weight gain ≤12 g/day vs. >15 g/day), and image findings at the first image session including number of quadrants with pre-plus (OR, 3.8; 95% CI, 1.5-9.7 for 4 pre-plus quadrants vs. no pre-plus), stage and zone of ROP (OR, 4.7; 95% CI, 2.1-11.8 for stage 1-2 zone I, OR, 5.9; 95% CI, 2.1-16.6 for stage 3 zone I vs. no ROP), and presence of blot hemorrhage (OR, 3.1; 95% CI, 1.4-6.7). Image findings predicted TR-ROP better than GA (area under receiver operating characteristic curve [AUC] = 0.82 vs. 0.75, P = 0.03). The risk of TR-ROP steadily increased with higher risk score and predicted TR-ROP well (AUC = 0.88; 95% CI, 0.85-0.92). Risk score ≥3 points for predicting TR-ROP had a sensitivity of 98.8%, specificity of 40.1%, and positive and negative predictive values of 17.0% and 99.6%, respectively.

CONCLUSIONS

Image characteristics at 34 PMA weeks or earlier independently predict TR-ROP. If externally validated in other infants, risk score, calculated from image findings, GA, weight gain, and respiratory support, enables early identification of infants in need of increased surveillance for TR-ROP.

Training retinal imagers for retinopathy of prematurity (ROP) screening

PURPOSE

To report the training/certification process of nonphysician imagers, image quality, and factors that affected image quality in the National Eye Institute sponsored multicentered e-ROP study.

METHODS

Nonphysician imagers underwent rigorous training and certification in obtaining retinal images, with attention to clarity, focus, and optic disk placement. Image readers measured pupil size in pupil image and graded posterior pole, temporal, nasal, superior, and inferior retinal images and classified them as good, adequate, poor, or missing. Good and adequate images were deemed acceptable.

RESULTS

In 4,003 image sessions of 1,257 infants, 3,453 (86.8%) were complete. Of 39,550 retinal images, 91.7% had acceptable quality, 5.6% poor, and 2.7% were missing. Inadequate pupil dilation negatively affected acceptable image quality: 54% acceptable images for pupil <5 mm versus 93% for >6 mm (P < 0.0001). When ventilatory equipment obstructed access to imaged infant, the percent of acceptable image quality decreased: 94% for no support versus 66.6% for oscillatory ventilation (P < 0.0001). Acceptable image quality rates improved from 87% to 90% (P = 0.03) from first 6 months to last 6 months at low patient volume centers, while high patient volume centers remained stable at 95%.

CONCLUSIONS

Nonphysicians successfully obtained acceptable quality images for ROP evaluation. Skills improved with experience. Image quality was negatively affected by inadequate pupil dilation and the presence of obstructive ventilatory equipment.

Optical coherence tomography of the preterm eye: from retinopathy of prematurity to brain development

Preterm infants with retinopathy of prematurity are at increased risk of poor neurodevelopmental outcomes. Because the neurosensory retina is an extension of the central nervous system, anatomic abnormalities in the anterior visual pathway often relate to system and central nervous system health. We describe optical coherence tomography as a powerful imaging modality that has recently been adapted to the infant population and provides noninvasive, high-resolution, cross-sectional imaging of the infant eye at the bedside. Optical coherence tomography has increased understanding of normal eye development and has identified several potential biomarkers of brain abnormalities and poorer neurodevelopment.