Retinopathy of prematurity in middle-income countries

Spermine oxidase inhibitor, MDL 72527, reduced neovascularization, vascular permeability, and acrolein-conjugated proteins in a mouse model of ischemic retinopathy

Disruptions in polyamine metabolism have been identified as contributing factors to various central nervous system disorders. Our laboratory has previously highlighted the crucial role of polyamine oxidation in retinal disease models, specifically noting elevated levels of spermine oxidase (SMOX) in inner retinal neurons. Our prior research demonstrated that inhibiting SMOX with MDL 72527 protected against vascular injury and microglial activation induced by hyperoxia in the retina. However, the effects of SMOX inhibition on retinal neovascularization and vascular permeability, along with the underlying molecular mechanisms of vascular protection, remain incompletely understood. In this study, we utilized the oxygen-induced retinopathy (OIR) model to explore the impact of SMOX inhibition on retinal neovascularization, vascular permeability, and the molecular mechanisms underlying MDL 72527-mediated vasoprotection in the OIR retina. Our findings indicate that inhibiting SMOX with MDL 72527 mitigated vaso-obliteration and neovascularization in the OIR retina. Additionally, it reduced OIR-induced vascular permeability and Claudin-5 expression, suppressed acrolein-conjugated protein levels, and downregulated P38/ERK1/2/STAT3 signaling. Furthermore, our results revealed that treatment with BSA-Acrolein conjugates significantly decreased the viability of human retinal endothelial cells (HRECs) and activated P38 signaling. These observations contribute valuable insights into the potential therapeutic benefits of SMOX inhibition by MDL 72527 in ischemic retinopathy.

Oxygen saturation targets in neonatal care: A narrative review

Optimal oxygenation requires the delivery of oxygen to meet tissue metabolic demands while minimizing hypoxic pulmonary vasoconstriction and oxygen toxicity. Oxygen saturation by pulse oximetry (SpO2) is a continuous, non-invasive method for monitoring oxygenation. The optimal SpO2 target varies during pregnancy and neonatal period. Maternal SpO2 should ideally be ≥95 % to ensure adequate fetal oxygenation. Term neonates can be resuscitated with an initial oxygen concentration of 21 %, while moderately preterm infants require 21-30 %. Extremely preterm infants may need higher FiO2, followed by titration to desired SpO2 targets. During the NICU course, extremely preterm infants managed with an 85-89 % SpO2 target compared to 90-94 % are associated with a reduced incidence of severe retinopathy of prematurity (ROP) requiring treatment, but with higher mortality. During the later stages of ROP progression, studies suggest that higher SpO2 targets may help limit progression. A target SpO2 of 90-95 % is generally reasonable for term infants with respiratory disease or pulmonary hypertension, with few exceptions such as severe acidosis, therapeutic hypothermia, and possibly dark skin pigmentation, where 93-98 % may be preferred. Infants with cyanotic heart disease and single-ventricle physiology have lower SpO2 targets to avoid pulmonary over-circulation. In low- and middle-income countries (LMICs), the scarcity of oxygen blenders and continuous monitoring may pose a challenge, increasing the risks of both hypoxia and hyperoxia, which can lead to mortality and ROP, respectively. Strategies to mitigate hyperoxia among preterm infants in LMICs are urgently needed to reduce the incidence of ROP.

Retinopathy of Prematurity: Incidence, Risk Factors, and Treatment Outcomes in a Tertiary Care Center

Retinopathy of prematurity (ROP) remains a major cause of childhood blindness. Its pooled prevalence worldwide is 31.9%, and that of severe ROP is 7.5% among prematurely born babies. Investigating risk factors is essential for improving early detection and treatment outcomes. Purpose: To determine the frequency and stages of ROP cases and evaluate the treatment methods for premature infants at the Medical University of Vienna. Methods: In this retrospective study, 352 children who underwent ROP screening between 2018 and 2021 with a gestational age (GA) ≤ 32 weeks and/or a birth weight (BW) ≤ 1500 g were included. Results: ROP was found in 144 (40.9%) of the 352 screened premature infants, with 17 (4.8%) requiring treatment. Significant risk factors included GA and BW, while sex and pregnancy type were not significant. The mean GA was 27.7 ± 2.5 weeks, and the mean BW was 989.1 ± 359.7 g. Infants with ROP had a lower GA (25.9 ± 1.7 weeks) and BW (778.6 ± 262.4 g) than those without ROP (28.9 ± 2.2 weeks; 1134.9 ± 345.9 g). GA and BW were significantly lower in infants developing ROP (p < 0.001). Stage 2 ROP was the most common severity in 74 children (51.4%). Laser therapy was the most common first-line treatment, used in 11 infants (64.7%), followed by anti-VEGF therapy, used in 6 infants (35.3%). Children were treated within 1.0 ± 0.6 days on average. Of the 17 infants treated, 14 (82.4%) showed initial regression. Three infants (17.6%) required re-treatment: two with initial anti-VEGF therapy and one after laser therapy. Conclusions: The findings provide insights into ROP's prevalence and treatment preferences at a university tertiary care center. GA and BW were confirmed to be significant predictors, aiding in early detection and informing treatment decisions. These insights will enable comparisons with similar studies and contribute to improved patient care.

Image Analysis-Based Machine Learning for the Diagnosis of Retinopathy of Prematurity: A Meta-analysis and Systematic Review

TOPIC

To evaluate the performance of machine learning (ML) in the diagnosis of retinopathy of prematurity (ROP) and to assess whether it can be an effective automated diagnostic tool for clinical applications.

CLINICAL RELEVANCE

Early detection of ROP is crucial for preventing tractional retinal detachment and blindness in preterm infants, which has significant clinical relevance.

METHODS

Web of Science, PubMed, Embase, IEEE Xplore, and Cochrane Library were searched for published studies on image-based ML for diagnosis of ROP or classification of clinical subtypes from inception to October 1, 2022. The quality assessment tool for artificial intelligence-centered diagnostic test accuracy studies was used to determine the risk of bias (RoB) of the included original studies. A bivariate mixed effects model was used for quantitative analysis of the data, and the Deek's test was used for calculating publication bias. Quality of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

Twenty-two studies were included in the systematic review; 4 studies had high or unclear RoB. In the area of indicator test items, only 2 studies had high or unclear RoB because they did not establish predefined thresholds. In the area of reference standards, 3 studies had high or unclear RoB. Regarding applicability, only 1 study was considered to have high or unclear applicability in terms of patient selection. The sensitivity and specificity of image-based ML for the diagnosis of ROP were 93% (95% confidence interval [CI]: 0.90-0.94) and 95% (95% CI: 0.94-0.97), respectively. The area under the receiver operating characteristic curve (AUC) was 0.98 (95% CI: 0.97-0.99). For the classification of clinical subtypes of ROP, the sensitivity and specificity were 93% (95% CI: 0.89-0.96) and 93% (95% CI: 0.89-0.95), respectively, and the AUC was 0.97 (95% CI: 0.96-0.98). The classification results were highly similar to those of clinical experts (Spearman's R = 0.879).

CONCLUSIONS

Machine learning algorithms are no less accurate than human experts and hold considerable potential as automated diagnostic tools for ROP. However, given the quality and high heterogeneity of the available evidence, these algorithms should be considered as supplementary tools to assist clinicians in diagnosing ROP.

FINANCIAL DISCLOSURE(S)

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

Retinal detachment

Retinal detachment (RD) occurs when the neurosensory retina, the neurovascular tissue responsible for phototransduction, is separated from the underlying retinal pigment epithelium (RPE). Given the importance of the RPE for optimal retinal function, RD invariably leads to decreased vision. There are three main types of RD: rhegmatogenous, tractional and exudative (also termed serous) RD. In rhegmatogenous RD, one or more retinal breaks enable vitreous fluid to enter the subretinal space and separate the neurosensory retina from the RPE. In tractional RD, preretinal, intraretinal or subretinal membranes contract and exert tangential forces and elevate the retina from the underlying RPE. Finally, in exudative RD, an underlying inflammatory condition, vascular abnormality or the presence of a tumour causes exudative fluid to accumulate in the subretinal space, exceeding the osmotic pump function of the RPE. The surgical management of RD usually involves pars plana vitrectomy, scleral buckling or pneumatic retinopexy. The approach taken often depends on patient characteristics as well as on practitioner experience and clinical judgement. Advances in surgical technology and continued innovation have improved outcomes for many patients. However, even if retinal re-attachment is achieved, some patients still experience decreased vision or other visual symptoms, such as metamorphopsia, that diminish their quality of life. Continued research in the areas of neuroprotection and retinal biology as well as continued surgical innovation are necessary to enhance therapeutic options and outcomes for these patients.

[Global ophthalmology : Update]

The aim of global ophthalmology is to maximize vision, ocular health and functional ability, thereby contributing to overall health and well-being, social inclusion and quality of life of every individual worldwide. Currently, an estimated 1.1 billion people live with visual impairment, 90% of which can be prevented or cured through largely cost-effective interventions. At the same time, 90% of people affected live in regions with insufficient eye health coverage. This challenge drove the World Health Organization (WHO) and a group of nongovernmental organizations to launch "VISION 2020: the Right to Sight", a global campaign which recently concluded after 20 years. The achievements, challenges and lessons learned were identified and incorporated into the current campaign "2030 IN SIGHT".

Retinopathy of Prematurity-Targeting Hypoxic and Redox Signaling Pathways

Retinopathy of prematurity (ROP) is a proliferative vascular ailment affecting the retina. It is the main risk factor for visual impairment and blindness in infants and young children worldwide. If left undiagnosed and untreated, it can progress to retinal detachment and severe visual impairment. Geographical variations in ROP epidemiology have emerged over recent decades, attributable to differing levels of care provided to preterm infants across countries and regions. Our understanding of the causes of ROP, screening, diagnosis, treatment, and associated risk factors continues to advance. This review article aims to present the pathophysiological mechanisms of ROP, including its treatment. Specifically, it delves into the latest cutting-edge treatment approaches targeting hypoxia and redox signaling pathways for this condition.

Anatomical outcome of laser treatment alone in aggressive retinopathy of prematurity

PURPOSE

The purpose is to study the anatomical outcome of eyes in aggressive retinopathy of prematurity (AROP), treated with laser photocoagulation alone and to evaluate factors affecting outcomes.

METHODS

Records of consecutive babies diagnosed with AROP, undergoing laser photocoagulation treatment in rural tertiary care centers from October 2016 to January 2021 were reviewed retrospectively. Anatomical outcome at 6 months follow-up was grouped as good in eyes with complete regression and poor in those who developed retinal detachment (stage IV a, IV b, and V). Both groups were compared with respect to the period of gestation, birth weight (BW), age at screening, age at treatment, zone of disease, presence of retinal fibrovascular proliferation (FVP), tunica vasculosa lentis, preretinal bleed, need for supplement laser, and associated systemic risk factors.

RESULTS

Of the total of 2468 babies screened, 124 (5.02%) were diagnosed with severe retinopathy of prematurity (ROP), of which 54 (43.5%) lasered AROP babies were analyzed. Mean BW and gestation period of the AROP cohort were 1.43 kg and 31.1 weeks, respectively. Eighty-six eyes (79.6%) had good outcomes with laser photocoagulation alone. Posterior location of disease, presence of FVP, neonatal sepsis, shock, and late screening for ROP were found to be factors associated with poor outcomes.

CONCLUSION

Adequate and timely treatment with laser photocoagulation in AROP can achieve good treatment outcomes in a significant proportion of babies. Although a combined approach using laser, anti-vascular endothelial growth factor and early vitrectomy is better, laser remains a viable treatment option in AROP, especially with limited resources and high risk of loss to follow-up.

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.

The impact after 20 years of an early detection program for severe retinopathy of prematurity in a Latin American city

Purpose

To evaluate the effects of long-standing early detection program in the incidence and trends of severe retinopathy of prematurity (ROP) in Cali, Colombia.

Methods

This was a retrospective cohort study of infants included in an ROP prevention, early detection, and prompt treatment program, from January 01, 2002, to December 31, 2021 (20 years). Infants with gestational age (GA) <37 weeks or birth weight (BW) <2000 g and those with known ROP risk factors were screened. The incidence of severe ROP was calculated, and the average annual percent change (AAPC) was estimated through a joinpoint model.

Results

16,580 infants were screened, with an average GA and BW of 31.4 ± 2.8 weeks and 1526.5 ± 56.7 g, respectively. The incidence of severe ROP was 2.69% (446 cases, 95% confidence interval [95%CI]: 2.45%; 2.95%), with an average annual decrease of - 14% (AAPC, 95%CI: -16.3%; -11.6%) from 13.6% in 2002 to 0.7% in 2021. In infants with GA <32 weeks, the incidence was 5.21%. A significant reduction in the risk of ROP was observed with increasing GA and BW (P < 0.05). Among the cases with severe ROP, 6.5% (29/446) had a GA ≥32 weeks with a maximum of 37 weeks; only 0.4% (2/446) of the detected infants had a BW >2000 g.

Conclusion

Awareness and screening as part of the early detection program to prevent ROP has shown a significant decline in the incidence of severe ROP over time. Screening infants with GA <32 weeks or BW <2000 g and preterm infants (<37 weeks) with risk factors may be a feasible decision for resource optimization.

Causes of Childhood Blindness in the United States Using the IRIS® Registry (Intelligent Research in Sight)

PURPOSE

To investigate causes of childhood blindness in the United States using the IRIS® Registry (Intelligent Research in Sight).

DESIGN

Cross-sectional study.

PARTICIPANTS

Patients ≤ 18 years of age with visual acuity (VA) 20/200 or worse in their better-seeing eye in the IRIS Registry during 2018.

METHODS

Causes of blindness were classified by anatomic site and specific diagnoses.

MAIN OUTCOME MEASURES

Percentages of causes of blindness.

RESULTS

Of 81 164 children with 2018 VA data in the IRIS Registry, 961 (1.18%) had VA 20/200 or worse in their better-seeing eye. Leading causes of blindness were retinopathy of prematurity (ROP) in 301 patients (31.3%), nystagmus in 78 patients (8.1%), and cataract in 64 patients (6.7%). The retina was the leading anatomic site (47.7%) followed by optic nerve (11.6%) and lens (10.0%). A total of 52.4% of patients had treatable causes of blindness.

CONCLUSIONS

This analysis offers a unique cross-sectional view of childhood blindness in the United States using a clinical data registry. More than one-half of blind patients had a treatable cause of blindness.

FINANCIAL DISCLOSURE(S)

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

Retinopathy of prematurity among infants admitted to two neonatal intensive care units in Ethiopia

OBJECTIVE

This study was conducted to determine the prevalence and risk factors for retinopathy of prematurity (ROP) in two neonatal intensive care units (NICUs) in Addis Ababa, Ethiopia.

METHODS AND ANALYSIS

A prospective screening survey was conducted from June 2019 to June 2020 in two level 3 public NICUs. Infants with a birth weight (BW) of ≤1500 g or gestational age (GA) of ≤32 weeks and those with a BW of >1500 g and GA of >32 weeks with an unstable clinical course were included. Data on demographic and neonatal characteristics, neonatal and maternal comorbidities, and therapeutic interventions were collected. Logistic regression analysis was used to identify predictors of ROP.

RESULTS

Two hundred and two infants were included: mean BW: 1658g (range: 700-2400 g) and mean GA: 32.4 weeks (range: 26-34 weeks). 32.2% had any stage of ROP, and 6.4% had Type 1 ROP. Lower BW, smaller GA and total days on oxygen were independent risk factors for severe ROP (Type 1 or worse). All 13 neonates with severe ROP were treated.

CONCLUSION

ROP is emerging as a concern in Ethiopia. ROP screening should include neonates with BW of <1800 g or GAs of ≤33 weeks, but further studies are needed in level 2 and private NICUs. Screening guidelines need to be developed and implemented in all hospitals with NICUs.

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.

Eyes as the windows into cardiovascular disease in the era of big data

Cardiovascular disease (CVD) is a major cause of mortality and morbidity worldwide and imposes significant socioeconomic burdens, especially with late diagnoses. There is growing evidence of strong correlations between ocular images, which are information-dense, and CVD progression. The accelerating development of deep learning algorithms (DLAs) is a promising avenue for research into CVD biomarker discovery, early CVD diagnosis, and CVD prognostication. We review a selection of 17 recent DLAs on the less-explored realm of DL as applied to ocular images to produce CVD outcomes, potential challenges in their clinical deployment, and the path forward. The evidence for CVD manifestations in ocular images is well documented. Most of the reviewed DLAs analyze retinal fundus photographs to predict CV risk factors, in particular hypertension. DLAs can predict age, sex, smoking status, alcohol status, body mass index, mortality, myocardial infarction, stroke, chronic kidney disease, and hematological disease with significant accuracy. While the cardio-oculomics intersection is now burgeoning, very much remain to be explored. The increasing availability of big data, computational power, technological literacy, and acceptance all prime this subfield for rapid growth. We pinpoint the specific areas of improvement toward ubiquitous clinical deployment: increased generalizability, external validation, and universal benchmarking. DLAs capable of predicting CVD outcomes from ocular inputs are of great interest and promise to individualized precision medicine and efficiency in the provision of health care with yet undetermined real-world efficacy with impactful initial results.

Global Disparities in Retinopathy of Prematurity: A Literature Review

PURPOSE

To provide an overview of the impact of retinopathy of prematurity (ROP), and the challenges in the screening, diagnosis, and treatment of ROP worldwide.

METHODS

A comprehensive search was conducted using the PubMed database from January 2011 to October 2021 using the following keywords: retinopathy of prematurity, laser, and anti-vascular endothelial growth factor (VEGF). Data on patient characteristics, ROP treatment type, and recurrence rates were collected. The countries included in these studies were classified based on 2021-2022 World Bank definitions of high, upper-middle, lower-middle, and low-income groups. Moreover, a search for surgical outcomes for ROP and screening algorithms and artificial intelligence for ROP was conducted.

RESULTS

Thirty-nine studies met the inclusion criteria. ROP treatment and outcomes showed a trend towards intravitreal anti-VEGF injections as the initial treatment for ROP globally and the treatment of recurrent ROP in high-income countries. However, laser remains the treatment of choice for ROP recurrence in middle-income countries. Surgical outcomes for ROP stage 4A, 4B and 5 are similar worldwide. The incidence of ROP and ROP-related visual impairment continue to increase globally. Although telemedicine and artificial intelligence offer potential solutions to ROP screening in resource-limited areas, the current models require further optimization to reflect the global diversity of ROP patients.

CONCLUSION

ROP screening and treatment paradigms vary widely based on country income group due to disparities in resources, limited access to care, and lack of universal guidelines.

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.

Blindness in infants presenting with advanced and untreated ROP: a single-centre study in Pakistan

To describe the ocular features and characteristics of young children presenting with advanced, untreated retinopathy of prematurity and to determine appropriate screening guidelines for retinopathy of prematurity (ROP) in Pakistan.

Material and methods

A retrospective case series of young children with stage5A or 5B or cicatricial changes (4B or 4A ROP) was undertaken in the Department of Ophthalmology, Lahore General Hospital, Lahore, Pakistan, from August 2017 to July 2019. Information was obtained from interviewing parents and from neonatal care discharge summaries, if available. An assessment of visual function and a dilated fundus examination were performed.

Results

51 children presented at mean age of 9.7 (1.5–36) months. Their mean gestational age (GA) was 28.84 (26–38) weeks, and mean birth weight (BW) was 1229 (800–2100) g. Four children (7.8%) had a GA of >31 weeks plus a BW of >1501 g. 40 (76.4%) children were blind and 11 (23.6%) had impaired vision. Sixty-five eyes (63.7%) had stage 5B; 13 (12.7%) eyes had stage 5A; 18 (17.6%) had falciform macular folds (4B ROP) and 6 eyes (5.9%) had macular dragging (4A ROP). 39 (76.5%) children had bilateral stage 5A/5B. Half (47%) of the children lived outside the capital city of Lahore, and 15 came from small cities (population <1 million).

Conclusion

The third epidemic of blindness due to ROP has arrived in Pakistan, and premature babies are going blind even in smaller cities. Initial screening guidelines of a GA of ≤35 weeks and BW of ≤2000 g seem reasonable. There is an urgent need to improve the quality of neonatal care and to increase the coverage of ROP screening and treatment services across the country.

Childhood visual impairment and blindness: 5-year data from a tertiary low vision center in Israel

BACKGROUND

To assess the main causes leading to childhood visual impairment/blindness in a center for low vision in Israel and to analyze the literature on pediatric blinding diseases in developed countries.

METHODS

Retrospective study based on observational case series. Data were obtained from medical records of visually impaired children, seen at a national referral low vision center. Children were divided into two groups: moderate visual impairment (6/18 to 6/60) and severe visual impairment (SVI)/blindness (<6/60). Inherited eye diseases (IED) were grouped together for analysis. Data from the Israeli blind registry from the same period of time were analyzed for comparison. A review of literature on childhood blindness in developed countries since 2000 was conducted.

RESULTS

A total of 1393 children aged 0-18 years were included in the study. Moderate visual impairment was seen in 1025 (73.6%) and SVI/blindness in 368 (26.4%) of the studied children. Among blind children, IED accounted for at least 51% of all diagnoses, including mainly albinism and retinal dystrophies. IED prevalence was equally high in both main ethnic groups (Jewish and Arab Muslims). Non-IED (22.6%) included mainly patients with cerebral visual impairment and retinopathy of prematurity.

CONCLUSIONS

The leading cause of childhood visual impairment and blindness in our patient cohort was IED. Analyses of the literature from the last two decades show that IED are a major cause for SVI/childhood blindness in other developed countries as well. Updated patterns of global childhood blindness may suggest a need for new approach for screening programs and modern tactics for prevention.

Association of fish oil containing lipid emulsions with retinopathy of prematurity: a retrospective observational study

Background

Retinopathy of prematurity (ROP) remains a leading cause of childhood blindness worldwide. This study aimed to investigate whether supplementation of n-3 polyunsaturated fatty acids (n-3 PUFAs) in parenteral nutrition may have beneficial effects on ROP in preterm infants.

Methods

A total of 89 preterm infants, admitted to Neonatal Intensive Care Unit (NICU) in Anhui Provincial Children’s Hospital from September 2017 to August 2020, were recruited in the study. Based on the medical documents, the subjects were categorised into two groups: administration of the fish oil emulsion (n=43) containing soy oil, medium-chain-triglycerides (MCT), olive oil and fish oil (6g/dL, 6g/dL, 5g/dL and 3g/dL respectively), and the soy oil emulsion (n=46) containing 10g/dL of soy oil and MCT each. At 4 weeks of hospitalization, ROP was screened and diagnosed. Fatty acids in erythrocytes were determined using gas chromatography.

Results

The averaged birth weight and gestational age were 1594±296 g and 31.9±2.3 wk, 1596±263 g and 31.6±2.3 wk respectively for preterm infants in the fish oil group and soy oil group. After 4 to 6 weeks of hospitalization, among all the preterm infants, 52 developed ROP (all stages) indicating an incidence of ROP at 58.43%. Although the incidence of ROP with any stages showed no differences between the two groups, the severe ROP incidence in the group with fish oil emulsions (2.33%) was significantly lower than that in the group with soy oil emulsions (23.91%) (P<0.05). After 14 days of nutrition support, the preterm infants administered fish oil emulsions had an increase in erythrocyte DHA content, with a reduction in ratio of arachidonic acid (AA) to DHA and an increase of n-3 index.

Conclusion

Supplementation of n-3 PUFAs through parenteral fish oil containing lipid emulsions resulted in an increase in erythrocyte DHA, and this might have beneficial effects on prevention of severe ROP in preterm infants.

Implementation of telemedicine screening for retinopathy of prematurity in rural areas in Guatemala

PURPOSE

To report findings of a telemedicine retinopathy of prematurity (ROP) screening program in six neonatal units in rural areas of Guatemala, using a portable, noncontact, 40° field digital fundus camera (Pictor Plus) operated by trained technicians.

METHODS

National ROP Program Guidelines screening criteria were used: gestational age <36 weeks and/or birth weight (BW) <2000 g, or GA <36 weeks but BW ≥2000 g, with qualifying medical history. Retinal images were obtained by two technicians and graded by ophthalmologists experienced in ROP. Infants with signs of pre-plus or plus disease in one or both eyes were referred for clinical examination. Screening was stopped when retinal vessels in anterior zone II were normal on two successive evaluations or the infant had reached 45 week's postmenstrual age.

RESULTS

A total of 418 of 1,890 eligible infants (22.1%) were screened. Mean GA was 33.9 ± 2.2 weeks (range, 27-36), and mean BW 1728.3 ± 379.3 g (range, 840-2830 g). Thirty-three infants (8.6%) developed plus or pre-plus disease, and 19 (58%) underwent ophthalmologic examination. Fifteen infants were confirmed with type 1 ROP, and 14 were treated. Mean GA of treated infants treated was 33.6 ± 3.0 weeks (range, 32-34.9), and mean BW was 1,646 ± 245.8 g (range, 1100-1774.1 g).

CONCLUSIONS

Imaging with a noncontact fundus camera can facilitate detection of treatable ROP in countries with limited resources. Strengthening the health systems, including motivation and continued training of neonatal intensive care personnel is essential to improve and maintain program effectiveness. Reasons for, and interventions to address the low uptake of screening need to be explored to extend coverage of ROP screening to district hospitals in Guatemala.

Prediction of Retinopathy of Prematurity Using the WINROP (Weight, IGF-1, Neonatal Retinopathy of Prematurity) Algorithm in a South African Population

AIM

This study aimed to assess the efficacy of the WINROP (Weight, IGF-1, Neonatal Retinopathy of Prematurity) screening algorithm in a South African population.

METHODS

A retrospective record review included infants born between 1 January 2013 and 1 December 2014 who underwent ROP (retinopathy of prematurity) screening. Outcomes of ophthalmology examinations were compared to alarms triggered on WINROP after gestational age, date of birth, and weekly weights were entered. Sensitivity, specificity, positive predictive, and negative predictive values and mean time of alarm were calculated.

RESULTS

Rates of ROP were 5.9% for all stages of ROP and 2.3% for severe ROP in the 220 infants included. Mean gestation age was 29.1 ± 1.3 weeks and mean birth weight 1,115.5 ± 201 g. WINROP triggered high-risk alarms in 70.5% of infants at a mean of 30.7 weeks of gestational age. Sensitivity for severe ROP was 100 and 76.9% for all stages of ROP. Specificity was low for both severe ROP and all stages of ROP at 30.2 and 30.0%, respectively.

CONCLUSION

Rates of ROP are low in this population. The high number of alarms with a low negative predictive value would reduce the number of screens by 29.5%. Alarms were triggered before scheduled screening, possibly helpful in planning discharges and follow-up visits.

Quantification of Early Neonatal Oxygen Exposure as a Risk Factor for Retinopathy of Prematurity Requiring Treatment

Purpose

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness related to oxygen exposure in premature infants. Since oxygen monitoring protocols have reduced the incidence of treatment-requiring ROP (TR-ROP), it remains unclear whether oxygen exposure remains a relevant risk factor for incident TR-ROP and aggressive ROP (A-ROP), a severe, rapidly progressing form of ROP. The purpose of this proof-of-concept study was to use electronic health record (EHR) data to evaluate early oxygen exposure as a predictive variable for developing TR-ROP and A-ROP.

Design

Retrospective cohort study.

Participants

Two hundred forty-four infants screened for ROP at a single academic center.

Methods

For each infant, oxygen saturations and fraction of inspired oxygen (FiO₂) were extracted manually from the EHR until 31 weeks postmenstrual age (PMA). Cumulative minimum, maximum, and mean oxygen saturation and FiO₂ were calculated on a weekly basis. Random forest models were trained with 5-fold cross-validation using gestational age (GA) and cumulative minimum FiO₂ at 30 weeks PMA to identify infants who developed TR-ROP. Secondary receiver operating characteristic (ROC) curve analysis of infants with or without A-ROP was performed without cross-validation because of small numbers.

Main Outcome Measures

For each model, cross-validation performance for incident TR-ROP was assessed using area under the ROC curve (AUC) and area under the precision-recall curve (AUPRC) scores. For A-ROP, we calculated AUC and evaluated sensitivity and specificity at a high-sensitivity operating point.

Results

Of the 244 infants included, 33 developed TR-ROP, of which 5 developed A-ROP. For incident TR-ROP, random forest models trained on GA plus cumulative minimum FiO₂ (AUC = 0.93 ± 0.06; AUPRC = 0.76 ± 0.08) were not significantly better than models trained on GA alone (AUC = 0.92 ± 0.06 [P = 0.59]; AUPRC = 0.74 ± 0.12 [P = 0.32]). Models using oxygen alone showed an AUC of 0.80 ± 0.09. ROC analysis for A-ROP found an AUC of 0.92 (95% confidence interval, 0.87–0.96).

Conclusions

Oxygen exposure can be extracted from the EHR and quantified as a risk factor for incident TR-ROP and A-ROP. Extracting quantifiable clinical features from the EHR may be useful for building risk models for multiple diseases and evaluating the complex relationships among oxygen exposure, ROP, and other sequelae of prematurity.

Angiographic findings in cases with a history of severe retinopathy of prematurity treated with anti-VEGFs: Follow-up to age 6 years

PURPOSE

To report the effects of anti-vascular endothelial growth factor (VEGF) treatment in vascular development for cases of acute retinopathy of prematurity (ROP) using fluorescent angiography (FA) and to present the results of our observational approach to retinal sequelae.

METHODS

A total of 31 eyes in 19 patients with a history of treatment with anti-VEGF agents for classic type 1 ROP and aggressive posterior ROP who underwent FA between March 2014 to February 2020 were reviewed. Angiograms of retinal developmental features of patients aged 4 months to 6 years were examined.

RESULTS

The patients mean gestational age were 26.06 ± 1.90 weeks and the mean birth weight were 837.68 ± 236.79 g. All cases showed various abnormalities at the vascular and avascular retina, and the posterior pole. All but one case showed a peripheral avascular area on FA evaluation during the follow-up period. We did not apply prophylactic laser treatment to these avascular retina. On the final examination, except one case, we did not observe any late reactivation in any patients.

CONCLUSION

FA is an important tool for assessing vascular maturation in infants. Every leakage should not be assumed to be evidence of late activation, as some leaks may be related to vascular immaturity. Retinal vascularization may not be completed in all patients, however this does not mean that all these patients need prophylactic laser application. Our observational approach may be more daring than the reports frequently encountered in the literature, but it should be noted that unnecessary laser treatment will also eliminate all the advantages of anti-VEGF treatment.

Scleral buckling surgery for stage 4A and 4B retinopathy of prematurity in critically ill neonates

PURPOSE

To determine the efficacy of scleral buckling in eyes with stage 4A and 4B retinopathy of prematurity (ROP).

METHODS

Seven eyes of five premature infants underwent scleral buckling for stage 4 ROP in zone II. Five eyes had stage 4A ROP, and two eyes had stage 4B ROP. Six eyes had previous diode laser photocoagulation, and one eye had received an intravitreal ranibizumab injection. Scleral buckling was the procedure of choice due to lack of access to specialized pediatric vitrectomy instrumentation. Average age at surgery was 3.4 months. Postoperative anatomic retinal status, visual acuity outcome and refractive error were assessed.

RESULTS

The scleral buckle was removed on average 8 months after surgery. Retinal reattachment was achieved in all seven eyes. At final follow-up one eye had macular ectopia and disc dragging, one eye had a macular traction fold and two eyes had optic disc pallor. Average myopic error after buckle removal was -7.5 D.

CONCLUSION

Scleral buckling can be performed safely and effectively in 4A and 4B stage ROP in critically ill infants, when access to specialized pediatric vitrectomy instrumentation is limited. This surgical technique may provide adequate relief of vitreoretinal traction with improved visual potential.

Clinical Features of Spontaneous Regression of Retinopathy of Prematurity in China: A 5-Year Retrospective Case Series

Purpose: The aim of this study is to explore the clinical features of spontaneous regression of retinopathy of prematurity (ROP) in China, including fundus appearance, time course, and affecting factors.

Methods: Data of pediatric patients in whom ROP spontaneously regressed without treatment were collected, including general demographics, medical history, zones and stages of ROP, and changes of fundus appearance. The fundus manifestations of spontaneous regression in ROP were systematically summarized. Meanwhile, the time course of spontaneous regression in ROP was further analyzed, including the onset time, completion time, and duration of regression, which were all compared across different ROP zones and stages. The associated factors were analyzed by survival analysis for their correlation with delayed regression for the first time.

Results: Two hundred thirty-seven eyes of 237 pediatric patients were included. The fundus manifestations of regression differed across stages. Lesions gradually subsided, and the retinal vessels gradually vascularized completely. However, despite ROP regression, some abnormalities remained. We observed avascular retina in the temporal periphery (19.0%), increased vascular branching (6.8%), retinal pigmentary changes (6.8%), and smaller angle between the upper and lower temporal retinal vessel trunks (3.0%). Acute ROP started to regress at a median 40 weeks of postmenstrual age (PMA) and completely regressed by median 49.0 weeks of PMA. The median duration for regression was 8.5 weeks. The zone II ROP and stage 3 ROP had a later time for onset and completion of regression, and longer duration. Anemia and retinal hemorrhage (RH) were identified as independent risk factors for delayed regression by survival analysis.

Conclusions: During spontaneous regression, the fundus appearance is diverse, and the retinal vessels gradually vascularized completely. The time course of regression differs depending on the ROP zone and stage. Anemia and RH are independent risk factors for delayed regression. Further research of the natural course of the regression of ROP is needed to help design effective screening and follow-up plans.

Strengthening retinopathy of prematurity screening and treatment services in Nigeria: a case study of activities, challenges and outcomes 2017-2020

Objectives

Retinopathy of prematurity (ROP) will become a major cause of blindness in Nigerian children unless screening and treatment services expand. This article aims to describe the collaborative activities undertaken to improve services for ROP between 2017 and 2020 as well as the outcome of these activities in Nigeria.

Design

Descriptive case study.

Setting

Neonatal intensive care units in Nigeria.

Participants

Staff providing services for ROP, and 723 preterm infants screened for ROP who fulfilled screening criteria (gestational age <34 weeks or birth weight ≤2000 g, or sickness criteria).

Methods and analysis

A WhatsApp group was initiated for Nigerian ophthalmologists and neonatologists in 2018. Members participated in a range of capacity-building, national and international collaborative activities between 2017 and 2018. A national protocol for ROP was developed for Nigeria and adopted in 2018; 1 year screening outcome data were collected and analysed. In 2019, an esurvey was used to collect service data from WhatsApp group members for 2017-2018 and to assess challenges in service provision.

Results

In 2017 only six of the 84 public neonatal units in Nigeria provided ROP services; this number had increased to 20 by 2018. Of the 723 babies screened in 10 units over a year, 127 (17.6%) developed any ROP; and 29 (22.8%) developed type 1 ROP. Only 13 (44.8%) babies were treated, most by intravitreal bevacizumab. The screening criteria were revised in 2020. Challenges included lack of equipment to regulate oxygen and to document and treat ROP, and lack of data systems.

Conclusion

ROP screening coverage and quality improved after national and international collaborative efforts. To scale up and improve services, equipment for neonatal care and ROP treatment is urgently needed, as well as systems to monitor data. Ongoing advocacy is also essential.

Automatic Staging for Retinopathy of Prematurity With Deep Feature Fusion and Ordinal Classification Strategy

Retinopathy of prematurity (ROP) is a retinal disease which frequently occurs in premature babies with low birth weight and is considered as one of the major preventable causes of childhood blindness. Although automatic and semi-automatic diagnoses of ROP based on fundus image have been researched, most of the previous studies focused on plus disease detection and ROP screening. There are few studies focusing on ROP staging, which is important for the severity evaluation of the disease. To be consistent with clinical 5-level ROP staging, a novel and effective deep neural network based 5-level ROP staging network is proposed, which consists of multi-stream based parallel feature extractor, concatenation based deep feature fuser and clinical practice based ordinal classifier. First, the three-stream parallel framework including ResNet18, DenseNet121 and EfficientNetB2 is proposed as the feature extractor, which can extract rich and diverse high-level features. Second, the features from three streams are deeply fused by concatenation and convolution to generate a more effective and comprehensive feature. Finally, in the classification stage, an ordinal classification strategy is adopted, which can effectively improve the ROP staging performance. The proposed ROP staging network was evaluated with per-image and per-examination strategies. For per-image ROP staging, the proposed method was evaluated on 635 retinal fundus images from 196 examinations, including 303 Normal, 26 Stage 1, 127 Stage 2, 106 Stage 3, 61 Stage 4 and 12 Stage 5, which achieves 0.9055 for weighted recall, 0.9092 for weighted precision, 0.9043 for weighted F1 score, 0.9827 for accuracy with 1 (ACC1) and 0.9786 for Kappa, respectively. While for per-examination ROP staging, 1173 examinations with a 4-fold cross validation strategy were used to evaluate the effectiveness of the proposed method, which prove the validity and advantage of the proposed method.

Evaluating Contrast Sensitivity in Asian Indian Pre-Term Infants With and Without Retinopathy of Prematurity

Purpose

The purpose of this study was to evaluate the contrast threshold in Asian Indian preterm infants with and without retinopathy of prematurity (ROP) using Newborn Contrast Cards measured during the first ROP screening and to correlate with final outcome and visual acuity at 3 months of corrected age.

Methods

Preterm infants born ≤ 2000 grams birth weight (BW) and/or ≤ 34 weeks gestational age (GA) undergoing ROP screening were enrolled prospectively. Visual acuity was recorded using Teller Acuity Cards. Contrast threshold was measured with Newborn Contrast Cards at first screening visit and at the end of ROP screening at 40 weeks of postmenstrual age or older.

Results

Of the 173 study infants, 134 (77.5%) did not have any stage of ROP. Of the remaining 39 (22.5%), 34 (87%) had type 2 ROP and 5 (13%) had type 1 ROP requiring treatment. The mean contrast threshold at the first visit of the no ROP type 1 and type 2 groups was 0.36 ± 0.07, 0.65 ± 0.19, and 0.46 ± 0.09, respectively (P < 0.001). Contrast threshold had a significant correlation with BW (R = −0.291, P = < 0.001) and gestational age (R = −0.47, P = < 0.001). The contrast threshold at the first visit correlated with visual acuity measured at 3 months of corrected age in logMAR (R = 0.36, P = 0.01). Other than BW and GA, no other systemic risk factors correlated with contrast threshold measured at the first screening visit.

Conclusions

Newborn Contrast Cards are a viable tool to test contrast threshold in preterm infants. The association between contrast threshold and ROP, and its correlation with visual acuity, suggest that contrast threshold measurement may help predict the clinical vision outcome among prematurely born infants.

Translational Relevance

Contrast threshold measurement may prove to be a useful tool in the estimation of visual potential in preterm infants.

Learning curve evaluation upskilling retinal imaging using smartphones

Smartphone-based fundus imaging (SBFI) is a low-cost approach for screening of various ophthalmic diseases and particularly suited to resource limited settings. Thus, we assessed how best to upskill alternative healthcare cadres in SBFI and whether quality of obtained images is comparable to ophthalmologists. Ophthalmic assistants and ophthalmologists received a standardized training to SBFI (Heine iC2 combined with an iPhone 6) and 10 training examinations for capturing central retinal images. Examination time, total number of images, image alignment, usable field-of-view, and image quality (sharpness/focus, reflex artifacts, contrast/illumination) were analyzed. Thirty examiners (14 ophthalmic assistants and 16 ophthalmologists) and 14 volunteer test subjects were included. Mean examination time (1st and 10th training, respectively: 2.17 ± 1.54 and 0.56 ± 0.51 min, p < .0001), usable field-of-view (92 ± 16% and 98 ± 6.0%, p = .003) and image quality in terms of sharpness/focus (p = .002) improved by the training. Examination time was significantly shorter for ophthalmologists compared to ophthalmic assistants (10th training: 0.35 ± 0.21 and 0.79 ± 0.65 min, p = .011), but there was no significant difference in usable field-of-view and image quality. This study demonstrates the high learnability of SBFI with a relatively short training and mostly comparable results across healthcare cadres. The results will aid implementing and planning further SBFI field studies.

Blindness Secondary to Retinopathy of Prematurity in Sub-Saharan Africa

Purpose: Retinopathy of Prematurity (ROP) has been suggested to be increasing in Africa. However, it was only previously documented as a cause of blindness in 8 of 48 (16.7%) sub-Saharan African countries. The purpose of this study was to better understand the magnitude and breadth of blindness from ROP in sub-Saharan Africa.Methods: A questionnaire was sent to 455 ophthalmologists practicing in sub-Saharan Africa; the questionnaire was available in English, French and Portuguese.Results: Responses were received from 132 of 455 (29%) ophthalmologists to whom the survey was sent. Eighty-three respondents were identified as ROP-involved ophthalmologists and were from 26 of 48 (54%) sub-Saharan African countries. Ophthalmologists in 23 countries reported that they examined at least one child who was blind from ROP during the last 5 years. Sixteen of these countries had not previously reported cases of blindness from ROP in the literature. The perceived occurrence of Type 1 or more severe ROP was reported to be increasing by 31 of 77 (40%) ROP-involved ophthalmologists. ROP-involved pediatric ophthalmologists and retinal surgeons reported the number of infants they examined annually with Type 1 or more severe ROP increased from a median of 1 (range: 0-15) to a median of 4 (range: 0-40) from 2015 to 2019. ROP was estimated to be the cause of blindness for 10% of all blind children examined by ROP-involved pediatric ophthalmologists and retinal surgeons during 2019.Conclusions: ROP is becoming a more important and widespread cause of childhood blindness in sub-Saharan Africa.

Causes of Blindness and Visual Impairment in Early Childhood at a Low Vision Service in Mexico City: A 15-year Review

Purpose: To evaluate the causes of blindness and visual impairment in children aged 0-7 years attending a Low Vision Centre in Mexico City, Mexico.Methods: Clinical records for patients aged 0-7 years attending the Centre from 2001 to 2015 were retrospectively reviewed. Causes of blindness and visual impairment, affected anatomy, and suspected time period of insult were recorded.Results: 1487 patients were included, 45.9% girls and 54.1% boys. Mean age of presentation was 39 months (SD 27.9 months). 36.0% had associated co-morbidities in addition to their ophthalmic pathology. 39.7% presented with developmental or psychomotor delay. Leading diagnoses were Retinopathy of Prematurity (ROP) (19.6%), optic nerve atrophy (11.5%), and congenital cataract (9.5%). The most affected anatomical regions were retina (33.8%), optic nerve (16.6%), and lens (10.5%). Half of all cases (50.9%) had insults in the prenatal period. Children with developmental delay were more likely to present before the age of one. There is a significant difference in risk of delayed presentation according to diagnosis. Only 13.5% of children with optic nerve atrophy presented to the Centre before the age of one, compared to 28.4% of children with ROP and 23.4% of children with cataract.Conclusion: The most common diagnoses for blindness and visual impairment among children were ROP, optic nerve atrophy, and congenital cataract. Late presentation to the Centre was common. There were significant differences in risk of delayed presentation depending on diagnosis. Co-existing systemic conditions and developmental and psychomotor delay were also common among patients attending the Centre.

ROP screening and treatment in four district-level special newborn care units in India: a cross-sectional study of screening and treatment rates

OBJECTIVE

Blindness from retinopathy of prematurity (ROP) in middle-income countries is generally due to absence of screening or inadequate screening. The objective of this study was to assess uptake of services in an ROP programme in four district-level special newborn care units in India.

DESIGN

Cross-sectional study.

SETTING

All four neonatal units of a state in India where model programme for ROP had been introduced.

PATIENTS

Infants eligible for screening and treatment of ROP between March and May 2017.

INTERVENTION

Data on sex, birth weight and gestational age of eligible infants were collected and medical records reviewed for follow-up.

MAIN OUTCOME MEASURES

Proportion of eligible infants screened and for those screened, age at first screening, completion of screening, diagnosis and treatment received if indicated. The characteristics of infants screened and not screened were compared.

RESULTS

137 (18%) of the 751 infants eligible for screening were screened at least once, with no statistically significant difference by sex. The mean birth weight and gestational age of those screened were significantly lower than those not screened. Among those screened, 43% underwent first screening later than recommended and 44% had incomplete follow-up. Fourteen infants (11% of those screened) were diagnosed with ROP. Five were advised laser treatment and all complied.

CONCLUSION

Uptake, completion and timing of first screening was suboptimal. Some planned interventions including training of nursing staff, use of integrated data-management software and providing material for parent counselling, which have been initiated, need to be fully implemented to improve uptake of ROP screening services.

Oxygen management among infants in neonatal units in sub-Saharan Africa: a cross-sectional survey

OBJECTIVES

To provide more comprehensive data on the management of oxygen supplementation in neonates in sub-Saharan Africa.

STUDY DESIGN

An online survey on the management of oxygen supplementation for infants in neonatal units was sent to 278 healthcare personnel in sub-Saharan Africa.

RESULTS

One hundred and nine responses from 82 neonatal care units in 54% (26/48) sub-Saharan African countries were received. All units had the capacity to provide oxygen supplementation. However, only 50% (38/76) had access to blend oxygen with medical air and 1% (1/75) had the capacity to blend oxygen/air for every infant. Although 96% (72/75) of units could monitor oxygen saturation, monitoring was mostly intermittent and only 32% (24/75) were able to monitor oxygen saturation in every infant receiving oxygen supplementation.

CONCLUSIONS

Findings indicate that oxygen supplementation is inadequately managed in neonatal units in sub-Saharan Africa, which may put infants at risk of developing severe ROP.

Rate and Treatment of Retinopathy of Prematurity in Extremely Low Birth Weight Infants with Gestational Age ≤28 Weeks in Eastern China

Purpose

To investigate the incidence and clinical characteristics of ROP in extremely preterm (EP) and extremely low birth weight (ELBW) infants in eastern China.

Patients and Methods

This retrospective study included 104 infants with a birth weight (BW) ≤ 1000 g and gestational age (GA) ≤ 28 weeks, who were admitted to the Eye and ENT Hospital of Fudan University over 10 years. The infants were examined for ROP with RetCam. Infants with type 1 ROP and aggressive posterior ROP (AP-ROP) were treated. The risk factors evaluated were GA and BW.

Results

Mean GA was 26.63 ± 0.88 weeks and mean BW was 892.39 ± 108.06 g. Of the 104 infants, 83 (79.8%) developed ROP, three (2.9%) had AP-ROP, 14 (13.5%) had type 1 ROP, and 10 (9.6%) had type 2 ROP. The proportions of infants with BW ≤750 g and 751-1000 g were 8.7% and 91.3%, respectively, and the incidences of severe ROP in these infants were 22.2% and 15.8%, respectively. The infants with severe ROP had a mean GA of 26.56 ± 0.68 weeks and mean BW of 860.00 ± 163.48 g, and 47.1% of severe ROP occurred in infants with a GA of 26 weeks. However, multivariate logistic regression showed that the severity of ROP was not directly inversely related to GA or BW in this study population.

Conclusion

In EP and ELBW Chinese infants, who were admitted to the Eye and ENT Hospital of Fudan University, the development of ROP was more frequent and the incidence of severe ROP that progressed to the stage that required treatment was high.

Outcomes of Pre-Early Treatment for Retinopathy of Prematurity (Pre-ETROP)

Introduction

The earlier treat stage 3 ROP is more likely to achieve better outcomes.

Primary Purpose

To study the unfavorable outcomes and regression after pre-early treatment for ROP.

Secondary Purpose

To evaluate the progression and recurrence of ROP requiring retreatment after pre-early treatment for ROP.

Patients and Methods

The data were retrieved retrospectively from the medical records of all infants who were screened and treated for ROP from January 2009 to January 2014 at a tertiary care facility. The outcomes measured the following: 1. unfavorable outcomes; 2. regression of ROP; 3. progression of ROP and 4. recurrence of ROP requiring retreatment. We treated all stage 3 ROP in any zone, with or without plus. The study also compared the outcomes between the pre-ETROP and the ETROP subgroups.

Results

There were 91 eyes with stage 3 ROP. Of the total of 91 eyes, there were 63 eyes with the pre-ETROP group and 28 eyes of the ETROP group. The unfavorable outcomes after treatment occur 6 eyes from 28 eyes (21.43%) in the ETROP group but no unfavorable outcomes in the pre-ETROP group (P=0.001). The pre-ETROP group who were treated with laser LIO alone had 100% regression, while the ETROP group who were treated with LIO (26 eyes) had 88.46% regression. There were 2 eyes of this group who were treated with a combination of LIO and IVT Bevacizumab. Both of them did not have regression. The recurrence of ROP requiring retreatment occurred in 2 eyes (7.14%) of the ETROP group, but no recurrence in the pre-ETROP group (P=0.092). The progression after treatment occurred in 3 eyes (10.71%) in the ETROP group, but no progression in the pre-ETROP group (P=0.027).

Conclusion

The pre-ETROP treatment is useful for reducing unfavorable outcomes and increasing the regression of ROP. Further, the treatment can reduce the recurrence of neovascularization and progression after treatment.

Development of Screening Criteria for Retinopathy of Prematurity in Ulaanbaatar, Mongolia, Using a Web-based Data Management System

PURPOSE

To describe a process for identifying birth weight (BW) and gestational age (GA) screening guidelines in Mongolia.

METHODS

This was a prospective cohort study in a tertiary care hospital in Ulaanbataar, Mongolia, of 193 premature infants with GA of 36 weeks or younger and/or BW of 2,000 g or less) with regression analysis to determine associations between BW and GA and the development of retinopathy of prematurity (ROP).

RESULTS

As BW and GA decreased, the relative risk of developing ROP increased. The relative risk of developing any stage of ROP in infants born at 29 weeks or younger was 2.91 (95% CI: 1.55 to 5.44; P < .001] compared to older infants. The relative risk of developing any type of ROP in infants with BW of less than 1,200 g was 2.41 (95% CI: 1.35 to 4.29; P = .003] and developing type 2 or worse ROP was 2.05 (95% CI: 0.99 to 4.25; P = .05).

CONCLUSIONS

Infants in Mongolia with heavier BW and older GA who fall outside of current United States screening guidelines of GA of 30 weeks or younger and/or BW of 1,500 g or less developed clinically relevant ROP. [J Pediatr Ophthalmol Strabismus. 2020;57(5):333-339.].

Retinopathy of Prematurity: How to Prevent the Third Epidemics in Developing Countries

Retinopathy of prematurity (ROP) is vasoproliferative disease affecting preterm infants and is a leading cause of avoidable childhood blindness worldwide. The world is currently experiencing the third epidemic of ROP, where majority of the cases are from middle-income countries. Over 40% of the world's premature infants were born in India, China, Bangladesh, Pakistan, and Indonesia. Together with other neighboring nations, this region has unique challenges in ROP management. Key aspects of the challenges including heavier and more mature infants developing severe ROP. Current strategies include adoption of national screening guidelines, telemedicine, integrating vision rehabilitation and software innovations in the form of artificial intelligence. This review overviews some of these aspects.

Incidence of Retinopathy of Prematurity in Botswana: A Prospective Observational Study

Background

Retinopathy of prematurity (ROP) is a widely recognized cause of blindness after preterm birth. The incidence of ROP is rising especially in low- and middle-income countries (LMIC) because of improved neonatal care and increased survival of very premature neonates. To date, there is no data on incidence of ROP in Botswana.

Objective

The purpose of this study was to provide initial data and determine ROP-associated risk factors from a single neonatal care center on the incidence of ROP in Gaborone, Botswana.

Methods

A prospective observational study was conducted at Princess Marina Hospital (PMH) in Gaborone, Botswana. Premature neonates with birth weights (BW) of <1,801 g or gestational age (GA) of <34 weeks were enrolled in this study. Diagnostic examinations were conducted using an indirect ophthalmoscope with 28D lens. ROP findings were classified according to the most advanced stage of ROP reached using the International Classification of ROP (2005). Data were entered into STATA version 15 statistical software for analysis.

Results

There were 264 premature infants enrolled in the study. ROP screening was performed on 200 (75.8%). Of all 264 enrolled patients 133 (50.4%) were female. The mean GA was 30.3±2.6 (range 24–37) weeks and the mean BW was 1302.2±285.9 g (range 725–2035). Out of 200 who were screened, we identified 22 with ROP with a ROP incidence of 11%. The incidence of type 1 ROP (sight-threatening) was found to be 3.5%. This study identified a significant difference in possible ROP risk factors between those infants who develop ROP and those who do not, eg, BW (p<0.001), GA (p=0.024) and blood transfusion (p=0.001).

Conclusion

This study demonstrates that ROP is a treatable cause of blindness in Botswana. Lack of a proper screening protocol, delay in diagnosis and management are plausible reasons for poor outcome in those who were diagnosed with type 1 ROP.

Postnatal Serum Insulin-Like Growth Factor I and Retinopathy of Prematurity in Latin American Infants

PURPOSE

Identifying at-risk infants for retinopathy of prematurity (ROP) is complex in countries with emerging economies as infants that lack conventional risk factors, such as low birth weight (BW) and young gestational age (GA), still go on to develop severe ROP. Potential biomarkers, like serum insulin-like growth factor 1 (IGF-1) and slow postnatal weight gain, have been identified as good predictors for ROP in developed countries. We sought to determine the relationship between IGF-1 levels and ROP in two Latin American countries where the burden of disease is still significant.

METHODS

Prospective cohort study of infants in Guadalajara, Mexico and La Plata, Argentina. Filter-paper bloodspot IGF-1 assays were performed weekly from birth until hospital discharge or 40 weeks' postmenstrual age (PMA).

RESULTS

112 infants were studied with a median BW of 1412 g (range 620 g-2390 g) and a median GA of 33 weeks (range 25-37). There was no significant difference in IGF-1 between infants who developed ROP and those who did not.

CONCLUSION

Low IGF-1 was not associated with ROP in these infants. The lack of an association between ROP and IGF-1 in Latin America supports the observation that growth-based predictive models do not perform as well in this setting where more mature babies still develop severe ROP.

Optimised retinopathy of prematurity screening guideline in China based on a 5-year cohort study

PURPOSES

To develop an optimised retinopathy of prematurity (ROP) screening guideline by adjusting the screening schedule and thresholds of gestational age (GA) and birth weight (BW).

METHODS

A multicentre retrospective cohort study was conducted based on data from four tertiary neonatal intensive care units in Shanghai, China. The medical records of enrolled infants, born from 2012 to 2016 who underwent ROP examinations, were collected and analysed. The incidence and risk factors for ROP were analysed in all infants. Postnatal age (PNA) and postmenstrual age (PMA) of infants, detected to diagnose ROP for the first time, were compared with the present examination schedule. The predictive performance of screening models was evaluated by internally validating sensitivity and specificity.

RESULTS

Of the 5606 eligible infants, ROP was diagnosed in 892 (15.9%) infants; 63 (1.1%) of them received treatment. The mean GA of ROP patients was 29.4±2.4 weeks, and the mean BW was 1260±330 g. Greater prematurity was associated with an older PNA at which ROP developed. The minimum PMA and PNA at which diagnosis of treatable ROP occurred were 32.43 and 3 weeks, respectively. The optimised criteria (GA <32 weeks or BW <1600 g) correctly predicted 98.4% type 1 ROP infants, reducing the infants requiring examinations by 43.2% when internally validated.

CONCLUSIONS

The incidence of type 1 ROP and the mean GA and BW of ROP infants have decreased in China. The suggested screening threshold and schedule may be reliably used to guide the modification of ROP screening guideline and decrease medical costs.

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.

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.

The role of semaphorins in small vessels of the eye and brain

Small vessel diseases, such as ischemic retinopathy and cerebral small vessel disease (CSVD), are increasingly recognized in patients with diabetes, dementia and cerebrovascular disease. The mechanisms of small vessel diseases are poorly understood, but the latest studies suggest a role for semaphorins. Initially identified as axon guidance cues, semaphorins are mainly studied in neuronal morphogenesis, neural circuit assembly, and synapse assembly and refinement. In recent years, semaphorins have been found to play important roles in regulating vascular growth and development and in many pathophysiological processes, including atherosclerosis, angiogenesis after stroke and retinopathy. Growing evidence indicates that semaphorins affect the occurrence, perfusion and regression of both the macrovasculature and microvasculature by regulating the proliferation, apoptosis, migration, barrier function and inflammatory response of endothelial cells, vascular smooth muscle cells (VSMCs) and pericytes. In this review, we concentrate on the regulatory effects of semaphorins on the cell components of the vessel wall and their potential roles in microvascular diseases, especially in the retina and cerebral small vessel. Finally, we discuss potential molecular approaches in targeting semaphorins as therapies for microvascular disorders in the eye and brain.

Automated diagnosis and quantitative analysis of plus disease in retinopathy of prematurity based on deep convolutional neural networks

BACKGROUND

The purpose of this study was to develop an automated diagnosis and quantitative analysis system for plus disease. The system provides a diagnostic decision but also performs quantitative analysis of the typical pathological features of the disease, which helps the physicians to make the best judgement and communicate the decisions.

METHODS

The deep learning network provided segmentation of the retinal vessels and the optic disc (OD). Based on the vessel segmentation, plus disease was classified and tortuosity, width, fractal dimension and vessel density were evaluated automatically.

RESULTS

The trained network achieved a sensitivity of 95.1% with 97.8% specificity for the diagnosis of plus disease. For detection of preplus or worse, the sensitivity and specificity were 92.4% and 97.4%. The quadratic weighted k was 0.9244. The tortuosities for the normal, preplus and plus groups were 3.61 ± 0.08, 5.95 ± 1.57 and 10.67 ± 0.50 (10⁴  cm^-3 ). The widths of the blood vessels were 63.46 ± 0.39, 67.21 ± 0.70 and 68.89 ± 0.75 μm. The fractal dimensions were 1.18 ± 0.01, 1.22 ± 0.01 and 1.26 ± 0.02. The vessel densities were 1.39 ± 0.03, 1.60 ± 0.01 and 1.64 ± 0.09 (%). All values were statistically different among the groups. After treatment for plus disease with ranibizumab injection, quantitative analysis showed significant changes in the pathological features.

CONCLUSIONS

Our system achieved high accuracy of diagnosis of plus disease in retinopathy of prematurity. It provided a quantitative analysis of the dynamic features of the disease progression. This automated system can assist physicians by providing a classification decision with auxiliary quantitative evaluation of the typical pathological features of the disease.

Using intermittent pulse oximetry to guide neonatal oxygen therapy in a low-resource context

OBJECTIVE

To evaluate the effectiveness of intermittent pulse oximetry in guiding oxygen therapy in neonates in a low-resource setting.

DESIGN AND SETTING

Prospective validation study at three hospitals in southwest Nigeria. We performed concealed continuous pulse oximetry on participants to evaluate intermittent SpO₂ monitoring.

PATIENTS

We recruited all preterm or low birthweight neonates, and all term neonates who required oxygen therapy, who were admitted to the neonatal ward(s) of the study hospitals during the study period.

MAIN OUTCOME MEASURES

Proportion of time preterm/low birthweight neonates on oxygen spent within, above and below the target SpO₂ range of 90%-95%; and the proportion of time term neonates and neonates not on oxygen spent within and below the target range of 90%-100%.

RESULTS

Preterm/low birthweight neonates receiving oxygen therapy (group A) spent 15.7% (95% CI 13.3 to 18.9) of time in the target SpO₂ range of 90%-95%. They spent 75.0% (63.6-81.1) of time above 95%, and 2.7% (1.7-5.6) of time below 85%. Term neonates and all neonates not receiving oxygen (group B) spent 97.3% (95% CI 96.4 to 98.6) of time within the target range of 90%-100%, and 0.9% (0.3-1.4) of time below 85%. Guidelines recommended SpO₂ monitoring 3 times per day for all patients, however neonates in groups A and B were monitored an average of 4.7 and 5.3 times per day, respectively.

CONCLUSIONS

To better maintain SpO₂ within the target range, preterm/low birthweight neonates on oxygen should have their SpO₂ monitored more frequently than the current 4.7 times per day. In all other neonates, however, monitoring SpO₂ 5.3 times per day appears suitable.

MicroRNAs in Vascular Eye Diseases

Since the discovery of the first microRNA (miRNA) decades ago, studies of miRNA biology have expanded in many biomedical research fields, including eye research. The critical roles of miRNAs in normal development and diseases have made miRNAs useful biomarkers or molecular targets for potential therapeutics. In the eye, ocular neovascularization (NV) is a leading cause of blindness in multiple vascular eye diseases. Current anti-angiogenic therapies, such as anti-vascular endothelial growth factor (VEGF) treatment, have their limitations, indicating the need for investigating new targets. Recent studies established the roles of various miRNAs in the regulation of pathological ocular NV, suggesting miRNAs as both biomarkers and therapeutic targets in vascular eye diseases. This review summarizes the biogenesis of miRNAs, and their functions in the normal development and diseases of the eye, with a focus on clinical and experimental retinopathies in both human and animal models. Discovery of novel targets involving miRNAs in vascular eye diseases will provide insights for developing new treatments to counter ocular NV.