Role of cytokines and treatment algorithms in retinopathy of prematurity

Essential Role of Multi-Omics Approaches in the Study of Retinal Vascular Diseases

Retinal vascular disease is a highly prevalent vision-threatening ocular disease in the global population; however, its exact mechanism remains unclear. The expansion of omics technologies has revolutionized a new medical research methodology that combines multiple omics data derived from the same patients to generate multi-dimensional and multi-evidence-supported holistic inferences, providing unprecedented opportunities to elucidate the information flow of complex multi-factorial diseases. In this review, we summarize the applications of multi-omics technology to further elucidate the pathogenesis and complex molecular mechanisms underlying retinal vascular diseases. Moreover, we proposed multi-omics-based biomarker and therapeutic strategy discovery methodologies to optimize clinical and basic medicinal research approaches to retinal vascular diseases. Finally, the opportunities, current challenges, and future prospects of multi-omics analyses in retinal vascular disease studies are discussed in detail.

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.

Use of an online screening algorithm - Weight, Insulin-derived growth factor 1, Neonatal Retinopathy of Prematurity (WINROP) for predicting retinopathy of prematurity in Indian preterm babies

Purpose:

Inopathy of prematurity (WINROP) Weight, insulin-derived growth factor 1, neonatal ROP algorithm is an online tool that has been validated as a predictor of retinopathy of prematurity (ROP) in various countries. The current study was designed to evaluate the predictive ability of WINROP algorithm (http://winrop.com) using postnatal weight gain in detecting Type 1 ROP in Indian babies.

Methods:

Prospective single centre observational study of 153 consecutive preterm babies who were eligible for screening for ROP as per the standard guidelines. Sixteen babies were excluded from the study because of various reasons. Thirty-five babies had gestational age ≥32 weeks and were ineligible for WINROP algorithm. Online WINROP algorithm was used for 102 babies with gestation at birth less than 32 weeks. The alarms triggered by WINROP were documented.

Results:

Laser treatment was done in 30 babies who developed Type 1 ROP. Of these, WINROP alarm was signaled in 24 babies and 6 babies developed ROP without any WINROP alarm. These babies had associated comorbidities like respiratory distress syndrome, patent ductus arteriosus, bacterial sepsis, and ventilatory support. WINROP alarm was significantly associated with Type 1 ROP (P < 0.001). The sensitivity of WINROP was 80% and specificity was 80.6% with a positive predictive value of 63.2% and negative predictive value of 90.6% in detecting Type 1 ROP. In the present study, no baby who was ineligible for WINROP developed Type 1 ROP.

Conclusion:

WINROP provides a novel online monitoring screening tool for identifying babies at risk of developing Type 1 ROP. In our cohort, none of the babies whose period of gestation was more than or equal to 32 weeks developed sight threatening Type 1 ROP. WINROP algorithm may also be useful in Indian population.

Experimental Evidence Behind Clinical Trial Outcomes in Retinopathy of Prematurity

Treatment of severe retinopathy of prematurity (ROP) has evolved over the last decade. This article reviews recent clinical trials and experimental evidence that supports clinical outcomes and observations, including the efficacy of anti-vascular endothelial growth factor (VEGF) agents in reducing the vascular activity of severe ROP, and the mechanisms behind recurrent stage 3 ROP and plus disease in some infants treated with anti-VEGF agents. Also discussed will be current imaging modalities that link experimental models of ROP with longitudinal human studies and which provide exciting future opportunities to enhance the understanding of pathophysiology of ROP and improve treatments. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:228-234.].

A review of treatment for retinopathy of prematurity

Introduction

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness worldwide.

Areas covered

Recent methods to identify and manage treatment-warranted vascularly active ROP are recognized and being compared to standard care by laser treatment in prospective large-scale clinical studies. Pharmacologic anti-angiogenic (anti-VEGF) treatment has changed the natural history of vascularly active ROP by reducing stage 3 intravitreal neovascularization and extending physiologic retinal vascularization in many infants. Tractional retinal detachments in stage 4 ROP after treatment with anti-VEGF agents show additional fibrovascular complexity compared to eyes treated with laser only. We review current management and outcomes for vascularly active and fibrovascular retinal detachment in ROP (stages 3, 4, 5 ROP), highlighting the evidence from recent clinical studies. Included are technical details important in surgery for retinal detachment in ROP. Literature searches were employed through PubMed.

Expert opinion

Methods in pediatric imaging, safer pharmacologic treatments, and surgical techniques continue to advance to improve future ROP outcomes.

Late-onset sepsis caused by Gram-negative bacteria in very low birth weight infants: a systematic review

INTRODUCTION

Very low birth weight (VLBW) infants are highly susceptible to late-onset sepsis (LOS). Compared to Gram-positive bacteria, Gram-negative bacteria are less common to cause LOS, but are associated with a more severe clinical manifestation, higher mortality, and increased risk of neonatal morbidity. So far, the clinical picture of late-onset Gram-negative sepsis (LOGNS) in VLBW infants has not been elucidated. An up-to-date and thorough understanding of the clinical picture of LOGNS in VLBW infants is important to optimize current anti-sepsis protocols. Areas covered: Literature published in the last three decades was searched for data on the epidemiology, pathogen profile, risk factors, clinical manifestations, laboratory parameters, mortality, and short-term and long-term morbidity of LOGNS in VLBW infants. Expert opinion: Gram-negative bacteria are major contributors of neonatal morbidity and mortality in VLBW infants with LOS, potentially posing a significant disease burden. Unravelling the pathogen-specific clinical picture of LOGNS and the underlying mechanisms is of particular interest. VLBW infants may differ from more mature neonates in terms of disease burden and clinical course of LOGNS. Epidemiologic studies aided by advanced molecular techniques may help to develop anti-sepsis protocols specialized for VLBW infants, with strategies targeting Gram-negative bacteria.

Beyond sepsis: Staphylococcus epidermidis is an underestimated but significant contributor to neonatal morbidity

Staphylococcus epidermidis accounts for the majority of cases of neonatal sepsis. Moreover, it has been demonstrated to be associated with neonatal morbidities, such as bronchopulmonary dysplasia (BPD), white matter injury (WMI), necrotizing enterocolitis (NEC) and retinopathy of prematurity (ROP), which affect short-term and long-term neonatal outcome. Imbalanced inflammation has been considered to be a major underlying mechanism of each entity. Conventionally regarded as a harmless commensal on human skin, S. epidermidis has received less attention than its more virulent relative Staphylococcus aureus. Particularities of neonatal innate immunity and nosocomial environmental factors, however, may contribute to the emergence of S. epidermidis as a significant nosocomial pathogen. Neonatal host response to S. epidermidis sepsis has not been fully elucidated. Evidence is emerging regarding the implication of S. epidermidis sepsis in the pathogenesis of neonatal inflammatory diseases. This review focuses on the interplay among S. epidermidis, neonatal innate immunity and inflammation-driven organ injury.

Chronic Placental Inflammation as a Risk Factor of Severe Retinopathy of Prematurity

Background

Chronic placental inflammation (CPI) has been implicated in the pathogenesis of diseases in premature infants, whereas retinopathy of prematurity (ROP) is a major complication primarily affecting preterm and very low-birth-weight (VLBW) infants. This study aims to investigate the association between CPI and ROP in VLBW infants.

Methods

We performed a retrospective review of clinical records of VLBW infants born between 2013 and 2016. Placental pathology findings including CPI cases were analyzed using logistic regression to study infants’ morbidities and other clinical characteristics.

Results

A total of 402 infants with a mean (standard deviation) gestational age of 28.5 (2.8) weeks and birth weight of 1,027.2 (304.4) g were included. The incidence of ROP was 24.1%. CPI was found in 90 infants (22.4%), among which 28.9% (26 of 90) developed ROP, and 21.1% (19 of 90) underwent laser photocoagulation. Lower gestational age, lower birth weight, longer duration of oxygen supply, and presence of CPI were associated with the development of ROP. After adjustment for gestational age, birth weight, sex, duration of oxygen supply, and other overlapping placental pathology, CPI was associated with the odds for type 1 ROP that required laser photocoagulation (adjusted odds ratio, 2.739; 95% confidence interval, 1.112 to 6.749; p = .029).

Conclusions

CPI was associated with severe ROP requiring treatment with laser photocoagulation in VLBW infants.

SiRNA silencing of VEGF, IGFs, and their receptors in human retinal microvascular endothelial cells

Vascular endothelial growth factor (VEGF) is a potent mitogen that regulates proliferation, migration, and tube formation of endothelial cells (EC). VEGF has recently become a target for severe retinopathy of prematurity (ROP) therapy. We tested the hypothesis that a specific VEGF isoform and/or receptor acts synergistically with insulin-like growth factor (IGF)-I to alter normal retinal microvascular EC angiogenesis and RNA interference can be used to reverse VEGF effects. We used small interfering RNA (SiRNA) transfection to target VEGF isoforms, IGFs, and their receptors in human retinal microvascular endothelial cells (HRECs). Media was collected at 24 and 48 hours post transfection for measurement of VEGF, sVEGFR-1 and IGF-1 levels; and HRECs were assessed for migration, tube formation, VEGF signaling genes, oxidative stress, and immune-reactivity. At 24 hours post transfection VEGF increased with VEGFR-2; sVEGFR-1 decreased with VEGF₁₆₅, VEGFR-2, and IGF-1R; and IGF-I increased with VEGF₁₈₉, VEGFR-1, IGF-2R, IGF+VEGF₁₆₅, and IGF+VEGF₁₂₁. IGF-I transfection with each VEGF isoform reduced sphere- forming and migration capacities with robust upregulation of caspase-9, COX-2, MAPK, PKC, and VEGF receptors. At 48 hours, the effects were reversed with a majority of genes downregulated, except with IGF-I and NP-1 transfection. Using RNA interference for targeted inhibition of VEGF isoforms in conjunction with IGF-I may be preferable for suppression of HREC overgrowth in vasoproliferative retinopathies such as ROP.

Tissue regeneration using endothelial colony-forming cells: promising cells for vascular repair

Repairing and rebuilding damaged tissue in diseased human subjects remains a daunting challenge for clinical medicine. Proper vascular formation that serves to deliver blood-borne nutrients and adequate levels of oxygen and to remove wastes is critical for successful tissue regeneration. Endothelial colony-forming cells (ECFC) represent a promising cell source for revascularization of damaged tissue. ECFCs are identified by displaying a hierarchy of clonal proliferative potential and by pronounced postnatal vascularization ability in vivo. In this review, we provide a brief overview of human ECFC isolation and characterization, a survey of a number of animal models of human disease in which ECFCs have been shown to have prominent roles in tissue repair, and a summary of current challenges that must be overcome before moving ECFC into human subjects as a cell therapy.

PDGF-C and PDGF-D in ocular diseases

PDGFs and their receptors are critical regulators of numerous tissues and organs, including the eye. Extensive studies have shown that PDGFs and their receptors play critical roles in many ocular neovascular diseases, such as neovascular age-related macular degeneration, retinopathy of prematurity, and proliferative vitreoretinopathy. In addition, PDGFs and PDGFRs are also important players in ocular diseases involving the degeneration of retinal neuronal and vascular cells, such as glaucoma and retinitis pigmentosa. Due to their critical roles in the pathogenesis of many blinding ocular diseases, the PDGFs and PDGFRs have been considered as important target molecules for the treatment of eye diseases. PDGF-C and PDGF-D are relatively new members of the PDGF family and are potent angiogenic and survival factors. Recent studies have demonstrated their important roles in different types of eye diseases. Thus, modulating PDGF-C and PDGF-D activities may have therapeutic values for the treatment of ocular neovascular and degenerative diseases. This review mainly summarizes the recent advances on PDGF-C and PDGF-D biology in relationship to some major ocular diseases.