Retinopathy of prematurity in very low birth weight infants and the potential protective role of indomethacin

Indomethacin Prophylaxis in Preterm Infants: Changes over Time

OBJECTIVE

Our objective was to examine changes in the use of indomethacin prophylaxis in the neonatal intensive care unit (NICU) between 2008 and 2018.

STUDY DESIGN

The design of the study included cohort of 19,715 infants born between 220/7 and 266/7 weeks' gestation from 213 NICUs. A nonparametric trend test evaluated indomethacin prophylaxis and the percentage of sites using any prophylaxis over time. We evaluated the prevalence of indomethacin prophylaxis by the center and the correlation between indomethacin prophylaxis and severe intraventricular hemorrhage prevalence among 12 centers with the largest relative change in indomethacin prophylaxis prevalence.

RESULTS

In total, 16% of infants received indomethacin prophylaxis. The use of indomethacin prophylaxis did not significantly decrease between 2008 and 2018 but it significantly decreased between 2014 and 2018 (p = 0.046). Among 74 centers with ≥10 infants included, 20% increased the use of indomethacin prophylaxis, while 57% decreased the use over the study period. Of the 12 centers with the largest relative change in indomethacin prophylaxis prevalence, 50% showed an inverse correlation between indomethacin prophylaxis prevalence and severe intraventricular hemorrhage, while 50% showed a positive correlation.

CONCLUSION

Receipt of indomethacin prophylaxis remained similar until 2014, decreased from 2014 to 2018, and varied by the center.Key Points · The receipt of indomethacin prophylaxis decreased over time.. · Center change in the use of indomethacin prophylaxis does not correlate with the center prevalence of IVH.. · Variability in the use of indomethacin prophylaxis across centers persists..

Systemic Cytokines in Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a vasoproliferative vitreoretinal disorder, is the leading cause of childhood blindness worldwide. Although angiogenic pathways have been the main focus, cytokine-mediated inflammation is also involved in ROP etiology. Herein, we illustrate the characteristics and actions of all cytokines involved in ROP pathogenesis. The two-phase (vaso-obliteration followed by vasoproliferation) theory outlines the evaluation of cytokines in a time-dependent manner. Levels of cytokines may even differ between the blood and the vitreous. Data from animal models of oxygen-induced retinopathy are also valuable. Although conventional cryotherapy and laser photocoagulation are well established and anti-vascular endothelial growth factor agents are available, less destructive novel therapeutics that can precisely target the signaling pathways are required. Linking the cytokines involved in ROP to other maternal and neonatal diseases and conditions provides insights into the management of ROP. Suppressing disordered retinal angiogenesis via the modulation of hypoxia-inducible factor, supplementation of insulin-like growth factor (IGF)-1/IGF-binding protein 3 complex, erythropoietin, and its derivatives, polyunsaturated fatty acids, and inhibition of secretogranin III have attracted the attention of researchers. Recently, gut microbiota modulation, non-coding RNAs, and gene therapies have shown promise in regulating ROP. These emerging therapeutics can be used to treat preterm infants with ROP.

Indomethacin Prophylaxis in Preterm Infants: Changes over Time

OBJECTIVE

 Our objective was to examine changes in the use of indomethacin prophylaxis in the neonatal intensive care unit (NICU) between 2008 and 2018.

STUDY DESIGN

 The design of the study included cohort of 19,715 infants born between 220/7 and 266/7 weeks' gestation from 213 NICUs. A nonparametric trend test evaluated indomethacin prophylaxis and the percentage of sites using any prophylaxis over time. We evaluated the prevalence of indomethacin prophylaxis by the center and the correlation between indomethacin prophylaxis and severe intraventricular hemorrhage prevalence among 12 centers with the largest relative change in indomethacin prophylaxis prevalence.

RESULTS

 In total, 16% of infants received indomethacin prophylaxis. The use of indomethacin prophylaxis did not significantly decrease between 2008 and 2018 but it significantly decreased between 2014 and 2018 (p = 0.046). Among 74 centers with ≥10 infants included, 20% increased the use of indomethacin prophylaxis, while 57% decreased the use over the study period. Of the 12 centers with the largest relative change in indomethacin prophylaxis prevalence, 50% showed an inverse correlation between indomethacin prophylaxis prevalence and severe intraventricular hemorrhage, while 50% showed a positive correlation.

CONCLUSION

 Receipt of indomethacin prophylaxis remained similar until 2014, decreased from 2014 to 2018, and varied by the center.Key Points · The receipt of indomethacin prophylaxis decreased over time.. · Center change in the use of indomethacin prophylaxis does not correlate with the center prevalence of IVH.. · Variability in the use of indomethacin prophylaxis across centers persists..

Stable incidence but regional differences in retinopathy of prematurity in Norway from 2009 to 2017

PURPOSE

To explore the changes over time and regional differences in the incidence of retinopathy of prematurity (ROP) in a national cohort of infants born <28 weeks' gestational age (GA).

METHODS

A population-based study of infants with GA <28 weeks in Norway from 2009 to 2017. Prospectively collected data on clinical variables and outcomes were obtained from the Norwegian Neonatal Network.

RESULTS

Of 1499 live-born infants transferred to a neonatal intensive care unit, 1156 were discharged alive. Four-hundred and fifty-eight infants (39.6%) had ROP, 152 (13.1%) had severe ROP, and 110 (9.5%) were treated for ROP. Eleven hundred infants (95.2%) had complete data sets. In a model comprising region of primary care, GA [odds ratios (OR): 0.65; 95% CI: 0.55-0.77], growth velocity (OR: 1.10; 95% CI: 1.00-2.00), medically treated patent ductus arteriosus (OR: 1.80; 95% CI: 1.19-2.72), weeks of supplemental oxygen (OR: 1.07; 95% CI: 1.03 to 1.11) and region of primary care (OR: 4.95; 95% CI: 3.05-8.04 for the pair of regions with the highest estimated OR) were significantly associated with severe ROP. Additionally, institutional differences for severe ROP were found, with ORs from 0.41 (95% CI: 0.05-3.23) to 5.36 (95% CI: 3.05-9.43) using the largest institution as reference. Incidences were stable over time after adjusting for GA. A larger proportion was treated with anti-vascular endothelial growth factor after 2011.

CONCLUSIONS

The incidence of severe ROP was stable between 2009 and 2017 in Norway. Regional and institutional differences need to be explored in future studies.

A safety review of drugs used for the treatment of retinopathy of prematurity

INTRODUCTION

Retinopathy of Prematurity (ROP) is a sight-threatening disease representing one of the main disabling diseases affecting premature newborns. Presently, ROP is treated by surgical interventions and drug therapies are limited to the off-label use of a little amount of molecules approved for other pathologies.

AREAS COVERED

Many drugs that may potentially be used in treating ROP are recently proposed, in many cases after the demonstration of their effectiveness in preclinical studies. In this review, the authors discuss safety and effectiveness of the main proposed approaches in the pharmacologic treatment of the disease, including approaches based on oxygen therapy and nutritional interventions.

EXPERT OPINION

Surgical approaches to ROP are not without side effects. However, most of the proposed pharmacologic interventions can also raise specific concerns. In particular, these approaches follow a curative paradigm and are proposed in patients once the disease has progressed, with an effectiveness that is often smaller than expected. A goal in the treatment of ROP would be moving the paradigm toward a preventive approach that could be potentially effective in treating extremely low birth weight preterm infants before ROP becomes manifest.

Pharmacologic synergism of ocular ketorolac and systemic caffeine citrate in rat oxygen-induced retinopathy

BACKGROUND

Caffeine or ketorolac decrease the risk of retinopathy of prematurity and may act synergistically to improve beneficial effect. Combination of caffeine (Caff) and ketorolac (Keto) to prevent oxygen-induced retinopathy was studied.

METHODS

Newborn rats exposed to room air (RA) or intermittent hypoxia (IH) consisting of 12% O2 during hyperoxia (50% O2) from birth (P0) had single daily IP injections of Caff from P0-P13 or saline; and/or ocular Keto (Acuvail, 0.45% ophthalmic solution) administered subcutaneously over the eyes from P5-P7. Pups were studied at P14 or placed in RA for recovery from IH (IHR) until P21. Eyes were examined for neovascularization, histopathology, growth factors, and VEGF-signaling genes.

RESULTS

Severe retinal damage noted during IHR in the untreated groups evidenced by hemorrhage, neovascularization, and oxygen-induced retinopathy (OIR) pathologies were prevented with Keto/Caff treatment. Keto and/or Caff treatment in IH also promoted retinal neural development evidenced by eye opening (92%, P < 0.001 vs. 31% in the placebo-treated IH group). No corneal pathologies were noted with Keto.

CONCLUSION

Caff or Keto given individually reduced retinal neovascularization, but the two drugs given together prevented severe OIR.

Pharmacologic interventions for the prevention and treatment of retinopathy of prematurity

Retinopathy of prematurity (ROP), a significant morbidity in prematurely born infants, is the most common cause of visual impairment and blindness in children and persists till adulthood. Strict control of oxygen therapy and prevention of intermittent hypoxia are the keys in the prevention of ROP, but pharmacologic interventions have decreased risk of ROP. Various drug classes such as methylxanthines (caffeine), VEGF inhibitors, antioxidants, and others have decreased ROP occurrence. The timing of pharmacologic intervention remains unsettled, but early prevention rather than controlling disease progression may be preferred. These drugs act through different mechanisms, and synergistic approaches should be considered to maximize efficacy and safety.

Screening for retinopathy of prematurity in a large tertiary neonatal intensive care unit in Turkey: frequency and risk factors

PURPOSE

We aimed to determine applicable guidelines for screening of retinopathy of prematurity (ROP), and evaluate the contribution of risk factors for severe ROP.

METHODS

A prospective cohort study of neonates with a gestational age (GA) < 34 weeks or birth weight < 2000g who were admitted to the Neonatal Intensive Care Unit (NICU) of a tertiary level hospital was conducted. The study group was classified into three groups according to eye examination findings as no ROP, mild ROP and severe ROP.

RESULTS

Of the 700 neonates screened, the frequencies of ROP for any stage and severe ROP were 32.7% and 3.1%, respectively. Laser photocoagulation was needed in 9.6% of neonates with ROP. None of the neonates with a GA ≥ 31 weeks required treatment. Any ROP was detected in 199 (53.6%) of the babies < 32 weeks (n = 371), 22 (5.9%) of whom were treated with laser photocoagulation. Independent risk factors for severe ROP in babies < 32 weeks GA were birth weight, duration of mechanical ventilation and patent ductus arteriosus (PDA).

CONCLUSION

This is the largest prospective cohort study including infants younger than 34 weeks GA from Turkey. Our data which belongs to the last 1-year period shows lower incidence of severe ROP when compared to previous reports from Turkey. According to our data, screening babies smaller than 32 weeks GA or 1500g birth weight seems reasonable. In the presence of long duration of mechanical ventilation and PDA, screening should be intensified.