Poor postnatal weight gain: a risk factor for severe retinopathy of prematurity

Postnatal weight gain and retinopathy of prematurity in preterm infants: a population-based retrospective cohort study

OBJECTIVE

Infants who meet the screening guidelines for retinopathy of prematurity (ROP) based on birth weight and gestational age undergo serial ophthalmological examinations for its detection and treatment. However, <10% of patients require treatment, and less than half develop ROP. Poor postnatal weight gain has been reported to be a strong indicator of ROP development; however, the information regarding this is unclear. Therefore, this study aimed to determine the relationship between postnatal weight gain and ROP development in preterm infants.

METHODS

The data of 675 preterm infants with gestational age ≤32 weeks, who were hospitalized in our neonatal intensive care unit, were obtained retrospectively from file records. The infants' demographic characteristics, clinical findings, and weekly weight gain (g/kg/day) during the first 8 weeks were recorded. The univariate was used to examine the risk factors for ROP followed by multivariate regression.

RESULTS

The incidence of ROP in the infants included in the study was 41% (n = 278) and 13.3% (n = 37) of them required treatment. In the infants of the group that developed ROP, the mean birth weight and gestational age were significantly lower than those in the group that did not develop ROP (973 ± 288 and 1301 ± 349 g, p = 0.001 and 28.48 ± 1.95 and 30.08 ± 1.60 weeks, p = 0.001, respectively). As the gestational week and birth weight decreased, ROP development and the risk of ROP-requiring treatment increased. In the infants of the group that developed ROP, the mean weight gain in the postnatal third week was detected as significantly lower compared to those in the group that did not develop ROP (13.9 ± 8.2 and 15.4 ± 6.8 g, p = 0.034). On multiple logistic regression analysis, birth weight (<750 g) (odds ratio [OR], 8.67; 95% confidence interval [CI], 3.99-18.82, p = 0.001), blood transfusion (OR, 2.39; 95% CI, 1.34-4.24, p = 0.003), necrotizing enterocolitis (OR, 4.79; 95% CI, 1.05-26.85, p = 0.045), bronchopulmonary dysplasia (OR, 2.03; 95% CI, 1.22-3.36, p = 0.006), antenatal steroid therapy (OR, 1.60; 95% CI, 1.05-2.43, p = 0.028), surfactant administration (OR, 2.06; 95% CI, 1.32-3.2, p = 0.001) were independent risk factors for ROP development.

CONCLUSION

Postnatal weight gain may not be an accurate predictor of ROP development after adjusting for confounding factors. However, the analysis of independent risk factors that influenced the development of ROP revealed a statistically significant effect in cases of low birth weight, blood transfusion, necrotizing enterocolitis, bronchopulmonary dysplasia, and antenatal steroid and surfactant therapies. These findings may help ophthalmologists and neonatologists to pay special attention to this patient group during ROP scanning.

Clinical and Growth Correlates of Retinopathy of Prematurity in Preterm Infants with Surgical Necrotizing Enterocolitis and Intestinal Perforation

OBJECTIVE

 This study aimed to identify the clinical and growth parameters associated with retinopathy of prematurity (ROP) in infants with necrotizing enterocolitis (NEC) and spontaneous ileal perforation (SIP).

STUDY DESIGN

 We conducted a retrospective cohort study that compared clinical data before and after NEC/SIP onset in neonates, categorizing by any ROP and severe ROP (type 1/2) status.

RESULTS

 The analysis included 109 infants with surgical NEC/SIP. Sixty infants (60/109, 55%) were diagnosed with any ROP, 32/109 (29.3%) infants (22% type 1 and 7.3% type 2) with severe ROP. On univariate analysis, those with severe ROP (32/109, 39.5%) were of lower median gestational age (GA, 23.8 weeks [23.4, 24.6] vs. 27.3 [26.3, 29.0], p < 0.001), lower median birth weight (625 g [512, 710] vs. 935 [700, 1,180], p < 0.001) and experienced higher exposure to clinical chorioamnionitis (22.6 vs. 2.13%, p < 0.006), and later median onset of ROP diagnosis (63.0 days [47.0, 77.2] vs. 29.0 [19.0, 41.0], p < 0.001), received Penrose drain placement more commonly (19 [59.4%] vs. 16 [34.0%], p = 0.04), retained less residual small bowel (70.0 cm [63.1, 90.8] vs. 90.8 [72.0, 101], p = 0.007) following surgery, were exposed to higher FiO2 7 days after birth (p = 0.001), received ventilation longer and exposed to higher FiO2 at 2 weeks (p < 0.05) following NEC and developed acute kidney injury (AKI) more often (25 [86.2%] vs. 20 [46.5%], p = 0.002) than those without ROP. Those with severe ROP had lower length, weight for length, and head circumference z scores. In an adjusted Firth's logistic regression, GA (adjusted odds ratio [aOR] = 0.51, 95% confidence interval [CI]: [0.35, 0.76]) and diagnosis at later age (aOR = 1.08, 95% CI: [1.03, 1.13]) was shown to be significantly associated with any ROP.

CONCLUSION

 Infants who develop severe ROP following surgical NEC/SIP are likely to be younger, smaller, have been exposed to more O2, develop AKI, and grow poorly compared with those did not develop severe ROP.

KEY POINTS

· Thirty percent of infants with NEC/SIP had severe ROP.. · Those with severe ROP had poor growth parameters before and after NEC/SIP.. · Risk factors based ROP prevention strategies are needed to have improved ophthalmic outcomes..

Neonatal sepsis as a cause of retinopathy of prematurity: An etiological explanation

Retinopathy of prematurity (ROP) is a complex neonatal disorder with multiple contributing factors. In this paper we have mounted the evidence in support of the proposal that neonatal sepsis meets all requirements for being a cause of ROP (not a condition, mechanism, or even innocent bystander) by means of initiating the early stages of the pathomechanism of ROP occurrence, systemic inflammation. We use the model of etiological explanation, which distinguishes between two overlapping processes in ROP causation. It can be shown that sepsis can initiate the early stages of the pathomechanism via systemic inflammation (causation process) and that systemic inflammation can contribute to growth factor aberrations and the retinal characteristics of ROP (disease process). The combined contribution of these factors with immaturity at birth (as intrinsic risk modifier) and prenatal inflammation (as extrinsic facilitator) seems to provide a cogent functional framework of ROP occurrence. Finally, we apply the Bradford Hill heuristics to the available evidence. Taken together, the above suggests that neonatal sepsis is a causal inducer of ROP.

Characteristics of posterior zone I retinopathy of prematurity

OBJECTIVE

To report the demographic profile and clinical characteristics of retinopathy of prematurity (ROP) in posterior Zone I.

METHODS

In a partly retrospective (ten years) and partly prospective (one year) study, we analysed the demographic profile and clinical characteristics of babies with ROP in posterior Zone I.

RESULTS

The study included 130 eyes of 67 infants with a mean gestational age and birth weight of 29.3 (±2.2) weeks and 1217.3 (±381.9) grams, respectively. All babies had received unblended oxygen. In 47 of 51 (91.1%) babies, the weekly weight gain was <100 g (details were not available in 16 babies). The ROP subtypes included aggressive, threshold, hybrid, stage 4, and atypical types in 78 (60%), 20 (15.4%), 11 (8.5%), 15 (11.5%), and 6 (4.6%) eyes, respectively. Fibrovascular proliferation, when present, was prominent nasally, occasionally overriding the disc margin. Extensive arteriovenous tortuosity was more prominent than vascular dilatation. Atypical observations included bleb-like detachment (6 eyes; 4.6%) and candle wax-like preretinal deposits (23 eyes; 17.7%).

CONCLUSIONS

Retinopathy of Prematurity in posterior Zone I in this cohort was strongly associated with 100% unblended oxygen supplementation, poor weight gain, and multiple systemic co-morbidities. ROP in posterior zone 1 has a distinct profile with several atypical characteristics different from ROP in other zones.

Gut Microbiome and Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a leading cause of childhood blindness worldwide, is strongly associated with gestational age and weight at birth. Yet, many extremely preterm infants never develop ROP or develop only mild ROP with spontaneous regression. In addition, a myriad of other factors play a role in the retinal pathology, one of which may include the early gut microbiome. The complications associated with early gestational age include dysbiosis of the dynamic neonatal gut microbiome, as evidenced by the development of often concomitant conditions, such as necrotizing enterocolitis. Given this, alongside growing evidence for a gut-retina axis, there is an increasing interest in how the early intestinal environment may play a role in the pathophysiology of ROP. Potential mechanisms include dysregulation of vascular endothelial growth factor and insulin-like growth factor 1. Furthermore, the gut microbiome may be impacted by other known risk factors for ROP, such as intermittent hypoxia and sepsis treated with antibiotics. This mini-review summarizes the literature supporting these proposed avenues, establishing a foundation to guide future studies.

Postnatal hyperglycemia alters amino acid profile in retinas (model of Phase I ROP)

Nutritional deprivation occurring in most preterm infants postnatally can induce hyperglycemia, a significant and independent risk factor for suppressing physiological retinal vascularization (Phase I retinopathy of prematurity (ROP)), leading to compensatory but pathological neovascularization. Amino acid supplementation reduces retinal neovascularization in mice. Little is known about amino acid contribution to Phase I ROP. In mice modeling hyperglycemia-associated Phase I ROP, we found significant changes in retinal amino acids (including most decreased L-leucine, L-isoleucine, and L-valine). Parenteral L-isoleucine suppressed physiological retinal vascularization. In premature infants, severe ROP was associated with a higher mean intake of parenteral versus enteral amino acids in the first two weeks of life after adjustment for treatment group, gestational age at birth, birth weight, and sex. The number of days with parenteral amino acids support independently predicted severe ROP. Further understanding and modulating amino acids may help improve nutritional intervention and prevent Phase I ROP.

Pathophysiology of Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a complex disease involving development of the neural retina, ocular circulations, and other organ systems of the premature infant. The external stresses of the ex utero environment also influence the pathophysiology of ROP through interactions among retinal neural, vascular, and glial cells. There is variability among individual infants and presentations of the disease throughout the world, making ROP challenging to study. The methods used include representative animal models, cell culture, and clinical studies. This article describes the impact of maternal-fetal interactions; stresses that the preterm infant experiences; and biologic pathways of interest, including growth factor effects and cell-cell interactions, on the complex pathophysiology of ROP phenotypes in developed and emerging countries.

Development of a joint set of database parameters for the EU-ROP and Fight Childhood Blindness! ROP Registries

BACKGROUND/AIMS

The incidence of retinopathy of prematurity (ROP) is increasing and treatment options are expanding, often without accompanying safety data. We aimed to define a minimal, patient-centred data set that is feasible to collect in clinical practice and can be used collaboratively to track and compare outcomes of ROP treatment with a view to improving patient outcomes.

METHODS

A multinational group of clinicians and a patient representative with expertise in ROP and registry development collaborated to develop a data set that focused on real-world parameters and outcomes that were patient centred, minimal and feasible to collect in routine clinical practice.

RESULTS

For babies receiving ROP treatment, we recommend patient demographics, systemic comorbidities, ROP status, treatment details, ophthalmic and systemic complications of treatment, ophthalmic and neurodevelopmental outcomes at initial treatment, any episodes of retreatment and follow-up examinations in the short and long-term to be collected for use in ROP studies, registries and routine clinical practice.

CONCLUSIONS

We recommend these parameters to be used in registries and future studies of ROP treatment, to reduce the variation seen in previous reports and allow meaningful assessments and comparisons. They form the basis of the EU-ROP and the Fight Childhood Blindness! ROP Registries.

Clinical and Growth Correlates of Retinopathy of Prematurity in Preterm infants with Surgical Necrotizing Enterocolitis and intestinal Perforation

Background

we sought to determine the clinical and growth parameters associated with retinopathy of prematurity (ROP) in infants with necrotizing enterocolitis (NEC) and spontaneous ileal perforation (SIP).

Methods

Retrospective cohort study comparing clinical information before and following NEC/SIP onset in neonates with and without severe ROP (Type 1 and 2).

Results

Those with severe ROP (32/109, 39.5%) had lower GA, BW, chorioamnionitis, later median onset of ROP diagnosis and received Penrose drain and had higher AKI, poor weight z scores, poor linear growth, longer duration of ventilation and higher FIo2 than those without ROP following NEC/SIP. The GA and diagnosis at later age remained significant for any ROP on multi regression modelling.

Conclusion

The surgical NEC/SIP infants with severe ROP were more likely to be younger, smaller, had AKI, had higher oxygen exposure and poor weight gain and linear growth than those without severe ROP.

Retinopathy of prematurity: risk stratification by gestational age

OBJECTIVE

To identify gestational age (GA) specific risk factors for severe ROP (sROP).

STUDY DESIGN

Single-center cohort stratified by GA into <24 weeks, 24-26 weeks and ≥27 weeks.

RESULTS

132/1106 (11.9%) developed sROP. Time to full feeds was the only risk factor [HR 1.003 (1.001-1.006), p = 0.04] for infants<24 weeks GA. For infants 24-26 weeks GA, a higher GA was protective [HR 0.66 (0.51-0.85), p < 0.01], whereas steroids for bronchopulmonary dysplasia (BPD) [HR 2.21 (1.28-3.26), p < 0.01], patent ductus arteriosus (PDA) ligation [HR 1.99 (1.25-3.11), p < 0.01] and use of nitric oxide [HR 1.96 (1.11-3.30), p = 0.01] increased the hazard of sROP. Increasing birthweight was protective [HR 0.70 (0.54-0.89), p < 0.01] in infants ≥27 weeks GA. Cumulative hazard of sROP reached 1.0 by fifteen weeks for <24 weeks GA, 0.4 by twenty weeks for 24-26 weeks GA, and 0.05 by twenty weeks after birth for ≥27 weeks GA.

CONCLUSIONS

Risk factors, cumulative hazard, and time to sROP vary by GA.

Modifiable Risk Factors and Preventative Strategies for Severe Retinopathy of Prematurity

Severe ROP is characterized by the development of retinal fibrovascular proliferation that may progress to retinal detachment. The purpose of this report is to review five of the most common and well-studied perinatal and neonatal modifiable risk factors for the development of severe ROP. Hyperoxemia, hypoxia, and associated prolonged respiratory support are linked to the development of severe ROP. While there is a well-established association between clinical maternal chorioamnionitis and severe ROP, there is greater variability between histologic chorioamnionitis and severe ROP. Neonatal sepsis, including both bacterial and fungal subtypes, are independent predictors of severe ROP in preterm infants. Although there is limited evidence related to platelet transfusions, the risk of severe ROP increases with the number and volume of red blood cell transfusions. Poor postnatal weight gain within the first six weeks of life is also strongly tied to the development of severe ROP. We also discuss preventative strategies that may reduce the risk of severe ROP. Limited evidence-based studies exist regarding the protective effects of caffeine, human milk, and vitamins A and E.

In-hospital outcomes in preterm and small-for-gestational-age newborns: a cohort study

Objective

To compare in-hospital outcomes between small-for-gestational-age and appropriate-for-gestational-age preterm neonates who needed intensive care.

Methods

A retrospective cohort study with preterm newborns, from January to December 2017. The results are presented as median, frequency, and odds ratio. Numerical variables were compared using the Wilcoxon test. Categorical variables were compared using the χ² test. We considered p<0.05 as significant.

Results

Out of 129 preterm newborns included, 20.9% were small-for-gestational-age. Median gestational age was 31 2/7 weeks, birthweight was 1,450g, and length of hospital stay was 39 days. Preterm small-for-gestational-age newborns presented a higher chance of peri-intraventricular hemorrhage (odds ratio of 3.23; p=0.02), retinopathy of prematurity (odds ratio of 2.78 p=0.02), patent ductus arteriosus (odds ratio of 2.50; p=0.04) and a lower chance of presumptive early-onset sepsis (odds ratio of 0.37; p=0.03).

Conclusion

Preterm small-for-gestational-age neonates were associated with peri-intraventricular hemorrhage, retinopathy of prematurity and patent ductus arteriosus. This emphasizes the need of special care for these neonates.

Time to regain birth weight - a marker to predict the severity of retinopathy of prematurity?

BACKGROUND

Poor weight gain in the first few weeks of life has been studied as a predictor of retinopathy of prematurity (ROP). Our aim was to assess whether time taken to regain birthweight (BW) be used as an additional marker to identify infants with type 1 ROP.

METHODS

In this retrospective study, preterm infants (< 27 weeks gestational age at birth) born during the period from 1/1/2010-31/12/2015 at a tertiary neonatal intensive care unit in Australia were included. Twenty-seven preterm infants with Type 1 ROP were identified. Controls (No ROP or ROP other than type 1) were matched with cases on gestational age at birth and BW (1:4 ratio). Data were collected from the database and medical records.

RESULTS

The median (IQR) gestational age for Type 1 ROP and control groups were 24 (24-26) and 25 (24-26) weeks respectively and median (IQR) BW for Type 1 ROP and control groups were 675 (635-810) and 773 (666-884) grams respectively. Preterm infants with Type 1 ROP were more likely to be small for gestational age (SGA) (18.5% vs 3.7%, p = 0.015) and had increased weeks on oxygen therapy (median 11.9 vs 9.1, p = 0.028). Time to regain BW was longer in preterm infants with type 1 ROP than controls but did not reach statistical significance (median 9 vs 7 days, OR 1.08, 95% CI 1.00-1.17, p = 0.059) adjusted for SGA and duration of oxygen therapy. The area under the curve from the time to regain BW model with adjustment for SGA and duration of oxygen therapy was 0.73 (95% CI 0.62-0.83).

CONCLUSION

We hypothesize that time to regain BW has potential to aid prediction of Type 1 ROP and this warrants further investigation in a larger prospective study.

Metabolism in Retinopathy of Prematurity

Retinopathy of prematurity is defined as retinal abnormalities that occur during development as a consequence of disturbed oxygen conditions and nutrient supply after preterm birth. Both neuronal maturation and retinal vascularization are impaired, leading to the compensatory but uncontrolled retinal neovessel growth. Current therapeutic interventions target the hypoxia-induced neovessels but negatively impact retinal neurons and normal vessels. Emerging evidence suggests that metabolic disturbance is a significant and underexplored risk factor in the disease pathogenesis. Hyperglycemia and dyslipidemia correlate with the retinal neurovascular dysfunction in infants born prematurely. Nutritional and hormonal supplementation relieve metabolic stress and improve retinal maturation. Here we focus on the mechanisms through which metabolism is involved in preterm-birth-related retinal disorder from clinical and experimental investigations. We will review and discuss potential therapeutic targets through the restoration of metabolic responses to prevent disease development and progression.

Novel multinutrient human milk-based human milk fortifier promotes growth and tolerance in premature infants

BACKGROUND

The objective of this study was to determine whether human milk supplemented with a novel human milk-based human milk fortifier (Novel HMF), compared with a bovine milk-based HMF (Bovine HMF), supports preterm infant growth through 36 weeks' postmenstrual age (PMA).

METHODS

This single-center, prospective trial compared growth and nutrition outcomes of preterm infants provided a human milk-based diet (mother's own milk or donor milk) supplemented with a Novel HMF with historic controls provided Bovine HMF. Preterm infants with an estimated gestational age (EGA) between 23 and 33 weeks' PMA and birth weight between 750 and 1800 g were eligible for study inclusion. Weight, length, and head circumference (HC) were monitored weekly. The occurrence of late-onset sepsis, nil per os (NPO) days, necrotizing enterocolitis, metabolic acidosis, and serious adverse events were monitored.

RESULTS

Birth weight, length, HC, and EGA were similar between the Novel HMF (n = 37) and Bovine HMF (n = 49) groups. The days to regain birth weight was shorter in the Novel HMF group (9.4 ± 4.0 vs 11.4 ± 4.8, P = .0343), with similar weight gain (g/day) from birth to 36 weeks' PMA. Adjusted weight growth velocity (g/kg/day) was significantly higher in the Novel HMF group at 14 and 21 days but similar at 36 weeks' PMA. The Novel HMF group experienced fewer NPO days with a similar total number of feeding days.

CONCLUSIONS

A novel, multinutrient, human milk-based HMF is well tolerated and meets the nutrition needs of preterm infants.

Association between postnatal weight gain and need for treatment in retinopathy of prematurity

OBJECTIVE

To study the association between gestational age (GA) and weight at birth and the development of retinopathy of prematurity (ROP), and in particular the link between postnatal weight gain during the first 6 weeks and need for ROP treatment.

MATERIAL AND METHODS

Retrospective observational study of premature infants who underwent ophthalmoscopy at Hospital Universitari Vall d'Hebron in Barcelona, Spain, between June 2017 and December 2018. We collected data on obstetric and birth characteristics, comorbidities, GA and weight at birth, and weekly weight for the first 6 weeks.

RESULTS

Ninety patients with a mean ± SD GA of 26.87 ± 1.90 weeks and a mean birth weight of 884.29 ± 227.40 g were studied. The mean weight at 6 weeks was 1656.89 ± 478.51 g, which corresponds to a gain of 776.17 ± 298.12 g. Thirty-seven patients (41.1%) were diagnosed with ROP and nine (10%) needed treatment. Significant predictors of the need for treatment in patients with ROP were GA (p = .018) and weight at 6 weeks (p = .021). Birth weight was not significant (p = .361).

CONCLUSIONS

GA and weight gain during the first 6 weeks of life are significantly associated with the need for treatment in infants with ROP. Sex and birth weight were not significant predictors. Postnatal weight gain at 6 weeks is predictive of the need for ROP treatment.

Perinatal determinants of growth trajectories in children born preterm

BACKGROUND

A growing amount of evidence indicates in utero and early life growth has profound, long-term consequences for an individual's health throughout the life course; however, there is limited data in preterm infants, a vulnerable population at risk for growth abnormalities.

OBJECTIVE

To address the gap in knowledge concerning early growth and its determinants in preterm infants.

METHODS

A retrospective cohort study was performed using a population of preterm (< 37 weeks gestation) infants obtained from an electronic medical record database. Weight z-scores were acquired from discharge until roughly two years corrected age. Linear mixed effects modeling, with random slopes and intercepts, was employed to estimate growth trajectories.

RESULTS

Thirteen variables, including maternal race, hypertension during pregnancy, preeclampsia, first trimester body mass index, multiple status, gestational age, birth weight, birth length, head circumference, year of birth, length of birth hospitalization stay, total parenteral nutrition, and dextrose treatment, were significantly associated with growth rates of preterm infants in univariate analyses. A small percentage (1.32% - 2.07%) of the variation in the growth of preterm infants can be explained in a joint model of these perinatal factors. In extremely preterm infants, additional variation in growth trajectories can be explained by conditions whose risk differs by degree of prematurity. Specifically, infants with periventricular leukomalacia or retinopathy of prematurity experienced decelerated rates of growth compared to infants without such conditions.

CONCLUSIONS

Factors found to influence growth over time in children born at term also affect growth of preterm infants. The strength of association and the magnitude of the effect varied by gestational age, revealing that significant heterogeneity in growth and its determinants exists within the preterm population.

Efficacy of the WINROP algorithm for retinopathy of prematurity screening in Southern China

AIM

To evaluate the predicting efficacy of severe retinopathy of prematurity (ROP) by the WINROP algorithm (http://winrop.com) in Southern China.

METHODS

All preterm infants with the gestational age (GA) less than 32wk were included. Their ROP screening results and serial postnatal body weight were analysed retrospectively. Weekly body weight was entered into and measured by the WINROP system. The outcomes were analysed, and the sensitivity, specificity, positive predictive value and negative predictive value (NPV) were calculated.

RESULTS

Totally 432 infants with a median GA of 30.0 (24.0-31.9)wk, and a median birth weight (BW) of 1360 (540-2700) g were included. Among these 432 infants, 50 were diagnosed as type 1 ROP but only 28 were identified by the WINROP algorithm. The sensitivity was 56% (28/50) and the NPV was 92% (252/274). However, for infants with BW <1000 g or GA <28wk, the sensitivity was 93.8% (15/16) and 93.3% (14/15), respectively. Meanwhile, with several postnatal complications added as additional risk factors, the sensitivity was increased to 96% (48/50).

CONCLUSION

The sensitivity of the WINROP algorithm from the Southern Chinese cohort is not as high as that reported in developed countries. This algorithm is effective for detecting severe ROP from extremely small or preterm infants. Modification of the algorithm with additional risk factors could improve the predictive value for infants with a GA>28wk in China.

A Good Way to Reduce Screening for Retinopathy of Prematurity: Development of the ROP Model in a China Preterm Population

Importance: Retinopathy of prematurity (ROP) is a preventable cause of blindness in children. Without treatment, more than 45% of eyes may suffer permanent vision loss. Current ROP screening guidelines, which include a range of birth weights (BWs) and gestational ages (GAs), may require screening many low-risk preemies who might develop severe ROP. Method: All high-risk infants in the neonatal intensive care unit (NICU) of the First Affiliated Hospital of Zhengzhou University from 2017 to 2021 were included in this retrospective cohort study. Each of the 27 candidate risk factors was evaluated in univariate analysis and adjusted for known risk factors (i.e., GA and BW). The significant results were analyzed in a backward selection multivariate logistic regression model. Receiver operating characteristic (ROC) curves and a nomogram were drawn. Results: The study included 2,040 infants who underwent ROP screening. The weight gain rate [OR, 2.65; 95% confidence interval (CI), 1.49-1.21 ≤ 12 g/d vs. > 18 g/d; P = 0.001], blood transfusion (OR, 2.03; 95% CI, 1.14-3.64; P = 0.017), invasive mechanical ventilation (OR, 1.74; 95% CI, 1.15-2.66; P = 0.009) and N-terminal segment of pro-B-type natriuretic peptide (NT-proBNP) ≥ 25,000 ng/L (OR, 1.51; 95% CI, 1.00-2.28; P = 0.048) were four new statistically independent risk factors in addition to GA and BW. The area under the curve (AUC) of the final multivariate model was 0.90 (95% CI, 0.88-0.92; P < 0.001). Conclusions and Relevance: These findings add to our understanding of ROP screening because they include all eligible infants rather than only high-risk infants, as in previous studies. Under the control of BW and GA, low weight gain rate, increased number of blood transfusion, invasive mechanical ventilation and NT-proBNP ≥ 25,000 ng/L were "new" statistically independent risk factors for ROP. The ROP risk can be calculated manually or represented by a nomogram for clinical use.

POOR POSTNATAL WEIGHT GAIN AS A PREDICTOR OF RETINOPATHY OF PREMATURITY

The purpose of this study was to re-evaluate cut-off values used in screening for retinopathy of prematurity (ROP) in Croatia and to propose postnatal weight gain as an additional criterion, based on the Colorado Retinopathy of Prematurity prediction model. Medical records of 267 premature infants from the Zagreb University Hospital Centre that underwent ROP screening between January 2009 and December 2010 were reviewed retrospectively. Collected data included gestational age, birth weight, sex, weekly weight measurements and fundus examination records. Results showed the cut-off values of gestational age (GA) and birth weight (BW) used in Croatia to be appropriate and postnatal weight gain in the first 28 days could be used as an additional criterion on screening in the following way: net weight gain in the first 28 days of ≤932 g for prediction of any form of ROP and of ≤660 g for prediction of severe ROP should be added to the existing criteria of GA (≤32 weeks) and/or BW (≤1500 g). Infants with a non-physiological postnatal weight gain are exception. This is the first Croatian study to propose postnatal weight gain as an additional criterion on ROP screening and requires further validation on a larger sample of Croatian infants.

Association between severe retinopathy of prematurity and postnatal weight gain in very low-birthweight infants at Chiang Mai University Hospital, Thailand

Background: Poor postnatal weight gain has been associated with low serum IGF-1, a key factor in the pathogenesis of retinopathy of prematurity (ROP).Aim: To investigate an association between relative weight gain (RWG) and severe ROP in very low-birthweight (VLBW) Thai infants.Methods: The medical records of VLBW infants who were admitted to the neonatal intensive care unit in Chiang Mai University Hospital from June 2014 to December 2016 and screened for ROP were reviewed. RWG and total calorie intake (TCI) in the 2nd, 4rth and 6th week of age were calculated and those with no ROP/mild ROP and severe ROP requiring laser treatment were compared.Results: The study included 139 VLBW infants, 24 (17.3%) of whom had ROP requiring laser treatment. Infants with severe ROP requiring laser treatment had a lower median birthweight (840 vs 1,195 g, p < 0.001) and median gestational age (GA) (27 vs 30 wk, p < 0.001) than those with no ROP/mild ROP. When RWG and TCI were compared, the infants with severe ROP requiring laser treatment had a lower RWG at the 2nd (p < 0.01) and 4th weeks of age (p < 0.05) and had a lower TCI at the 2nd week of age (p < 0.001) than those with no ROP/mild ROP. Multivariate logistic analysis demonstrated that GA <29.5 w (p < 0.01), hypotension (p < 0.05), RWG <2.9 g/kg/d (p < 0.05) and TCI <98.5 kcal/kg/day (p < 0.001) at the 2nd week of age were independent risk factors for severe ROP requiring laser treatment.Conclusions: Poor weight gain and low calorie intake at the 2nd week of age were associated with severe ROP requiring laser treatment in VLBW infants. Monitoring weight gain and calorie intake during this period are essential and may improve the outcome of ROP.Abbreviations: BPD, bronchopulmonary dysplasia; IVH, intraventricular haemorrhage; NEC, necrotising enterocolitis; PDA, patent ductus arteriosus; PRC, packed red cells; PVL, periventricular leucomalacia; RDS, respiratory distress syndrome; ROP, retinopathy of prematurity; RWG, relative weight gain; SGA, small for gestational age; TCI, total calorie intake; VLBW, very low birthweight.

Risk of development of treated retinopathy of prematurity in very low birth weight infants

OBJECTIVE

Quantify the risk of treatment for retinopathy of prematurity (ROP) among infants meeting current U.S. screening guidelines.

STUDY DESIGN

Among infants ≤1500 g birth weight or ≤30 weeks gestation screened for ROP from 2006-2015, we developed a risk prediction model to identify infants treated for ROP. We applied our model to a separate infant cohort discharged in 2016.

RESULT

Seventy-five thousand eight hundred and twenty one infants met inclusion criteria; 2306 (3%) were treated for ROP. Infants with several risk factor combinations (no ventilator support or oxygen on postnatal day 28, no history of necrotizing enterocolitis, and no intraventricular hemorrhage) were at low risk of ROP. Applied to 6127 infants discharged in 2016, our model had 97.9% sensitivity, 63.3% specificity, positive predictive value of 4.0%, and negative predictive value of 99.9%.

CONCLUSION

Large numbers of infants at low risk of developing ROP are required to undergo screening. Refining current ROP guidelines may reduce unnecessary examinations.

Postnatal weight gain and retinopathy of prematurity

Infants meeting retinopathy of prematurity (ROP) screening guidelines based on birth weight and gestational age undergo serial examinations by ophthalmologists for detection and treatment. However, less than 10% require treatment, and less than half develop ROP. Slow postnatal weight gain is highly predictive of ROP, and investigators have incorporated weight gain measures to develop more specific criteria for ROP screening. Such clinical prediction model use involves a large development study, validation studies specific to the target populations, and ongoing impact surveillance, with adjustment as necessary. Of the many weight gain inclusive prediction models intended to improve the precision of ROP screening, the Postnatal Growth and ROP (G-ROP) modified screening criteria were developed using the largest dataset and may provide the most robust model for clinical use. A recently completed G-ROP validation study will evaluate the generalizability of these modified criteria prior to clinical use.

Children's Hospital of Philadelphia Score to predict severe retinopathy in Indian preterm infants

BACKGROUND

Retinopathy of Prematurity (ROP) screenings are expensive and entail heavy workload. Predictive models using postnatal weight gain reduces the number of ophthalmological examinations. The objective was to validate Children's Hospital of Philadelphia (CHOP) score to predict severe ROP in resource limited settings.

METHODS

Prior to ophthalmic examination, the CHOP score was calculated to predict severe ROP (point estimate = 0.014) in 191 preterm infants. Cut-off point estimate, most suitable in resource limited settings was assessed.

RESULTS

CHOP Score cutoff point (0.014) showed 67% sensitivity, 75% specificity. With CHOP score cut-off point (0.010), the corresponding values were 100% sensitivity, 51% specificity, PPV 12% and NPV 100%.

CONCLUSION

CHOP Score (0.014) is a poor tool to predict the onset of severe ROP. However, CHOP Score (0.010) is a promising tool to predict the onset of severe ROP and reduces the need for ophthalmological examinations by 50% in resource limited settings.

Retinopathy of prematurity: a review of risk factors and their clinical significance

Retinopathy of prematurity (ROP) is a retinal vasoproliferative disease that affects premature infants. Despite improvements in neonatal care and management guidelines, ROP remains a leading cause of childhood blindness worldwide. Current screening guidelines are primarily based on two risk factors: birth weight and gestational age; however, many investigators have suggested other risk factors, including maternal factors, prenatal and perinatal factors, demographics, medical interventions, comorbidities of prematurity, nutrition, and genetic factors. We review the existing literature addressing various possible ROP risk factors. Although there have been contradictory reports, and the risk may vary between different populations, understanding ROP risk factors is essential to develop predictive models, to gain insights into pathophysiology of retinal vascular diseases and diseases of prematurity, and to determine future directions in management of and research in ROP.

A predictive score for retinopathy of prematurity by using clinical risk factors and serum insulin-like growth factor-1 levels

AIM

To detect the impact of insulin-like growth factor-1 (IGF-1) and other risk factors for the early prediction of retinopathy of prematurity (ROP) and to establish a scoring system for ROP prediction by using clinical criteria and serum IGF-1 levels.

METHODS

The study was conducted with 127 preterm infants. IGF-1 levels in the 1^st day of life, 1^st, 2^nd, 3^rd and 4^th week of life was analyzed. The score was established after logistic regression analysis, considering the impact of each variable on the occurrences of any stage ROP. A validation cohort containing 107 preterm infants was included in the study and the predictive ability of ROP score was calculated.

RESULTS

Birth weights (BW), gestational weeks (GW) and the prevalence of breast milk consumption were lower, respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD) and necrotizing enterocolitis (NEC) were more frequent, the duration of mechanical ventilation and oxygen supplementation was longer in patients with ROP (P<0.05). Initial serum IGF-1 levels tended to be lower in newborns who developed ROP. Logistic regression analysis revealed that low BW (<1250 g), presence of intraventricular hemorrhage (IVH) and formula feeding increased the risk of ROP. Afterwards, the scoring system was validated on 107 infants. The negative predictive values of a score less than 4 were 84.3%, 74.7% and 79.8% while positive predictive values were 76.3%, 65.5% and 71.6% respectively.

CONCLUSION

In addition to BW <1250 g and IVH, formula consumption was detected as a risk factor for the development of ROP. Breastfeeding is important for prevention of ROP in preterm infants.

Early postnatal hyperglycaemia is a risk factor for treatment-demanding retinopathy of prematurity

BACKGROUND

To investigate whether neonatal hyperglycaemia in the first postnatal week is associated with treatment-demanding retinopathy of prematurity (ROP).

METHODS

This is a Danish national, retrospective, case-control study of premature infants (birth period 2003-2006). Three national registers were searched, and data were linked through a unique civil registration number. The study sample consisted of 106 cases each matched with two comparison infants. Matching criteria were gestational age (GA) at birth, ROP not registered and born at the same neonatal intensive care unit. Potential 'new' risk factors were analysed in a multivariate logistic regression model, while adjusted for previously recognised risk factors (ie, GA at birth, small for gestational age, multiple birth and male sex).

RESULTS

Hospital records of 310 preterm infants (106 treated; 204 comparison infants) were available. Nutrition in terms of energy (kcal/kg/week) and protein (g/kg/week) given to the preterm infants during the first postnatal week were statistically insignificant between the study groups (Mann-Whitney U test; p=0.165/p=0.163). Early postnatal weight gain between the two study groups was borderline significant (t-test; p=0.047). Hyperglycaemic events (indexed value) were statistically significantly different between the two study groups (Mann-Whitney U test; p<0.001). Hyperglycaemia was a statistically independent risk factor (OR: 1.022; 95% CI 1.002 to 1.042; p=0.031).

CONCLUSION

An independent association was found between the occurrence of hyperglycaemic events during the first postnatal week and later development of treatment-demanding ROP, when adjusted for known risk factors.

Screening Tool for Early Postnatal Prediction of Retinopathy of Prematurity in Preterm Newborns (STEP-ROP)

BACKGROUND

Retinopathy of prematurity (ROP) is a disorder of the preterm newborn characterized by neurovascular disruption in the immature retina that may cause visual impairment and blindness.

OBJECTIVE

To develop a clinical screening tool for early postnatal prediction of ROP in preterm newborns based on risk information available within the first 48 h of postnatal life.

METHODS

Using data submitted to the Vermont Oxford Network (VON) between 1995 and 2015, we created logistic regression models based on infants born <28 completed weeks gestational age. We developed a model with 60% of the data and identified birth weight, gestational age, respiratory distress syndrome, non-Hispanic ethnicity, and multiple gestation as predictors of ROP. We tested the model in the remaining 40%, performed tenfold cross-validation, and tested the score in ELGAN study data.

RESULTS

Of the 1,052 newborns in the VON database, 627 recorded an ROP status. Forty percent had no ROP, 40% had mild ROP (stages 1 and 2), and 20% had severe ROP (stages 3-5). We created a weighted score to predict any ROP based on the multivariable regression model. A cutoff score of 5 had the best sensitivity (95%, 95% CI 93-97), while maintaining a strong positive predictive value (63%, 95% CI 57-68). When applied to the ELGAN data, sensitivity was lower (72%, 95% CI 69-75), but PPV was higher (80%, 95% CI 77-83).

CONCLUSIONS

STEP-ROP is a promising screening tool. It is easy to calculate, does not rely on extensive postnatal data collection, and can be calculated early after birth. Early ROP screening may help physicians limit patient exposure to additional risk factors, and may be useful for risk stratification in clinical trials aimed at reducing ROP.

Postnatal Growth and Retinopathy of Prematurity Study: Rationale, Design, and Subject Characteristics

PURPOSE

Postnatal-growth-based predictive models demonstrate strong potential for improving the low specificity of retinopathy of prematurity (ROP) screening. Prior studies are limited by inadequate sample size. We sought to study a sufficiently large cohort of at-risk infants to enable development of a model with highly precise estimates of sensitivity for severe ROP.

METHODS

The Postnatal Growth and ROP (G-ROP) Study was a multicenter retrospective cohort study of infants at 30 North American hospitals during 2006-2012. A total of 65 G-ROP-certified abstractors submitted data to a secure, web-based database. Data included ROP examination findings, treatments, complications, daily weight measurements, daily oxygen supplementation, maternal/infant demographics, medical comorbidities, surgical events, and weekly nutrition. Data quality was monitored with system validation rules, data audits, and discrepancy algorithms.

RESULTS

Of 11,261 screened infants, 8334 were enrolled, and 2927 had insufficient data due to transfer, discharge, or death. Of the enrolled infants, 90% (7483) had a known ROP outcome and were included in the study. Median birth weight was 1070 g (range 310-3000g) and mean gestational age 28 weeks (range 22-35 weeks). Severe ROP (Early Treatment of Retinopathy type 1 or 2) developed in 931 infants (12.5%).

CONCLUSION

Successful incorporation of a predictive model into ROP screening requires confidence that it will capture cases of severe ROP. This dataset provides power to estimate sensitivity with half-confidence interval width of less than 0.5%, determined by the high number of severe ROP cases. The G-ROP Study represents a large, diverse cohort of at-risk infants undergoing ROP screening. It will facilitate evaluation of growth-based algorithms to improve efficiency of ROP screening.

Screening and Treatment in Retinopathy of Prematurity

BACKGROUND

More than 11 000 children are examined for possible retinopathy of prematurity in Germany each year, and 2-5% of them are treated for it. Even though screening and treatment programs are in place, the affected children can still suffer visual impairment.

METHODS

In this article, we summarize the pathogenesis, screening, and treatment of retinopathy of prematurity on the basis of a selective review of pertinent literature, retrieved by a PubMed search. The article centers on publications from 2011 to 2015 on the new option of treatment with VEGF inhibitors and discusses it in comparison to laser therapy.

RESULTS

All premature neonates with a low gestational age at birth, low birth weight, or prolonged exposure to supplemental oxygen must undergo screening by an ophthalmologist. Laser therapy is effective for stages 1-3 and for aggressive posterior retinopathy of prematurity. Its disadvantages are the induction of scarring and the development of severe myopia in 17-40% of the children so treated. Anti-VEGF treatment (VEGF = vascular endothelial growth factor) does not induce any visible scarring and seems to cause less myopia, but long-term data on safety, dosing, and the choice of anti-VEGF drug are still lacking.

CONCLUSION

The available evidence for anti-VEGF treatment is on a much lower level than the evidence for laser therapy. Anti-VEGF may be a way to avoid the disadvantages of laser therapy (scarring and severe myopia). Unlike laser therapy, however, the intravitreal injection of VEGF inhibitors may suppress systemic VEGF levels and potentially harm the developing brain, lungs, or other organs. The currently open questions about anti-VEGF treatment concern its dosing, choice of drug, and long-term safety.

Low energy intake during the first 4 weeks of life increases the risk for severe retinopathy of prematurity in extremely preterm infants

OBJECTIVES

Poor weight gain during the first weeks of life in preterm infants is closely associated with the risk of developing the retinopathy of prematurity (ROP) and insufficient nutrition might be an important contributing factor. This study aimed to evaluate the effect of energy and macronutrient intakes during the first 4 weeks of life on the risk for severe ROP (stages 3-5).

STUDY DESIGN

A population-based study including all Swedish extremely preterm infants born before 27 gestational weeks during a 3-year period. Each infant was classified according to the maximum stage of ROP in either eye as assessed prospectively until full retinal vascularisation. The detailed daily data of actual intakes of enteral and parenteral nutrition and growth data were obtained from hospital records.

RESULTS

Of the included 498 infants, 172 (34.5%) had severe ROP and 96 (19.3%) were treated. Energy and macronutrient intakes were less than recommended and the infants showed severe postnatal growth failure. Higher intakes of energy, fat and carbohydrates, but not protein, were significantly associated with a lower risk of severe ROP. Adjusting for morbidity, an increased energy intake of 10 kcal/kg/day was associated with a 24% decrease in severe ROP.

CONCLUSIONS

We showed that low energy intake during the first 4 weeks of life was an independent risk factor for severe ROP. This implies that the provision of adequate energy from parenteral and enteral sources during the first 4 weeks of life may be an effective method for reducing the risk of severe ROP in extremely preterm infants.

Oxygen Monitoring Reduces the Risk for Retinopathy of Prematurity in a Mexican Population

BACKGROUND

Retinopathy of prematurity (ROP), a potentially blinding disease, affects preterm infants. High levels of oxygen saturation are a well-known risk factor for ROP.

OBJECTIVES

To assess the frequency of ROP type 1 needing treatment after improved oxygen monitoring (2011) in a Mexican preterm population selected for WINROP analyses and to retrospectively revalidate WINROP, an online surveillance system identifying infants at risk of developing ROP type 1.

METHODS

Preterm infants born with birth weight (BW) <1,750 g and/or at gestational age (GA) ≤34 weeks, screened for ROP in 2012-2014 at the Hospital Civil de Guadalajara, Mexico were included (n = 151). Eighty-five infants with GA <32 weeks qualified for WINROP analyses. GA, BW, maximal ROP stage, ROP treatment and weekly weights were recorded. The results in the present study were compared to those of a previous WINROP study in the same hospital (2005-2010; n = 352).

RESULTS

In the present WINROP cohort, 11.8% of the infants born at GA <32 weeks received treatment compared to 51.0% of the infants in the previous WINROP cohort. One infant (3%) born at GA ≥32 weeks received treatment during the present study period compared to 35.6% during the previous period. WINROP displayed 80.0% sensitivity in infants born at GA <32 weeks in the present study compared to 84.7% in the previous study.

CONCLUSIONS

Uncontrolled oxygen supplementation is the major risk factor for severe ROP in infants born at GA ≥32 weeks. After improved oxygen monitoring, the frequency of ROP treatment was dramatically reduced at the Hospital Civil de Guadalajara, Mexico.

Postnatal weight gain in very low birth weight infants in Beijing and the risk of retinopathy of prematurity

AIM

To analyze the low weight gain (WG) from birth to 4 and 6wk of life to predict the development of retinopathy of prematurity (ROP) among very low birth weight (VLBW) preterm babies.

METHODS

Three hundred and three newborns with VLBW were analyzed. Body weight measurements were recorded weekly. In all patients, the proportion of the WG was defined as the preterm weight measured at the 4(th) and 6(th) weeks of life minus the birth weight (BW) divided by the BW. Other risk factors for ROP were also analyzed.

RESULTS

Mean gestational age and mean BW of the whole cohort were 29.56±1.44wk and 1270.58±176.18g respectively. WG proportion at 4wk postnatal age (18.89%±13.58%) were significantly lower in infants with ROP (P=0.003). WG proportion at 6wk was not different between ROP and no ROP group (42.48%±20.36% vs 46.43%±15.65% P=0.118). When all the other risk factors significant for ROP were included in the logistic regression poor WG did not arise as an independent risk factor. Area under the ROC curve was 0.591 (95%CI: 0.515-0.666; P=0.016). For ROP, the best discriminative cutoff of 18.06% of the proportional WG at the 4(th) week over the BW, sensitivity and specificity values were 67.3% and 50.0% respectively.

CONCLUSION

Low WG proportion in the first 4wk of life is maybe an additional predictor of ROP in very low BW infants. Preterm babies with low BW and low WG proportion should be followed closely for ROP.

Postnatal weight gain in the first two weeks as a predicting factor of severe retinopathy of prematurity requiring treatment

Purpose

This study aimed to investigate the relative weight gain at 2-week intervals up to 6 weeks after birth to predict retinopathy of prematurity (ROP) requiring treatment among very low birth weight infants.

Methods

A total of 211 preterm infants with birth weights <1,500 g and gestational age <32 weeks were retrospectively reviewed. The main outcome was the development of ROP requiring treatment. Body weight measurements were recorded daily. Relative weight gains (g/kg/day) were calculated at the second, fourth, and sixth week after birth.

Results

Of the 211 infants, 89 developed ROP, of which 41 spontaneously regressed and 48 with early treatment of ROP type I required laser treatment. The relative weight gain at 2, 4, and 6 weeks postnatal age was significantly lower in infants with ROP requiring treatment than in infants without ROP or those with spontaneous regression (P<0.001, P=0.005, and P=0.004, respectively). On logistic regression, poor relative weight gain in the first 2 weeks was found to be related to ROP requiring treatment (adjusted odds ratio, 0.809; 95% confidence interval, 0.695-0.941; P=0.006). Relative weight gain at 2 weeks postnatal age was significantly lower in infants with ROP requiring treatment compared to that in ROP requiring no treatment (P=0.012).

Conclusion

Poor postnatal weight gain in the first 2 weeks of life is an important and independent risk factor for ROP requiring treatment. Postnatal weight gain can predict the development of severe ROP requiring treatment.

Low birth weight is a risk factor for severe retinopathy of prematurity depending on gestational age

Objective

To evaluate the impact of low birth weight as a risk factor for retinopathy of prematurity (ROP) that will require treatment in correlation with gestational age at birth (GA).

Study design

In total, 2941 infants born <32 weeks GA were eligible from five cohorts of preterm infants previously collected for analysis in WINROP (Weight IGF-I Neonatal ROP) from the following locations: Sweden (EXPRESS) (n = 426), North America (n = 1772), Boston (n = 338), Lund (n = 52), and Gothenburg (n = 353). Data regarding GA at birth, birth weight (BW), gender, and need for ROP treatment were retrieved. Birth weight standard deviation scores (BWSDS) were calculated with Swedish as well as Canadian reference models. Small for gestational age (SGA) was defined as BWSDS less than −2.0 SDS using the Swedish reference and as BW below the 10^th percentile using the Canadian reference charts.

Results

Univariate analysis showed that low GA (p<0.001), low BW (p<0.001), male gender (p<0.05), low BWSDS_Canada (p<0.001), and SGA_Canada (p<0.01) were risk factors for ROP that will require treatment. In multivariable logistic regression analysis, low GA (p<0.0001), male gender (p<0.01 and p<0.05), and an interaction term of BWSDS*GA group (p<0.001), regardless of reference chart, were risk factors. Low BWSDS was less important as a risk factor in infants born at GA <26 weeks compared with infants born at GA ≥26 weeks calculated with both reference charts (BWSDS_Sweden, OR = 0.80 vs 0.56; and BWSDS_Canada, OR = 0.72 vs 0.41).

Conclusions

Low BWSDS as a risk factor for vision-threatening ROP is dependent on the infant's degree of immaturity. In more mature infants (GA ≥26 weeks), low BWSDS becomes a major risk factor for developing ROP that will require treatment. These results persist even when calculating BW deficit with different well-established approaches.

Insulin-like growth factor-1 and anti-vascular endothelial growth factor in retinopathy of prematurity: has the time come?

Treatment of retinopathy of prematurity (ROP) is currently evolving. Novel therapeutic options are emerging that have the potential to complement existing therapies and improve treatment outcomes. However, any new therapeutic option must be thoroughly evaluated before existing (and successful) treatment paradigms can be amended. This is particularly so when switching from locally effective therapies like photoablative laser therapy to systemic pharmacological treatments, which may have hitherto unknown widespread side effects. This review compiles the current knowledge of where and when the two most advanced pharmacological treatment options for ROP, insulin-like growth factor-1 supplementation and anti-vascular endothelial growth factor treatment, may have their place in future therapy regimens for ROP. The requirement for clinical studies is emphasized: these are needed to address safety considerations before any of these interventions can achieve the status of standard clinical care in the very vulnerable population of ROP infants.

Analysis of prenatal and postnatal risk factors of retinopathy of prematurity in a tertiary care hospital in South India

CONTEXT

Recent advances in neonatology have influenced the incidence and severity of ROP in a dichotomous fashion.

AIMS

To determine the incidence of ROP and to analyse its risk factors.

SETTINGS AND DESIGN

Prospective clinical case series.

MATERIALS AND METHODS

282 preterm infants with birthweight < 1500 g and/or gestational age ≤ 32 weeks and also those with gestational age > 32 weeks, with birthweight between 1500-2000 g, who were at risk for ROP were selected. Weight gain proportion was measured as weight at 6 weeks minus birthweight divided by birthweight.

STATISTICAL ANALYSIS

Univariate and multivariate logistic regression.

RESULTS

Incidence of any ROP was 21.6% while severe ROP was 6.7%. Prenatal factors like multiple gestation (P = 0.510) and antenatal steroids (P = 0.104) were not significantly associated with ROP. On multivariate analysis, postnatal factors like weight at birth < 1250 g (P = 0.01) and gestational age between 31-32 weeks (P = 0.02) were independent risk factors for any ROP, while intraventricular hemorrhage (P = 0.03) was the only independent risk factor for severe ROP. Mean birthweight of infants with severe ROP was 1056 μ 207 g (P = 0.004), which was significantly low. After logistic regression, the mean weight gain proportion at 6 weeks, of those neonates with severe ROP was 30%.

CONCLUSIONS

Low birthweight and prematurity were the most important risk factors for developing any ROP, while intraventricular hemorrhage was the independent risk factor for developing severe ROP. The mean postnatal weight gain at 6 weeks was not statistically significant in neonates with severe ROP.

Influence of the difference of breastfeeding volume on a rat model of oxygen-induced retinopathy

This study aimed to investigate the effects of abundant breast milk intake on rats model of oxygen-induced retinopathy (OIR). Neonatal Sprague–Dawley rats were randomly assigned to expand litters of 7 pups/litter (7-rats group) and 14 pups/litter (14-rats group). They were exposed to 80% oxygen from postnatal day (P) 0 to P12. Body weights were measured daily. At P13 and 18, rats were sacrificed, and the blood and eyes were collected. Retinal neovascularization (NV) score, total retinal area (TRA), avascular area (AVA), and vascularized area (VA) were measured in ADPase stained retinas. Retinal vascular endothelial growth factor (VEGF) and serum insulin-like growth factor (IGF-1) were measured using ELISA. Body weight gain was significantly greater in 7-rats group from P2. Serum IGF-1 levels at P13 and 18 were significantly higher in 7-rats group. Retinal VEGF and TRA at P18 were significantly larger in 7-rats group. NV score at P18 tended to be higher in 7-rats group. There was no significant difference in VA between the 2 groups at P13 and 18. Excess breast milk intake in OIR rat pups caused body weight gain and retinal development, whereas there was less effect on retinal vascularization in our study.

Importance of birth weight as a risk factor for severe retinopathy of prematurity when gestational age is 30 or more weeks

PURPOSE

To determine whether birth weight less than 1500 g is a relevant guideline indicating the need for examination for retinopathy of prematurity (ROP) when gestational age at birth is 30 or more completed weeks.

DESIGN

A retrospective observational cohort study.

METHODS

A total of 266 infants in a single institutional neonatal intensive care unit (NICU), whose gestational age at birth was 30 or more weeks but whose birth weight was less than 1500 g, were examined according to published guidelines. Infants with lethal congenital anomalies or major ocular abnormalities were excluded. Outcomes were vascularization in retinal zone III without a prior need for treatment, or ROP warranting treatment.

RESULTS

A study outcome was reached by 212 infants. Two hundred and eleven (99.5%) became vascularized through zone III without needing treatment. Only 1 (0.5%) required treatment for ROP. The 95% confidence interval for the occurrence rate of ROP requiring treatment in this cohort was 0.01%-2.60%.

CONCLUSION

Our results suggest that the occurrence rates of ROP requiring treatment in infants with gestational age 30 or more weeks and birth weight less than 1500 g is very low, and could indicate the need to revise examination guidelines for this subgroup of infants.

Prediction of severe retinopathy of prematurity using the WINROP algorithm in a birth cohort in South East Scotland

PURPOSE

We tested the ability of the 'Weight, IGF-1, Neonatal Retinopathy of Prematurity (WINROP)' clinical algorithm to detect preterm infants at risk of severe Retinopathy of Prematurity (ROP) in a birth cohort in the South East of Scotland. In particular, we asked the question: 'are weekly weight measurements essential when using the WINROP algorithm?'

STUDY DESIGN

This was a retrospective cohort study. Anonymised clinical data were uploaded to the online WINROP site, and infants at risk of developing severe ROP were identified. The results using WINROP were compared with the actual ROP screening outcomes. Infants with incomplete weight data were included in the whole group, but were excluded from a subgroup analysis of infants with complete weight data. In addition, data were manipulated to test whether missing weight data points in the early neonatal period would lead to loss of sensitivity of the algorithm.

RESULTS

The WINROP algorithm had 73% sensitivity for detecting infants at risk of severe ROP when all infants were included and 87% when the complete weight data subgroup was analysed. Manipulation of data from the complete weight data subgroup demonstrated that one or two missing weight data points in the early postnatal period lead to loss of sensitivity performance by WINROP.

IMPLICATIONS

The WINROP program offers a non-invasive method of identifying infants at high risk of severe ROP and also identifying those not at risk. However, for WINROP to function optimally, it has to be used as recommended and designed, namely weekly body weight measurements are required.

Retinopathy of prematurity

The immature retinas of preterm neonates are susceptible to insults that disrupt neurovascular growth, leading to retinopathy of prematurity. Suppression of growth factors due to hyperoxia and loss of the maternal-fetal interaction result in an arrest of retinal vascularisation (phase 1). Subsequently, the increasingly metabolically active, yet poorly vascularised, retina becomes hypoxic, stimulating growth factor-induced vasoproliferation (phase 2), which can cause retinal detachment. In very premature infants, controlled oxygen administration reduces but does not eliminate retinopathy of prematurity. Identification and control of factors that contribute to development of retinopathy of prematurity is essential to prevent progression to severe sight-threatening disease and to limit comorbidities with which the disease shares modifiable risk factors. Strategies to prevent retinopathy of prematurity will depend on optimisation of oxygen saturation, nutrition, and normalisation of concentrations of essential factors such as insulin-like growth factor 1 and ω-3 polyunsaturated fatty acids, as well as curbing of the effects of infection and inflammation to promote normal growth and limit suppression of neurovascular development.

WINROP identifies severe retinopathy of prematurity at an early stage in a nation-based cohort of extremely preterm infants

Objective

To evaluate the ability of a postnatal weight-gain algorithm (WINROP) to identify sight-threatening retinopathy of prematurity (ROP type 1) in a nation-based extremely preterm infant cohort.

Methods

This study enrolled all 707 live-born extremely preterm (gestational age [GA] <27 weeks) infants, born 2004–2007 in Sweden; the Extremely preterm Infants in Sweden Study (EXPRESS). WINROP analysis was performed retrospectively in 407 of the infants using weekly weight gain to assess the preterm infant’s risk of developing ROP type 1 requiring treatment. GA, birthweight (BW), and weekly postnatal weight measurements were entered into WINROP. WINROP signals with an alarm to indicate if the preterm infant is at risk for ROP type 1.

Results

In this extremely preterm population, WINROP correctly identified 96% (45/47) of the infants who required treatment for ROP type 1. The median time from alarm to treatment was 9 weeks (range, 4–20 weeks).

Conclusions

WINROP, an online surveillance system using weekly weight gain, identified extremely preterm infants at risk for ROP type 1 requiring treatment at an early stage and with high sensitivity in a Swedish nation-based cohort.

Relationships between maternal ethnicity, gestational age, birth weight, weight gain, and severe retinopathy of prematurity

OBJECTIVE

To develop an algorithm that allows advanced identification of infants requiring treatment for retinopathy of prematurity (ROP).

STUDY DESIGN

A retrospective observational study was performed at 2 tertiary neonatal units serving a multiethnic population in the UK, using data on 929 infants eligible for ROP screening. The relationships between study variables and the risk of developing ROP requiring treatment were analyzed using multiple logistic regression.

RESULTS

After applying exclusion criteria, data from 589 infants were analyzed; of these, 57 required laser treatment. The proportion of treated infants was 5.9% of those born to black mothers, 9.39% of those born to white mothers, and 12.8% of those born to Asian mothers (P = .047). Multiple logistic regression showed that gestational age, birth weight, maternal ethnicity, and early weight gain were predictors for the development of ROP requiring treatment, with maternal ethnicity having greater predictive power compared with early weight gain. We developed an algorithm for predicting the development of ROP requiring treatment with sensitivity, specificity, and positive and negative predictive values of 100%, 65.7%, 23.8%, and 100%, respectively.

CONCLUSION

Gestational age, birth weight, early weight gain, and maternal ethnicity are important predictors for the development of ROP requiring treatment. In a multiethnic population, an algorithm to predict development of ROP requiring treatment should include maternal ethnicity. If confirmed through prospective studies, this algorithm could reduce the number of opthalmologic examinations performed for ROP screening.

Nutrition, insulin-like growth factor-1 and retinopathy of prematurity

Retinopathy of prematurity is a potentially blinding disease starting with impaired retinal vessel growth in the neonatal period. Weeks to months later, peripheral retinal hypoxia induces pathologic neovascularization that may lead to retinal detachment and blindness. Current treatment strategies target late stage disease and it would be advantageous if retinopathy of prematurity could be prevented. Poor general growth after very preterm birth is a universal problem associated with increased risk of retinopathy. Loss of the maternal-fetal interaction results not only in loss of nutrients but also of other factors provided in utero. The importance of nutrition and factors such as insulin-like growth factor-1 and ω-3 long chain fatty acids for proper retinal vascularization has been defined in animal studies. Increasing evidence of the applicability of these findings to human infants is accumulating. This review focuses on factors essential for neonatal growth and possible strategies to improve growth and prevent retinopathy.