Retinopathy of Prematurity among Very-Low-Birth-Weight Infants in Korea: Incidence, Treatment, and Risk Factors

Histological Chorioamnionitis and Funisitis as New Risk Factors for Retinopathy of Prematurity: A Meta-analysis

OBJECTIVE

 The role of placental inflammation in neonatal morbidities is underestimated due to lack of placental examination. This meta-analysis aims to assess the association between histological chorioamnionitis (HCA) with and without funisitis (FUN) and risk of retinopathy of prematurity (ROP).

STUDY DESIGN

 Forty-five studies reporting (unadjusted) data on HCA without FUN and HCA with FUN in neonates with ROP were included. Primary outcomes were any stage ROP and severe ROP. Potential confounders explored were gestational age (GA) at birth, birthweight, maternal steroid use, necrotizing enterocolitis, sepsis (suspected/proven) and mechanical ventilation duration.

RESULTS

 Neonates with HCA had increased risk for any stage ROP (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.3-2.4) and severe ROP (OR 1.5; 95% CI 1.2-1.8) compared with neonates without HCA. The rates of any stage ROP (OR 1.8; 95% CI 1.4-2.2) and severe ROP (OR 1.4; 95% CI 1.1-1.6) were higher in neonates with FUN compared with neonates without FUN. Multivariate meta-regression analysis suggests that lower GA increases the effect size between FUN and severe ROP.

CONCLUSION

 This meta-analysis confirms that presence of HCA and FUN are risk factors for any stage ROP and severe ROP. Structured histological placental examination of HCA and FUN may be a tool to further refine the ROP risk profile.

KEY POINTS

· This systematic review confirms that HCA is a risk factor for ROP.. · This meta-analysis reveals that FUN results in an even higher risk for developing ROP.. · Placental examination of HCA/FUN may be a tool to further refine the ROP risk profile..

Exposure to persistent hemodynamically significant patent ductus arteriosus is associated with retinopathy of prematurity

BACKGROUND

Hemodynamically significant patent ductus arteriosus (hsPDA) shunt may predispose infants to retinopathy of prematurity (ROP) because of its higher preductal cardiac output and blood oxygen content, which may augment ocular oxygen delivery.

METHODS

A retrospective cohort study of preterm infants, born at <27 weeks' gestation and admitted at <24h postnatal age to a large quaternary referral was conducted. The primary composite outcome was death at <32 weeks or moderate-to-severe ROP (≥stage 2 or requiring treatment) in either eye. Secondary outcomes included ROP requiring treatment, and any ROP. Univariate analysis of patient characteristics and outcomes was performed as well as logistic regression. A receiver operating characteristics curve was generated for the outcome of ROP ≥stage 2 or requiring treatment.

RESULTS

A total of 91 patients were screened, of whom 86 (54 hsPDA, 32 controls) were eligible for inclusion. hsPDA patients were younger and lighter at birth and had a higher burden of hyperglycemia and respiratory illness. The rates of the composite outcome (death <32 weeks or moderate-to-severe ROP) and of any ROP were more frequent in the hsPDA group. hsPDA shunt exposure was independently associated with development of any ROP among survivors to assessment (P = 0.006). PDA cumulative exposure score of 78 (clinical equivalent = 7 days high-volume shunt exposure) predicts moderate-to-severe ROP with 80% sensitivity and 78% specificity.

CONCLUSIONS

Among infants <27 weeks, hsPDA shunt is associated with increased risks of a composite outcome of death or moderate-to-severe ROP, as well as ROP of any stage. Shunt modulation as a strategy to reduce ROP represents a biologically plausible avenue for investigation.

Critical period of oxygen supplementation and invasive ventilation: implications for severe retinopathy of prematurity

BACKGROUND

Several studies have identified graded oxygen saturation targets to prevent retinopathy of prematurity (ROP), a serious complication in preterm infants. We aimed to analyze the critical period of oxygen supplementation and/or invasive ventilation associated with severe ROP.

METHODS

This retrospective case-control study included neonates with a gestational age (GA) < 29 weeks. Participants were divided into two groups: treated retinopathy and untreated/no retinopathy. Time-weighted average FiO2 (TWAFiO2) and weekly invasive ventilation were compared between groups by postnatal age (PNA) and postmenstrual age (PMA). The association of treated retinopathy with TWAFiO2 and invasive ventilation was analyzed.

RESULTS

Data from 287 neonates were analyzed; 98 were treated for ROP and had lower GAs (25.5 vs. 27.4 weeks, p < 0.01) and lower birthweights (747.6 vs. 1014 g, p < 0.001) than those with untreated/no ROP. TWAFiO2 was higher from PMA 26-34 weeks, except for PMA 31 weeks in treated ROP, and higher in the first nine weeks of life in treated ROP. On multiple logistic regression, TWAFiO2 and invasive ventilation were associated with ROP treatment during the first seven weeks PNA. Invasive ventilation was associated with ROP treatment from PMA 26-31 weeks; no association was found for TWAFiO2 and PMA.

CONCLUSIONS

Amount of oxygen supplementation and/or invasive ventilation during the first 7 weeks of life or up to 31 weeks PMA was associated with development of severe ROP. This period might be candidate timing for strict oxygen supplementation strategies in preterm infants, while concerns of mortality with low oxygen supplementation should be further explored.

Global Prevalence and Severity of Retinopathy of Prematurity over the Last Four Decades (1985-2021): A Systematic Review and Meta-Analysis

BACKGROUND

Retinopathy of prematurity (ROP) is a vasoproliferative disease of the retina that occurs in premature infants. The prevalence of ROP reported so far is inconsistent.

AIM

To conduct a systematic review to describe the trend of ROP prevalence between 1985 and 2021, and to determine the influence of countries' economic conditions on ROP prevalence.

METHODS

We searched PubMed, Embase, and Google Scholar for studies published between January 1985 and December 2021 using the following MeSH terms: "retinopathy of prematurity", "ROP", "incidence", and "prevalence". Two independent reviewers examined the articles to select studies that met the selection criteria and performed data extraction and study quality assessment. For the meta-analysis, the pooled prevalence was calculated using a random-effects model and R software.

RESULTS

Of 5,250 titles and abstracts, 139 original studies met the inclusion criteria; a total of 121,618 premature infants were included in these studies. The pooled prevalence of ROP was 31.9% (95% confidence interval [CI] 29.0-34.8) and that of severe ROP was 7.5% (6.5-8.7). In general, no significant differences in prevalence were found over the four decades; however, we found a higher prevalence in premature infants ≤28 weeks of gestational age. In addition, the highest ROP prevalence was found in lower-middle-income countries with high mortality rates. In contrast, the highest severe ROP prevalence was found in high-income countries.

CONCLUSION

ROP remains a common cause of morbidity in premature infants worldwide. Therefore, it seems necessary to maintain early identification strategies for patients at higher risk, particularly in low- and middle-income countries.

Impact of postnatal steroids on peripheral avascular retina and severity of retinopathy of prematurity

BACKGROUND

We investigated the role of postnatal steroids on the severity of retinopathy of prematurity (ROP) and its impact on peripheral avascular retina (PAR).

METHODS

A retrospective cohort study of infants born at ≤32 weeks gestation and/or birth weight ≤1500 g. Demographics, the dose and duration of steroid treatment, and age when full retinal vascularization occurred were collected. The primary outcomes were the severity of ROP and time to full vascularization of the retina.

RESULTS

A total of 1695 patients were enrolled, 67% of whom received steroid therapy. Their birth weight was 1142 ± 396 g and gestational age was 28.6 ± 2.7 weeks. The total hydrocortisone-equivalent dose prescribed was 28.5 ± 74.3 mg/kg. The total days of steroid treatment were 8.9 ± 35.1 days. After correction for major demographic differences, infants who received a higher cumulative dose of steroids for a longer duration had a significantly increased incidence of severe ROP and PAR (P < 0.001). For each day of steroid treatment, there was a 3.2% increase in the hazard of the severe form of ROP (95% CI: 1.022-1.043) along with 5.7% delay in achieving full retinal vascularization (95% CI: 1.04-1.08) (P < 0.001).

CONCLUSION

Cumulative dose and duration of postnatal steroid use were independently associated with the severity of ROP and PAR. Thus, postnatal steroids should be used very prudently.

IMPACT

We report ROP outcomes in a large cohort of infants from two major healthcare systems where we have studied the impact of postnatal steroids on the severity of ROP, growth, and development of retinal vessels. After correcting our data for three major outcome measures, we show that high-dose postnatal steroids used for a prolonged duration of time are independently associated with severe ROP and delay in retinal vascularization. Postnatal steroids impact the visual outcomes of VLBW infants significantly, so their clinical use needs to be moderated.

The Effect of Holder Pasteurization and Different Variants on Breast Milk Antioxidants

BACKGROUND

After birth, breast milk (BM) is a known essential source of antioxidants for infants. We analyzed the non-enzymatic total antioxidant capacity (TAC), oxygen radical absorbance capacity (ORAC), and glutathione, calcium, transferrin, and total protein levels of human breast milk before and after Holder pasteurization (HoP).

METHODS

The collected donor BM samples were pasteurized with HoP.

RESULTS

HoP decreased TAC (-12.6%), ORAC (-12.1%), transferrin (-98.3%), and total protein (-21.4%) levels; HoP did not influence the glutathione concentration, and it increased the total calcium (+25.5%) concentration. Mothers who gave birth via Cesarean section had significantly lower TAC in their BM. TAC and glutathione levels were elevated in the BM of mothers over the age of 30. BM produced in the summer had higher glutathione and calcium levels compared to BM produced in the winter. The glutathione concentration in term milk samples was significantly higher in the first two months of lactation compared to the period between the third and sixth months. The transferrin level of BM for female infants was significantly higher than the BM for boys, and mothers with a BMI above 30 had increased transferrin in their samples.

CONCLUSIONS

Antioxidant levels in human milk are influenced by numerous factors. Environmental and maternal factors, the postpartum age at breast milk collection, and Holder pasteurization of the milk influence the antioxidant intake of the infant.

Risk factors in the development of retinopathy of prematurity: A 10-year retrospective study

OBJECTIVE

To evaluate Retinopathy of Prematurity (ROP) rate and risk factors in a large cohort of preterm newborns.

METHODS

Single center retrospective study. All preterm inborn hospitalized at the Neonatal Intensive Care Unit of the Policlinico of Catania from January 1, 2009 till December 31, 2018, were included. ROP stage and location, treatments required, maternal and infant risk factors were evaluated.

RESULTS

Medical records of 898 preterms were retrospectively examined (mean gestational age 32.9 ± 2.3 weeks). Of them 149 (16.6 %) developed bilateral ROP (92 stage 1, 44 stage 2 and 13 stage 3); 66 (7.3 %) received bilateral laser treatment. Six eyes of three patients affected by zone I ROP 1, with plus persistence 15 days after an optimal laser treatment, also received intravitreal ranibizumab injection. Risk factors for ROP development were gestational age (GA) (p < 0.001), birthweight (p < 0.001), assisted ventilation duration (p < 0.001), multiple birth (p = 0.003), erythropoietin (EPO) administration (p = 0.005) and persistence of tunica vasculosa lentis. The decision-tree analysis showed gestational age as the most significant predictive factor (P < 0.001); secondary predictive factors were EPO administration (p = 0.001) in newborns 29-31 weeks GA and birthweight lower than 2090 g (p < 0.001) in 32-34 weeks GA; in this latter group patent ductus arteriosus (PDA) was a tertiary predictive factor (p = 0.043).

CONCLUSIONS

In our study ROP incidence was 16,6 %; 7.3 % of the patients required laser treatment. Besides well-known factors, such as GA and birthweight, other factors like duration of assisted ventilation, EPO, multiple births, PDA, tunica vasculosa lentis persistence should be considered to tailor ophthalmic evaluation and follow-up.

Variations in medical practice of retinopathy of prematurity among 8 Asian countries from an international survey

Advances in perinatal care have led to the increased survival of preterm infants with subsequent neonatal morbidities, such as retinopathy of prematurity (ROP). This study aims to compare the differences of neonatal healthcare systems, resources, and clinical practice concerning ROP in Asia with review of current literature. An on-line survey at the institutional level was sent to the directors of 336 neonatal intensive care units (NICU) in 8 collaborating national neonatal networks through the Asian Neonatal Network Collaboration (AsianNeo). ROP screening was performed in infants born at < 34 weeks in Indonesia and Japan. In South Korea, Malaysia, and Taiwan, most screened for ROP in infants born at < 32 weeks. In all networks, majority of NICUs conducted ROP screening to infants with birth weight < 1500 g. In most NICU's in-hospital ophthalmologists performed indirect ophthalmoscopy and some were supplemented with digital imaging. Both laser photocoagulation and anti-vascular endothelial growth factor injection are performed for treatment and, vitreous surgeries are conducted less frequently in all countries. Despite limited information collected by the survey, this first study to compare ROP practices implemented in eight Asian countries through AsianNeo will enable an understanding of the differences and facilitate quality improvement by sharing better practices.

The incidence and risk factors associated with the retinopathy of prematurity in a tertiary hospital using 10-year retrospective data

BACKGROUND

The study aimed to examine the incidence and risk factors associated with retinopathy of prematurity at Phramongkutklao Hospital.

METHODS

A retrospective review was conducted on the medical records of premature infants screened for retinopathy of prematurity between January 2011 and December 2021. The screening examination was performed on infants who met the screening criteria, and retinopathy of prematurity was diagnosed according to the International Classification of Retinopathy of Prematurity. Maternal, obstetric, neonatal, and medical data were retrieved. Logistic regression analysis was used to identify the risk factors associated with retinopathy of prematurity.

RESULTS

A total of 403 premature infants were screened. The mean ± SD birth weight and gestational ages were 1,538 ± 543 grams and 31 ± 3 weeks, respectively. The incidence of any retinopathy of prematurity and stages 2 and 3 were 13.6%, 3.5%, and 10.1%, respectively. Multiple logistic regression analysis demonstrated that gestational age (adjusted odds ratio = 1.98, 95% CI:1.15-3.39), low birth weight (adjusted odds ratio = 0.99, 95% CI: 0.99-1.00), and phototherapy (adjusted odds ratio = 0.41, 95% CI: 0.17-1.00) were significant factors associated with the development of retinopathy of prematurity, after controlling for other confounding factors.

CONCLUSIONS

The incidence of total retinopathy of prematurity cases in this population was 13.6%. Overall, retinopathy of prematurity cases classified as stage 2 equated to 3.5% and stage 3 to 4.1%. Our data suggest that factors associated with retinopathy of prematurity consist of birth weight, gestational age, and phototherapy.

The Male to Female Ratio in Treatment-Warranted Retinopathy of Prematurity: A Systematic Review and Meta-analysis

Importance

Literature and anecdotal evidence suggest a relationship between male sex and retinopathy of prematurity (ROP). It is not known whether a difference, if present, is sex-related pathophysiologic predisposition or sex difference in meeting ROP screening criteria.

Objective

To evaluate the association of sex with the development of treatment-warranted ROP.

Data Sources

PubMed, Embase, and Web of Science databases were searched from 2000 to 2022. The search strategy used keywords including retinopathy of prematurity or ROP or retrolental fibroplasia and treatment or anti-VEGF or bevacizumab or ranibizumab or aflibercept or conbercept or laser or cryotherapy and gender or sex or male or female and medical subject headings terms.

Study Selection

All studies reporting on treatment with anti-vascular endothelial growth factor, laser photocoagulation, and/or cryotherapy for ROP were identified. Studies reporting sex distribution in the treatment group were included in the meta-analysis. Exclusion criteria included case reports, case series of fewer than 10 treated patients, systematic reviews, conference abstracts, letters to the editor, animal studies, and non-English records.

Data Extraction and Synthesis

Two reviewers independently screened and extracted the data following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The proportions of treated male and female infants were combined using random-effects meta-analysis.

Main Outcomes and Measures

Numbers and percentages of male and female infants treated for ROP.

Results

Of 11 368 identified studies, 316 met inclusion criteria, yielding a total of 31 026 treated patients. A higher percentage of male infants were treated for ROP (55% [95% CI, 0.54%-0.55%]), with low heterogeneity between studies (I2 = 34%; P < .001). Thirty-eight studies reported sex distribution in the screened population (170 053 patients; 92 612 [53%] male vs 77 441 [47%] female). There was no significant difference in the odds of receiving treatment between screened male and female infants (pooled odds ratio, 1.04 [95% CI, 0.91-1.18]; P = .67).

Conclusions and Relevance

More male infants are treated for ROP than female infants. This could be due to a known relative pathophysiological fragility of preterm male infants in addition to a difference in ROP screening rates, with more male infants meeting the criteria than female infants. These findings have implications for future studies and may prompt more careful clinical monitoring of male neonates.

The U.S. National Trend for Retinopathy of Prematurity

OBJECTIVE

The use of supplemental oxygen in premature infants is essential for survival. However, its use has been associated with unintended complications. The restricted use of oxygen is associated with increased mortality and necrotizing enterocolitis (NEC), whereas its liberal use is associated with increased risk for retinopathy of prematurity (ROP). Although there is no clear consensus on the acceptable oxygen saturation range, clinicians have recently become more liberal with the use of oxygen. We aim to assess (1) the national trends for ROP in very low birth weight preterm infants, and (2) the associated trends in mortality, NEC, intraventricular hemorrhage (IVH), and length of hospital stay (LOS).

STUDY DESIGN

We analyzed deidentified patient data from the National Inpatient Sample (NIS) of the Healthcare Cost and Utilization Project (HCUP) from 2002 to 2017. All infants with gestational age ≤32 weeks and birth weight <1,500 g were included. Trends in ROP, severe ROP, mortality, NEC, IVH, severe IVH, and LOS were analyzed using Jonckheere-Terpstra test.

RESULTS

A total of 818,945 neonates were included in the study. The overall mortality was 16.2% and the prevalence of ROP was 17.5%. There was a significant trend for increased ROP over the years (p < 0.001). Severe ROP was also significantly increased (p < 0.001). This was associated with a significant trend for increased median LOS in survived infants (p < 0.001). Mortality was significantly decreased (p < 0.001), whereas NEC and severe NEC did not change over time (p = 0.222 and p = 0.412, respectively).

CONCLUSION

There is a national trend for increased ROP and severe ROP over the 16 years of the study period. This trend was associated with a significant increase in the LOS in survived infants without change in NEC.

KEY POINTS

· Prevalence of ROP and severe ROP has increased in VLBW infants over the 16-year study period.. · The prevalence of NEC did not change over the same time period.. · Increased ROP and severe ROP were consistent in all three GA and BW subgroups..

Incidence and risk factors for retinopathy of prematurity in premature, extremely low birth weight and extremely low gestational age infants

BACKGROUND

The aim of the study was to determine the incidence and risk factors of retinopathy of prematurity (ROP) in premature, extremely low birth weight (BW, ELBW) and extremely low gestational age (GA, ELGA) infants.

METHODS

The medical records of preterm infants who were screened for ROP between January 2012 and December 2020 were retrospectively reviewed. Only one eye of each infant with higher grade ROP was included in the study. BW; GA; medical characteristics; the presence, severity, and need for treatment of ROP were recorded. Infants were divided into groups according to BW (≤1000 g, 1001-1750 g, > 1750 g) and GA (≤25w, 26-28w, 29-31w, 32-34w, ≥35w) and data were analyzed.

RESULTS

Data of 2186 infants were evaluated. The overall incidences of any stage ROP and ROP requiring treatment were 43.5 and 8.0%, respectively. These rates were 81.1 and 23.9% in ELBW (≤1000 g) infants and were 92.9 and 64.3% in ELGA (≤25w) infants, respectively. The rates of ROP, the median duration of oxygen therapy and systemic diseases increased significantly as BW and GA decreased. The median duration of oxygen therapy and the rates of sepsis, pulmonary dysplasia (BPD), and intraventricular hemorrhage (IVH) were statistically higher in infants with ROP compared to those without ROP (p < 0.001). Multivariate regression analysis demonstrated that low BW and GA; prolonged duration of oxygen therapy; presence of PDA and necrotizing enterocolitis (NEC) were important risk factors for ROP.

CONCLUSIONS

ELBW and ELGA infants develop higher rates of ROP and severe ROP. Prolonged duration of oxygen therapy, the presence of concomitant neonatal sepsis, BPD, IVH, PDA, and NEC further increases the risk of ROP.

Postnatal administration of systemic steroids increases severity of retinopathy in premature infants

BACKGROUND

Postnatal systemic steroids are known to increase the risk of developing retinopathy of prematurity (ROP). However, whether the total dosage and type of postnatal systemic steroids are related to the development and severity of ROP in premature infants remains unclear. This study was conducted to identify the risk factors for ROP and investigate the relationship between photocoagulation (PC)-demanding severe ROP and the postnatal dosage of any type of systemic steroids.

METHODS

A total of 75 infants born at <28 weeks of postmenstrual age (PMA) were enrolled. The number of PC procedures for ROP was evaluated as the objective variable. This study analyzed the following independent variables: gestational age; birth weight; sex; Apgar scores; duration of mechanical ventilation; duration of nasal intermittent positive pressure ventilation; mean saturation and mean oxygen concentration administration until 36 weeks of PMA; total accumulation dosage of hydrocortisone, dexamethasone, and systemic steroids; dosage number of times of erythropoietin; total dosage of red cell concentrates (RCC); incidence of necrotizing enterocolitis (NEC) and focal intestinal perforation; sepsis; bronchopulmonary dysplasia (BPD); and intraventricular hemorrhage (IVH). Logistic regression was used to estimate the relative risk (odds ratio (OR)) associated with risk factors for PC-demanding severe ROP.

RESULTS

Compared with infants in the non-PC group, PC-treated infants had younger gestational age, longer mechanical ventilation periods, and higher dosage of systemic steroids and dexamethasone. Multivariate logistic regression analysis revealed total dosage of systemic steroids as the only risk factor for PC-demanding severe ROP. Based on receiver operating characteristic (ROC) curve analysis, a cutoff value of 8.95 mg/kg of postnatal systemic steroid administration was identified as a useful marker to predict PC-demanding severe ROP.

CONCLUSION

By focusing on the method of systemic steroid administration and avoiding excessive doses for infants born at <28 weeks of PMA, preventing the development of severe ROP is possible.

Incidence of retinopathy of prematurity treatment in extremely preterm infants in China

BACKGROUND

Retinopathy of prematurity (ROP) continues to be a major cause of visual impairment and blindness in premature infants and children.

OBJECTIVES

To investigate the incidence of severe ROP receiving treatment in extremely preterm (EP) infants in China over time. The risk factors for ROP treatment were also assessed.

METHODS

This was a multicentre retrospective study and a subanalysis of baseline data from the "Outcomes of EP infants in China 2010-2019" study. This study was conducted in 68 tertiary neonatal care centres from 31 provinces of China. Infants with a gestational age of 23⁰ -27⁶  weeks and admitted to a neonatal unit within the first 72 h of life between 2010 and 2019 were enrolled. Incidence of ROP was analysed in infants who survived to 32 weeks postmenstrual age and screened for ROP. Multivariable modified Poisson regression models were used to identify risk factors for ROP treatment.

RESULTS

Among 7295 eligible infants, 4701 (64.5%) survived to 32 weeks postmenstrual age and met ROP screening criteria. Of the 3756 infants who screened and with ROP data, 2320 (61.8%) developed ROP of any stage. The overall incidence of ROP treatment was 12.6%, decreasing from 45.5% at 23 weeks to 8.3% at 27 weeks. During the 10-year period, the incidence of ROP treatment did not change, although the incidence of any ROP increased over time. Independent risk factors associated with ROP treatment included lower gestational age, small for gestational age, multiple birth, severe intraventricular haemorrhage, patent ductus arteriosus and supplemental oxygen duration.

CONCLUSIONS

The incidence of EP infants receiving ROP treatment showed no change during this 10-year period in China. Prevention of prematurity and foetal growth restriction, judicious use of oxygen and reducing comorbidities are promising factors that may reduce the incidence of ROP needing treatment in these high-risk infants.

Retinopathy of prematurity: a review of epidemiology and current treatment strategies

Retinopathy of prematurity (ROP) is among the most common causes of childhood blindness. Three phases of ROP epidemics have been observed worldwide since ROP was first described in the 1940s. Despite advances in neonatal care, the occurrence of ROP and associated visual impairment has been increasing somewhere on Earth and remains difficult to control. Conventional treatment options for preventing ROP progression include retinal ablation using cryotherapy or laser therapy. With the emergence of anti-vascular endothelial growth factor (anti-VEGF) treatment for ocular diseases, the efficacy and safety of anti-VEGF therapy for ROP have recently been actively discussed. In the advanced stage of ROP with retinal detachment, surgical treatment including scleral buckling or vitrectomy is needed to maintain or induce retinal attachment. At this stage, the visual outcome is usually poor despite successful anatomical retinal attachment. Therefore, preventing ROP progression by timely screening examinations and treatment remains the most important part of ROP management.

Risk of Retinopathy of Prematurity in Preterm Births with Respiratory Distress Syndrome: A Population-Based Cohort Study in Taiwan

Background

Methods

Results

Conclusion

Vision-Related Quality of Life in Malaysian Children with Threshold and Pre-Threshold Retinopathy of Prematurity

Purpose

The prevalence of retinopathy of prematurity (ROP) is higher in developing countries compared to developed countries. There is limited data on vision-related quality of life (VRQoL) among children with severe type of ROP in developing countries. This study evaluated the influence of threshold and prethreshold ROP on VRQoL in Malaysian children.

Methods

Multicenter prospective cross-sectional study conducted in three tertiary hospitals in 2018 to 2019. Children less than 7 years old with previous ROP diagnosis were recruited. Patients with systemic comorbidities that affected vision or daily activities were excluded. A parent or guardian completed the Children’s Visual Function Questionnaire (CVFQ) for the assessment of child’s general health, general vision, competence, personality, family impact, and treatment difficulty.

Results

Eight were categorized with threshold ROP, 16 with high-risk prethreshold ROP, and 26 with low-risk prethreshold ROP. Fifty age-matched controls were also included. Mean visual acuity in logarithm of the minimum angle of resolution was 0.46 in the threshold, 0.08 in high-risk prethreshold, and 0.01 in low-risk prethreshold subgroups. Threshold ROP was associated with myopia and strabismus, and associated with poor visual acuity compared to prethreshold ROP. Mean total CVFQ score was significantly lower in the ROP group (p < 0.001) compared to the control group. Mean score and all mean subscale scores were significantly lower in the threshold subgroup compared to high-risk and low-risk prethreshold subgroups, with lowest subscale scores on general vision and general health. There was significant association between gestational age, visual acuity of the better eye, family income, and VRQoL (p < 0.05).

Conclusions

ROP was associated with lower VRQoL in children born prematurely in Malaysia. The threshold ROP group is the most affected. General vision and health domains are their main difficulties encountered. Gestational age, visual acuity of the better eye, and family income affects the VRQoL.

Demographic Risk Factors of Retinopathy of Prematurity: A Systematic Review of Population-Based Studies

INTRODUCTION

Current national guidelines use gestational age (GA) and birth weight (BW) as their basis for retinopathy of prematurity (ROP) screening. The strength of association of these and other demographic risk factors is inconsistent across studies. This review aims to evaluate the strength of association of documented risk factors for ROP in large sample, population-based studies.

METHODS

MEDLINE, EMBASE, and Cochrane Library were searched from January 2010 to May 2020. Original studies reporting the risk of ROP in a region and demographic risk factors were included.

RESULTS

Eighteen studies comprising 342,005 infants were included. The overall risk of ROP in preterm infants was 18.8%. For every week decrease in GA, there was a median adjusted odds ratio (aOR) of 1.4 times (range 1.2-1.9) of developing ROP. For every 100-g decrease in BW, the median aOR was 1.8 times (range 1.2-2.7). Higher risk was found in infants with neonatal sepsis and bronchopulmonary dysplasia. The risk of any, severe, and treatment-requiring ROP was highest for 23 weeks GA, which was 66.5, 40.3, and 39.4%, respectively. Regions with higher neonatal mortality rates had the highest mean GA of infants with ROP.

CONCLUSION

For every week decrease in GA and every 100-g decrease in BW, there was a median of 1.4 times and 1.8 times the odds of developing ROP, respectively. Further research is required to clarify the role of additional risk factors.

Severe Retinopathy of Prematurity Associated With Neurodevelopmental Disorder in Children

OBJECTIVE

This study aimed to investigate whether severe retinopathy of prematurity (ROP) could be an association factor for neurodevelopmental disorders in premature infants without other risk factors-such as congenital anomalies, birth injuries, and neurological diseases-that may cause developmental delay.

METHODS

We used health claims data recorded between 2007 and 2018 in the Korean National Health Insurance Service (KNHIS) database. We recruited a total of 18,256 premature infant born between 2007 and 2008 without congenital anomaly or birth injury (with ROP 6,995, without ROP 11,261) and divided them into four groups as follows: Group A, 209 extremely premature infants [gestational age (GA) < 28] with mild ROP; Group B, 75 extremely premature infants (GA < 28) with severe ROP; Group C, 6,510 other premature infants (28 ≤ GA <37)with mild ROP; and Group D, 201 other premature infants (28 ≤ GA < 37) with severe ROP. Using regression analysis, we analyzed whether there was a correlation between ROP prevalence, severity, and developmental delay in premature infants without other risk factors.

RESULTS

The prevalence of developmental delay, according to GA and ROP severity, was higher in patients with severe ROP than in the other patients. The prevalence gradually decreased after birth. Among extremely premature infants with ROP, those with severe ROP had a 3.082-fold higher association with neurodevelopmental complications than those with mild ROP (p < 0.001). Compared with other premature infants with ROP, those with severe ROP had a 3.269-fold higher association with neurodevelopmental complications than those with mild ROP.

CONCLUSION

The severity of ROP may be associated with neurodevelopmental disorders in premature infants.

Retinopathy prematurity: a systematic review and meta-analysis study based on neonatal and maternal risk factors

BACKGROUND

Retinopathy of prematurity is the abnormal development of retinal arteries in preterm neonates less than 32 weeks and weighing 1500 g, and less, which can lead to visual impairment during life and blindness. This study aims to investigate the relationship between some clinical characteristics of neonates and mothers with Retinopathy of prematurity in the world via a systematic review and meta-analysis.

MATERIALS AND METHODS

The present study is a systematic review and meta-analysis on the relationship between maternal and neonatal clinical variables with Retinopathy of prematurity in the world from the beginning of 2000 to the end of 2020. Accordingly, all English articles published on the topic were searched in scientific databases of Web of Science, PubMed, Google Scholar, Science Direct, and Scopus. The articles were searched independently by two researchers. Statistical analysis of data was performed using fixed and random effects model statistical tests in the meta-analysis, Cochran, meta-regression, I² index, Funnel plot, and Begg's by STATA software program, version 14.

RESULT

A total of 191 studies with a sample size of 140,921 persons were including in the meta-analysis. Accordingly, Preterm delivery ≤28 weeks (OR:6.3, 95% CI:4.9-8.1), Birth Weight ≤1000 g (OR:5.8, 95% CI:4.8-6.8), Birth Weight ≤1500 g (OR:4.8, 95% CI:3.8-6.1), PROM (OR:1.2, 95% CI:1.0-1.4), induced fertility (OR:1.9, 95% CI:1.1-3.0) and Chorioamnionitis (OR:1.5, 95% CI:1.0-2.2) There was a statistically significant association with retinopathy.

CONCLUSION

Based on the results of the present meta-analysis, the risk of retinopathy of prematurity in neonates born at 28 weeks and less, LBW (weight 1500 g and less), neonatal hypotension, chorioamnionitis, and induced fertility increases.

Impact of early postnatal exposure of red blood cell transfusions on the severity of retinopathy of prematurity

BACKGROUND

Postnatal exposure to red blood cell transfusion (RBCT) in premature infants is an important risk factor for Retinopathy of Prematurity (ROP) progression. We hypothesized that higher number and earlier timing of RBCT are associated with worse ROP severity and result in laser treatment at an earlier postmenstrual age (PMA) in very low birth weight (≤1500 g, VLBW) infants.

METHODS

A retrospective medical record review of 631 VLBW infants over a 5-year period was performed. Demographic features and potential clinical risk factors including number of RBCT, ROP severity, and progression to laser treatment were collected to evaluate predictors of severe ROP. ANCOVA, pairwise post-hoc analyses, and multivariate regression were used to determine associations between frequency and timing of RBCT and ROP severity.

RESULTS

Of the 456 eligible infants, 61 developed severe ROP (13%). There was significant correlation between number of RBCTs and ROP severity, adjusted for gestational age and birthweight (Adjusted R2 = 0.53; p <  0.001). Compared to infants with No/Mild and Type 2 ROP, infants with Type 1 ROP received more RBCTs, with higher number of RBCTs per week during the first month of life (mean RBCT in ROP No/Mild 5.7±0.4 vs Type 2 16.3±1.8 vs Type 1 22.4±1.5, p = 0.042). Laser-treated infants received a higher number of RBCTs than non-treated infants (mean RBCT 22.3 vs. 6.5, p <  0.001) but no correlation was observed between number of RBCTs and PMA at time of laser treatment.

CONCLUSION

Higher number of RBCTs in early postnatal life of VLBW infants was associated with more severe ROP.

Nationwide incidence and treatment pattern of retinopathy of prematurity in South Korea using the 2007-2018 national health insurance claims data

The aim of this study is to investigate the nationwide incidence and treatment pattern of retinopathy of prematurity (ROP) in South Korea. Using the population-based National Health Insurance database (2007–2018), the nationwide incidence of ROP among premature infants with a gestational age (GA) < 37 weeks (GA < 28 weeks, GA28; 28 weeks ≤ GA < 37 weeks; GA28-37) and the percentage of ROP infants who underwent treatment [surgery (vitrectomy, encircling/buckling); retinal ablation (laser photocoagulation, cryotherapy)] were evaluated. We identified 141,964 premature infants, 42,300 of whom had ROP, with a nationwide incidence of 29.8%. The incidence of ROP in GA28 group was 4.3 times higher than in GA28-37 group (63.6% [2240/3522] vs 28.9% [40,060/138,442], p < 0.001). As for the 12-year trends, the incidence of ROP decreased from 39.5% (3308/8366) in 2007 to 23.5% (2943/12,539) in 2018. 3.0% of ROP infants underwent treatment (25.0% in GA28; 1.7% in GA28-37); 0.2% (84/42,300) and 2.9% (1214/42,300) underwent surgery and retinal ablation, respectively. The overall percentage of ROP infants who underwent treatment has decreased from 4.7% in 2007 to 1.8% in 2018. This first Korean nationwide epidemiological study of ROP revealed a decreased incidence of ROP and a decreased percentage of ROP infants undergoing conventional treatment during a 12-year period.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

Retinopathy of prematurity in infants without fetal growth restriction is decreased with the progression of acute histologic chorioamnionitis: New observation as a protective factor against retinopathy of prematurity

INTRODUCTION

IGF-1 deficiency in prenatal period is known to be a definite pathophysiology of retinopathy of prematurity(ROP), which is more frequent in infants with fetal growth restriction(FGR). Of note, recent reports demonstrated intra-amniotic inflammation(IAI) closely linked to acute histologic chorioamnionitis(acute-HCA) is associated with a decrease in intact-form of IGFBP-1, ultimately rising the probability of an increase in IGF-1. Therefore, we hypothesized ROP in preterm-infants without FGR would be decreased with the progression of acute-HCA.

METHODS

The frequency of ROP was examined in 85 singleton preterm-infants(24.5weeks ≤ gestational-age[GA] at delivery<30weeks) due to either preterm-labor and intact-membranes(PTL) or preterm premature rupture of membranes(preterm-PROM) without FGR(birth-weight<5th percentile for GA). Patients were divided according to the progression of inflammation in extra-placental membranes(EPM) and the progression of inflammation in chorionic-vessel(CV) and umbilical-cord(UC).

RESULTS

1) ROP was present in 40%(34/85) of study-population; 2) Of note, there was a significant stepwise-decrease in ROP with the progression of inflammation in EPM(inflammation-free EPM vs. inflammation restricted to CD vs. amnionitis; 55.6%[15/27]vs.39.5%[17/43]vs.13.3%[2/15]) and the progression of inflammation in CV and UC(inflammation-free CV and UC vs. inflammation restricted to CV and umbilical vessels vs. inflammation in Wharton's jelly[WJ]; 49.2%[29/59]vs.25.0%[3/12]vs.14.3%[2/14])(each-for P < 0.05, Chi-square test and each-for P < 0.01, linear-by-linear association); 3) Multiple logistic-regression analysis demonstrated amnionitis(Odds-Ratio 0.120, 95%Confidence-Interval 0.022-0.654, P = 0.014) and inflammation in WJ(Odds-Ratio 0.124, 95%Confidence-Interval 0.022-0.694, P = 0.018) were independent protective-factors against ROP.

DISCUSSION

ROP in preterm-infants due to PTL or preterm-PROM without FGR is decreased with the progression of acute-HCA. This finding may be an evidence to suggest the progression of acute-HCA is closely associated with reducing the pathophysiology of ROP.

Survival rate dependent variations in retinopathy of prematurity treatment rates in very low birth weight infants

As increased oxidative stress causes increased mortality and morbidities like bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP) in very low birth weight infants (VLBWIs), the conundrum of improved survival but increased ROP observed with the high oxygen saturation target range of 91–95% is difficult to explain. To determine the survival rate-dependent variation in ROP treatment rate, 6292 surviving eligible VLBWIs registered in the Korean Neonatal Network were arbitrarily grouped according to the survival rate of infants at 23–24 weeks’ gestation as group I (> 70%, n = 1626), group II (40–70%, n = 2984) and group III (< 40%, n = 1682). Despite significantly higher survival and lower BPD rates in group I than in groups II and III, the ROP treatment rate was higher in group I than in groups II and III. However, the adjusted odds ratios for ROP treatment were not significantly different between the study groups, and the ROP treatment rate in the infants at 23–24 weeks’ gestation was 21-fold higher than the infants at ≥ 27 weeks’ gestation. The controversial association between improved survival and reduced BPD reflecting quality improvement of neonatal intensive care but increased ROP treatment rate might be primarily attributed to the improved survival of the most immature infants.

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

PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

International Perspectives: Implementation of the Korean Neonatal Network

Although there has been a marked increase in the number of NICUs in Korea, the gap in quality improvement has remained a national focus. The Korean Neonatal Network (KNN) was established in 2013 by the Korean Society of Neonatology with support from the Korea Centers for Disease Control and Prevention, with the aim of improving neonatal outcomes by offering data-driven interactive tools to all participating NICUs. Approximately 2,000 very-low-birthweight (VLBW) infants from 70 participating hospital NICUs are registered annually in the KNN, with a total of over 12,000 to date. In addition to providing a national registry of VLBW infants, this unique system also leads to an infrastructure for quality improvement in neonatal care, which in turn has an effect on the development of evidence-based neonatal medicine in Korea. Furthermore, it is encouraging that the KNN plans to develop tools to facilitate multicenter clinical trials and to join the global international network for international collaboration.

Retinopathy of prematurity treatment: Asian perspectives

Retinopathy of prematurity (ROP) is a vasoproliferative disease of developing retinal vessels that affects premature infants and can lead to severe and irreversible visual loss if left untreated. India and some other Asian countries are in the middle of a 'third ROP epidemic'. Blindness due to ROP is largely preventable if appropriate, adequate and accessible screening programmes are available. Screening of the premature babies is the first step in ROP management. With the increase in use of tele-screening techniques, more premature babies have been brought under the screening network both from urban and rural regions. Laser photocoagulation to the avascular retina using indirect ophthalmoscopy delivery system is the gold standard for ROP treatment and is usually done under topical anaesthesia in the Asian region in contrast to the western world. Use of intravitreal anti-vascular endothelial growth factors (VEGF) although controversial in management of ROP has been found to be effective in various Asian studies as well. ROP surgery in India and other middle-income Asian countries is largely performed only in few tertiary eye care centres. Poor visual prognosis, late presentation with advanced retinal detachments, lack of adequate number of trained paediatric retinal surgeons and paediatric anaesthetists also contribute to this problem. This current paper summarizes the Asian experience of ROP management.

The effect of desflurane on retinal angiogenesis in a mouse model of oxygen-induced retinopathy

PURPOSE

Retinopathy of prematurity (ROP) is an ocular disorder that primarily occurs in premature infants and is the most common cause of vision impairment. This study examined the effect of desflurane on angiogenesis in a mouse model of oxygen-induced retinopathy (OIR).

METHODS

Mice were randomly allocated to the control (C), ROP control (R_c), or ROP with desflurane exposure (R_d) group. To induce ROP, 7-day-old mice were exposed to 75% oxygen in a chamber for 5 days [postnatal days (P) 7-12], and thereafter returned to room air. Age-matched mice exposed to room air formed the C group. The R_d group was exposed to 8% desflurane for 2 h on P12, P13, and P14 with 40% oxygen. To observe changes in angiogenesis of the retina, mice were sacrificed at P16.

RESULTS

The ratio of avascular area/total retinal area was not changed significantly in the R_d group, compared to the R_c group. The expression of endothelial growth factor A (VEGF-A) and hypoxia inducible factor-1α (HIF-1α) in the R_d group and R_c group was not significantly different.

CONCLUSIONS

Desflurane does not have a significant influence on retinal angiogenesis via HIF-1α and VEGF-A expression in the OIR mouse model. However, these findings are not directly applicable to premature infants, and it is thus necessary to perform further studies to determine the effect of desflurane on angiogenesis.

Early Risk Factors for Retinopathy of Prematurity in Very and Extremely Preterm Chinese Neonates

Objective: To investigate the incidence and risk factors of retinopathy of prematurity (ROP) in very and extremely preterm (28⁺⁰- <32⁺⁰, and <28⁺⁰ weeks gestation, respectively) neonates, and the predictive factors for ROP in the early hours after birth and during hospitalization. Methods: Using a prospective database supplemented with a retrospective chart review, we identified preterm neonates born at gestation <32 weeks at the University of Hong Kong-Shenzhen Hospital between January 2015 and August 2018. Demographic and clinical variables were studied including indicators of disease acuity in the first 24 h after birth. We also compared the difference in risk factors between survivors with ROP and survivors without ROP. Results: During the study period, there were 529 preterm neonates admitted to our neonatal intensive care unit with 120 (23%) born at <32 weeks' gestation. Thirteen (11%) neonates died. Among the 107 survivors, 23 (21%) had ROP, of whom five (22%) received laser and/or medical therapy for severe ROP. Compared with survivors without ROP, infants with ROP had lower mean blood pressure in the first 12 and 24 h after birth, respectively. Using multivariate regression, gestation age, mean blood pressure in the first 12 h after birth, hospital length of stay, and total days of blood gases pH <7.2 were independent risk factors for ROP. Conclusions: In this small cohort of Chinese neonates born <32⁺⁰ weeks' gestation, survivors with ROP had a lower blood pressure in the early hours after birth, younger gestation, longer hospital stay, and duration of acidosis when compared to those without ROP.

Pain Management with ROP Position in Turkish Preterm Infants During Eye Examinations: A Randomized Controlled Trial

PURPOSE

The purpose of this study was to evaluate the effects of infant positioning on pain, heart rate, oxygen saturation and crying time during examination.

DESIGN & METHODS

The randomized controlled experimental study was carried out on 70 preterm infants. ROP position + pacifier was used in the experimental group (n = 35) while only the pacifier was used in the control group. Heart rates, oxygen saturation, crying duration and pain score (Premature Infant Pain Profile-PIPP) were evaluated before, during and after the screening.

RESULTS

The preterm infants in the experimental group recorded lower pain scores at the beginning of the screening (p = 0.01), at the end of the screening (p = 0.01) and after screening (p = 0.01) than those in the control group. The heart rate was higher in the control group during screening (p = 0.010) and after screening (p = 0.008) than in the preterm infants in the experimental group. Oxygen saturation was not significantly different between the groups before, during or after screening. Crying duration was lower in the experimental group than in the control group (p = 0.010).

CONCLUSIONS

Positioning of the infant to support behavioral organization was found to be effective in reducing pain and shortening crying time during eye examination, and had favorable effects on physiological variables with ROP position during eye examinations.

PRACTICE IMPLICATIONS

ROP position is a practical and effective non-pharmacological method during eye examinations by neonatal nurses.

Case control study of risk factors and ophthalmological outcomes of very low birth weight infants with Type 1 retinopathy of prematurity

INTRODUCTION

We evaluated the risk factors associated with Type 1 retinopathy of prematurity (ROP) in very low birth weight (VLBW) infants and compared ophthalmologic outcomes between cases with Type 1 ROP who received treatment and gestational age-matched controls with mild or no ROP not requiring treatment.

METHODS

This was a retrospective case-control study of VLBW infants born in National University Hospital, Singapore, from January 2001 to December 2013. 17 cases with Type 1 ROP were each matched for gestational age with controls who had either mild (below Stage 2) or no ROP. Antenatal, perinatal and postnatal variables, as well as childhood ophthalmologic outcomes, were collected from their clinical records and analysed.

RESULTS

The number of packed cell transfusions and highest fraction of inspired oxygen given at weeks 7-10 were found to be statistically significant on multivariate analysis (p = 0.045 and p = 0.049, respectively). None of the infants had blindness or retinal detachment, and there were no significant differences in refractive errors between the groups at 1-4 years of age. Strabismus at four years of age was more common in the group with Type 1 ROP (p = 0.023).

CONCLUSION

Increased episodes of blood transfusions and chronic lung disease requiring high oxygen supplementation at 7-10 weeks of life are significant risk factors associated with Type 1 ROP in VLBW infants in our study. Strabismus at four years is more common in this group of patients. This study highlights the importance of long-term ophthalmologic surveillance for these high-risk children.

Refractive Outcomes of 4-Year-old Children after Intravitreal Anti-vascular Endothelial Growth Factor versus Laser Photocoagulation for Retinopathy of Prematurity

Purpose

To compare long-term refractive outcomes associated with intravitreal anti-vascular endothelial growth factor (VEGF) versus laser photocoagulation treatment for retinopathy of prematurity (ROP).

Methods

A total of 52 eyes from 27 ROP patients treated at two tertiary referral-based hospitals from August 2006 to December 2013 were reviewed. The primary outcome was refractive error measured at the age of 4 years, accounting for within-patient inter-eye correlation. Secondary outcomes included the recurrence rate and treatment complications.

Results

The mean age at refraction was 4.7 ± 0.3 years in the laser group (n = 30) and 4.4 ± 0.3 years in the anti-VEGF group (n = 22). No significant differences were noted in gestational age, birthweight, post-menstrual age at treatment, or ROP stage/zone distribution between groups. Mean spherical equivalent was also not significantly different (−1.0 diopters in the laser group and −0.3 diopters in the injection group, p = 0.603). Clustered regression analysis revealed that only gestational age was significantly correlated with mean spherical equivalent (p < 0.001; 95% confidence interval, −0.007 to −0.002). Recurrence was noted in four eyes (13.3%) in the laser group, but this difference was not significant (p = 0.128). There were no major systemic complications reported in either group.

Conclusions

Treatment type, whether laser or anti-VEGF injection, does not appear to influence long-term refractive outcomes in ROP. Concern regarding refractive outcomes should not be the most important factor when selecting ROP treatment modality.

Perinatal risk factors for development of retinopathy of prematurity in a tertiary neonatal intensive care unit

OBJECTIVE

Retinopathy of prematurity (ROP) is a vasoproliferative disorder that is one of the main preventable causes of blindness among preterm neonates. This study aimed to determine the incidence of ROP and investigate the relationship between perinatal risk factors and ROP development.

METHODS

This retrospective, non-interventional, non-comparative, hospital-based study was conducted at a tertiary-level neonatal intensive care unit. A total of 163 consecutive patients who met the inclusion criteria were recruited in this study.

RESULTS

ROP prevalence was 0.01. During the study period, 44 patients developed ROP (27%), and 119 (73%) did not. Stage I ROP was detected in 8 patients (4.9%); stage II ROP without plus-disease in 26 patients (16%); stage II disease with comorbidities in 1 patient (0.6%); and stage III disease in 9 patients (5.5%). None of the patients showed stage IV and V disease. The mean gestational age was 27.7 ± 2.08 weeks in babies who had ROP and 29.59 ± 1.80 weeks in the other group. Neonates with ROP required more frequent blood transfusion (average, 4.89 ± 3.164 transfusions) compared to their counterparts who received an average of 1.19 ± 1.733 transfusions. Intracranial haemorrhage was identified in 55 (33.7%) patients, of whom 14.1% had ROP. Moreover, neonatal seizures occurred in 23 (14.11%) babies and were more common among babies who had ROP (n = 14).

CONCLUSION

This study identified key factors associated with ROP, such as intracranial haemorrhage with or without neonatal seizures and a high frequency of blood transfusions.

Estimate of incidence of ROP requiring treatment in extreme preterms and impact on service-7 year review in tertiary unit

BACKGROUND/OBJECTIVES

Retinopathy of prematurity (ROP) is a potentially blinding disorder affecting premature infants. Our Eye Unit supports two neonatal intensive care units (NICUs), one provides neonatal surgical and medical facilities and the other is exclusively medical. Our objectives were to (1) to identify the annual rate of ROP treatments during the period 2009-2015 and (2) to estimate the incidence of ROP treatment in babies born very prematurely (<27 weeks).

SUBJECTS/METHODS

Records for all infants treated for ROP by our unit during the period 2009-2015 were reviewed. We calculated numbers treated in each year. Records of babies born under 27 weeks of gestation and cared for in the non-surgical NICU were also reviewed. Their requirement for laser treatments for ROP was calculated by the week of gestation at birth.

RESULTS

In the two NICUs combined, 95 infants were treated for ROP between 2009 and 2015. The numbers treated increased from 9/158 (5.7%) of babies screened in 2009 to 22/159 (13.8%) in 2015 (p_trend = 0.004). The rate of laser treatment for ROP increased as gestation at birth decreased: from 12/100 (12%) of babies born at 26 weeks to 17/29 (59%) of babies born at 23 weeks (p_trend = 0.001).

CONCLUSION

The number of laser treatments for ROP carried out by this unit has increased steadily between 2009 and 2015 and this may in part be due to the increased need for ROP treatment in extremely preterm babies, whose survival has increased in the same period. These data may aid planning for ROP services.

Intravitreal ranibizumab versus laser photocoagulation for retinopathy of prematurity: efficacy, anatomical outcomes and safety

Background/Aims

To compare the efficacy, anatomical outcomes and complications of intravitreal ranibizumab with those of laser photocoagulation for retinopathy of prematurity (ROP).

Methods

This is a retrospective case series of 314 eyes from 165 infants diagnosed with type I ROP and treated with either laser photocoagulation (161 eyes) or intravitreal ranibizumab (0.25 mg/0.025 mL) injection (153 eyes) between January 2006 and December 2016 in a tertiary referral-based hospital. The main outcome was the rate of recurrence requiring additional treatment. Secondary outcomes included the incidence of major complications and final refractive error.

Results

The mean follow-up was 36.3±31.9 months. Recurrences requiring further intervention were noted in 22 (13.7%) laser-treated and 15 (9.8%) ranibizumab-treated eyes (p=0.196). Retinal detachment (8 vs 1, p=0.037) and macular dragging (7 vs 1, p=0.039) were observed in the laser-treated and injection-treated groups, respectively, but no systemic or neurodevelopmental adverse events were reported. In the ranibizumab group, 95.6% showed fully vascularised retinas. Multivariate analyses revealed that birth weight (OR 0.993, p=0.023) and higher ROP stage (OR 11.222, p=0.008) influenced the incidence of major complications.

Conclusion

Intravitreal ranibizumab for ROP appears to achieve similar therapeutic effects than did laser photocoagulation, but with fewer surgical complications such as retinal detachment or macular dragging.

Anti-vascular Endothelial Growth Factor Treatment of Retinopathy of Prematurity: Efficacy, Safety, and Anatomical Outcomes

PURPOSE

To investigate the efficacy, safety, and anatomical outcomes associated with intravitreal anti-vascular endothelial growth factor (VEGF) treatment of retinopathy of prematurity (ROP).

METHODS

We performed a retrospective review of intravitreal anti-VEGF (bevacizumab or ranibizumab) treatment of 153 eyes (83 infants) diagnosed with ROP at two tertiary hospitals from June 2011 to January 2017. The primary outcome was the rate of recurrence requiring additional treatment; secondary outcomes included incidence of major complications and final refractive error.

RESULTS

A total of 101 eyes were treated with bevacizumab, and 52 with ranibizumab. The bevacizumab and ranibizumab groups were characterized by mean birthweights of 941.8 ± 296.1 and 1,257.7 ± 514.5 g, gestational ages at birth of 26.9 ± 1.9 and 28.1 ± 3.2 weeks, and postmenstrual ages at treatment of 40.4 ± 2.4 and 39.2 ± 2.3 weeks, respectively. The two groups differed significantly in birthweights and gestational ages at birth, but not in postmenstrual ages at treatment. The mean follow-up duration was 30.9 ± 18.4 months for the bevacizumab group, and 13.9 ± 12.5 months for ranibizumab. More cases were classified as zone 1 ROP in the ranibizumab group (44.2% vs. 11.9%, p < 0.001). Major surgical interventions included scleral encircling and vitrectomy (one and two eyes, respectively, both in the bevacizumab group). Retinal detachment was noted in one eye treated with bevacizumab. There was no significant difference in the most recent spherical equivalence for the two groups (+0.10 ± 3.66 and +0.22 ± 3.00 diopters for bevacizumab and ranibizumab, respectively). Univariable analysis revealed that only ROP stage influenced the occurrence of major complications (odds ratio, 9.046; p = 0.012).

CONCLUSIONS

Intravitreal anti-VEGF treatment of ROP with both bevacizumab and ranibizumab achieved stable retinal vascularization with a low rate of complications and recurrence. Ranibizumab achieved similar anatomical outcomes as bevacizumab, without additional risk for major complications.

Chorioamnionitis as a risk factor for retinopathy of prematurity: An updated systematic review and meta-analysis

The role of chorioamnionitis (CA) in the development of retinopathy of prematurity (ROP) is difficult to establish, because CA-exposed and CA-unexposed infants frequently present different baseline characteristics. We performed an updated systematic review and meta-analysis of studies reporting on the association between CA and ROP. We searched PubMed and EMBASE for relevant articles. Studies were included if they examined preterm or very low birth weight (VLBW, <1500g) infants and reported primary data that could be used to measure the association between exposure to CA and the presence of ROP. Of 748 potentially relevant studies, 50 studies met the inclusion criteria (38,986 infants, 9,258 CA cases). Meta-analysis showed a significant positive association between CA and any stage ROP (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.11 to 1.74). CA was also associated with severe (stage ≥3) ROP (OR 1.63, 95% CI 1.41 to 1.89). Exposure to funisitis was associated with a higher risk of ROP than exposure to CA in the absence of funisitis. Additional meta-analyses showed that infants exposed to CA had lower gestational age (GA) and lower birth weight (BW). Meta-regression showed that lower GA and BW in the CA-exposed group was significantly associated with a higher risk of ROP. Meta-analyses of studies with data adjusted for confounders could not find a significant association between CA and ROP. In conclusion, our study confirms that CA is a risk factor for developing ROP. However, part of the effects of CA on the pathogenesis of ROP may be mediated by the role of CA as an etiological factor for very preterm birth.

Trends in the incidence of retinopathy of prematurity over a 10-year period

AIM

To describe and evaluate the trends in the incidence of retinopathy of prematurity over a 10-year period in a tertiary hospital in Hong Kong.

METHODS

A retrospective review was performed on all preterm infants screened and/or treated for retinopathy of prematurity from January 2006 to December 2015 at Prince of Wales Hospital, Hong Kong. Preterm infants with incomplete records or transferred-in from other hospitals/region solely for treatment of ROP were excluded. The incidence of any ROP or Type 1 ROP was analysed with gestational age and birth weight over a 10-year period with consecutive 2-year intervals to evaluate the trends.

RESULTS

Of all 754 infants included in the study, 234 (31.0%) patients had any ROP and 34 (4.5%) infants developed Type 1 ROP. The incidence of any ROP demonstrated a statistically significant decreasing trend over the five consecutive 2-year intervals (p = 0.016), but the incidence trend of Type 1 ROP is not statistically significant. No infants weighing more than 1250 g developed Type 1 ROP.

CONCLUSION

We observed a decreasing trend in the incidence of any ROP across the 10-year period in a tertiary hospital in Hong Kong, while the incidence of Type 1 ROP remained stable at 4.5%. The factors leading to the trend were unclear. Improved prenatal care, changing proportion of cases with different birth weight and gestational age, oxygenation level practice in neonatal unit may all contribute to the decreasing trend. Revision of screening criteria may be made according to local experience to maximise cost-effectiveness.

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.

Prevalence and risk factors of retinopathy of prematurity in Iran: a systematic review and meta-analysis

Background

Retinopathy of prematurity (ROP) refers to the developmental disorder of the retina in premature infants and is one of the most serious and most dangerous complications in premature infants. The prevalence of ROP in Iran is different in various parts of Iran and its prevalence is reported to be 1–70% in different regions. This study aims to determine the prevalence and risk factors of ROP in Iran.

Methods

This review article was conducted based on the preferred reporting items for systematic review and meta-analysis (PRISMA) protocols. To find literature about ROP in Iran, a comprehensive search was done using MeSH keywords in several online databases such as PubMed, Ovid, Science Direct, EMBASE, Web of Science, CINAHL, EBSCO, Magiran, Iranmedex, SID, Medlib, IranDoc, as well as the Google Scholar search engine until May 2017. Comprehensive Meta-analysis Software (CMA) Version 2 was used for data analysis.

Results

According to 42 studies including 18,000 premature infants, the prevalence of ROP was reported to be 23.5% (95% CI: 20.4–26.8) in Iran. The prevalence of ROP stages 1, 2, 3, 4 and 5 was 7.9% (95% CI: 5.3–11.5), 9.7% (95% CI: 6.1–15.3), 2.8% (95% CI: 1.6–4.9), 2.9% (95% CI: 1.9–4.5) and 3.6% (95% CI: 2.4–5.2), respectively. The prevalence of ROP in Iranian girls and boys premature infants was 18.3% (95% CI: 12.8–25.4) and 18.9% (95% CI: 11.9–28.5), respectively. The lowest prevalence of ROP was in the West of Iran (12.3% [95% CI: 7.6–19.1]), while the highest prevalence was associated with the Center of Iran (24.9% [95% CI: 21.8–28.4]). The prevalence of ROP is increasing according to the year of study, and this relationship is not significant (p = 0.181). The significant risk factors for ROP were small gestational age (p < 0.001), low birth weight (p < 0.001), septicemia (p = 0.021), respiratory distress syndrome (p = 0.036), intraventricular hemorrhage (p = 0.005), continuous positive pressure ventilation (p = 0.023), saturation above 50% (p = 0.023), apnea (p = 0.002), frequency and duration of blood transfusion, oxygen therapy and phototherapy (p < 0.05), whereas pre-eclampsia decreased the prevalence of ROP (p = 0.014).

Conclusion

Considering the high prevalence of ROP in Iran, screening and close supervision by experienced ophthalmologists to diagnose and treat the common complications of pre-maturity and prevent visual impairment or blindness is necessary.

Risk factors associated with low birth weight in the Americas: literature review

Introducción. El bajo peso al nacer (BPN) es uno de los principales factores de riesgo que afecta la morbimortalidad infantil en todo el mundo; cerca de 1/3 de las muertes neonatales son atribuibles a este.Objetivo. Revisar los artículos más relevantes sobre BPN en las Américas en el periodo de 2010-2016.Materiales y métodos. Revisión narrativa de literatura. La información se obtuvo de las bases de datos PubMed, SciELO, LILACS, Portal Regional da BVS, con el uso de los descriptores DeCS y MeSH.Resultados. La mayoría de los estudios fueron publicados entre el 2012 y el 2015. De los 27 artículos publicados, 11 (40.7%) fueron atribuidos a factores sociodemográficos, 9 (33.3%) a riesgos ambientales, 3 (11.1%) a factores conductuales, 2 (7.4%) a controles prenatales o por cobertura y 2 (7.4%) se interrelacionaban con otros factores de riesgo.Conclusión. La mayoría de los estudios coinciden en la asociación de factores sociodemográficos, biológicos y conductuales. Los estudios que refieren la asociación de BPN con factores de riesgo ambientales están tomando fuerza.

The omega-3 and retinopathy of prematurity relationship

The aim of this article is to examine the effect of omega-3 (ω-3) long-chain polyunsaturated fatty acids (LCPUFAs) intake on retinopathy of prematurity (ROP) by reviewing the experimental and clinical trials conducted on animal models and infants. LCPUFAs demonstrate cytoprotective and cytotherapeutic actions contributing to a number of anti-angiogenic and neuroprotective mechanisms within the retina. Their intake appears to have a beneficial effect on ischemia, oxidative stress, inflammation and cellular signaling mechanisms, influencing retinal cell gene expression and cellular differentiation. ω-3 LCPUFAs may modulate metabolic processes that activate molecules implicated in the pathogenesis of vasoproliferative and neurodegenerative retinal diseases such as ROP.

Incidence and factors predisposing to retinopathy of prematurity in inborn infants less than 32 weeks of gestation

PURPOSE

Retinopathy of prematurity (ROP) is a visual-impairing disorder of the developing retinal vasculature in premature infants. Recent advances in neonatal care have led to an increase in the vulnerable premature population. The aim of this retrospective study was to assess the incidence of ROP and its risk factors according to degree of prematurity.

METHODS

Data from a sequence of 1,562 infants <32 weeks of gestational age, admitted to the Jewish General Hospital Neonatal Intensive Care Unit, a tertiary care perinatal center in Montreal, Canada, were reviewed to determine the incidence and risk factors of ROP. Perinatal risk factors for ROP were analyzed using univariate and multivariate analyses in four consecutive gestational age (GA) groups (24-25^+6/7weeks, 26-27^+6/7 weeks, 28-29^+6/7 weeks and 30-31^+6/7 weeks).

RESULTS

The overall incidence in our study was 15.6 %. Severe ROP, defined as stage 3 or plus disease was detected in 5.2 % of the neonates screened. In the univariate analyses, many risk factors in each GA group were found to have a significant association with ROP. On subsequent multivariate logistic regression analysis, birth weight, small for gestational age, the presence of patent ductus arteriosus (PDA), sepsis, necrotizing enterocolitis (NEC), and mechanical ventilation >7 days were independently associated with the development of ROP. Birth weight was consistently an independent risk factor for ROP in all GA groups.

CONCLUSION

Our study confirmed the importance of birth weight as an independent ROP risk factor. Sepsis, NEC, PDA, and prolonged mechanical ventilation have been shown to be independent risk factors in the different gestational age groups. Hippokratia 2016, 20(2): 121-126.