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

Retinal blood flow association with age and weight in infants at risk for retinopathy of prematurity

This prospective study evaluated the relationship between laser speckle contrast imaging (LSCI) ocular blood flow velocity (BFV) and five birth parameters: gestational age (GA), postmenstrual age (PMA) and chronological age (CA) at the time of measurement, birth weight (BW), and current weight (CW) in preterm neonates at risk for retinopathy of prematurity (ROP). 38 Neonates with BW < 2 kg, GA < 32 weeks, and PMA between 27 and 47 weeks underwent 91 LSCI sessions. Correlation tests and regression analysis were performed to quantify relationships between birth parameters and ocular BFV. Mean ocular BFV index in this cohort was 8.8 +/- 4.0 IU. BFV positively correlated with PMA (r = 0.3, p = 0.01), CA (r = 0.3, p = 0.005), and CW (r = 0.3, p = 0.02). BFV did not correlate with GA nor BW (r = - 0.2 and r = - 0.05, p > 0.05). Regression analysis with mixed models demonstrated that BFV increased by 1.2 for every kilogram of CW, by 0.34 for every week of CA, and by 0.36 for every week of PMA (p = 0.03, 0.004, 0.007, respectively). Our findings indicate that increased age and weight are associated with increased ocular BFV measured using LSCI in premature infants. Future studies investigating the associations between ocular BFV and ROP clinical severity must control for age and/or weight of the infant.

Retinal blood flow association with age and weight in infants at risk for retinopathy of prematurity

This prospective study evaluated the relationship between laser speckle contrast imaging (LSCI) ocular blood flow velocity (BFV) and five birth parameters: gestational age (GA), postmenstrual age (PMA), and chronological age (CA) at the time of measurement, birth weight (BW), and current weight (CW) in preterm neonates at risk for retinopathy of prematurity (ROP).38 Neonates with BW < 2 kg, GA < 32 weeks, and PMA between 27-47 weeks underwent 91 LSCI sessions. Correlation tests and regression analysis were performed to quantify relationships between birth parameters and ocular BFV. Mean ocular BFV index in this cohort was 8.8 +/- 4.0 IU. BFV positively correlated with PMA (r = 0.3, p = 0.01), CA (r = 0.3, p = 0.005), and CW (r = 0.3, p = 0.02). BFV did not correlate with GA nor BW (r=-0.2 and r=-0.05, p > 0.05). Regression analysis with mixed models demonstrated that BFV increased by 1.2 for every kilogram of CW, by 0.34 for every week of CA, and by 0.36 for every week of PMA (p = 0.03, 0.004, 0.007, respectively). Our findings indicate that increased age and weight are associated with increased ocular BFV measured using LSCI in premature infants. Future studies investigating the associations between ocular BFV and ROP clinical severity must control for age and/or weight of the infant.

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.

Analysis of trends in retinopathy of prematurity over 5 years in a tertiary neonatal intensive care unit

AIM

The aim of the study was to look at the incidence and trend of retinopathy of prematurity (ROP) between 2017 and 2021 in a tertiary neonatal intensive care unit (NICU) in Australia and to compare potential modifiable risk factors of ROP between preterm infants who required treatment for ROP and who did not need treatment.

METHODS

This retrospective study used the data of newborn infants who were <31 weeks gestational age (GA) or birth weight (BW) of <1250 g born between 2017 and 2021 at a tertiary NICU in Australia (n = 261). Univariate analysis using t test for continuous data, Fischer exact test for categorical data and multiple logistic regression analysis were undertaken to identify any significant differences between two groups.

RESULTS

A total number of 261 infants were studied. 55.9% of infants developed any type of ROP (146 infants out of 261 infants), type 1 ROP was 5.4% (14 out of 261) and aggressive ROP (AROP) was 3% (8 out of 261). Out of 146 infants who were diagnosed with ROP, 22 (15%) of them required treatment. Mean GA for those who underwent ROP treatment was 25.6 (±1.47) weeks and for those who did not require treatment was 27.6 (±1.95) weeks. The mean BWs for those who needed treatment was 764 (±189.32) g and for those who did not need treatment was 1039 (±306.06) g. The mean duration of invasive ventilation for infants with ROP requiring treatment and those who did not require treatment were 23.95 (±22.41) days and 9.89 (±17.2) days. The total duration of oxygen requirement was 235.54 (±160.5) days and 121.11 (±117.34) days for those who needed treatment and those who did not need treatment respectively. Among infants who required treatment for ROP, 68.18% required blood transfusion whereas among those who did not need treatment, 24.19% required blood transfusion.

CONCLUSION

Lower GA, lower BW, longer duration of invasive ventilation, longer total duration of oxygen requirement and blood transfusion in first 2 weeks of life were significant in preterm infants who required treatment for ROP compared with those who did not.

Incidence and Risk Factors for Retinopathy of Prematurity in a Tertiary Hospital in China

Purpose

To investigate the incidence and risk factors for the retinopathy of prematurity (ROP) in the neonatal intensive care unit (NICU) of Obstetrics and Gynecology Hospital of Affiliated to Nanjing Medical University, China.

Methods

This retrospective case-control study included 611 preterm infants with birth weight (BW)<1500 grams admitted to the Department of Neonatology, Obstetrics and Gynecology Hospital of Affiliated to Nanjing Medical University between January 2019 and December 2022. The incidence and risk factors for any stage and severe ROP were analyzed.

Results

Within 611 infants, 245(40.1%) developed ROP; 160(26.2%) infants were stage 1, 54(8.8%) were stage 2, and 31(5.1%) were stage 3, no stage 4 and 5. Among them, 22(3.6%) infants needed treatment. Multivariate analysis showed a higher gestational age (GA) was protective, whereas twin birth and moderate-to-severe BPD increased the hazard of any stage ROP; higher BW and male gender were significant risk factors for severe ROP.

Conclusion

Compared to other tertiary hospitals, the incidence of any stage ROP in our NICU was higher, but the rate of ROP needed treatment was lower. A higher GA was protective, whereas twin birth and moderate-to-severe BPD increased the hazard of any stage ROP; higher BW was protective, whereas male gender were risk factors for the development of severe ROP.

Research hotspots and trends in retinopathy of prematurity from 2003 to 2022: a bibliometric analysis

Background

In order to understand the research hotspots and trends in the field of retinopathy of prematurity (ROP), our study analyzed the relevant publications from 2003 to 2022 by using bibliometric analysis.

Methods

The Citespace 6.2.R3 system was used to analyze the publications collected from the Web of Science Core Collection (WoSCC) database.

Results

In total, 4,957 publications were included in this study. From 2003 to 2022, the number of publications gradually increased and peaked in 2022. The United States was the country with the most publications, while Harvard University was the most productive institution. The top co-cited journal PEDIATRICS is published by the United States. Author analysis showed that Hellström A was the author with the most publications, while Good WV was the top co-cited author. The co-citation analysis of references showed seven major clusters: genetic polymorphism, neurodevelopmental outcome, threshold retinopathy, oxygen-induced retinopathy, low birth weight infant, prematurity diagnosis cluster and artificial intelligence (AI). For the citation burst analysis, there remained seven keywords in their burst phases until 2022, including ranibizumab, validation, trends, type 1 retinopathy, preterm, deep learning and artificial intelligence.

Conclusion

Intravitreal anti-vascular endothelial growth factor therapy and AI-assisted clinical decision-making were two major topics of ROP research, which may still be the research trends in the coming years.

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.

Correlation between tear levels of vascular endothelial growth factor and vitamin D at retinopathy of prematurity stages in preterm infants

Deregulation of vascular endothelial growth factor (VEGF) levels leads to retinopathy of prematurity (ROP). Vitamin D (VIT-D) is known to regulate VEGF in an oxygen dependent manner. The purpose of this study was to correlate tear levels of VEGF and VIT-D with different ROP stages in preterm infants. In this prospective cross-sectional study, we enrolled 104 pre-term infants. They were grouped into: Group-1 (Classical ROP) and Group-2 (Aggressive ROP), which were further subdivided into Group-1A (progressing), Group-1B (regressing), Group-2A (pre-treatment), and Group-2B (post-treatment). Tear VEGF and VIT-D levels and their association with different ROP stages were assessed. Stage 1 and stage 2 had higher whereas stage 3 had lower VEGF levels in Group-1B compared to Group-1A. Stage 1 and stage 3 showed higher levels of VIT-D with no difference in stage 2 in Group-1B compared to Group-1A., Group-2B showed higher VEGF and lower VIT-D levels compared to Group-2A. Presence of a positive correlation at an early stage (stage 1) of ROP and a negative correlation at a more advanced stage (stage 3) of ROP with VIT-D and VEGF implies stage-specific distinct signaling crosstalk. These findings suggest that VIT-D supplementation may have the potential to modify the course and outcome of ROP.

Associations of VEGF Polymorphisms With Retinopathy of Prematurity

Purpose

This study investigated the associations between vascular endothelial growth factor (VEGF) polymorphisms and retinopathy of prematurity (ROP) risk.

Methods

Infants born prematurely at any time from 2009 to 2018 were included. Five single-nucleotide polymorphisms (SNPs) of VEGF were analyzed using real-time PCR in all infants. Multivariate logistic regression was applied to model the associations between VEGF polymorphisms and ROP susceptibility, severity, and premature clinicopathologic characteristics.

Results

A total of 334 patients were included and categorized into three groups: those without ROP, those with mild ROP (i.e., ROP not requiring treatment), and those with severe ROP (i.e., ROP for whom treatment was indicated). Among the female patients with ROP, those with VEGF rs3025035 CT (3.231-fold; 95% confidence interval [CI], 1.238-8.431) and a combination of CT and TT genotypes (2.643-fold; 95% CI, 1.056-6.619) exhibited significantly higher risks of severe ROP compared with those with wild-type genotypes. Female ROP infants with VEGF rs3025010 C (TC + CC) alleles had a lower risk of ROP stage ≥3 (odds ratio [OR] = 0.406; 95% CI, 0.165-0.999) than those with TT homozygotes. ROP patients with the VEGF rs10434 A allele (GA + AA) exhibited higher risks of necrotizing enterocolitis (OR = 2.750; 95% CI, 1.119-6.759) and lower risk of bronchopulmonary dysplasia (OR = 0.390; 95% CI, 0.173-0.877) than those with GG homozygotes did.

Conclusions

VEGF polymorphisms affect ROP risks differently in male and female infants. In female infants, VEGF rs3025035 with T alleles may predict ROP severity, and VEGF rs3025010 with C alleles may protect against severe ROP.

Epidemiology of Retinopathy of Prematurity in the US From 2003 to 2019

Importance

Retinopathy of prematurity (ROP) is a potentially blinding retinal disease with poorly defined epidemiology. Understanding of which infants are most at risk for developing ROP may foster targeted detection and prevention efforts.

Objective

To identify changes in ROP incidence in the US from 2003 to 2019.

Design, Setting, and Participants

This retrospective database cohort study used the Healthcare Cost and Utilization Project Kids' Inpatient Databases. These nationwide databases are produced every 3 years, include data from over 4000 hospitals, and are designed to generate national estimates of health care trends in the US. Participants included pediatric newborns at risk for ROP development between 2003 and 2019. Data were analyzed from September 30, 2021, to January 13, 2022.

Exposures

Premature or low-birth-weight infants with relevant International Classification of Diseases, Ninth Revision or Tenth Revision codes were considered ROP candidates. Infants with ROP were identified using relevant codes.

Main Outcomes and Measures

ROP incidence in selected subpopulations (based on database-reported race and ethnicity, sex, location, income) was measured. To determine whether incidences varied across time or subpopulations, χ2 tests of independence were used.

Results

This study included 125 212 ROP discharges (64 715 male infants [51.7%]) from 23 187 683 births. The proportion of premature infants diagnosed with ROP increased from 4.4% (11 720 of 265 650) in 2003 to 8.1% (27 160 of 336 117) in 2019. Premature infants from the lowest median household income quartile had the greatest proportional increase of ROP diagnoses from 4.9% (3244 of 66 871) to 9.0% (9386 of 104 235; P < .001). Premature Black infants experienced the largest increase from 5.8% (2124 of 36 476) to 11.6% (7430 of 63 925; P < .001) relative to other groups (2.71%; 95% CI, 2.56%-2.87%; P < .001). Hispanic infants experienced the second largest increase from 4.6% (1796 of 39 106) to 8.2% (4675 of 57 298; P < .001) relative to other groups (-0.16%; 95% CI, -0.29% to -0.03%; P = .02). The Southern US experienced the greatest proportional growth of ROP diagnoses, increasing from 3.7% (3930 of 106 772) to 8.3% (11 952 of 144 013; P < .001) relative to other groups (1.61%; 95% CI, 1.51%-1.71%; P < .001). ROP diagnoses proportionally increased in urban areas and decreased in rural areas.

Conclusions and Relevance

This cohort study found that ROP incidence among premature infants increased from 2003 to 2019, especially among Black and Hispanic infants. Infants from the lowest-income areas persistently had the highest proportional incidence of ROP, and all regions experienced a significant increase in ROP incidence with the most drastic changes occurring in the South. These trends suggest that ROP is a growing problem in the US and may be disproportionately affecting historically marginalized groups.

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.

Screening and Risk Factors for Retinopathy of Prematurity in a Tertiary Care Hospital in Cairo, Egypt

Purpose

To evaluate the retinopathy of prematurity (ROP) prevalence, risk factors and screening outcome in a tertiary hospital in Cairo, Egypt.

Methods

A prospective observational study was done in Neonatal Intensive Care Unit in Ain Shams University Hospital. A total of 159 premature infants were screened for ROP based on the most inclusive criteria reported to date. Screening included premature infants with gestational age (GA) of ≤34 weeks or birth weight (BW) of ≤2000 grams, or GA >34 weeks or BW >2000 grams, with multiple co-morbidities. The prevalence of ROP, plus disease and their correlation with risk factors of interest were studied.

Results

The GA of the included infants ranged from 27 to 36 weeks, mean (SD) 31.87 (± 1.81) weeks. The BW ranged from 640 to 3900 grams, mean (SD) 1784.71 (± 560.30) grams. The prevalence of ROP more than stage 0 was 25.8% (41 infants), 7.3% of the cases (11 infants) showed plus disease and 6.3% (10 infants) showed severe ROP requiring treatment. Of those, 2 cases (20%) fell outside the British Guideline's criteria for Screening. There was a highly significant (p < 0.0001) correlation between ROP more than stage 0 and low GA, low BW, mechanical ventilation, respiratory distress syndrome, necrotizing enterocolitis, intraventricular haemorrhage, and blood transfusion. No significant correlation was found between appearance of ROP more than stage 0 and gender (p = 0.911), patent ductus arteriosus (p =0.187), or sepsis (p =0.998).

Conclusion

ROP is a significant problem in the premature infants in Egypt. Extremely premature infants with lower BW are more prone to develop ROP. However, cases with higher GA and BW than mentioned in the British guidelines screening criteria especially with multiple comorbidities showed severe ROP requiring intervention, which implies the need to develop a screening guideline for the Egyptian population.

Retinopathy of prematurity: contribution of inflammatory and genetic factors

Retinopathy of prematurity (ROP) is a retinal vasoproliferative disorder that represents an important cause of childhood visual impairment and blindness. Although oxidative stress has long been implicated in ROP etiology, other prenatal and perinatal factors are also involved. This review focuses on current research involving inflammation and genetic factors in the pathogenesis of ROP. Increasing evidence suggests that perinatal inflammation or infection contributes to ROP pathogenesis. Cytokines and chemokines with a fundamental role in inflammatory responses and that significantly contributing to angiogenesis are analyzed. Microglia cells, the retinal-resident macrophages, are crucial for retinal homeostasis, however, under sustained pathological stimuli release exaggerated amounts of inflammatory mediators and can promote pathological neovascularization. Current modulation of angiogenic cytokines, such as treatment with antibodies to vascular endothelial growth factor (anti-VEGF), has shown efficacy in the treatment of ocular neovascularization; however, some patients are refractory to anti-VEGF agents, suggesting that other angiogenic or anti-angiogenic cytokines need to be identified. Much evidence suggests that genetic factors contribute to the phenotypic variability of ROP. Several studies have implicated the involvement of candidate genes from different signaling pathways in the development of ROP. However, a genetic component with a major impact on ROP has not yet been discovered. Most studies have limitations and did not replicate results. Future research involving bioinformatics, genomics, and proteomics may contribute to finding more genes associated with ROP and may allow discovering better solutions in the management and treatment of ROP.

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

Background

Methods

Results

Conclusion

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.

Maternal smoking as an independent risk factor for the development of severe retinopathy of prematurity in very preterm infants

BACKGROUND/OBJECTIVES

Retinopathy of prematurity (ROP) is a severe neonatal complication potentially leading to visual impairment and blindness. Known risk factors include preterm birth, low birth weight and respiratory support. Limited and contradictory data exist on the risk of maternal smoking during pregnancy on the development of ROP. This study aims to investigate smoking as an independent risk factor for the development of severe ROP (≥stage 3).

SUBJECTS/METHODS

This is a single centre retrospective case-control study of prospectively collected clinical data of infants born before 32 weeks of gestation between 2001 and 2012 at a tertiary care university hospital. The association between maternal smoking during pregnancy and the development of severe ROP was analyzed by multivariate logistic regression.

RESULTS

In total, n = 751 infants born < 32 weeks of gestation were included in this study. In total, 52.9% (n = 397) were diagnosed with ROP and 10.8% (n = 81) developed ROP ≥ stage 3. In total, 8.4% (n = 63) mothers presented with a history of smoking during pregnancy, which was associated to a higher rate of ROP (OR 2.59, 95% CI 1.10-6.12). Low gestational age, low birth weight and prolonged respiratory support were confirmed as independent risk factors for the development of severe ROP.

CONCLUSIONS

To date, this is the largest study evaluating the effect of maternal smoking on the development of ROP. Maternal smoking during pregnancy is identified as an independent risk factor for the development of severe ROP in preterm infants born < 32 weeks of gestation.

Association of small for gestational age with retinopathy of prematurity: a systematic review and meta-analysis

CONTEXT

The association between small for gestational age (SGA) and retinopathy of prematurity (ROP) is unclear.

OBJECTIVE

A systematic review and meta-analysis was conducted to evaluate the association between ROP and SGA in preterm infants <37 weeks' gestational age (GA) admitted to neonatal intensive care unit.

METHODS

Medline, PubMed, Web of Science and Cochrane Central databases were searched from inception through 15 January 2019. Studies reporting outcomes based on SGA as the primary exposure variable were included. Data were extracted independently by two coauthors. Modified Newcastle-Ottawa scale was used for risk of bias assessment.

RESULTS

Database search yielded 536 records (Medline=152, PubMed=171, Web of Science=144 and Cochrane Central=69). Twenty-one studies evaluating 190 946 infants were included. SGA was associated with significantly higher odds of any stage of ROP on unadjusted analysis (unadjusted OR (uOR) 1.55; 95% CI 1.22 to 1.98; 10 studies) but not on adjusted analysis (adjusted OR (aOR) 2.16; 95% CI 0.66 to 7.11; 3 studies). SGA was associated with significantly higher odds of severe ROP (aOR 1.92; 95% CI 1.57 to 2.34; nine studies). SGA was also significantly associated with higher odds of treated ROP (aOR 1.39; 95% CI 1.18 to 1.65; three studies). In subgroup analysis of infants <29 weeks' GA, SGA was significantly associated with increased odds of ROP (uOR 1.64; 95% CI 1.19 to 2.26; two studies), severe ROP (aOR 1.61; 95% CI 1.23 to 2.10; four studies) and treated ROP (aOR 1.37; 95% CI 1.16 to 1.62; two studies).

CONCLUSION

SGA was associated with increased odds of any stage of ROP, severe ROP and treated ROP in preterm infants. Neonatologists should incorporate SGA into the risk assessment during ROP evaluation and while providing counselling to the families of preterm SGA infants. ROP screening guidelines should look into the frequency of follow-up examination in SGA infants in aim to offer early detection and treatment.

Asymmetric retinopathy of prematurity in presumed fungal endophthalmitis

Purpose

To report a case of asymmetric retinopathy of prematurity (ROP) in a neonate with endophthalmitis.

Observations

A 25-week old female was born by caesarean section due to preeclampsia. The patient required supplemental oxygen after birth. The neonatal period was complicated by sepsis secondary to necrotizing enterocolitis with intestinal perforation. The patient subsequently developed endophthalmitis in the right eye. A fungal ball was seen overlying the termination of a persistent hyaloid artery. The patient also had ROP, identified at 31 weeks postconceptional age, which progressed asymmetrically and demonstrated greater severity in the eye affected by endophthalmitis. The endophthalmitis resolved with intravitreal antifungal treatment and systemic therapy. The right eye was also treated with intravitreal bevacizumab, demonstrating regression of ROP severity on follow up.

Conclusions and Importance

The present case describes the first reported case of asymmetric ROP associated with endophthalmitis. The more severe ROP occurred in the eye with endophthalmitis suggesting that, outside of systemic factors, the local ocular inflammatory environment is important in determining the progression of ROP. Additionally, the fungal ball present in the eye affected by endophthalmitis was seen at the termination of the hyaloid artery, suggesting the hyaloid artery as the route of entry of the fungus into the vitreous.

Antenatal exposure to fenoterol is not associated with the development of retinopathy of prematurity in infants born before 32 weeks of gestation

PURPOSE

Despite safety concerns, β₂-sympathomimetics are still widely used as tocolytic agents. β-Blockers in turn are used to treat vasculo-proliferative diseases of the newborn such as retinopathy of prematurity (ROP), which may lead to visual impairment and blindness. The scope of this study was to investigate whether antenatal exposure to the β₂-sympathomimetic fenoterol contributes to the development of ROP.

METHODS

For this single-center retrospective case-control study of prospectively collected clinical data, all infants born before 32 weeks of gestation between 2001 and 2012 were included. The association of prenatal exposure to fenoterol and the development of ROP were analyzed by multivariate logistic regression.

RESULTS

n = 1134 infants < 32 weeks of gestation were screened for eligibility, out of which n = 722 met the inclusion criteria. Exposure to fenoterol (n = 505) was not associated with a higher rate of ROP (OR 0.721, 95% CI 0.463-1.122). Further, duration of exposure (days) did not alter the incidence of ROP (OR 1.001, 95% CI 0.986-1.016). Frequency distribution of different ROP stages and the need for therapeutic intervention was also not affected by prenatal exposure to fenoterol. Risk factors for the development of ROP like low birth weight, low gestational age, prolonged respiratory support and multiple gestation were confirmed in our large study cohort.

CONCLUSION

β₂-Sympathomimetic tocolysis does not increase the rate of ROP in premature infants born < 32 weeks of gestation. Our results render fenoterol a safe tocolytic agent regarding neonatal ROP development.

Newborn gender as a predictor of neonatal outcome in mixed gender twins born with very low birth weight

Background

Most studies have revealed that the incidence of morbidity and mortality of preterm male infants is greater than that of preterm female infants. Recently, conflicting outcomes have been reported regarding mixed-gender twins. The aim of this study was to estimate the association between gender and outcome in newborn twins of different gender.

Methods

We conducted a retrospective review of mixed-gender twins weighing < 1500 g that were born at Shamir Medical Center (Assaf Harofeh) between the years 1995 and 2016 (158 newborns). The incidence of morbidity and mortality until discharge from the hospital were evaluated while looking at gender differences.

Results

No significant differences were found in neonatal mortality or morbidity between females and males from different-gender twins. Even after considering confounding variables (gestational age, birth weight & birth order) in linear and logistic regression models, no significant differences were found between the genders.

Conclusions

Our study suggests that there are no significant differences in neonatal mortality or morbidity among different-gender twins. Our results support the need for further studies.

Perinatal Risk Factors for the Retinopathy of Prematurity in Postnatal Growth and Rop Study

Objective: To evaluate perinatal risk factors for retinopathy of prematurity (ROP), in a large, broad-risk cohort of premature infants. Study design: Secondary analysis of data from the Postnatal Growth and ROP (G-ROP) Study, a retrospective cohort study of infants undergoing ROP examinations at 29 North American hospitals in 2006-2012. Results: Among 7483 infants, 3224 (43.1%) had any ROP and 931 (12.4%) had severe ROP (Type 1 or 2 ROP). In multivariable logistic regression analysis, significant risk factors for any ROP were lower birth weight (BW, odds ratio (OR) = 5.2, <501 g vs. >1250 g), younger gestational age (GA, OR = 32, <25 vs. >29 weeks), 1-min Apgar score <4 (OR = 1.2), race (OR = 1.6, White vs. Black), outborn (OR = 1.5), and delivery room intubation (OR = 1.3); and for severe ROP were lower BW (OR = 20, <501 g vs. >1250 g), younger GA (OR = 30, <25 vs. >29 weeks), male (OR = 1.5), Hispanic ethnicity (OR = 1.8), race (OR = 1.6, White vs. Black), outborn (OR = 1.6), and delivery room intubation (OR = 1.6). Together, these factors predicted well for any ROP (area under ROC curve (AUC) = 0.87) and severe ROP (AUC = 0.89), but BW and GA were the dominant factors for ROP (AUC = 0.86) and severe ROP (AUC = 0.88). Conclusions: Based on the largest report to date with detailed ROP data from infants meeting current screening guidelines, ROP risk is predominantly determined by the degree of prematurity at birth, with other perinatal factors contributing minimally.

Vessel Tortuosity Cutoff Values Using the Modified ROPtool May Predict Need for Treatment in Retinopathy of Prematurity

BACKGROUND AND OBJECTIVE

To quantify vessel tortuosity among infants with retinopathy of prematurity (ROP).

PATIENTS AND METHODS

This was a retrospective study including 61 RetCam images from 33 infants. The laser treatment (LT) group included 17 infants who underwent laser for ROP. The no-treatment (NT) group included 16 infants. The modified ROPtool was used to calculate mean vessel tortuosity (MVT) and highest vessel tortuosity (HVT) for the participants and for the standard plus disease photograph from the Early Treatment for Retinopathy of Prematurity (ETROP) study.

RESULTS

The median MVT was 1.226 versus 1.056 for the LT and NT groups, respectively (P < .001). The median HVT was 1.346 versus 1.088 (P < .001). An MVT of 1.124 was 96.7% sensitive and 100% specific for identifying infants with treatment-requiring ROP. Both MVT and HVT cutoff values correctly captured plus disease in the standard ETROP trial photograph.

CONCLUSION

The modified ROPtool can be used to identify infants who have treatment-requiring ROP with a high level of sensitivity and specificity. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:215-220.].

Spatial identification of environmental health hazards potentially associated with adverse birth outcomes

Reduced birth weight (RBW) and reduced head circumference (RHC) are adverse birth outcomes (ABOs), often linked to environmental exposures. However, spatial identification of specific health hazards, associated with these ABOs, is not always straightforward due to presence of multiple health hazards and sources of air pollution in urban areas. In this study, we test a novel empirical approach to the spatial identification of environmental health hazards potentially associated with the observed RHC and RBW patterns. The proposed approach is implemented as a systematic search, according to which alternative candidate locations are ranked based on the strength of association with the observed birth outcome patterns. For empirical validation, we apply this approach to the Haifa Bay Area (HBA) in Israel, which is characterized by multiple health hazards and numerous sources of air pollution. We identified a spot in the local industrial zone as the main risk source associated with the observed RHC and RBW patterns. Multivariate regressions, controlling for personal, neighborhood, and geographic factors, revealed that the relative risks of RHC and RBW tend to decline, other things being equal, as a function of distance from the identified industrial spot. We recommend the proposed identification approach as a preliminary risk assessment tool for environmental health studies, in which detailed information on specific sources of air pollution and air pollution dispersion patterns is unavailable due to limited reporting or insufficient monitoring.

Environmental risk factors associated with low birth weight: The case study of the Haifa Bay Area in Israel

BACKGROUND

Low birth weight (LBW) is known to be associated with infant mortality and postnatal health complications. Previous studies revealed strong relationships between LBW rate and several socio-demographic factors, including ethnicity, maternal age, and family income. However, studies of association between LBW rate and environmental risk factors remain infrequent.

STUDY METHODS

We retrieved a geo-referenced data set, containing 7216 individual records of children born in 2015 in the Haifa Bay Area in Israel. Using this dataset, we analysed factors affecting LBW prevalence by applying two alternative techniques: analysis of LBW rates in small census area (SCAs) and more recently developed double kernel density (DKD) relative risk (RR) estimates.

RESULTS

In the SCA models, LBW rate was found to be associated with proximity to petrochemical industries (B=-0.26, 95%CI=-0.30, -0.22), road density (B=0.05, 95%CI=0.02, 0.08), distance to the seashore (B=0.17, 95%CI=0.14, 0.22), PM_2.5 (B=0.06, 95%CI=0.04, 0.09) and NO_x (B=0.10, 95%CI=0.06, 0.13) exposure estimates. Although similar factors emerged in the DKD models as well, in most cases, the effects of these factors in the latter models were found to be stronger: proximity to petrochemical industries (B=-0.48, 95%CI= -0.51, -0.30), road density (B=0.05, 95%CI=0.02, 0.08), distance to the seashore (B=0.24, 95%CI=0.21, 0.27), PM_2.5 (B=0.08, 95%CI=0.05, 0.10) and NO_x (B=0.20, 95%CI=0.17, 0.23) exposure estimates. In addition, elevation above the sea level was found to be statistically significant in spatial dependence models estimated for both DKD and SCA rates (P < 0.01).

CONCLUSION

The analysis revealed an excess LBW rate in residential areas located close to petrochemical industries and a protective effect of seashore proximity and elevation above the sea level on the LBW rate. We attribute the latter finding to the moderating effect of elevated seashore locations on outdoor temperatures during the hot summer season.

Incidence and risk factors for retinopathy of prematurity: a retrospective cohort study

BACKGROUND AND OBJECTIVES

Advances in neonatal care promoted increased survival rates of preterm infants, with a consequent increase in the number of children affected by retinopathy of prematurity (ROP). This study estimates the incidence of ROP and evaluates potential risk factors associated.

METHODS

A retrospective cohort study of preterm infants born in a tertiary neonatal intensive care unit was conducted from March 2005 to August 2015. Six hundred and thirty-nine newborns were included based on the following criteria: infants born with less than 32 weeks' gestation or birth weight below 1500 g; or neonates born with 32-37 weeks' gestation or birth weight above 1500 g and any of the following associated: multiple gestation, respiratory distress syndrome, sepsis, blood transfusions or intraventricular hemorrhage. Neonates were followed up until disease resolution or until treatment criteria was achieved.

RESULTS

A total of 602 newborns were evaluated after applying the exclusion criteria. Mean gestational age was 30.7 ± 2.5 weeks. The incidences of ROP at any stage and of type 1 prethreshold ROP were 33.9 and 5.0% respectively. Logistic regression analysis revealed that risk factors associated with ROP at any stage were extremely low birth weight (ELBW) (odds ratio [OR] = 3.10; 95% confidence interval [95% CI]:1.73-5.55), pulmonary diseases (OR = 2.49; 95% CI: 1.35-4.59), intraventricular hemorrhage (OR = 2.17; 95% CI: 1.10-4.30), and low gestational age (OR = 0.81; 95% CI: 0.73-0.91). The main risk factors associated with type 1 prethreshold ROP were pulmonary diseases (OR = 9.58; 95% CI: 1.27-72.04) and ELBW (OR = 3.66; 95% CI: 1.67-8.00).

CONCLUSION

This study found a significant incidence of ROP (33.9%) in the studied population, and highlighted pulmonary diseases as a significant risk factor for type 1 prethreshold ROP.

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.

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.

Mast cell hyperactivity underpins the development of oxygen-induced retinopathy

Mast cells are classically thought to play an important role in protection against helminth infections and in the induction of allergic diseases; however, recent studies indicate that these cells also contribute to neovascularization, which is critical for tissue remodeling, chronic inflammation, and carcinogenesis. Here, we demonstrate that mast cells are essential for sprouting angiogenesis in a murine model of oxygen-induced retinopathy (OIR). Although mouse strains lacking mast cells did not exhibit retinal neovascularization following hypoxia, these mice developed OIR following infusion of mast cells or after injection of mast cell tryptase (MCT). Relative hypoxia stimulated mast cell degranulation via transient receptor potential ankyrin 1. Subsequent surges in MCT stimulated retinal endothelial cells to produce monocyte chemotactic protein-1 (MCP1) and angiogenic factors, leading to sprouting angiogenesis. Mast cell stabilizers as well as specific tryptase and MCP1 inhibitors prevented the development of OIR in WT mice. Preterm infants with early retinopathy of prematurity had markedly higher plasma MCT levels than age-matched infants without disease, suggesting mast cells contribute to human disease. Together, these results suggest therapies that suppress mast cell activity should be further explored as a potential option for preventing eye diseases and subsequent blindness induced by neovascularization.

Validation of WINROP for detecting retinopathy of prematurity in a North American cohort of preterm infants

BACKGROUND

WINROP (weight, insulin-like growth factor 1, neonatal, retinopathy of prematurity) is a web-based retinopathy of prematurity (ROP) risk algorithm that uses postnatal weight gain as a surrogate of insulin-like growth factor-1 (IGF-1) to predict the risk of severe ROP in premature infants. The purpose of this study was to validate the web-based algorithm WINROP in detecting severe (type 1 or type 2) ROP in a North American cohort of infants.

METHODS

The records of consecutive infants who underwent ROP examinations between 2008 and 2011 were reviewed retrospectively. Infants were classified into categories of "alarm" (at risk for developing severe ROP) and "no alarm" (minimal risk for severe ROP).

RESULTS

A total of 483 were included. Alarm occurred in 241 neonates (50%), with the median time from birth to alarm of 2 weeks. WINROP had a sensitivity of 81.8% (95% CI, 67.3%-91.8%) and specificity of 53.3% (95% CI, 48.5%-58.0%) for identifying infants with severe ROP. Eight of the 44 infants with severe ROP were not detected (5 with type 1 and 3 with type 2). Of these 8 infants, 7 (88%) had birth weight in excess of the 70^th pecentile. With additional weight data entry, sensitivity of WINROP rose to 88.6%.

CONCLUSIONS

Very preterm infants (gestational age of ≤27 weeks) with relatively high birth weight for gestational age may not be detected by WINROP as high risk for developing severe ROP.

Assessment of WINROP algorithm as screening tool for preterm infants in Manitoba to detect retinopathy of prematurity

Objective

Developing less invasive methods for early detection of retinopathy of prematurity (ROP) is vital to minimizing blindness in premature infants. Lofqvist and colleagues developed a computer-based ROP risk algorithm (WINROP) (https://winrop.com), which detects downtrends in postnatal weight gain that correlate with the development of sight-threatening ROP. The aim of this study is to investigate the sensitivity and specificity of the WINROP algorithm to detect vision-threatening ROP.

Methods

This is a retrospective chart review study between January 2008 and December 2013. This study was conducted in the neonatal intensive care unit in Children's Hospital at Health Sciences Centre, Winnipeg, Manitoba, Canada. The study included preterm infants, less than 32 weeks' gestation, who were admitted to the hospital during the study period. The included 215 infants were eligible for ROP screening and had sufficient data to be entered into the WINROP algorithm. Infants were screened by a paediatric ophthalmologist for retinopathy of prematurity. The body weight of infants was measured weekly and entered into the WINROP algorithm; the sensitivity and the specificity of the WINROP algorithm were assessed.

Results

The mean gestational age was 28.6 ± 1.8 weeks. The mean body weight was 1244 ± 294 g. The sensitivity of the WINROP algorithm to detect vision-threatening retinopathy of prematurity in our cohort was 90% (P=0.021) with a specificity of 60% (P=0.002).

Conclusion

The WINROP algorithm lacks sufficient sensitivity to be used clinically in our population. The algorithm needs to be reassessed in contemporary populations.

Retinopathy of prematurity: A comprehensive risk analysis for prevention and prediction of disease

BACKGROUND

Retinopathy of prematurity (ROP) is a blinding morbidity of preterm infants. Our current screening criteria have remained unchanged since their inception and lack the ability to identify those at greatest risk.

OBJECTIVES

We sought to comprehensively analyze numerous proposed maternal, infant, and environmental ROP risk variables in a robustly phenotyped population using logistic regression to determine the most predictive model for ROP development and severity. We further sought to determine the statistical interaction between significant ROP risk variables, which has not previously been done in the field of ROP. We hypothesize that our comprehensive analysis will allow for better identification of risk variables that independently correlate with ROP disease. Going forward, this may allow for improved infant risk stratification along a time continuum from prenatal to postnatal development, making prevention more feasible.

METHODS

We performed a retrospective cohort analysis of preterm infants referred for ROP screening in one neonatal intensive care unit from 2010-2015. The primary outcome measure was presence of ROP. Secondary outcome measures were ROP requiring treatment and severe ROP not clearly meeting current treatment criteria. Univariate, stepwise regression and statistical interaction analyses of 57 proposed ROP risk variables was performed to identify variables which were significantly associated with each outcome measure.

RESULTS

We identified 457 infants meeting our inclusion criteria. Within this cohort, numerous factors showed a significant individual association with our ROP outcome measures; however, stepwise regression analysis found the most predictive model for overall ROP risk included estimated gestational age, birth weight, the need for any surgery, and maternal magnesium prophylaxis. The corresponding Area Under the Curve (AUC) for this model was 0.8641, while the traditional model of gestational age and birth weight predicted ROP disease less well with an AUC of 0.8489. Development of severe ROP was best predicted by estimated gestational age (week), the need for any surgery and increased probability of death or moderate-severe BPD at 7 days. Finally, the model most predictive for type 1 ROP included estimated gestational age (week) and the presence of severe chronic lung disease. No significant statistical interaction was found between variables.

CONCLUSIONS

Our work is unique as we report comprehensive analysis of the greatest number of proposed ROP risk variables to date in a robustly phenotyped population. We describe novel risk models for our ROP outcome measures and demonstrate independence of these variables using statistical modeling not previously applied to ROP. This may better allow for individual infant risk stratification and importantly mitigation of future risk.

Cohort study of growth patterns by gestational age in preterm infants developing morbidity

OBJECTIVES

To examine differences in growth patterns in preterm infants developing major morbidities including retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), necrotising enterocolitis (NEC) and intraventricular haemorrhage (IVH).

STUDY DESIGN

Cohort study of 2521 infants born at a gestational age (GA) of 23-30 weeks from 11 level III neonatal intensive care units in USA and Canada, and 3 Swedish population-based cohorts.

OUTCOMES

Birth weight and postnatal weight gain were examined relative to birth GA and ROP, BPD, NEC and IVH development.

RESULTS

Among infants with a birth GA of 25-30 weeks, birth weight SD score and postnatal weight were lower in those developing ROP and BPD. Infants developing ROP showed lower growth rates during postnatal weeks 7-9 in the 23-24 weeks GA group, during weeks 4-6 in the 25-26 weeks GA group and during weeks 1-5 in the 27-30 weeks GA group. Infants with BPD born at 27-30 weeks GA showed lower growth rates during postnatal weeks 3-5. Infants with NEC had lower growth rates after postnatal week 6 in all GA groups, with no significant differences in birth weight SD score. IVH was not associated with prenatal or postnatal growth.

CONCLUSIONS

In this cohort study of extremely preterm infants, we found that the postnatal growth pattern was associated with morbidities such as ROP, BPD and NEC as well as with gestational age at birth.

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.

Correlation of central visual function and ROP risk factors in prematures with and without acute ROP at the age of 6-13 years: the Giessen long-term ROP study

AIM

To correlate light increment sensitivity (LIS) and visual acuity (VA) with birth weight (BW), gestational age (GA) and stage of acute retinopathy of prematurity (ROP) (STG) in premature children at school age.

METHODS

180 children (150 former prematures and 30 age-matched term-born children) were enrolled at age 6-13 years. Former prematures were categorised by the results of the initial ROP screening based on digital wide-field fundus imaging: absence of ROP (n=100) and spontaneously resolved ROP (n=50). The latter group was further subdivided according to their STG (Stg 1; Stg 2; Stg 3). Both groups were categorised into sectors by BW (<1000 g; 1000-1500 g; >1500 g), and GA (≤28 weeks; >28<32 weeks; ≥32 weeks). VA was assessed with Early Treatment of Diabetic Retinopathy Study letters, LIS was measured at 0°, 2.8° and 8° in the visual field (Microperimeter MP1, Nidek Technologies), and spherical equivalent refraction assessed with a Nidek autorefractor (Nidek, Italy).

RESULTS

Central and pericentral LIS (0° and 2.8°) and VA were significantly lower in all groups and sectors compared with term-born controls except for BW >1500 g for LIS and GA >28 to <32 W for VA. No significant differences were found for LIS at 8° in all groups. No correlation was found between LIS and VA on an individual basis.

CONCLUSIONS

Low BW, GA and increasing severity of spontaneously resolving ROP were associated with significantly decreased central visual function. In addition to VA, LIS measurement further describes foveal function and is a unique parameter to assess parafoveal function.

Ultrasonographic demonstration of the superior ophthalmic vein in the orbit of premature infants with and without retinopathy of prematurity

Retinopathy of prematurity (ROP), which develops due to abnormal retinal vascularization in premature babies, can lead to irreversible vision loss. B-scan ocular ultrasonography is a noninvasive examination which makes it possible to image the eye and orbit. Our purpose was to echographically assess the orbit of premature babies with and without retinopathy of prematurity (ROP), with a focus on the superior ophthalmic vein (SOV) which is normally not detected by orbital ultrasound. A prospective study design was used after approved by the local institutional review board. ROP was diagnosed by routine ophthalmoscopic exam. Orbital ultrasound was performed by a single experienced ophthalmologist and ultra-sonographer who was masked to the routine ROP screening results. The results of the ophthalmoscopic exam were compared to the orbital ultrasound findings. The study group was divided into those diagnosed with ROP and those not diagnosed with ROP and were found to be comparable by age and weight at the time of the US examination. The SOV was dilated in 21 of 22 eyes (95.4%) with ROP and in only 5 of 32 eyes (15.6%) without ROP. The present study suggests an association between ROP and dilatation of the SOV.

Frizzled-4 Variations Associated with Retinopathy and Intrauterine Growth Retardation: A Potential Marker for Prematurity and Retinopathy

PURPOSE

To present the association between mutations affecting the Wnt-signaling receptor protein (FZD4), inherited vitreoretinopathies, and retinopathy of prematurity (ROP).

DESIGN

Retrospective analysis of prospective samples at a tertiary referral center.

PARTICIPANTS

Patients referred to our practice for management of a variety of pediatric vitreoretinopathies were offered participation in an ophthalmic biobank (421 participants with vitreoretinopathies were included in this study). Full-term healthy infants (n = 98) were recruited to the study as controls.

METHODS

Patients with various vitreoretinopathies were prospectively enrolled in an ophthalmic biobank, approved by the Human Investigation Committee at William Beaumont Hospital. Retrospective genetic analysis of the FZD4 gene was performed (Sanger sequencing). Participants with a diagnosis of familial exudative vitreoretinopathy (FEVR), Norrie disease, Coats' disease, bilateral persistent fetal vasculature, and ROP were reviewed for the presence of a FZD4 variant. Data retrieval included status of retinopathy (including staging when possible), gestational age (GA), birth weight (BW) (when available), and family and birth histories.

MAIN OUTCOME MEASURES

The association of FZD4 variants with the presence of vitreoretinopathy.

RESULTS

The sequence variation p.[P33S(;)P168S] is the most prevalent FZD4 variant and is statistically significant for ROP and FEVR (P = 4.6E-04 and P = 2.4E-03, respectively) compared with full-term newborns (P = 1.7E-01). In addition, infants expressing the sequence variation tended to have significantly lower BWs for respective GA (P = 0.04). This suggests that the FZD4 p.[P33S(;)P168S] variant may be a risk factor for retinopathy and restricted intrauterine growth.

CONCLUSIONS

Testing for FZD4 gene mutations is useful in patients with suspected FEVR and ROP. The relatively high prevalence of the p.[P33S(;)P168S] variant in ROP and intrauterine growth restriction suggests that it also may be a marker for increased risk of developing ROP and preterm birth.

The Specificity of the WINROP Algorithm Can Be Significantly Increased by Reassessment of the WINROP Alarm

BACKGROUND

Retinopathy of prematurity (ROP) is a sight-threatening disease affecting extremely preterm infants. The introduction of new ROP screening surveillance systems, with higher sensitivity and specificity than established ROP screening guidelines, has the potential to reduce the number of stressful eye examinations in these infants.

OBJECTIVES

To improve the specificity of the WINROP (Weight, Insulin-like growth factor-I, Neonatal, ROP) surveillance system, identifying extremely preterm infants requiring treatment for ROP.

METHODS

Two cohorts that had previously been subjected to WINROP analyses were included and reevaluated in this study. The weight at WINROP alarm for extremely preterm infants, born at gestational age <27 weeks, was reevaluated and by establishing 'safe' WINROP alarm weight limits, an intersample reassessment of WINROP alarm was performed. The two cohorts were as follows: (1) the Extremely Preterm Infants in Sweden Study (EXPRESS) cohort, infants born in Sweden during 2004-2007 (n = 407), and (2) extremely preterm infants in a North American cohort, born during 2006-2009 (n = 566).

RESULTS

In the EXPRESS cohort, 12.5% (40/319) of the infants who previously received a WINROP alarm were now reassessed as having no alarm; the specificity of WINROP in EXPRESS increased from 23.9% (86/360) to 35.0% (126/360). In the North American cohort, 15.4% (81/526) were reassessed as having no alarm; the specificity increased from 8.5% (38/447) to 26.6% (119/447). The sensitivity persisted as 97.5% in EXPRESS (45/47) and 98.3% (117/119) in the North American cohort.

CONCLUSIONS

The specificity of the WINROP surveillance system for extremely preterm infants can be significantly improved by reassessment using the weight at WINROP alarm.