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

A meta-analysis of intravitreal ranibizumab versus laser photocoagulation for the treatment of retinopathy of prematurity

PURPOSE

Laser photocoagulation (LPC) has been a traditional treatment for retinopathy of prematurity (ROP). However, intravitreal anti-VEGF agents such as bevacizumab and ranibizumab (IVR) have also been increasingly used. This meta-analysis aims to rigorously compare IVR to LPC in the treatment of ROP.

METHODS

Medline, Embase and Cochrane CENTRAL were used to identify studies comparing IVR monotherapy to LPC (PROSPERO ID: CRD42023390855). The primary outcome was ROP regression. Secondary outcomes included likelihood of additional treatment, time from treatment to reactivation or re-treatment, refractive outcomes and adverse events such as retinal detachment, cataract, macular dragging/ectopia, vitreous or retinal hemorrhage, glaucoma, and endophthalmitis. A random effects meta-analysis was designed.

RESULTS

2361 articles were identified. 1947 eyes from 7 cohort studies, 1 case-control study and 2 RCTs were included with a median follow-up of 21 months (range: 11-75 months). There was no significant difference in disease regression between IVR and LPC (risk ratio [RR]=0.96, 95% confidence interval [CI] [0.83, 1.10], p=0.52), however, eyes that underwent IVR were associated with a higher likelihood of requiring additional treatment (RR= 2.70, CI= [1.55, 4.68], p<0.001). Although less frequent, retreatment occurred earlier with LPC compared to IVR (weighted mean difference (WMD)= -4.29 weeks, CI= [-6.48, -2.10], p<0.001). Furthermore, eyes that received IVR had a lower refractive error, with a WMD of -0.93 diopters (CI= [-1.54, -0.32], p=0.003) at a median age of assessment of 5.0 years (range 1.5-6.3 years). There was no difference in the rate of adverse events between LPC and IVR (p>0.05 for RD, MDR, VH and cataract). Quality of evidence was rated moderate for likelihood and time of additional treatment, as well as refractive error, but was considered low for disease regression and adverse events.

CONCLUSION

Compared to LPC, IVR was associated with a higher likelihood of requiring additional treatment but a lower risk of myopia. More studies are needed to evaluate dose-response relationships and temporal trends in ROP regression following these treatments.

Retrospective Analysis of the Prevalence and Risk Factors of Retinopathy of Prematurity in a Single-Center Cohort in Romania and Comparison with National and European Data

Background and Objectives: This study investigated and compared with European literature data the incidence, severity, and perinatal risk factors of retinopathy of prematurity (ROP) in preterm infants admitted to the Premature Department of Mureş County Clinical Hospital over a two-year period (January 2022-December 2023). Materials and Methods: ROP screening was performed in 96 infants (76.8%) according to professional guidelines. A literature review was conducted to compare our findings with national and European data. Significant differences were identified in comparisons with studies from Cluj-Napoca (p = 0.0125), Timișoara, and Bucharest (p < 0.0074), as well as Serbia and Croatia when stratified by gestational age limits. The variations in GA thresholds (32 vs. 34 weeks) between studies required stratified analyses to ensure meaningful comparisons. The included European studies provided data on screening criteria, prevalence, and associated risk factors, offering a comprehensive perspective on screening effectiveness. Results: Among the 149 admitted patients, 125 were preterm (n = 125). Of the screened patients, 20 (20.83%) infants were diagnosed with ROP, including 13 boys (65%) and 7 girls (35%), all requiring prolonged respiratory support, and 55% of them needed blood transfusion. The average birth weight of affected infants was 1030.5 g (550-1700 g ), and the mean gestational age was 28.3 weeks (25-34 weeks). In those found to have stage 2 and 3 ROP in zone II with plus disease (n = 6), intravitreal anti-VEGF injections and/or retinal laser treatments were performed. Notably, no cases of ROP-related blindness were recorded. Conclusions: To our knowledge, this is the first study to compare ROP prevalence and screening outcomes across Romanian national centers. Identified risk factors in this cohort, such as respiratory distress syndrome, oxygen therapy, blood transfusion, and intraventricular hemorrhage, are consistent with the existing literature data. These findings underscore the importance of standardized screening criteria and effective management protocols to prevent ROP-related blindness. The comparative approach of this study highlights the necessity of harmonized internationally applied criteria to facilitate robust comparisons and, more importantly, improve patient care outcomes.

Analysis of Salivary Cytokines in Retinopathy of Prematurity

BACKGROUND/OBJECTIVES

This cohort study aimed to establish a correlation between salivary cytokines and retinopathy of prematurity (ROP) in premature neonates. Additionally, we sought to identify a minimally invasive method for cytokine detection in this population.

METHODS

We recruited premature neonates born at less than 34 weeks gestational age (GA), with no history of maternal or neonatal infections. Salivary samples were collected on their first (D1) and seventh (D7) days of life, and cytokine levels were measured using the MILLPLEXMAP Human multiplex assay.

RESULTS

A total of 125 neonates were included in the study, categorized into two groups based on the severity of ROP: None to Mild and Moderate to Severe. The salivary levels of interleukin (IL)-6, IL-8, vascular endothelial growth factor (VEGF), and tumor necrosis factor (TNF)-α on D1 and D7 were significantly higher in the Moderate to Severe ROP group compared to the None to Mild ROP group (p = 0.005, 0.004, 0.026, 0.018, 0.001, 0.007, 0.025, and 0.002, respectively). After adjusting for GA, the levels of IL-6 and VEGF on D7 were significantly elevated in the Moderate to Severe ROP group compared to the None to Mild ROP group (p = 0.024 and 0.016, respectively).

CONCLUSIONS

This study establishes a novel, non-invasive method for the early prediction of ROP in premature neonates by correlating salivary cytokine levels in early life with the subsequent development of ROP.

Construction of a nomogram model to predict the risk of retinopathy of prematurity reactivate after intravitreal anti-vascular endothelial growth factor therapy: a retrospective study

Objective

To explore the risk factors for the reactivate of retinopathy of prematurity (ROP) after intravitreal injection of anti-vascular endothelial growth factor (VEGF) and to construct a nomogram model to predict the risk of ROP reactivate.

Methods

A retrospective analysis was conducted on 185 ROP children who underwent anti-VEGF treatment at the First Affiliated Hospital of Zhengzhou University from January 2017 to October 2023. They were randomly divided into a training set (129 cases) and a validation set (56 cases) at a ratio of 7:3. The training set was further divided into a reactivate group (n = 18) and a non-reactivate group (n = 111) based on whether ROP recurred after treatment. Multivariable logistic regression analysis was used to screen for risk factors for ROP reactivate. A nomogram model was constructed using R software and validated using the validation set. The discrimination, calibration, and clinical net benefit of the model were evaluated using the receiver operating characteristic curve (ROC curve), calibration curve, and decision curve analysis, respectively.

Results

Multivariable logistic regression analysis showed that the number of red blood cell transfusions, use of pulmonary surfactant (PS) 2 times or more, and preoperative fundus hemorrhage were independent risk factors for ROP reactivate (P < 0.05). The area under the ROC curve (AUC) of the training set was 0.810 (95% CI: 0.706-0.914), and that of the validation set was 0.756 (95% CI: 0.639-0.873). The Hosmer-Leme show goodness-of-fit test indicated a good fit of the model (P = 0.31). Calibration curve analysis and decision curve analysis suggested high predictive efficacy and clinical application value of the model.

Conclusions

The number of red blood cell transfusions, use of PS 2 times or more, and preoperative fundus hemorrhage are independent risk factors for ROP reactivate. The nomogram model constructed based on these factors has high predictive efficacy and clinical application value.

Structural Equation Modelling of Retinopathy of Prematurity Treatment Integrating Both Physical and Clinical Effects

Background: We sought to develop a structural equation model (SEM) identifying physical and clinical risk factors associated with treatment for retinopathy of prematurity (ROP). Methods: This retrospective, observational, case-control study included 314 infants screened for ROP between April 2004 and July 2024. A bivariate binary logistic regression model, decision tree, and structural equation model (SEM) were employed to develop a more general model for ROP requiring treatment. Results: In the SEM, the factors significantly associated with ROP treatment included the retinal avascular area according to disk diameter (DD) (p < 0.001), weekly vascularisation rate (DD/w) (p < 0.001), and duration of intubation (days) (p < 0.001). In addition, the following significant associations were identified in both the bivariate analysis and the SEM: lower gestational age (p < 0.001) and birth weight (p <0.001) were associated with greater retinal avascular area; low postnatal weight gain (p < 0.027) was associated with a slow rate of retinal vascularisation; sepsis (p < 0.001), ductus arteriosus (p < 0.001), and the need for transfusion (p < 0.001) were associated with longer intubation mechanical ventilation (IMV). Conclusions: Lower gestational age, lower birth weight, sepsis, ductus arteriosus, transfusion, and lower weight gain increase the risk of requiring ROP treatment. In the SEM, this association is represented through three intermediate physical endogenous variables, namely, the greater temporal avascular area of the retina, the lower postnatal vascularisation rate, and the greater duration of IMV.

Red blood cell parameters as biomarkers of retinopathy of prematurity in preterm infants born before 30 weeks of gestation

Retinopathy of prematurity (ROP) is a major cause of preventable blindness in preterm infants. The association between red blood cell (RBC) parameters and the development of ROP remains unclear. The objectives of the present study were to evaluate the association between RBC parameters and ROP treatment. This single-center, retrospective cohort study included preterm infants born at < 30 weeks of gestation. Data pertaining to RBC parameters and ROP treatment were obtained from the medical records. A receiver operating characteristic (ROC) analysis was performed to determine the cut-off values of the RBC parameters according to the need for ROP treatment. Multiple logistic regression analyses assessed the association between ROP treatment and RBC parameters at birth and on day of life (DOL) 28. We included 202 infants, and 44.1% were treated for ROP. After adjusting for confounders, we observed associations between ROP treatment and mean corpuscular volume (MCV) values > 117.3 fL at birth (adjusted odds ratio [aOR]:2.3; 95% confidence intervals CI 1.0-5.3). Additionally, on DOL 28, hemoglobin (Hb) values < 9.9 g/dL (aOR:3.0; 95% CI 1.4-6.7), hematocrit (Hct) values < 31.0% (aOR:2.7; 95% CI 1.3-5.6), and red cell distribution width (RDW) values > 18.5% (aOR:2.6; 95% CI 1.1-6.2) were associated with ROP treatment. In conclusion, our study indicated that infants born at < 30 weeks of gestation with an MCV > 117.3 fL at birth, along with Hb < 9.9 g/dL, Hct < 31.0%, and RDW > 18.5% on DOL 28, had an increased risk of requiring ROP, warranting treatment.

The relationship between inflammatory markers and retinopathy of prematurity in extremely premature infants

PURPOSE

This study aimed to evaluate the relationships among blood parameters, clinical factors, and retinopathy of prematurity (ROP) in extremely premature (EP) infants.

METHODS

This retrospective study included 153 EP infants who were categorized into two groups based on the presence of inflammatory diseases such as necrotizing enterocolitis, neonatal sepsis, bronchopulmonary dysplasia, severe intraventricular hemorrhage, preeclampsia, and premature rupture of membranes. Complete blood count parameters, neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio, platelet-lymphocyte ratio (PLR), systemic inflammatory index, and platelet mass index were recorded during the first week and first month after birth. The study analyzed the impact of parameters obtained through blood tests during the first week and first month on the development of ROP and the requirement for treatment.

RESULTS

In this study, 96 infants were diagnosed with inflammatory diseases. After multivariate regression analyses, the duration of mechanical ventilation (p = 0.010) was found to be the only factor that led to ROP development. Moreover, lower gestational age (GA) (p = 0.006), higher NLR (p = 0.026), and lower PLR (p = 0.019) were observed in infants requiring treatment compared to infants with spontaneous resolution of ROP in this group. 57 infants did not have inflammatory diseases. Although the duration of mechanical ventilation (p = 0.041) and low levels of platelets (PLT) (p = 0.046) measured in the first month postnatally were significantly found to be associated with ROP developement, no parameter affecting the required treatment could be determined.

CONCLUSION

EP infants with longer mechanical ventilation durations and lower PLT counts are vulnerable to ROP development. GA, PLR, and NLR are predictive factors for treatment.

Validation of the "TWO-ROP" Algorithm at a Multi-Neonatal Intensive Care Unit Tertiary Referral Center

PURPOSE

We aim to validate the previously published TWO-ROP algorithm on an external data set.

DESIGN

Retrospective consecutive study.

SUBJECTS

Infants screened for retinopathy of prematurity (ROP) between January 2013 and August 2023 at a tertiary referral multi-site.

METHODS

Infants with higher birth weight (BW) and greater gestational age (GA) were included and stratified into 3 groups as follows: group 1 (BW <1500 g, GA ≥30 weeks), group 2 (BW ≥1500 g, GA <30 weeks), and group 3 (BW ≥1500 g, GA ≥30 weeks).

MAIN OUTCOME MEASURES

The rate of ROP, treatment-warranted ROP (TW-ROP), and number of inpatient examinations were evaluated in the 3 groups.

RESULTS

In total, 1095 (33.8%) patients met the inclusion criteria. The number of patients in groups 1, 2, and 3 was 837 (76.4%), 72 (6.6%), and 186 (17.0%), respectively. Retinopathy of prematurity was detected in 120 (11.0%) patients; the rate was 9.8% in group 1, 20.8% in group 2, and 12.4% in group 3 (P = 0.013). The overall mean number of inpatient examinations for patients undergoing traditional, TWO-ROP 36-week, and TWO-ROP 40-week screening systems was 1.95, 1.43, and 0.99, respectively (P < 0.001). Stage 3 was found in 9 eyes of 5 patients (0.5%, all zone II). Three eyes of 2 patients (0.2%) had plus disease. Two patients had bilateral laser treatment at 44 and 39.4 weeks postconceptional age (PCA); 3 out of 4 of these eyes met type 1 treatment criteria. Overall, the ROP screening burden saved was 9.0% and 16.7% for the TWO-ROP 36-week and 40-week systems, respectively. The sensitivity for TW-ROP was 100% for TWO-ROP 36-week system and 99.4% for TWO-ROP 40-week system.

CONCLUSION

The TWO-ROP algorithm can reduce the number of inpatient examinations while maintaining safety. To ensure timely management, we recommend that the single first ROP examination occur at 38 to 39 weeks PCA.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Bedside bilateral sequential intravitreal anti-VEGF injections for retinopathy of prematurity

PURPOSE

To evaluate the outcome and ocular adverse events of bedside bilateral sequential intravitreal anti-vascular endothelial growth factor injections for retinopathy of prematurity (ROP) (BBSIR).

METHODS

This retrospective interventional study included infants who received BBSIR with a follow-up of at least 1 month. Clinical history, intravitreal injection details, indications, intraoperative and postoperative ocular adverse events, and outcomes were analyzed.

RESULTS

The study cohort included 192 babies (384 eyes) spread over 9 years. The mean gestational age was 30.2 ± 2.6 weeks (28.8-34.1), and the birth weight was 1098.11 ± 271.65 g (650-2000). The indications for BBSIR were as follows: 73.4% (n = 141 infants) were too sick to transfer to an ophthalmic unit, 10.9% (n = 21 infants) due to the parents' inconvenience of traveling to the ophthalmic center, and 15. 6% (n = 30 infants) due to both reasons. The injections were given by an ROP specialist/ROP-trained ophthalmologist after due parental consent, considering each eye as a fresh eye with separate scrubbing and draping. Light from the head-worn indirect ophthalmoscope served as the source of illumination. The retinopathy was regressing/regressed in 92.4% of babies until the last follow-up. The major ocular complication was cataract in 2 eyes (0.5%). There was no incidence of endophthalmitis till last follow-up (median 5.7 months).

CONCLUSIONS

As per this study, BBSIR was observed to be effective and safe if given by those fully trained in the management of ROP. Though the rate of complications like cataract is small, they can pose management challenges and impact vision in a growing child.

Predictive factors of early reactivation after ıntravitreal ranibizumab in agressive retinopathy of prematurity

OBJECTIVE

Anti-VEGF agents are used in the treatment of aggressive retinopathy of prematurity (A-ROP), which is a rapidly progressive form of retinopathy of prematurity (ROP). This study aimed to evaluate risk factors for the early reactivation after anti-VEGF therapy with intravitreal ranibizumab (IVR) injection.

METHODS

Consecutive cases of A-ROP were included in this retrospective study. Intravitreal ranibizumab (0.25mg, Lucentis, Novartis AG) was injected in all A-ROP cases as initial therapy. Probable risk factors were reviewed. A reactivation in 4 weeks or less was defined as "early", and greater than 4 weeks was defined as "late". Since reactivations were observed in Zone II in all cases, laser photocoagulation (LP) was performed as rescue therapy.

RESULTS

The study consisted of 16 patients with A-ROP, all of whom experienced reactivation. In 6 cases,reactivation was seen early (Group-E), and in 10 cases, reactivation was late (Group-L). The mean gestational age of Group-E and Group-L were 26.60 (±0.89) and 26.73 (±2.10) weeks respectively (P=0.9), and mean birth weights were 918 (±282) and 898 (±0188) grams respectively (P=0.8). Zone I ROP was seen at a higher rate in Group-E (83.3%) than Group-L (30%) (P=0.009). Total O2 treatment duration in Group-E was statistically significantly longer than Group-L (P=0.03). The mean value of platelet distribution width (PDW) in Group-E was statistically significantly higher (P=0.002).

CONCLUSIONS

In patients with A-ROP, extended duration of O2 therapy and high values of PDW might be factors predictive of early reactivation after intravitreal ranibizumab injection.

SN promote retinal pathological neovascularization through activation of EGFR, IR and IGF-1R

Secretoneurin (SN) is a neuropeptide derived from secretogranin II (SgII), mainly are involved in neuroendocrine system. The present study is aimed to investigate the role of SN in retinal pathological neovascularization and physiological vasculature. In the study, we found the overexpression of SgII in retina of Oxygen-Induced Retinopathy (OIR) mouse model, and SgII knockdown could alleviate pathological retinal neovascularization in OIR. Conversely, SgII knockdown have no detectable effect in embryonic physiological vasculature. Experiments in vitro and in vivo further verified SN's angiogenic effect on the eye. In further, we identified that SN promoted angiogenesis via activation of Epidermal Growth Factor Receptor (EGFR), Insulin Receptor (IR), and Insulin-like Growth Factor 1 Receptor (IGF-1R), and followed by the phosphorylation of PI3K-AKT-mTOR signaling. In summarize, our study suggests that SN might be a postnatal angiogenic factor, which was critically involved in retinal pathological neovascularization, but not in embryonic retinal physiological vasculature. Moreover, we identified the receptors and the downstream signaling involved in SN induced retinal angiogenesis.

Neonatal gut microbiota profile and the association with retinopathy of prematurity in preterm infants

BACKGROUND

To explore the role of gut microbiota in preterm infants at high risk of developing retinopathy of prematurity (ROP).

METHODS

Preterm infants with gestational age (GA) < 32 weeks and/or birth weight (BW) < 1500 g born between 2020 and 2021 were prospectively enrolled. Their faecal samples were collected and analysed at different postnatal ages of life using 16S rRNA gene sequencing on the Miseq platform. The main outcome measures were the microbial diversity, taxonomy, relative abundance, bacterial predicted functional analysis, and their associations with different ROP groups. Subgroup analyses were performed by matching their GA and BW across different ROP groups.

RESULTS

A total of 268 stool samples were collected from 110 preterm infants, including 13 with type 1 ROP, 44 with type 2 or mild ROP, and 53 without ROP. Type 1 ROP showed no significant difference in microbial diversity up to 8 postnatal weeks (p = 0.057), while type 2 and no ROP groups displayed increased diversity (p = 0.0015 and p = 0.049, respectively). Bifidobacterium genera was notably less abundant in type 1 ROP group at first postnatal week (p = 0.022) and remained low in subsequent weeks. Predicted functional analysis revealed enriched pathways in membrane transport, carbohydrate metabolism, amino acid metabolism, and replication and repair.

CONCLUSIONS

Reduced gut microbial diversity may be associated with ROP development in high-risk preterm infants. Further research is needed to comprehend how early-life Bifidobacterium reduction affects metabolism and how targeting microbiome may help for ROP prevention and management.

Evaluation of the Risk Factors for Retinopathy of Prematurity in Preterm Infants Admitted to the Neonatal Intensive Care Unit (NICU)

BACKGROUND

Retinopathy of prematurity (ROP) is a disordered retinal blood vessel growth in preterm infants sustained in neonatal intensive care units (NICUs).

OBJECTIVE

The objective of this study is to identify the risk factors linked to the occurrence of ROP in preterm infants.

METHODS

This study was a prospective longitudinal study involving neonates hospitalized in the NICU at Shri Mahant Indiresh Hospital, Dehradun, India, from December 2018 to December 2019. A total of 320 preterm neonates were admitted, with only 113 included in our study due to the absence of parental permission, patients leaving against medical advice, or failure to attend follow-up appointments.

RESULTS

In our study, 51 (45.13%) newborns developed ROP, while 62 (54.87%) did not, resulting in an incidence of 45.13%. Among 37 children diagnosed with hyaline membrane disease (HMD), 25 (67.57%) tested positive for ROP. Fifty percent of infants with an appearance, pulse, grimace, activity, and respiration(APGAR) score of 6 or lower at one minute had retinopathy, in contrast to just 32.69% of those with a score greater than 6. Anemia and the transfusion of blood products emerged as significant risk factors for the onset of retinal detachment. Meningitis was also identified as a significant risk factor for the development of retinopathy.

CONCLUSION

The findings indicate that low gestational age, low birth weight, HMD, oxygen therapy, and acute ophthalmopathy are independent risk factors associated with ROP development. Additional risk factors such as low APGAR score, anemia, surfactant therapy, abnormal cranial ultrasound, and blood product transfusion should be considered when monitoring preterm babies.

The effect of early-onset sepsis on retinopathy of prematurity in extremely premature infants based on propensity score matching

To investigate the effects of early-onset sepsis (EOS) on retinopathy of prematurity (ROP) in extremely premature infants (EPIs) by using propensity score matching (PSM). Clinical data of 591 EPIs admitted to NICU, Senior Department of Pediatric, PLA General Hospital from May 1, 2015 to May 1, 2022 were retrospectively analyzed. They were divided into an EOS group and a non-EOS group according to whether they had confirmed EOS or not. The incidence of ROP and severe ROP was compared between the two groups using the 1:1 PSM method. Of the 591 EPIs, 57 (9.6%) fell in the EOS group and the remaining 534 in the non-EOS group. There were statistical differences in artificial conception, cesarean section, bronchopulmonary dysplasia, duration of invasive mechanical ventilation, days of oxygen use, amniotic fluid contamination, and premature rupture of membranes between the two groups (all P < 0.05), and then match these variables as covariates. Before matching, the incidence of ROP and severe ROP in the EOS group was higher than that in the non-EOS group [ROP: (35/57)61.4% vs. (224/534)41.9%, OR  2.202, 95% CI 1.257 to 3.856, P = 0.005; severe ROP: (25/57)43.9% vs. (149/534)27.9%, OR  2.019, 95% CI 1.157 to 3.521, P = 0.012], and after matching all covariables were well matched (all P > 0.05). Of the 57 cases in the EOS group, 51 were successfully matched, in which the incidence of severe ROP was higher than that in the non-EOS group [47.1% (24/51) vs. 27.5% (14/51), OR  2.349,95% CI 1.030 to 5.360, P < 0.05]. There was no significant difference in the incidence of ROP between the two groups [62.7% (32/51) vs. 49.0% (25/51), OR 1.752,95% CI 0.795 to 3.858, P > 0.05]. EOS didn't seem to increase the incidence of ROP in EPIs, but was associated with an increase in the degree of ROP lesions. The progression of fundus lesions in EPIs with EOS during hospitalization should be closely monitored.

Endostatin in disease modulation: From cancer to beyond

Angiogenesis plays a pivotal role in various pathological conditions, making it a key target in therapeutic development. Anti-angiogenic therapies are gaining traction for their potential in treating a range of angiogenesis-dependent diseases. Among these, endogenous angiogenesis inhibitors, particularly endostatin, have garnered significant attention for their therapeutic potential. While extensively studied for its anti-angiogenic effects in cancer, endostatin also exhibits anti-atherosclerotic and anti-fibrotic properties, broadening its therapeutic scope. Despite the successful clinical use of recombinant human endostatin in China for nearly two decades, its broader therapeutic potential remains underexplored. Thus, this review delves into the multifaceted applications of endostatin, examining its role in ocular diseases, inflammation, reproductive disorders, and tumor angiogenesis. Furthermore, it provides a comprehensive overview of its emerging roles beyond angiogenesis, particularly in the context of atherosclerosis and fibroproliferative conditions.

Survival and characteristics of retinopathy of prematurity in micro-premature infants

OBJECTIVE

To describe the risk and nature of retinopathy of prematurity (ROP) in micro-premature infants (≤26 weeks' gestational age [GA]).

METHODS

Retrospective analysis of prospectively collected data from infants born at 22-26 weeks' GA over a 5-year period.

RESULTS

A total of 502 infants were identified, of whom 414 survived to discharge (82.5%). The Vermont Oxford Network database documented clinical follow-up data and ROP outcomes for all 414 patients; complete ROP clinical records were available for 294 of the infants who survived (70.8%). Forty infants were born between 22 and 23 weeks' GA (group A, 13.6%), and 254 were born between 24 and 26 weeks' GA (group B, 86.4%). Survival for group A infants was worse than that of group B infants (66.2% vs 85.4%; p < 0.01). Survival of group A infants improved during the study period (R2 = 0.625). Overall, 59.9% of infants developed any ROP and 8.5% developed type 1 ROP. Group A infants were more likely to develop ROP (90.0% vs 48.6%; p < 0.01) and type 1 ROP (30.0% vs 5.1%; p < 0.01) than group B infants. Group A infants developed ROP at an earlier age (32 + 6 weeks vs 33 + 3 weeks; p = 0.02) and were more likely to have zone I disease on presentation (65.0% vs 20.5%; p < 0.01), but there was no difference in the corrected gestational age of peak severity of ROP (35 + 2 weeks vs 34 + 5 weeks; p = 0.36).

CONCLUSION

The most premature infants, born at 22-23 weeks' GA, develop ROP at an earlier age, are more likely to present with posterior disease, and have a high risk of disease requiring treatment.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Risk factors for severe retinopathy of prematurity stratified by birth weight and gestational age in privately insured infants

PURPOSE

To evaluate risk factors associated with severe retinopathy of prematurity ROP (sROP) in two separate cohorts of infants.

METHODS

We performed a retrospective study of the Merative MarketScan Commercial Database between 2003 and 2022. Infants with ROP were stratified into two cohorts: group A (defined as infants with both birth weight [BW] <1000 g and gestational age [GA] <29 weeks) and group B (defined as infants with either BW ≥1000 g or GA ≥29 weeks). Infants with sROP were defined as those who received treatment for ROP. Outpatient and inpatient claims using International Classification of Diseases and Current Procedural Terminology codes were used to identify neonatal comorbidities. Multivariable logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for sROP requiring treatment with respect to various comorbidities.

RESULTS

A total of 425 of 8,789 infants with ROP developed sROP (4.8%). We identified 2,726 infants in group A, of whom 387 (14.2%) required a procedure, and 6,063 in group B, of whom 38 (0.6%) required a procedure. In group A, intraventricular hemorrhage (OR = 1.38; 95% CI, 1.09-1.74) and patent ductus arteriosus ligation (OR = 1.65; 95% CI, 1.25-2.16) were the comorbidities that significantly increased the odds of sROP on multivariable analysis. In group B, infection (OR = 1.96; 95% CI, 1.01-3.80) was the only comorbidity that significantly increased the adjusted odds of sROP.

CONCLUSIONS

Risk factors for sROP may differ between smaller and larger infants. Infection may serve as an important risk factor for ROP progression amongst larger infants due to its connection with poor postnatal growth.

Investigation of the rates of retinopathy of prematurity and other diseases in infants born late preterm: is routine ROP examination required?

BACKGROUND/OBJECTIVES

The objective of this study was to ascertain the prevalence of ROP and other ocular diseases in late preterm infants and to evaluate the necessity of routine ROP examination in a tertiary hospital in Turkey.

SUBJECTS/METHODS

This retrospective cohort study included late preterm infants treated in the neonatal intensive care unit (NICU) and referred to the ROP outpatient clinic. Those who were discharged or died before the first screening and those who did not complete all screening sessions were excluded. The data set comprised demographic information, gestational age, birth weight, stages of ROP, treatments, and the presence of other ocular comorbidities.

RESULTS

The study cohort comprised 600 late preterm infants, with a median gestational age of 35 weeks and a mean birth weight of 2392 ± 451 g. Of the infants included in the study, 3.3% developed ROP, with one infant requiring treatment. Furthermore, 4.8% of the subjects exhibited additional ocular comorbidities. The results indicated a statistically significant correlation between lower birth weight and gestational age with an increased prevalence of ROP and other ocular pathologies.

CONCLUSIONS

ROP incidence in late preterm infants is relatively low, although comorbidities are notable. Infants born late preterm with lower birth weight and gestational age are at greater risk for ROP and additional pathologies. It is recommended that routine screening for ROP be conducted in order to ensure that ROP and other ocular conditions are diagnosed and treated in a timely manner, thus preventing severe visual impairments.

The macular microvascular changes in children with a history of retinopathy of prematurity treated with intravitreal Bevacizumab injection using optical coherence tomography angiography: a retrospective cohort

OBJECTIVE

Our study aims to evaluate and compare the macular microvascular condition of the intravitreal Bevacizumab (IVB)-treated retinopathy of prematurity (ROP) cases to the preterm cases without ROP and spontaneously regressed ROPs.

METHODS

It is a retrospective cohort of 50 premature neonates visited from 2016 to 2017 for ROP screening in Nikookari Eye Hospital and recalled for re-evaluation in 2022. These patients were classified into three groups based on their medical documents: 1. Preterm cases without ROP (PT), 2. Spontaneously regressed ROPs (SR), and 3. IVB-treated ROPs (IVB). All the included cases underwent a thorough ophthalmic exam, cyclo-refraction, Best-corrected visual acuity (BCVA) assessment, and macular optical coherence tomography angiography (OCTA). The foveal thickness, foveal avascular zone (FAZ) area, foveal, parafoveal, and perifoveal vascular density (VD) were evaluated as the quantitative variables.

RESULTS

Twenty-five male and 25 female cases with a median age of 5.0 entered the study. Twenty-six eyes were evaluated in the PT group, 50 in the SR group, and 24 in the IVB group. The SR group consisted of 25 zone-2 and 25 zone-3 ROPs. In comparison, the IVB group consisted of 9 zone-1 and 15 zone-2 ROPs (p: < 001). Also, zone-2 cases were more advanced in the IVB group. The IVB-treated eyes demonstrated a significantly higher foveal superficial capillary plexus (SCP) VD than the others (28.5% vs. 23.1 and 22.9, respectively, in PT and SR, p:0.008). However, the parafoveal deep capillary plexus (DCP) VD was lower than the PT cases (48.5% vs. 53.4, p:0.034). The FAZ area was also smaller than the PT cases (0.113 vs.0.219 mm2, p:0.032). The FAZ area was significantly positively correlated with the foveal SCP and DCP VD and negatively correlated with parafoveal DCP VD (CC: -0.770, -0.719, 0.377, respectively, p: < 0.001).

CONCLUSION

In the long term, although the IVB-treated ROP cases experience an excellent visual outcome comparable to those without ROP, they may show some macular microvascular changes. These changes might be related to the effect of IVB or the nature of more advanced stages of ROP.

Use of an Artificial Intelligence-Generated Vascular Severity Score Improved Plus Disease Diagnosis in Retinopathy of Prematurity

PURPOSE

To evaluate whether providing clinicians with an artificial intelligence (AI)-based vascular severity score (VSS) improves consistency in the diagnosis of plus disease in retinopathy of prematurity (ROP).

DESIGN

Multireader diagnostic accuracy imaging study.

PARTICIPANTS

Eleven ROP experts, 9 of whom had been in practice for 10 years or more.

METHODS

RetCam (Natus Medical Incorporated) fundus images were obtained from premature infants during routine ROP screening as part of the Imaging and Informatics in ROP study between January 2012 and July 2020. From all available examinations, a subset of 150 eye examinations from 110 infants were selected for grading. An AI-based VSS was assigned to each set of images using the i-ROP DL system (Siloam Vision). The clinicians were asked to diagnose plus disease for each examination and to assign an estimated VSS (range, 1-9) at baseline, and then again 1 month later with AI-based VSS assistance. A reference standard diagnosis (RSD) was assigned to each eye examination from the Imaging and Informatics in ROP study based on 3 masked expert labels and the ophthalmoscopic diagnosis.

MAIN OUTCOME MEASURES

Mean linearly weighted κ value for plus disease diagnosis compared with RSD. Area under the receiver operating characteristic curve (AUC) and area under the precision-recall curve (AUPR) for labels 1 through 9 compared with RSD for plus disease.

RESULTS

Expert agreement improved significantly, from substantial (κ value, 0.69 [0.59, 0.75]) to near perfect (κ value, 0.81 [0.71, 0.86]), when AI-based VSS was integrated. Additionally, a significant improvement in plus disease discrimination was achieved as measured by mean AUC (from 0.94 [95% confidence interval (CI), 0.92-0.96] to 0.98 [95% CI, 0.96-0.99]; difference, 0.04 [95% CI, 0.01-0.06]) and AUPR (from 0.86 [95% CI, 0.81-0.90] to 0.95 [95% CI, 0.91-0.97]; difference, 0.09 [95% CI, 0.03-0.14]).

CONCLUSIONS

Providing ROP clinicians with an AI-based measurement of vascular severity in ROP was associated with both improved plus disease diagnosis and improved continuous severity labeling as compared with an RSD for plus disease. If implemented in practice, AI-based VSS could reduce interobserver variability and could standardize treatment for infants with ROP.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Different Catch-Up Growth Patterns in Very Preterm and Small for Gestational Age Infants

This study aimed to describe the growth pattern in preterm infants and identify factors influencing catch-up growth. A total of 288 preterm infants were divided into groups based on the degree of prematurity, sex, and size for gestational age. Growth in head circumference, length, weight-for-length, and weight was compared between groups at corrected age of 0, 3, 6, 9, 12, 18, and 24 months. Logistic regression analysis was conducted to determine risk factors for catch-up growth. At a corrected age of 24 months, the proportions of preterm infants with z-scores less than -2 for head circumference, length, weight-for-length, and weight were less than the expected 2.3% at 0.9%, 1.7%, 2.1%, and 1.7%, respectively. The head circumference, length, weight-for-length, and weight z-scores at corrected ages of 24 months were lower in the small for gestational age (SGA) group than in the non-SGA group (P < .05). The weight-for-length z-scores were higher in the late preterm birth infants than in the very preterm birth infants at a corrected age of 24 months (P < .05). At a corrected age 24 months, the proportion of male with weight z-scores <-2 was lower than that of female (P < .05). The differences in proportion of the z-scores (head circumference, length, weight-for-length, and weight) <-2 at a corrected age of 24 months among different gestational age groups and intrauterine growth status groups were not statistically significant (P > .05). We found that the factors influencing catch-up growth in preterm infants varied at different corrected age stages, and the impact of factors during hospitalization gradually diminished as the infants grew.

Innovative Use of Nanomaterials in Treating Retinopathy of Prematurity

BACKGROUND/OBJECTIVES

Retinopathy of prematurity (ROP) is a severe condition primarily affecting premature infants with a gestational age (GA) of 30 weeks or less and a birth weight (BW) of 1500 g or less. The objective of this review is to examine the risk factors, pathogenesis, and current treatments for ROP, such as cryotherapy, laser photocoagulation, and anti-VEGF therapy, while exploring the limitations of these approaches. Additionally, this review evaluates emerging nanotherapeutic strategies to address these challenges, aiming to improve ROP management.

METHODS

A comprehensive literature review was conducted to gather data on the pathogenesis, traditional treatment methods, and novel nanotherapeutic approaches for ROP. This included assessing the efficacy and safety profiles of cryotherapy, laser treatment, anti-VEGF therapy, and nanotherapies currently under investigation.

RESULTS

Traditional treatments, while effective in reducing disease progression, exhibit limitations, including long-term complications, tissue damage, and systemic side effects. Nanotherapeutic approaches, on the other hand, have shown potential in offering targeted drug delivery with reduced systemic toxicity, improved ocular drug penetration, and sustained release, which could decrease the frequency of treatments and enhance therapeutic outcomes.

CONCLUSIONS

Nanotherapies represent a promising advancement in ROP treatment, offering safer and more effective management strategies. These innovations could address the limitations of traditional therapies, reducing complications and improving outcomes for premature infants affected by ROP. Further research is needed to confirm their efficacy and safety in clinical practice.

Flicker electroretinogram in preterm infants

BACKGROUND

Infants born prematurely are at risk of developing retinopathy of prematurity, which is associated with abnormalities in retinal function as measured using electroretinography. The aim of this study was to record non-invasive flicker electroretinograms (ERGs) in preterm infants and compare function of moderate and very or extremely preterm infants.

METHODS

In this non-randomized, cross-sectional study, 40 moderate preterm (gestational age (GA) 34 0/7 to 36 6/7 weeks, Group A) and 40 very or extremely preterm infants (GA ≤ 31 weeks, Group B) were recruited for flicker ERG recording through closed eyelids using the RETeval® device and skin electrodes. Group A was tested within the first week of life and Group B between 34th and 37th week postmenstrual age. Flicker stimuli were presented at 28.3 Hz with stimulus levels of 3, 6, 12, 30 and 50 cd•s/m2. Primary endpoints were peak time (ms) and amplitude (µV).

RESULTS

Flicker ERGs were recordable in most infants with the highest proportion of reproducible ERGs at 30 cd•s/m2. Amplitudes increased with stronger flicker stimulation, while peak times did not differ significantly between stimulus levels nor groups. Amplitudes were significantly greater in Group B at the strongest stimulus level (Mann-Whitney-U-Test=198.00, Z = 4.097, p = <0.001).

CONCLUSIONS

Feasibility of collecting flicker ERG data in most preterm infants was confirmed. We found no evidence of reduced retinal responses to flicker stimuli associated with extreme prematurity. Higher amplitudes in very and extremely preterm infants could indicate acceleration of retinal development following birth, triggered by visual stimulation.

Clinical Risk Factors for Retinopathy of Prematurity Reactivation after Intravitreal Antivascular Endothelial Growth Factor Injection

OBJECTIVE

To assess the rate and risk factors for reactivation of retinopathy of prematurity (ROP) after intravitreal injection (IVI) of antivascular endothelial growth factor (VEGF) agents.

STUDY DESIGN

Infants who received IVI therapy between 2017 and 2022 were enrolled and divided into 2 groups: those with and without ROP reactivation. Information on ROP variables and patient variables were analyzed using multivariable logistic regression.

RESULTS

A total of 114 infants with 223 eyes were enrolled in the study. The ROP reactivation rate was 11.4% of infants (9.9% of eyes). The mean duration of reactivation was 84 ± 45 days. Among the 223 eyes treated with IVI, reactivation rates were 6% for bevacizumab, 13.9% for aflibercept, and 22.2% for ranibizumab. A multivariable regression model showed that ranibizumab was an independent risk factor (OR 11.4, P = .008) for reactivation. Other risk factors included infants with periventricular leukomalacia (OR 13.8, P = .003), patent ductus arteriosus ligation (OR 10.7, P = .032), and infants who still required invasive mechanical ventilation on the day of IVI therapy (OR 7.0, P = .018).

CONCLUSIONS

All anti-VEGF agents carry a risk of ROP reactivation, with the risk being greater with ranibizumab 0.25 mg than with bevacizumab 0.625 mg. Reactivation of ROP should be assessed vigilantly, especially in those infants with increased risks. Future research to determine the optimal anti-VEGF selection and dosage in high-risk infants is warranted.

Predictive role of systemic immune-inflammation index and neutrophil/lymphocyte ratio values in infants with retinopathy of prematurity

PURPOSE

To search the relationship between serum neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and systemic immune-inflammation index (SII) values with the development of retinopathy of prematurity (ROP) and the requirement for laser treatment.

METHODS

This retrospective cohort study was carried out with 195 preterm infants between 2012 and 2023. The NLR, PLR, LMR, and SII values were calculated on both the first day and at the end of the first month after birth. The association between development of ROP and other risk factors were analyzed using univariate analysis and multivariate logistic regression analysis.

RESULTS

Of patients, 92 infants were diagnosed with ROP. Laser treatment was administered to 36 infants. The postnatal first-day NLR and SII values were higher in infants with ROP than in infants without ROP (p < 0.001 for both). Postnatal first-month NLR, LMR, and SII values were higher in infants with ROP (p < 0.001, p = 0.007, and p < 0.001, respectively). In multivariate analyses, postnatal first-day NLR and first-month LMR values were regarded as independent risk factors for the development of ROP (OR:8.867 and 1.286, p = 0.002 and p = 0.009, respectively). In multivariate analyses performed for laser treatment requirement, postnatal first-month PLR and SII values were determined as independent risk factors (OR:0.951 and 1.011, respectively, p = 0.004 for both).

CONCLUSIONS

Postnatal first-day NLR and first-month LMR values were determined as independent risk factors for the development of ROP. For the requirement of laser treatment, the postnatal first-month PLR and SII values were determined as independent risk factors.

Genetic susceptibility for retinopathy of prematurity and its associated comorbidities

BACKGROUND

Retinopathy of prematurity (ROP) is one of the leading cause of child blindness. Preterm newborns of very low gestational age (GA) and very low birth weight are at the greatest risk. Our objective was to evaluate the role of genetic variants associated with ROP risk and its comorbidities in an Argentinian sample of premature infants.

METHODS

A sample of 437 preterm infants <33 weeks GA, born at a maternity hospital in Tucumán, Argentina, 2005-2010, was analyzed. Environmental factors, perinatal outcomes, and fourteen single nucleotide polymorphisms associated with ROP were evaluated, comparing ROP with non-ROP newborns. A lasso logistic regression was performed to select variables; then, a conditional logistic regression was used to identify ROP maternal and perinatal risk factors adjusting by maternal and gestational ages, respectively.

RESULTS

ROP maternal risk factors were alcohol intake, periodontal infections, and severe stress. Respiratory distress, sepsis, and intracranial hemorrhage were the ROP perinatal risk factors. Markers rs186085 of EPAS1 and rs427832 of AGTR1 were significantly associated with ROP newborns.

CONCLUSION

We identified three maternal and three perinatal risk factors associated with ROP. Genes EPAS1 and AGTR1, involved in angiogenesis and vascularization, were identified to be of risk for ROP.

IMPACT

Genetic and environmental risk factors associated with ROP and its comorbidities are evaluated in a Latin American population. Genes EPAS1 and AGTR1, involved in angiogenesis and vascularization, were identified to be of risk for ROP. Three maternal and three perinatal risk factors associated with ROP were also identified. A matrix of significant relationships among genetic markers and comorbidities is presented. Reported data may help develop more effective preventive measures for ROP in the Latin American region.

Isolated Retinal Neovascularization in Retinopathy of Prematurity: Clinical Associations and Prognostic Implications

OBJECTIVE

Isolated retinal neovascularization (IRNV) is a common finding in patients with stage 2 and 3 retinopathy of prematurity (ROP). This study aimed to further classify the clinical course and significance of these lesions (previously described as "popcorn" based on clinical appearance) in patients with ROP as visualized with ultrawidefield OCT (UWF-OCT).

DESIGN

Single center, retrospective case series.

PARTICIPANTS

Images were collected from 136 babies in the Oregon Health and Science University neonatal intensive care unit.

METHODS

A prototype UWF-OCT device captured en face scans (>140°), which were reviewed for the presence of IRNV along with standard zone, stage, and plus classification. In a cross-sectional analysis we compared demographics and the clinical course of eyes with and without IRNV. Longitudinally, we compared ROP severity using a clinician-assigned vascular severity score (VSS) and compared the risk of progression among eyes with and without IRNV using multivariable logistic regression.

MAIN OUTCOME MEASURES

Differences in clinical demographics and disease progression between patients with and without IRNV.

RESULTS

Of the 136 patients, 60 developed stage 2 or worse ROP during their disease course, 22 of whom had IRNV visualized on UWF-OCT (37%). On average, patients with IRNV had lower birth weights (BWs) (660.1 vs. 916.8 g, P = 0.001), gestational age (GA) (24.9 vs. 26.1 weeks, P = 0.01), and were more likely to present with ROP in zone I (63.4% vs. 15.8%, P < 0.001). They were also more likely to progress to stage 3 (68.2% vs. 13.2%, P < 0.001) and receive treatment (54.5% vs. 15.8%, P = 0.002). Eyes with IRNV had a higher peak VSS (5.61 vs. 3.73, P < 0.001) and averaged a higher VSS throughout their disease course. On multivariable logistic regression, IRNV was independently associated with progression to stage 3 (P = 0.02) and requiring treatment (P = 0.03), controlling for GA, BW, and initial zone 1 disease.

CONCLUSIONS

In this single center study, we found that IRNV occurs in higher risk babies and was an independent risk factor for ROP progression and treatment. These findings may have implications for OCT-based ROP classifications in the future.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Retinopathy of Prematurity in Eight Portuguese Neonatal Intensive Care Units: Incidence, Risk Factors, and Progression-A Prospective Multicenter Study

BACKGROUND/OBJECTIVES

Retinopathy of prematurity (ROP) is a retinal neovascular disease affecting preterm infants. Identifying risk factors for its development and progression is critical for effective screening and prevention. This study aimed to analyze the incidence of ROP and identify key risk factors for its development and progression.

METHODS

We conducted a prospective, observational cohort study on 455 neonates (gestational age [GA] < 32 weeks or birth weight < 1500 g) across eight Portuguese NICUs.

RESULTS

ROP incidence was 37.8%, with 4.6% requiring treatment. Multivariate analysis identified low GA and the number of red blood cell (RBC) transfusions as significant factors for ROP development and progression. After adjusting for these variables, platelet transfusions, high maximum fraction of inspired oxygen (FiO2) in the second week, and surfactant use remained significantly associated with ROP development, while early and late sepsis, maternal chronic hypertension, and delayed enteral nutrition were associated with progression to ROP requiring treatment.

CONCLUSIONS

These findings underscore the importance of addressing low GAs and adult RBC transfusions in ROP risk management and suggest that maximum FiO2, platelet transfusions, and sepsis also play crucial roles. Larger studies are needed to validate these results and explore preventive interventions, particularly regarding the impact of multiple adult RBC transfusions on fetal hemoglobin percentages.

Neurofilament light chain associates with IVH and ROP in extremely preterm infants

BACKGROUND

Neurofilament light chain (NfL) is known for indicating adult brain injury, but the role of NfL in extremely preterm infants is less studied. This study examines the relationship between NfL and neurovascular morbidities in these infants.

METHODS

A secondary analysis of the Mega Donna Mega trial was conducted on preterm infants <28 weeks gestational age (GA). The study measured NfL levels and proteomic profiles related to the blood-brain barrier in serum from birth to term-equivalent age, investigating the association of NfL with GA, retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH), and blood-brain barrier proteins.

RESULTS

Higher NfL levels were seen in the first month in infants with severe IVH and for those born <25 weeks GA (independent of ROP or IVH). Additionally, infants born at 25-27 weeks GA with high NfL were at increased risk of developing severe ROP (independent of IVH). NfL was significantly associated with the proteins CDH5, ITGB1, and JAM-A during the first month.

CONCLUSION

NfL surges after birth in extremely preterm infants, particularly in those with severe IVH and ROP, and in the most immature infants regardless of IVH or ROP severity. These findings suggest NfL as a potential predictor of neonatal morbidities, warranting further validation studies.

IMPACT STATEMENT

This study shows that higher NfL levels are related to neurovascular morbidities in extremely preterm infants. The degree of immaturity seems important as infants born <25 weeks gestational age exhibited high postnatal serum NfL levels irrespective of neurovascular morbidities. Our findings suggest a potential link between NfL and neurovascular morbidities possibly affected by a more permeable blood-brain barrier.

Impact of antenatal corticosteroids-to-delivery interval on very preterm neonatal outcomes: a retrospective study in two tertiary centers in Japan

BACKGROUND

Antenatal corticosteroids (ACS) are administered to prevent neonatal complications and death in women at risk of imminent preterm birth. Internationally, the optimal interval from ACS to delivery (ACS-to-delivery interval) is within seven days; however, evidence in Asian populations specifically is limited. This study aimed to investigate the association between ACS-to-delivery interval and the incidence of neonatal complications in Japan.

METHODS

This retrospective observational study enrolled singleton neonates born preterm at < 32 weeks of gestational age between 2012 and 2020 at two tertiary centers. A total of 625 neonates were divided into the following four groups according to the timing of ACS (measured in days): no ACS (n = 145), partial ACS (n = 85), ACS 1-7 (n = 307), and ACS ≥ 8 (n = 88). The following outcomes were compared between the groups: treated respiratory distress syndrome (RDS), severe intraventricular hemorrhage (IVH), treated patent ductus arteriosus (PDA), necrotizing enterocolitis, sepsis, bronchopulmonary dysplasia (BPD), treated retinopathy of prematurity (ROP), periventricular leukomalacia, and death discharge.

RESULTS

The ACS 1-7 group had significantly decreased adjusted odds ratios (ORs) for treated RDS (0.37 [95% confidence interval: 0.23, 0.57]), severe IVH (0.21 [0.07, 0.63]), treated PDA (0.47 [0.29, 0.75]), and treated ROP (0.50 [0.25, 0.99]) compared with the no ACS group. The ACS ≥ 8 group also showed significantly reduced adjusted ORs for RDS (0.37 [0.20, 0.66]) and treated PDA (0.48 [0.25, 0.91]) compared with the no ACS group. However, the adjusted ORs for BPD significantly increased in both the ACS 1-7 (1.86 [1.06, 3.28]) and ACS ≥ 8 groups (2.94 [1.43, 6.05]) compared to the no ACS group.

CONCLUSIONS

An ACS-to-delivery interval of 1-7 days achieved the lowest incidence of several complications in preterm neonates born at < 32 weeks of gestational age. Some of the favorable effects of ACS seem to continue even beyond ≥ 8 days from administration. In contrast, ACS might be associated with an increased incidence of BPD, which was most likely to be prominent in neonates delivered ≥ 8 days after receiving ACS. Based on these findings, the duration of the effect of ACS on neonatal complications should be studied further.

Clinical and Demographic Characteristics of Treatment Requiring Retinopathy of Prematurity in Big Premature Infants in Turkiye: Report No. 1 (BIG-ROP Study)

INTRODUCTION

The aim of the study was to analyse the clinical and demographic features of infants with gestational age (GA) of 32-37 weeks and birth weight (BW) of >1,500 g who developed treatment requiring retinopathy of prematurity (ROP).

METHODS

Data on the infants with a GA of 32-37 weeks and BW >1,500 g who developed treatment requiring ROP (TR-ROP) were collected retrospectively from the 33 ROP centres in Turkiye. GA, BW, type of hospital, neonatal intensive care units (NICUs) level, presence of an ophthalmologist and neonatologist in the same hospital, length of stay in NICU, duration of oxygen therapy, comorbidities, type of ROP, and timing for TR-ROP development were analysed.

RESULTS

A total of366 infants were included in the study. Mean GA and BW were 33 ± 1 weeks and 1,896 ± 316 g, respectively. Duration of hospitalization was 3-4 weeks in 46.8% of them. The first ROP examination was performed at postnatal 4-5 weeks in 80.3% of infants, which was significantly later in level 2 and lower NICUs and non-university clinics. At the first ROP examination, any stage of ROP was detected in 90.9% and TR-ROP was detected in 15.3% of the infants. The mean postnatal week of TR-ROP development was 6.16 ± 2.04.

CONCLUSION

Routine ROP screening thresholds need to be expanded in hospitals with suboptimal NICU conditions considering the development of TR-ROP in more mature and heavier preterm infants. The first ROP examination should be earlier than the fourth postnatal week.

A retrospective study of the incidence, patterns, and risk factors of retinopathy of prematurity in infants with birth weight >1500 g in a South Indian tertiary care hospital

OBJECTIVE

The objective of the study was to determine the incidence, patterns, and risk factors for the development of retinopathy of prematurity (ROP) in infants weighing >1500 g at birth.

MATERIALS AND METHODS

A retrospective analysis was done of the ROP screening records between April 2019 and March 2022. All the infants with birth weight >1500 g who underwent ROP screening were included. Data collected included demographic details, details of the risk factors (respiratory distress syndrome [RDS], hypoxia, anemia, septicemia, patent ductus arteriosus, congenital heart disease [CHD], i.e., atrial septal defects or ventricular septal defects, and multiple gestations), and ocular examination findings. Statistical analyses included calculation of mean, range, Chi-square test, and bivariate logistic regression for associations of risk factors with ROP.

RESULTS

ROP was noted in 16.6% of the 336 eyes of 168 infants. The mean birth weight and mean gestational age (GA) of the infants were 1850 ± 33 g and 33.33 weeks ± 1.71 weeks, respectively. Eighteen eyes (32.1%) had Stage I, 17 eyes (30.35%) had Stage II, and 11 eyes (19.64%) had Stage III ROP in Zone II. Aggressive ROP was seen in 8 eyes (14.28%) and stage 5 ROP in two eyes (0.59%). Male gender, GA, CHD, and RDS showed a statistically significant association with the development of ROP in these infants.

CONCLUSION

ROP was seen in 16.66% of our subjects. Treatment was required in 6.25% of infants. Risk factors for the development of ROP were low gestational age, male gender, the presence of RDS, and congenital heart disease.

Hyperbilirubinemia and retinopathy of prematurity: a retrospective cohort study

Retinopathy of prematurity (ROP) is a vasoproliferative retinal disease in preterm infants. Oxidative stress plays a key role in the pathogenesis of ROP. Due to its antioxidant effects, bilirubin has been proposed to be protective against ROP. This study explored the association between hyperbilirubinemia and ROP. We analyzed a 10-year cohort from a neonatal intensive care unit in Milan, Italy, including 1606 infants born under 32 weeks and/or < 1500 g. Data from 1606 infants meeting specific inclusion criteria were reviewed. Eighty infants were excluded due to lack of data, 1526 were deemed eligible for analysis, and 1269 had hyperbilirubinemia requiring phototherapy. There was a higher incidence of ROP among infants with hyperbilirubinemia (13.8%) versus those without (7.8%, p<0.01). Infants with any ROP, non-severe or severe ROP, were exposed to hyperbilirubinemia for a significantly higher number of days compared with those without ROP. Each additional day of exposure increases the risk of developing any ROP by 5%, non-severe ROP by 4%, and severe ROP by 6%. However, this correlation was not observed in infants with gestational age less than 27 weeks and/or body weight less than 1000 g.    Conclusion: Our data show that hyperbilirubinemia requiring phototherapy is associated with an increased risk of developing ROP. However, severe hyperbilirubinemia and ROP share many of their risk factors. Therefore, rather than being a risk factor itself, hyperbilirubinemia may be a surrogate for other risk factors for ROP.    Clinical Trial Registration: NCT05806684. What is Known: • The development of retinopathy of prematurity (ROP) is influenced by several critical risk factors, including low gestational age, low birth weight, supplemental oxygen use, and increased oxidative stress. • In vitro, unconjugated bilirubin is an effective scavenger of harmful oxygen species and a reducing agent, highlighting its potential protective role against oxidative stress. What is New: • Hyperbilirubinemia requiring phototherapy was associated with an increased risk of developing ROP, but this association was not observed in the most vulnerable population of extremely preterm infants. • Every additional day of phototherapy for hyperbilirubinemia increases the risk of ROP by 5% for any ROP, 4% for non-severe ROP, and 6% for severe ROP.

Incidence, Risk Factors and Development of Retinopathy of Prematurity in Mid-Preterm and Late-Preterm Infants

PURPOSE

To evaluate the incidence, risk factors, and development of retinopathy of prematurity (ROP) in midpreterm and late-preterm infants born at 32 to 36 6/7 weeks of gestational age.

METHODS

The ophthalmic examination findings and risk factors of 5,477 preterm infants who underwent ophthalmological examination were evaluated retrospectively. The rates of any stage and severe ROP (requiring treatment) development and treatment options were recorded. The risk factors were analyzed by using logistic regression analysis.

RESULTS

A total of 5,477 infants were included in the study, of whom 2,715 (49.57%) were mid-preterm and 2,762 (50.43%) were late-preterm. The rates of any stage and severe ROP were 8.2% (n = 223) and 0.6% (n = 15) in mid-preterm infants, respectively. In late-preterm infants, the rate of any stage ROP was 2.1% (n = 59), and no severe ROP was detected. There was no significant difference in mean birth weight in mid-preterm infants between infants with any stage ROP and severe ROP (P = .104). Of the 15 infants (0.3%) who required treatment, 14 (0.2%) infants had laser photocoagulation, 1 (0.01%) had intravitreal bevacizumab, and 2 (0.03%) had additional therapy (laser photocoagulation and intravitreal bevacizumab). In logistic regression analysis, a significant association was found between treatment requirement and transport from an external center (P < .001, ß = 0.04).

CONCLUSIONS

Although ROP development rates decrease as birth weight and gestational age increase, late-preterm infants should be examined for ROP at least once, especially those born in low-income countries because ROP development can still be observed. [J Pediatr Ophthalmol Strabismus. 2024;61(5):351-357.].

Automated detection of type 1 ROP, type 2 ROP and A-ROP based on deep learning

PURPOSE

To provide automatic detection of Type 1 retinopathy of prematurity (ROP), Type 2 ROP, and A-ROP by deep learning-based analysis of fundus images obtained by clinical examination using convolutional neural networks.

MATERIAL AND METHODS

A total of 634 fundus images of 317 premature infants born at 23-34 weeks of gestation were evaluated. After image pre-processing, we obtained a rectangular region (ROI). RegNetY002 was used for algorithm training, and stratified 10-fold cross-validation was applied during training to evaluate and standardize our model. The model's performance was reported as accuracy and specificity and described by the receiver operating characteristic (ROC) curve and area under the curve (AUC).

RESULTS

The model achieved 0.98 accuracy and 0.98 specificity in detecting Type 2 ROP versus Type 1 ROP and A-ROP. On the other hand, as a result of the analysis of ROI regions, the model achieved 0.90 accuracy and 0.95 specificity in detecting Stage 2 ROP versus Stage 3 ROP and 0.91 accuracy and 0.92 specificity in detecting A-ROP versus Type 1 ROP. The AUC scores were 0.98 for Type 2 ROP versus Type 1 ROP and A-ROP, 0.85 for Stage 2 ROP versus Stage 3 ROP, and 0.91 for A-ROP versus Type 1 ROP.

CONCLUSION

Our study demonstrated that ROP classification by DL-based analysis of fundus images can be distinguished with high accuracy and specificity. Integrating DL-based artificial intelligence algorithms into clinical practice may reduce the workload of ophthalmologists in the future and provide support in decision-making in the management of ROP.

Eyecare-cloud: an innovative electronic medical record cloud platform for pediatric research and clinical care

Background and objectives

Clinical data are essential for developing cloud platforms for intelligent diagnosis and treatment decision of diseases. However, cloud platforms for data sharing and exchange with clinicians are poorly suited. We aim to establish Eyecare-cloud, a platform which provide a novel method for clinical data and medical image sharing, to provide a convenient tool for clinicians.

Methods

In this study, we displayed the main functions of Eyecare-cloud that we established. Based on clinical data from the cloud platform, we analyzed the incidence trend of the most common infantile retinal diseases, such as retinopathy of prematurity (ROP), over the past 20 years, as well as the associated risk factors for ROP occurrence. Statistical analyses were performed using GraphPad Prism (V.8.0) and SPSS software (V.26.0).

Results

The Eyecare-cloud offers numerous advantages, including systematic archiving of patient information, one-click export data, simplifying data collection and management, eliminating the need for manual input of clinical information, reducing clinical data migration time, and lowering data management costs significantly. A total of 22,913 premature infants from Eyecare-cloud were included in the data analysis. Based on 20 years of premature infant screening data analysis, we found that the ROP incidence began to slowly decline starting in 2003 but showed a gradual increase trend again in 2016. The incidence of severe ROP remained relatively stable at a low level since 2010. The number of premature infants increased steadily before 2016 but decreased since then. ROP occurrence was significantly associated with male sex, lower gestational age, and lower birth weight (P < 0.001).

Conclusion

Eyecare-cloud provides clinicians and researchers with convenient tools for big data analysis, which helps alleviate clinical workloads and integrate research data. This cloud platform supports the principles of predictive, preventive, and personalized medicine (PPPM/3PM), empowering clinicians and researchers to deliver more precise, proactive, and patient-centered eye care.

Oxygen delivery and monitoring in neonatal intensive care units in Mexico in 2011 and in 2023: an observational longitudinal study

BACKGROUND

Retinopathy of prematurity (ROP) is a leading cause of avoidable blindness in children, particularly in Latin America, where hyperoxia is a significant risk factor. This study evaluated resource availability and use for administering and monitoring supplemental oxygen in Mexico.

METHODS

In 2011, an observational study in which 32 government neonatal intensive care units (NICUs) across Mexico were visited. Data collected included occupancy, staffing levels, and equipment to deliver and monitor supplemental oxygen. Preterm infants receiving oxygen were observed. In 2023, 13 NICUs were revisited, and similar data collected. Staffing levels were benchmarked against Argentinian and US recommendations.

RESULTS

In 2011, only 38% of NICUs had adequate medical and staffing levels to meet recommended cot-to-staff ratios for all shifts. Staffing ratios were worse during weekends and at night than during weekdays. Only 25.5% of cots had blenders, and 80.1% had saturation monitors. 153 infants were observed 87% of whom were being monitored. Upper and lower oxygen saturations were ≥ 96% in 53%, and ≤ 89% in 8%, respectively. Alarm settings were inadequate, as 38% and 32% of upper and lower alarms were switched off and 16% and 53% were incorrectly set, respectively. In the 13 NICUs with data from 2011  and 2023, cot-to-staff ratios deteriorated over time, and in 2023 no unit had recommended ratios for all shifts. Equipment provision did not change, with similar proportions of babies in oxygen being monitored (79% 2011; 75% 2023). Rates of hyperoxia decreased slightly from 54% in 2011 to 49% in 2023. More upper alarms were set (46% 2011; 75% 2023), but a higher proportion were incorrectly set (52% 2011; 68% 2023).

CONCLUSIONS

Between 2011 and 2023, cot-to-staff ratios worsened, and equipment for safe oxygen delivery and monitoring remained insufficient. Despite available monitoring equipment, oxygen saturations often exceeded recommended levels, and alarms were frequently not set or incorrectly configured. Urgent improvements are needed in healthcare workforce numbers and practices, along with ensuring adequate equipment for safe oxygen delivery.

Animal Models of Retinopathy of Prematurity: Advances and Metabolic Regulators

Retinopathy of prematurity (ROP) is a primary cause of visual impairment and blindness in premature newborns, characterized by vascular abnormalities in the developing retina, with microvascular alteration, neovascularization, and in the most severe cases retinal detachment. To elucidate the pathophysiology and develop therapeutics for ROP, several pre-clinical experimental models of ROP were developed in different species. Among them, the oxygen-induced retinopathy (OIR) mouse model has gained the most popularity and critically contributed to our current understanding of pathological retinal angiogenesis and the discovery of potential anti-angiogenic therapies. A deeper comprehension of molecular regulators of OIR such as hypoxia-inducible growth factors including vascular endothelial growth factors as primary perpetrators and other new metabolic modulators such as lipids and amino acids influencing pathological retinal angiogenesis is also emerging, indicating possible targets for treatment strategies. This review delves into the historical progressions that gave rise to the modern OIR models with a focus on the mouse model. It also reviews the fundamental principles of OIR, recent advances in its automated assessment, and a selected summary of metabolic investigation enabled by OIR models including amino acid transport and metabolism.

Novel Small Molecules with Anti-Inflammatory and Anti-Angiogenic Activity in a Mouse Model of Oxygen-Induced Retinopathy

Retinopathy of prematurity (ROP) has a dual-phase disease pathology; in phase 1, hyperoxia-induced vaso-obliteration occurs in the retinal vasculature due to increased oxidative stress (OS) and inflammation, followed by phase 2, where hypoxia increases the overproduction of growth factors, inducing retinal neovascularization. Toll-like receptor 2 and -4 (TLR2 and TLR4) overactivation, hyper-inflammation, macrophages, and neutrophil infiltration contribute to the developing ROP. AVR-121 and AVR-123 are novel classes of small-molecule dual inhibitors of TLR2/4 tested in a human leukemia monocytic cell line (THP-1) and cord-blood-derived mononuclear cells (CBMCs). Both compounds inhibited TLR2/4 signaling-related inflammatory cytokines in THP-1 cells and inhibited VEGF-induced neovascularization in human retinal endothelial cells (HRECs), which are hallmarks of ROP. In an oxygen-induced retinopathy (OIR) murine model, the intraperitoneal injection of AVR-123 in the hyperoxia phase (P7-P12) or a nanosuspension eyedrop of AVR-123 in the hypoxic phase (P12-P17) significantly reduced vaso-obliteration, angiogenesis, and inflammatory cytokine profiles while not inhibiting the necessary growth factor VEGF in the juvenile mouse eyes. The results are consistent with our hypothesis that targeting the dual TLR2/4 pathway will reduce inflammation, angiogenesis, and vaso-obliteration in vitro and in vivo and reduce cytotoxic immune cells. AVR-123 has the potential to be developed as a therapy for ROP.

Oral DHA supplementation and retinopathy of prematurity: the Joinville DHA Clinical Trial

Retinopathy of prematurity (ROP) is a leading cause of blindness in premature infants. The condition is associated with DHA deficiency. This study aimed to investigate the effect of DHA supplementation on the occurrence of ROP in infants receiving oral oil drops. It is part of the Joinville DHA study, a non-parallel-group cohort study conducted from March 2020 to January 2023 at a public maternity hospital in Brazil. Infants born before 33 weeks of gestational age or with a birth weight ≤ 1500 g were recruited. Among 155 infants, 81 did not receive and 74 received DHA supplementation until complete vascularisation of the peripheral retina. There was a higher incidence of infants with ROP in the unsupplemented group (58·6 %) compared with the DHA group (41·4 %), but this difference was NS (P = 0·22). Unadjusted logistic regression analysis showed that patent ductus arteriosus and neonatal corticosteroids were significantly (P < 0·05) associated with ROP in both groups. In the DHA group, surfactant use was also associated with ROP (P = 0·003). After adjusting for important covariates, patent ductus arteriosus and neonatal corticosteroids continued to be significant for infants in the unsupplemented group (OR = 3·99; P = 0·022 and OR = 5·64; P = 0·019, respectively). In the DHA group, only surfactant use continued to be associated with ROP (OR = 4·84; P = 0·015). In summary, DHA supplementation was not associated with ROP. Further studies are necessary to better understand the relationship between DHA supplementation, ROP and associated comorbidities.

Prediction models for retinopathy of prematurity occurrence based on artificial neural network

INTRODUCTION

Early prediction and timely treatment are essential for minimizing the risk of visual loss or blindness of retinopathy of prematurity, emphasizing the importance of ROP screening in clinical routine.

OBJECTIVE

To establish predictive models for ROP occurrence based on the risk factors using artificial neural network.

METHODS

A cohort of 591 infants was recruited in this retrospective study. The association between ROP and perinatal factors was analyzed by univariate analysis and multivariable logistic regression. We developed predictive models for ROP screening using back propagation neural network, which was further optimized by applying genetic algorithm method. To assess the predictive performance of the models, the areas under the curve, sensitivity, specificity, negative predictive value, positive predictive value and accuracy were used to show the performances of the prediction models.

RESULTS

ROP of any stage was found in 193 (32.7%) infants. Twelve risk factors of ROP were selected. Based on these factors, predictive models were built using BP neural network and genetic algorithm-back propagation (GA-BP) neural network. The areas under the curve for prediction models were 0.857, and 0.908 in test, respectively.

CONCLUSIONS

We developed predictive models for ROP using artificial neural network. GA-BP neural network exhibited superior predictive ability for ROP when dealing with its non-linear clinical data.

Retrospective cohort evaluation of postnatal growth and retinopathy of prematurity (G-ROP) criteria in a tertiary centre in Turkey

PURPOSE

The postnatal growth and retinopathy of prematurity (G-ROP) study has proposed a new model to increase the effectiveness of screening retinopathy of prematurity (ROP). The present study aimed to evaluate the effectiveness of the G-ROP model in a tertiary centre in Turkey.

METHODS

The medical records of infants screened for ROP in our hospital between January 2018 and December 2022 were reviewed retrospectively. Babies with a documented ROP result and regular body weight measurements up to the 40th day of life were included in the study, and the G-ROP model was applied. The sensitivity of the G-ROP prediction model in detecting treated ROP, Type 1 ROP, Type 2 ROP, and low-grade ROP and the reduction in the number of babies to be screened by applying the model were calculated.

RESULTS

The G-ROP model was applied to a total of 242 infants. While 194 babies were determined for screening, 22 of them were treated. The sensitivity to predict treated ROP was 100%, and the specificity was 21.8%. The model successfully predicted all cases of Type 1 ROP in the cohort, while the sensitivity was 90.9% for Type 2 ROP and 90.7% for low-grade ROP. The G-ROP model reduced the number of infants requiring screening by 19.8% in our study.

CONCLUSIONS

The G-ROP model was successfully validated in our cohort in detecting treated ROP and Type 1 ROP, reducing the number of infants requiring screening by approximately 1 in 5.

Progress in the study of association between hematological indicators and retinopathy of prematurity (Review)

Retinopathy of prematurity (ROP) is a retinopathy caused by abnormal proliferation of blood vessels in premature infants. It can lead to retinal detachment and, in severe cases, blindness, rendering ROP a critical condition. Advances in neonatal medicine have improved survival rates of low birth weight and low gestational age infants. However, this progress has also led to a rise in incidence of ROP. Currently, premature birth, low birth weight and high postpartum oxygen levels are independent risk factors for ROP. Other factors include mode of delivery, multiple births, anemia, blood transfusion, maternal pregnancy factors, neonatal bronchopulmonary dysplasia, use of surfactants, arterial ductus arteriosus and necrotizing enterocolitis. Laboratory indicators in premature infants such as platelet count, levels of blood glucose, inflammatory cells, lipid and hemoglobin and blood transfusion may also be associated with ROP. However, the etiology and pathogenesis of ROP are not fully understood. A number of factors may influence the onset and progression of ROP, including decreased platelet counts, decreased hemoglobin levels, increased white blood cell counts, increased blood glucose levels, and disorders of lipid metabolism. The present study reviewed the effects of platelet count, hemoglobin, blood glucose, inflammatory cells and factors, blood lipids, and plasma metabolic pathways on ROP.

Bacterial species in cord blood and their significance in the context of clinical use

Approximately 90 % of infants born before 28 full weeks(extremely-preterm-infants) receive erythrocyte transfusions in early life. Umbilical cord blood(UCB) has been investigated as an alternative source for erythrocyte transfusions to preterm neonates. This retrospective study aimed to compile/evaluate spectrum of bacteria groups/species intermittently detected in processed UCB at National-Swedish-Cord blood bank, (NS-CBB) during the years 2008-2020. Consecutive data from the years 2008-2020 were investigated. UCB from healthy newborns born after 37 full weeks of gestation was collected following clamping of cord (1 min) through cannulation of umbilical vein(vaginal-and C-section-deliveries). In total, 5194 cord blood units (UCBUs) that met NS-CBB-guidelines for total nucleated-cell-content(TNC) were manufactured from 8875 collections. Of 5194 UCBUs,77,6 % were from vaginal-and 22,4 % from C-section deliveries.Samples(10 mL) were collected from surplus eryhtrocyte fraction post-processing(n = 5194), transferred into BACT/ALERT® aerobic/anaerobic culture flasks and monitored 10 days using BACT/ALERT®-3D-Microbial-Detection-Systems. Positive samples were subcultured and typed for bacterial groups and/or species. Out of 5194 processed sampled UCB units,186 (3,6 %) were discarded due to positive sterility tests, 92 % were detected in samples from vaginal-deliveries and 8 % from C-section-deliveries. In all,16 different groups of bacteria and 27 species were identified. Common bacterial/groups and species were anaerobe gram-negative rods(n = 28),coagulase-negative-staphylococci(n = 21),gram-positive rods(n = 21),anaerobe-gram-positive cocci(n = 20) and viridans-streptococci(n = 13). Extracted from these results,in positive samples(n = 13) from C-section deliveries, bacteria were found:viridans-streptococci(n = 7),Aerococcus-urinae(n = 1), Staphylococcus lugdunensis(n = 1),other coagulase-negative staphylococci(n = 1) or a mix of aerobic/anaerobic bacteria(n = 3). Our results are in alignment with previously published contamination rates in processed UCBUs. Still, results point towards importance of strict microbial monitoring when manufacturing UCBUs to achieve patient-safe- products for stem-cell transplantation/transfusion.

The impact of intermittent hypoxemia on type 1 retinopathy of prematurity in preterm infants

BACKGROUND

Intermittent hypoxemia (IH) may influence retinopathy of prematurity (ROP) development in preterm infants, however, previous studies had mixed results. This study tests the hypothesis that increased IH is associated with Type 1 ROP; a stage beyond which treatment is indicated.

METHODS

IH was quantified by continuously monitoring oxygen saturation (SpO2) using high-resolution pulse oximeters during the first 10 weeks of life. Statistical analyses assessed the relationship and predictive ability of weekly and cumulative IH for Type 1 ROP development.

RESULTS

Most analyses showed no association between IH and Type 1 ROP adjusting for gestational age (GA) and birth weight (BW). However, cumulative IH of longer duration during weeks 5-10, 6-10, and 7-10 were significantly associated with Type 1 ROP adjusting for GA and BW, e.g., the adjusted odds ratio of Type 1 ROP was 2.01 (p = 0.03) for every 3.8 seconds increase in IH duration from week 6-10. IH did not provide statistically significant added predictive ability above GA and BW.

CONCLUSIONS

For most analyses there was no significant association between IH and Type 1 ROP adjusting for GA and BW. However, infants with longer IH duration during the second month of life had higher risk for Type 1 ROP.

IMPACT

The relationship and predictive ability of intermittent hypoxemia (IH) on retinopathy of prematurity (ROP) is controversial. This study shows no significant association between IH events and Type 1 ROP after adjusting for gestational age (GA) and birth weight (BW), except for cumulative IH of longer duration in the second month of life. In this cohort, IH does not provide a statistically significant improvement in ROP prediction over GA and BW. This study is the first to assess the cumulative impact of IH measures on Type 1 ROP. Interventions for reducing IH duration during critical postnatal periods may improve ROP outcomes.

Comparison of Single-Treatment Efficacy of Bevacizumab and Ranibizumab for Retinopathy of Prematurity

BACKGROUND

Retinopathy of prematurity (ROP) is a significant cause of blindness in infants. Appropriate therapeutic intervention is essential because retinal detachment due to the progression of ROP is critical to visual function. The intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents has been increasingly applied to inhibit the development and progression of ROP. In this study, we compared the efficacy of single intravitreal bevacizumab (IVB) and ranibizumab (IVR) injections for the treatment of ROP.

METHODS

A total of 39 eyes in 21 patients with severe ROP and IVB (15 eyes of 8 patients) and IVR (24 eyes of 13 patients) were retrospectively reviewed. Patient background, the severity of ROP, and the percentage of cases in which ROP regressed without additional treatment were compared between the two groups.

RESULTS

Patient background and ROP severity were not significantly different between the two groups. Recurrence was observed in one eye of one patient in the IVB group, and thirteen eyes in seven patients in the IVR group required additional laser photocoagulation, which was significantly different in the two groups (p < 0.01, Fisher's exact test). In the IVR group, two eyes of two patients underwent vitreous surgery.

CONCLUSION

Compared with IVR, IVB is likely to control the severity of ROP with a single treatment.

Tear fluid cytokine analysis: a non-invasive approach for assessing retinopathy of prematurity severity

PURPOSE

To determine whether there is a significant association between inflammatory cytokines in the tear fluid and the severity of Retinopathy of Prematurity (ROP).

STUDY DESIGN

Retrospective cohort study.

METHODS

The cytokine levels in tear fluids were determined in 34 eyes with ROP and 18 eyes without ROP. There were 15 eyes with severe ROP requiring treatment and 19 eyes with mild ROP not requiring treatment. For severe ROP eyes, tear fluids were collected before treatment.

RESULTS

Significantly higher levels of CCL2 and vascular endothelial growth factor (VEGF) were detected in eyes with severe ROP compared to eyes with mild ROP and no ROP. When assessed for cytokine levels that discriminate each disease group, CCL2 showed a significant odds ratio of 1.76 for severity change (/quintile, P = 0.032, after adjusting for birth weight). Correlation analysis showed that birth weight correlated with IL-1α levels, and decreased weight gain increased IFN-γ levels. We next determined tear fluid cytokines which discriminate severe ROP using receiver operating characteristics' analysis. We found that combination of higher CCL2 levels, higher VEGF levels, and lower IFN-γ levels in the tear fluid had a stronger predictive value for severe ROP (area under curve, 0.85).

CONCLUSION

The levels of CCL2, VEGF, and IFN-γ in tear fluid may serve as useful biomarkers for assessing the severity of ROP.

Genetic Variants of the Beta-Adrenergic Receptor Pathways as Both Risk and Protective Factors for Retinopathy of Prematurity

PURPOSE

There is strong evidence that genetic factors influence retinopathy of prematurity (ROP), a neovascular eye disease. It has been previously suggested that polymorphisms in the genes involved in β-adrenergic receptor (ADRβ) pathways could protect against ROP. Antagonists for the ADRβ are actively tested in clinical trials for ROP treatment, but not without controversy and safety concerns. This study was designed to assess whether genetic variations in components of the ADRβ signaling pathways associate with risk of developing ROP.

DESIGN

An observational case-control targeted genetic analysis.

METHODS

A study was carried out in premature participants with (n = 30) or without (n = 34) ROP and full-term controls (n = 20), who were divided into a discovery cohort and a validation cohort. ROP was defined using International Classification of Retinopathy of Prematurity criteria (ICROP). Targeted sequencing of 20 genes in the ADRβ pathways was performed in the discovery cohort. Polymerase chain reaction (PCR)/restriction enzyme analysis for some of the discovered ROP-associated variants was performed for validation of the results using the validation cohort.

RESULTS

The discovery cohort revealed 543 bi-allelic variants within 20 genes of the ADRβ pathways. Ten single-nucleotide variants (SNVs) in 5 genes including protein kinase A regulatory subunit 1α (PRKAR1A), rap guanine exchange factor 3 (RAPGEF3), adenylyl cyclase 4 (ADCY4), ADCY7, and ADCY9 were associated with ROP (P < .05). The most significant SNV was found in PRKAR1A (P = .001). Multiple variants located in the 3'-untranslated region (3'UTR) of RAPGEF3 were also associated with ROP (P < .05). PCR/restriction enzyme analysis of the 3'UTR of RAPGEF3 methodologically validated these findings.

CONCLUSION

SNVs in PRKAR1A may represent protective factors whereas SNVs in RAPGEF3 may represent risk factors for ROP. PRKAR1α has previously been implicated in retinal vascular development whereas the RAPGEF3 product has a role in the maintenance of vascular barrier function, 2 processes important in ROP. Multicenter validation of these newly discovered risk factors could lead to valuable tools for predicting and preventing the development of severe ROP.