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

Visual impairment burden in retinopathy of prematurity: trends, inequalities, and improvement gaps

Retinopathy of prematurity (ROP) is an important cause of avoidable childhood visual impairment, and the increase in number and survival of premature infants may inflate its burden globally. We aimed to comprehensively assess the trends and inequalities in the burden of ROP-related visual impairment and to identify improvement gaps to facilitate appropriate actions in neonatal care systems. We obtained ROP data from the Global Burden of Disease 2019 study. We employed joinpoint regression analysis to assess the trends of the burden of ROP-related visual impairment, measured by age-standardised prevalence rates, health equity analysis methods to evaluate cross-country burden inequalities, and data envelopment and stochastic frontier analyses to identify improvement gaps based on the development status, i.e., sociodemographic index (SDI). Between 1990 and 2019, the age-standardised prevalence rates of ROP-related visual impairment significantly increased worldwide (average annual percentage change: 0.23 [95% confidence interval, 0.21-0.26] among males and 0.26 [0.25-0.27] among females), primarily in developed regions. Although significant SDI-related cross-country inequalities were identified, these reduced over time (slope index of inequality: -57.74 [-66.22 to -49.25] in 1990 to -29.68 [-38.39 to -20.97] in 2019; health concentration index: -0.11 [-0.13 to -0.09] in 1990 to -0.07 [-0.09 to -0.06] in 2019). Notably, some less-developed countries exhibited superior performance despite limited resources, whereas others with a higher SDI delivered lagging performance.  Conclusion: The global burden of ROP-related visual impairment has steadily increased between 1990 and 2019, with disproportionate burden concentration among less-developed countries, requiring appropriate preventive and intervention measures. What is Known: • Retinopathy of prematurity (ROP) is an important cause of avoidable childhood visual impairment. • The prevalence of ROP is anticipated to increase due to the growing number of extremely premature infants. What is New: • The prevalence of ROP-related visual impairment has increased worldwide, primarily in developed regions, with declining but persisting cross-country inequalities. • The increasing burden of ROP-related visual impairment should be considered as part of global and national health agendas, requiring interventions with proven efficacy.

Validation of the East London Retinopathy of Prematurity algorithm to detect treatment-warranted retinopathy of prematurity: a cohort study

AIM

To validate the East London Retinopathy of Prematurity algorithm (EL-ROP) in a cohort of infants at risk of developing retinopathy of prematurity (ROP).

METHODS

The EL-ROP algorithm was applied retrospectively to routinely collected data from two tertiary neonatal units in England on infants eligible for ROP screening. The EL-ROP recommendation, to screen or not, was compared with the development of treatment-warranted ROP (TW-ROP) for each infant. The main outcome measures were (1) EL-ROP's sensitivity for predicting the future development of TW-ROP and (2) potential to reduce ROP screening examinations.

RESULTS

Data from 568 infants were included in the trial. The median (IQR) birth weight (g) was 875 (704 - 1103) and gestational age (weeks) was 27.0 (25.4 - 29.0). Maternal ethnicity was black (33%) and non-black (67%). 58(10%) developed TW-ROP and in every case this was predicted by the EL-ROP algorithm. It's sensitivity was 100% (95% CI 94-100%) specificity: 44% (95% CI 39-48%) positive predictive value: 17% (95%CI 16-18%), negative predictive value: 100%.

CONCLUSIONS

EL-ROP has been validated in a cohort of infants from two tertiary neonatal units in England. Further validation is required before its clinical usefulness can be assessed.

Racial Differences in Retinopathy of Prematurity

PURPOSE

To delineate racial differences in the incidence and time course of ROP in a large cohort of premature infants.

METHODS

The secondary analysis of data from the two Postnatal Growth and ROP Studies (G-ROP-1 and G-ROP-2) that were collected in 41 hospitals in North America from 2006 to 2017. According to self-reported maternal race, premature infants were classified into 3 groups: White (N = 5580), Black (N = 3252), and Asian (N = 353). Incidence, severity, and time course of ROP; plus disease; and postnatal weight gain rate were compared among racial groups.

RESULTS

Black infants had significantly smaller BW (mean 1035 vs. 1131 vs.1144 grams, P < .001) and lower GA (28.2 vs. 28.6, vs. 29.1 weeks, P < .001) than White and Asian infants. However, Black infants had lower incidences of severe ROP (11.1% vs. 12.4% vs. 11.9%), ROP (42.1% vs. 43.2% vs. 30.6%), and plus disease (3.6% vs. 6.3%, vs. 5.9%) than White and Asian infants (BW and GA adjusted risk ratio for Black vs. White 0.69 for severe ROP, 0.83 for ROP, 0.44 for plus disease, all P < .0001). Mean daily-weight-gain on days of life 11-20 and 21-30 were similar across groups (P > .05), but lower in Black and Asian infants on days 31-40 (P < .001). There were no differences in the timing of severe ROP and ROP across racial groups.

CONCLUSIONS

Despite relatively lower GA, BW, and daily-weight-gain, Black preterm infants had lower incidences of ROP and plus disease than White preterm infants. The mechanisms for these differences require further investigation.

Association of Surgical Necrotizing Enterocolitis and Its Timing with Retinopathy of Prematurity

OBJECTIVE

The study aimed to determine the association of surgical necrotizing enterocolitis (NEC) and its timing, with the development and timing of retinopathy of prematurity (ROP).

STUDY DESIGN

This was a secondary data analysis of 7,483 preterm infants from the Postnatal Growth and Retinopathy of Prematurity Study. Associations between infants with surgical NEC, early-onset surgical NEC (8-28 days), and late-onset surgical NEC (over 28 days) with ROP were evaluated by using multivariable logistic regression models, controlling for birth weight, gestational age, small for gestational age status, chronic lung disease, intraventricular hemorrhage, hydrocephalus, patent ductus arteriosus, and periventricular leukomalacia.

RESULTS

Three hundred fifty-six (4.8%) infants had surgical NEC, with 56% having early surgical NEC. Infants with surgical NEC had a higher risk of any ROP and severe ROP (adjusted odds ratio [OR]: 2.7; 95% CI: 1.9-3.7) and 2.5 (95% CI: 1.9-3.3), respectively; p < 0.001) compared with infants without surgical NEC. Infants with early surgical NEC were at the highest risk of developing ROP and severe ROP (adjusted OR: 3.1 [95% CI: 2.1-4.8], and 3.3 [95% CI: 2.3-4.7] respectively, p < 0.001). Infants with late surgical NEC were also at increased risk of developing ROP and severe ROP (adjusted OR: 2.1 [95% CI: 1.3-3.4], and 1.9 [95% CI: 1.3-2.8] respectively, p < 0.001) compared with infants without surgical NEC.

CONCLUSION

Infants with surgical NEC, especially early surgical NEC, are at higher risk of ROP and severe ROP.

KEY POINTS

· Infants with surgical NEC are at higher risk of ROP and severe ROP than those without surgical NEC.. · Increased ROP risk is seen in infants with both early- or later onset surgical NEC.. · Early-onset surgical NEC is associated with a higher ROP risk compared with later onset surgical NEC..

ASSESSMENT OF NEONATAL CARE STANDARD BY THE PREDICTIVE MODEL FOR RETINOPATHY OF PREMATURITY BASED ON WEIGHT GAIN

Care of extremely premature infants is in constant need for evaluation and progress. WINROP, a predictive model based on weight gain, has been developed to reduce the number of stressful examinations for retinopathy for prematurity. Validation studies of WINROP emphasize the difference of applicability in neonatal units of various practice. The aim of the study was to assess the standard of neonatal care by WINROP. Data on extremely premature infants were collected from medical records and entered in WINROP. High- and low-risk WINROP distribution and retinopathy of prematurity outcomes were analyzed. Fifty-four infants, gestational age ≤28 weeks, were included in the study after exclusion of weight related comorbidities. High risk was noted in 74% (n=40) of infants with 24% (n=13) developing retinopathy of prematurity requiring treatment. In low alarm group, there were 3 cases with severe disease. In conclusion, WINROP is not just a provider of predictive information on the severity of retinopathy of prematurity. High-risk alarm indicates the need of adjustment of nutritional strategies. Infants without pathological growth morbidities who develop severe retinopathy of prematurity in low-risk group point to other risk factors for retinopathy of prematurity to be evaluated and changed in future practice.

Development and validation of machine learning-based clinical decision support tool for identifying malnutrition in NICU patients

Hospitalized newborns have an increased risk of malnutrition and, especially preterm infants, often experience malnutrition-related extrauterine growth restriction (EUGR). The aim of this study was to predict the discharge weight and the presence of weight gain at discharge with machine learning (ML) algorithms. The demographic and clinical parameters were used to develop the models using fivefold cross-validation in the software-R with a neonatal nutritional screening tool (NNST). A total of 512 NICU patients were prospectively included in the study. Length of hospital stay (LOS), parenteral nutrition treatment (PN), postnatal age (PNA), surgery, and sodium were the most important variables in predicting the presence of weight gain at discharge with a random forest classification (AUROC:0.847). The AUROC of NNST-Plus, which was improved by adding LOS, PN, PNA, surgery, and sodium to NNST, increased by 16.5%. In addition, weight at admission, LOS, gestation-adjusted age at admission (> 40 weeks), sex, gestational age, birth weight, PNA, SGA, complications of labor and delivery, multiple birth, serum creatinine, and PN treatment were the most important variables in predicting discharge weight with an elastic net regression (R² = 0.748). This is the first study on the early prediction of EUGR with promising clinical performance based on ML algorithms. It is estimated that the incidence of EUGR can be improved with the implementation of this ML-based web tool ( http://www.softmed.hacettepe.edu.tr/NEO-DEER/ ) in clinical practice.

Daily Oxygen Supplementation and Risk of Retinopathy of Prematurity

PURPOSE

Excessive oxygen supplementation increases risk of retinopathy of prematurity (ROP). While numerous oxygen parameters could be considered when predicting ROP (saturation targets, actual saturation, fraction of inspired oxygen, etc.), complicated measures are impractical as screening criteria. We sought to develop a simple, clinically useful measure of daily oxygen supplementation during ages 0-28 days to improve prediction of ROP.

METHODS

Secondary analysis of two Postnatal Growth and ROP (G-ROP) Study cohorts (G-ROP-1 and G-ROP-2) at 45 hospitals. Infants with a known ROP outcome and complete oxygen data were included. Associations between severe ROP and days on supplemental oxygen (FiO2 > 21%), during ages 0-28 days (DSO28) were assessed, controlling for birth weight (BW) and gestational age (GA). New screening criteria incorporating DSO were developed and compared to current guidelines.

RESULTS

Among 8,949 studied infants, 459 (5.1%) developed type 1 ROP. DSO28 was associated with severe ROP (adjusted-OR 1.05 per day supplemental oxygen, 95%CI 1.03-1.07, p < .0001). The following criteria had 100% sensitivity for type 1 ROP and higher specificity than current guidelines: new BW/GA criteria with DSO (BW<901 g, GA<26 weeks, or DSO >3), 23.4% fewer infants examined; modified G-ROP criteria including DSO, 29.0% fewer infants; original G-ROP criteria, 31.8% fewer infants.

CONCLUSION

In high-level neonatal-care settings, incorporating DSO (a simple measure of oxygen supplementation) into screening criteria improves sensitivity and specificity for type 1 ROP over current BW-GA criteria, but does not perform as well as the validated G-ROP criteria.

Changes in institutional oxygen saturation targets are associated with an increased rate of severe retinopathy of prematurity

PURPOSE

To evaluate the effect of changes in institutional peripheral oxygen saturation (SpO₂) targets, made in response to recent randomized trials, on risk of developing severe retinopathy of prematurity (ROP).

METHODS

This study was a secondary analysis of data from 21 North American hospitals during the periods 2006-2012 and 2015-2017. Hospitals were categorized based on whether or not SpO₂ targets were increased between the two study periods. Severe ROP (type 1, type 2, or zone III stage 3+) rates were compared within and between groups. Generalized mixed effect models with random intercepts were used to account for within-center clustering and to calculate odds ratios (aOR) adjusted by birth weight (BW) and gestational age (GA), using patient-level data.

RESULTS

A total of 8,142 infants underwent ROP examinations at 21 hospitals during the two study periods: 5,716 in 2006-2012 (mean BW, 1109 ± 369 g; GA, 28.0 ± 2.6; 11.6% severe ROP); 2,426 in 2015-2017 (mean BW, 1086 ± 347 g; GA, 28.0 ± 2.8; 12.8% severe ROP). Fourteen hospitals increased SpO₂ targets, and 7 hospitals did not. Hospitals that increased targets had a 3% increase in severe ROP (from 12% to 15%; aOR = 1.25; 95% CI, 1.01-1.55; P = 0.044); hospitals without SpO₂ changes had a 2% decrease (from 11% to 9%; aOR = 0.72; 95% CI, 0.52-1.00; P = 0.049). The difference in change of severe ROP between groups of hospitals was significant (P = 0.005).

CONCLUSIONS

Increases in institutional SpO₂ targets in response to recent randomized trials were associated with increased severe ROP. Hospitals considering increasing their SpO₂ targets should anticipate increases in rates of severe ROP and manage screening and treatment resources accordingly.

Retrospective validation of the postnatal Growth and Retinopathy of Prematurity (G-ROP) criteria in a Swiss cohort

BACKGROUND

Currently used screening criteria for retinopathy of prematurity (ROP) show high sensitivity for predicting treatment-requiring ROP but low specificity; over 90% of examined infants do not develop ROP that requires treatment (type 1 ROP). A novel weight gain-based prediction model was developed by the G-ROP study group to increase the specificity of the screening criteria and keep the number of ophthalmic examinations as low as possible. This retrospective cohort study aimed to externally validate the G-ROP screening criteria in a Swiss cohort.

METHODS

Data from 645 preterm infants in ROP screening at Inselspital Bern between January 2015 and December 2019 were retrospectively retrieved from the screening log and analysed. The G-ROP screening criteria, consisting of 6 trigger parameters, were applied in infants with complete data. To determine the performance of the G-ROP prediction model for treatment-requiring ROP, sensitivity and specificity were calculated.

RESULTS

Complete data were available for 322 infants who were included in the analysis. None of the excluded infants had developed type 1 ROP. By applying the 6 criteria in the G-ROP model, 214 infants were flagged to undergo screening: among these, 14 developed type 1 ROP, 9 developed type 2 ROP, and 43 developed milder stages of ROP. The sensitivity for predicting treatment-requiring ROP was 100% (CI, 0.79-1.00), and the specificity was 41% (CI, 0.35 -0.47). Implementing the novel G-ROP screening criteria would reduce the number of infants entering ROP screening by approximately one third.

CONCLUSIONS

The overall prevalence of treatment-requiring ROP was low (2.15%). Previously published performance parameters for the G-ROP algorithm were reproducible in this Swiss cohort. Importantly, all treatment-requiring infants were correctly identified. By using these novel criteria, the burden of screening examinations could be significantly reduced.

Incidence, timing and risk factors of type 1 retinopathy of prematurity in a North American cohort

BACKGROUND/AIMS

Early detection and timely treatment of type 1 retinopathy of prematurity (ROP) can reduce the risk of blindness. To evaluate the incidence, timing and risk factors of type 1 ROP in a large, broad-risk cohort of premature infants.

METHODS

Secondary analysis of data from the two Postnatal Growth and Retinopathy of Prematurity studies. Main outcomes are the incidence and timing of type 1 ROP.

RESULTS

Among 11 463 infants (mean birth weight (BW), 1095 g; mean gestational age (GA), 28 weeks), 677 (5.9%, 95% CI 5.5% to 6.3%) developed type 1 ROP. Rate of type 1 ROP decreased with larger GA (28.8% for GA ≤23 weeks, 0.2% for GA of 31-32 weeks) and no infants with GA >32 weeks developed type 1 ROP. Type 1 ROP was first diagnosed at a median postmenstrual age (PMA) of 36 weeks (range 30-46 weeks) or postnatal age (PNA) of 11 weeks (range 5-21 weeks). The mean PMA at diagnosis of type 1 ROP increased with GA (35 weeks for GA of 22-24 weeks, 41 weeks for GA of 29-30 weeks), but the mean PNA at diagnosis of type 1 ROP was similar (11-13 weeks) across GA of 22-29 weeks. GA and BW dominate the association (area under the receiver operating characteristic curve=0.87, 95% CI 0.86 to 0.88).

CONCLUSIONS

Type 1 ROP developed in about 6% of premature infants over wide time windows in terms of both PMA and PNA. BW and GA are the dominant risk factors for type 1 ROP, while other prenatal factors add minimal predictive power for type 1 ROP.

Validation of the Postnatal Growth and Retinopathy of Prematurity Screening Criteria

Importance

The first Postnatal Growth and Retinopathy of Prematurity Study (G-ROP-1) developed new screening criteria with 100% sensitivity for type 1 retinopathy of prematurity (ROP) and 30% reduction of infants requiring examinations in a retrospective development cohort of 7483 infants from 29 North American hospitals in 2006-2012. Infants meeting 1 or more of the following criteria undergo examinations: gestational age less than 28 weeks or birth weight less than 1051 g; weight gain less than 120 g during age 10 to 19 days, weight gain less than 180 g during age 20 to 29 days, or weight gain less than 170 g during age 30 to 39 days; or hydrocephalus.

Objective

To evaluate the generalizability of the G-ROP screening criteria in a new cohort of at-risk infants.

Design, Setting, and Participants

This prospective validation cohort study (G-ROP-2) was conducted at 41 hospitals in the United States and Canada (25 G-ROP-1 hospitals and 16 new hospitals) from September 8, 2015, to June 13, 2017, among 3981 premature infants at risk for ROP and with known ROP outcomes.

Main Outcomes and Measures

Sensitivity for Early Treatment for Retinopathy of Prematurity Study type 1 ROP and potential reduction in infants receiving examinations.

Results

Among the 3981 infants in the study (1878 girls and 2103 boys; median gestational age, 28 weeks [range, 22-35 weeks]; median birth weight, 1072 g [range, 350-4080 g]; 1966 white; 942 black; 321 Latino; 120 Asian; 22 Native Hawaian or Pacific Islander; and 25 American Indian or Alaskan Native), the G-ROP criteria correctly predicted 219 of 219 cases of type 1 ROP (sensitivity, 100%; 95% CI, 98.3%-100%), while reducing the number of infants undergoing examinations by 35.6% (n = 1418). In a combined G-ROP-1 and G-ROP-2 cohort of 11 463 infants, the G-ROP criteria predicted 677 of 677 cases of type 1 ROP (sensitivity, 100%; 95% CI, 99.4%-100%), reducing the number of infants receiving examinations by 32.5% (n = 3730), while current criteria (birth weight <1501 g or gestational age ≤30 weeks 0 days) predicted 674 of 677 type 1 cases (sensitivity, 99.6%; 95% CI, 98.7%-99.8%).

Conclusions and Relevance

This study found that the G-ROP screening criteria were generalizable on validation and, if used clinically in the United States and Canada, could reduce the number of infants receiving examinations. The large G-ROP cohorts provide evidence-based screening criteria that have higher sensitivity and higher specificity (fewer infants receiving examinations) for type 1 ROP than currently recommended guidelines.

Clinical features of premature twin babies with intersibling asymmetry of retinopathy of prematurity severity

OBJECTIVE

To report the clinical features of premature twin babies showing intersibling asymmetry in their severity of retinopathy of prematurity (ROP) and analyze risk factors associated with development of severe ROP between twin siblings with discordant ROP severity.

METHODS

A retrospective study of records of 105 premature twin pairs was conducted. The criteria for discordant ROP with an intersibling difference in ROP severity were as follows: (i) two or more stages of difference in ROP between siblings, (ii) one sibling having treatment-requiring ROP and the other having no ROP or ROP that regressed spontaneously, or (iii) one sibling having aggressive posterior ROP and the other having staged or no ROP. Twin siblings were classified into two groups according to the severity of ROP (no or less ROP and more severe ROP). We examined ocular features in twins having intersibling asymmetry of ROP and analyzed perinatal risk factors for ROP.

RESULTS

Of 105 twin pairs, 32 pairs (30.5%) showed intersibling asymmetry of ROP severity, and 15 pairs (14.3%) showed ROP asymmetry in terms of need for ROP treatment. The development of more severe ROP was associated with longer duration of oxygen supplementation and greater frequency of total blood and packed red blood cell transfusion (p = 0.020, p = 0.045, and p = 0.036, respectively). Longer duration of oxygen supplementation remained a statistically independent risk factor of severe ROP using multivariate logistic regression analysis.

CONCLUSIONS

Ophthalmologists caring for premature infants should be aware of the variable courses and progressions of ROP between twin babies. Longer duration of oxygen supplementation and greater frequency of blood transfusions were associated with higher ROP severity in twins.

Poor postnatal weight growth is a late finding after sepsis in very preterm infants

OBJECTIVE

To characterise the association between sepsis and postnatal weight growth when accounting for the degree of growth restriction present at birth.

DESIGN

Retrospective matched cohort study using data from the Postnatal Growth and Retinopathy of Prematurity study. Participants were born with birth weights of <1500 g or gestational ages of <32 weeks between 2006 and 2011 at 29 neonatal centres in the USA and Canada. Sepsis was defined as a culture-confirmed bacterial or fungal infection of the blood or cerebrospinal fluid before 36 weeks' postmenstrual age (PMA). Growth was assessed as the change in weight z-score between birth and 36 weeks' PMA.

RESULTS

Of 4785 eligible infants, 813 (17%) developed sepsis and 693 (85%) were matched 1:1 to controls. Sepsis was associated with a greater decline in weight z-score (mean difference -0.09, 95% CI -0.14 to -0.03). Postnatal weight growth failure (decline in weight z- score>1) was present in 237 (34%) infants with sepsis and 179 (26%) controls (adjusted OR 1.49, 95% CI 1.12 to 1.97). Longitudinal growth trajectories showed similar initial changes in weight z-scores between infants with and without sepsis. By 3 weeks after sepsis onset, there was a greater decline in weight z-scores relative to birth values in those with sepsis than without sepsis (delta z-score -0.89 vs -0.77; mean difference -0.12, 95% CI -0.18 to -0.05). This significant difference persisted until 36 weeks or discharge.

CONCLUSION

Infants with sepsis had similar early weight growth trajectories as infants without sepsis but developed significant deficits in weight that were not apparent until several weeks after the onset of sepsis.

Digital Values for Alpha Acuities

PURPOSE

The lack of consistent data formatting for visual acuity in electronic medical records has led to inefficient data extraction and analysis.

METHODS

Prior acuity efforts were reviewed and analyzed relative to alpha-designated visual acuity. Prominent electronic medical record formatting was reviewed.

RESULTS

A table was generated facilitating the assignment of digital values to alpha acuities for metric and United States designation including centered steady maintained for infants and counting fingers, hand motions, light perception, and no light perception for patients with low vision.

DISCUSSION

Consistent and usable visual acuity data should lead to better research and eventually improve physician burn-out. [J Pediatr Ophthalmol Strabismus. 2021;58(2):132-135.].

Using ROPScore and CHOP ROP for early prediction of retinopathy of prematurity in a Chinese population

PURPOSE

Retinopathy of prematurity (ROP) is a disease that causes vision loss, vision impairment, and blindness, most frequently manifesting among preterm infants. ROPScore and CHOP ROP (Children's Hospital of Philadelphia ROP) are similar scoring models to predict ROP using risk factors such as postnatal weight gain, birth weight (BW), and gestation age (GA). The purpose of this study was to compare the accuracy and difference between using ROPScore and CHOP ROP for the early prediction of ROP.

METHODS

A retrospective study was conducted from January 2009 to December 2019 in China. Patients eligible for enrollment included infants admitted to NICU at ≤32 weeks GA or those with ≤1500 g BW. The sensitivity and specificity of ROPScore and CHOP ROP were analyzed, as well as its suitability as an independent predictor of ROP.

RESULTS

Severe ROP was found in 5.0% of preterm infants. The sensitivity and specificity of the ROPScore test at any stage of ROP was 55.8 and 77.8%, respectively. For severe ROP, the sensitivity and specificity was 50 and 87.0%, respectively. The area under the receiver operating characteristic curve for the ROPScore for predicting severe ROP was 0.76. This value was significantly higher than the values for birth weight (0.60), gestational age (0.73), and duration of ventilation (0.63), when each was category measured separately. For the CHOP ROP, it correctly predicted infants who developed type 1 ROP (sensitivity, 100%, specificity, 21.4%).

CONCLUSIONS

The CHOP ROP model predicted infants who developed type 1 ROP at a sensitivity of 100% whereas ROPScore had a sensitivity of 55.8%. Therefore, the CHOP ROP model is more suitable for Chinese populations than the ROPScore test.

CLINICAL REGISTRATION NUMBER AND STROBE GUIDELINES

This article was a retrospective cohort study and reported the results of the ROPScore and CHOP ROP algorithms. No results pertaining to interventions on human participants were reported. Thus, registration was not required and this study followed STROBE guidelines.

Ocular complications following intravitreal bevacizumab injection for retinopathy of prematurity and assessment of risk factors

Purpose

Laser ablation of the avascular peripheral retina has been the standard method of ROP treatment. Intravitreal anti-VEGF is useful in the management of ROP patients, especially for aggressive posterior ROP. However, ocular and systemic complication after intravitreal bevacizumab was the main concern. This study aimed to investigate the treatment-related ocular and systemic complications of intravitreal bevacizumab (IVB) in patients with retinopathy of prematurity (ROP).

Method

This retrospective study included neonates receiving intravitreal injections of bevacizumab (IVB) (0.625 mg) to treat ROP. Medical records of the patients were evaluated about the ocular complications after receiving IVB from 2012 to 2019. Treatment-related complications (vitreous hemorrhage, glaucoma, cataract, hyphema, corneal abrasion/opacity, and endophthalmitis), and disease-progression signs including retinal fold or stage 4 or 5 detachment were documented. Any reports of systemic events after injections were also recorded.

Result

Mean gestational age and birth weight of 441 patients receiving IVB for type-1 ROP were 28 ± 2 (22–34 weeks) and 1121 ± 312 (550–2700 g), respectively. The median follow-up after treatment in all patients and patients with complications was 289.43 ± 257 days (5–1899 days) and 385.89 ± 311.59 (196–1192) days, respectively. Out of 865 eyes, 20 eyes (2.31%, 95% Clopper-Pearson Confidence Interval: 1.14–3.54%) have been affected by ocular complications. The rates of different complications included progression of retinopathy in 17 eyes (1.96%), cataracts in 2 eyes (0.23%), and vitreous hemorrhage in one eye (0.11%). No cases of endophthalmitis, thromboembolic events, or death occurred in this study. We evaluated the prevalence ratio (PR) on the multiple risk factors to determine the prediction of the complications. The existence of neovascularization of iris has the highest susceptibility to predict the complication (PR = 5.091, P-value 0.014) following by the presence of retinopathy in zone 1 of the infant’s retina (PR = 4.386, P-value = 0.010).

Conclusion

The incidence rate of complications related to Intravitreal bevacizumab injection was low, which was compatible with previous studies. Bevacizumab injection seems well tolerated in most cases of ROP. Iris neovascularization and the presence of retinopathy in zone 1 were associated with a higher occurrence of complications than the absence of these risk factors.

Retinal Detachment after Treatment of Retinopathy of Prematurity with Laser versus Intravitreal Anti-Vascular Endothelial Growth Factor

PURPOSE

To compare rates of short-term retinal detachment (RD) of infants treated for type 1 retinopathy of prematurity (ROP) with intravitreal anti-vascular endothelial growth factor (VEGF) therapy with infants treated with laser therapy. The choice between these 2 treatments remains controversial. Comparative data are limited and describe re-treatment rates rather than retinal structural outcomes predictive of long-term vision. Anti-vascular endothelial growth factor acts faster than laser therapy, which may be beneficial for more aggressive ROP.

DESIGN

Nonrandomized, comparative cohort study.

PARTICIPANTS

The study included 1167 eyes of 640 infants treated for type 1 ROP. Among these, 164 eyes received anti-VEGF therapy and 1003 eyes received laser therapy.

METHODS

Pretreatment and posttreatment examinations and treatments were completed by ophthalmologists with expertise in ROP. The study was a secondary analysis of data from the retrospective Postnatal Growth and Retinopathy of Prematurity Study (G-ROP) 1 study (2006-2012) and the prospective G-ROP 2 study (2015-2017).

MAIN OUTCOME MEASURES

Rate of RD (ROP stages 4A, 4B, or 5) within 8 weeks of initial treatment, an end point predictive of poor long-term vision. The results were stratified by postmenstrual age (PMA) at treatment as occurring before versus at or after 36 weeks and 0 days, because earlier disease may be considered more aggressive.

RESULTS

Among 458 eyes treated before PMA 36 weeks and 0 days, the short-term RD rate was higher after laser therapy (29/368 eyes [7.9%]) than after anti-VEGF therapy (0/90 eyes [0%]; P < 0.001). Of 709 eyes treated at or after PMA 36 weeks and 0 days, short-term RD risk did not differ between groups (laser [20/635 eyes], 3.1%; anti-VEGF [1/74 eyes], 1.4%; P = 0.27).

CONCLUSIONS

Anti-vascular endothelial growth factor therapy results in better short-term structural outcomes than laser therapy when type 1 ROP is treated before 36 weeks' PMA. After this age, both treatments have very low rates of short-term RD. The faster action of anti-VEGF agents likely is responsible for these findings.

Prenatal intrauterine growth restriction and risk of retinopathy of prematurity

Low birthweight and decreased postnatal weight gain are known predictors of worse retinopathy of prematurity (ROP) but the role of prenatal growth patterns in ROP remains inconclusive. To distinguish small for gestational age (SGA) from intrauterine growth restriction (IUGR) as independent predictors of ROP, we performed a retrospective cohort study of patients who received ROP screening examinations at a level IV neonatal intensive care unit over a 7-year period. Data on IUGR and SGA status, worst stage of and need for treatment for ROP, and postnatal growth was obtained. 343 infants were included for analysis (mean gestational age = 28.6 weeks and birth weight = 1138.2 g). IUGR infants were more likely to have a worse stage of ROP and treatment-requiring ROP (both p < 0.0001) compared to non-IUGR infants. IUGR infants were more likely to be older at worst stage of ROP (p < 0.0001) and to develop postnatal growth failure (p = 0.01) than non-IUGR infants. Independent of postnatal growth failure status, IUGR infants had a 4-5 × increased risk of needing ROP treatment (p < 0.001) compared to non-IUGR infants. SGA versus appropriate for gestational age infants did not demonstrate differences in retinopathy outcomes, age at worst ROP stage, or postnatal growth failure. These findings emphasize the importance of prenatal growth on ROP development.

Symmetry of Disease in Retinopathy of Prematurity in the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study

PURPOSE

To determine the symmetry of retinopathy of prematurity (ROP) between fellow eyes in a broad-risk cohort.

METHODS

A retrospective cohort study, the Postnatal Growth and ROP (G-ROP) Study, of 7483 infants undergoing ROP examinations conducted at 29 hospitals in the United States and Canada from 2006 to 2012. The main outcomes were the symmetry for the highest stage and the most severe type (1, 2, not 1 or 2, no ROP) of ROP and disease course of the fellow eye when only one eye developed type 1.

RESULTS

93% of infants had eyes symmetric for the highest stage and 94% for type. Among 459 infants who developed type 1, 379 (82.6%) did so in both eyes simultaneously and were treated bilaterally; 44 (10%) were treated for type 1 in one eye and type 2 in the fellow eye; and 36 (8%) were treated unilaterally initially, of which 6 fellow eyes developed type 1 and were treated (4 within 2 weeks, all within 4 weeks); 5 developed type 2 and regressed; and 25 developed ROP less than type 1 or 2, which was treated in 13 cases and regressed spontaneously in 12 cases.

CONCLUSIONS

ROP was highly symmetric between eyes with respect to the presence and severity of disease in a large, broad-risk cohort representative of infants undergoing ROP screening. When type 1 develops in one eye and type 2 in the fellow eye, the risk of progression to type 1 in the fellow eye appears very low if it has not occurred within 4 weeks.

Treatment of non-type 1 retinopathy of prematurity in the Postnatal Growth and Retinopathy of Prematurity (G-ROP) study

PURPOSE

To determine the prevalence and characteristics of eyes treated for retinopathy of prematurity (ROP) not meeting currently recommended early treatment (type 1) criteria.

METHODS

This was a secondary analysis of data from the Postnatal Growth and ROP (G-ROP) study, a retrospective cohort study of 7,483 infants undergoing ROP examinations and treatment at 29 North American hospitals between January 2006 and June 2012. Medical records were reviewed to determine the prevalence and characteristics of eyes treated for ROP less severe than type 1 ROP.

RESULTS

Of 1,004 eyes that received ROP treatment, 126 eyes of 91 infants (0.8% of all eyes; 12.5% of treated eyes) underwent treatment for ROP less severe than type 1. Mean age at treatment was 38 weeks' post-menstrual age (range, 32-49 weeks). Reasons for treatment included type 1 ROP in the fellow eye (43%), stage 3 ROP with pre-plus in the treated eye (30%), concerning structural changes in the retina (7%), persistent stage 3 ROP for ≥6 weeks without regression (6%), stage 3 ROP with no plus disease in the treated eye (5%), stage 3, zone III ROP with plus disease (3%), logistical considerations (3%), or stage 2 disease in the treated eye (2%).

CONCLUSIONS

Of all eyes treated for ROP, 1/8 were treated for disease less severe than currently recommended type 1 criteria. Clinician judgment of risk for permanent vision impairment superseded recommended treatment criteria and was usually related to type 1 disease in the fellow eye or pre-plus vascular changes in one or both eyes.

Association of Weight Gain Acceleration With Risk of Retinopathy of Prematurity

Importance

Early slow postnatal weight gain, a surrogate for low insulinlike growth factor 1 (IGF-1) levels, is predictive of retinopathy of prematurity (ROP). While low IGF-1 levels inhibit retinal vessel growth, a later rise theoretically activates vascular endothelial growth factor, causing neovascularization. Rate of rise of IGF-1 level is represented by weight gain acceleration (WGA) and may be used to evaluate risk of ROP.

Objective

To evaluate whether faster WGA during a later postnatal period is associated with a higher, rather than lower, risk of severe ROP.

Design, Setting, and Participants

This secondary analysis of data from the Postnatal Growth and Retinopathy of Prematurity (G-ROP) study included 6835 infants undergoing ROP examinations from 29 hospitals in North America from January 2006 to June 2012. Data were analyzed from September to December 2016.

Main Outcomes and Measures

Early weight gain rate (WGR) during 29 to 33 weeks' postmenstrual age and late WGA during 34 to 38 weeks' postmenstrual age were determined using linear regression of daily weight measurements and changes in daily weight measurements, respectively. The primary outcome was the association of late WGA with severe ROP.

Results

Of the 6835 included infants, the mean (SD) birth weight was 1086 (357) g, and the mean (SD) gestational age was 27.9 (2.5) weeks. Risk of severe ROP increased with increasing late WGA up to about the 80th percentile of WGA. After adjusting for birth weight and gestational age, among infants in the lowest early WGR tertile, there was no association of late WGA with severe ROP, and among infants in the moderate and highest early WGR tertiles, the moderate WGA tertiles had the highest risk of ROP (moderate early WGR tertile: adjusted odds ratio, 1.38; 95% CI, 0.98-1.94; highest early WGR tertile: adjusted odds ratio, 1.63; 95% CI, 1.02-2.60).

Conclusions and Relevance

Although much attention has been paid to the association of slow weight gain with ROP, the association may be more complex than appreciated. These findings suggest that low early WGR is associated with severe ROP regardless of subsequent WGA, but if early WGR is moderate or high, subsequent rapid rises in WGR are associated with increasing risk of severe ROP. If validated in additional cohorts, this finding may affect potential therapies, such as the timing of IGF-1 supplementation.

Incidence and Early Course of Retinopathy of Prematurity: Secondary Analysis of the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study

Importance

The current guidelines for retinopathy of prematurity (ROP) detection programs in the United States include a range of birth weights (BWs) and gestational ages and likely require examinations of many premature infants who are at low risk for developing serious retinopathy.

Objective

To determine the incidence, onset, and early course of ROP in what to our knowledge is the largest cohort to date that is representative of infants who are undergoing ROP screening.

Design, Setting, and Participants

This secondary analysis of data from the Postnatal Growth and Retinopathy of Prematurity (G-ROP) retrospective cohort study was conducted in 29 hospitals in the United States and Canada between January 2006 and December 2011 and included 7483 infants who underwent serial ROP examinations.

Main Outcomes and Measures

Most severe ROP in either eye, classified as no ROP, mild ROP, type 2 ROP, or type 1 ROP (per Early Treatment for ROP Study criteria). Onset at postmenstrual age for zone I disease and stage of ROP, plus disease, and treatment.

Results

This study included 7483 infants with a mean (SD) BW of 1099 (259) g and a mean (SD) gestational age of 28 (3) weeks who underwent ROP examinations. Of these, 3224 infants (43.1%) developed ROP, 459 (6.1%) developed type 1 and 472 (6.3%) type 2 ROP, 514 (6.9%) underwent treatment in 1 or both eyes, and 147 (2%) had zone I disease. Additionally, 98.1% of type 1 or 2 ROP cases occurred in infants with a BW of less than 1251 g. Only about half of the eyes (49.4%) were vascularized into zone III by 37 weeks postmenstrual age.

Conclusions and Relevance

These findings add to our knowledge of ROP screening as they include all eligible infants, not just high-risk infants as in previous studies. More than 40% of at-risk premature infants develop some stage of ROP, and most retinopathy regresses without treatment. However, approximately 12.5% develop severe ROP, which occurs almost exclusively among infants with a BW of less than 1251 g.

Development of Modified Screening Criteria for Retinopathy of Prematurity: Primary Results From the Postnatal Growth and Retinopathy of Prematurity Study

Importance

Current retinopathy of prematurity (ROP) guidelines, which are based on studies of high-risk infants and expert opinion, have low specificity for disease requiring treatment. Postnatal weight gain-based models improve specificity but have been limited by complexity and small development cohorts, which results in model overfitting and resultant decreased sensitivity in validation studies.

Objective

To develop a birth weight (BW), gestational age (GA), and weight gain (WG) prediction model using data from a broad-risk cohort of premature infants.

Design, Setting, and Participants

The Postnatal Growth and ROP Study was a retrospective multicenter cohort study conducted in 29 hospitals in the United States and Canada from 2006 to 2012 that included 7483 premature infants at risk for ROP with a known ROP outcome. A hybrid modeling approach was used that combined BW/GA criteria, weight comparison with expected growth from infants without ROP, multiple growth-interval assessments, consideration of nonphysiological WG, and user-friendly screening criteria. Numerous BW/GA levels, postnatal age periods, time intervals, and WG percentile thresholds were evaluated to identify the most robust parameters.

Main Outcome and Measures

Sensitivity for Early Treatment of ROP Study type 1 ROP and potential reduction in infants who require examinations.

Results

Of 7483 infants, the median (SD) BW was 1099 (359) g, the median GA was 28 weeks (range, 22-35), 3575 (47.8%) were female, 3615 (48.4%) were white, 2310 (30.9%) were black, 233 (3.1%) were Asian, 93 (1.2%) were Pacific Islander, and 40 (0.5%) were American Indian/Alaskan Native. Infants who met any of 6 criteria would undergo examinations: (1) a GA of younger than 28 weeks; (2) a BW of less than 1051 g; a WG of less than 120 g, 180 g, or 170 g during ages 10 to 19, 20 to 29, or 30 to 39 days, respectively; or hydrocephalus. These criteria predicted 459 of 459 (100%) type 1 (sensitivity, 100%; 95% CI, 99.2%-100%), 524 of 524 (100%) treated, and 466 of 472 (98.7%) type 2 cases while reducing the number of infants who required examinations by 2269 (30.3%).

Conclusions and Relevance

This cohort study, broadly representative of infants who are undergoing ROP examinations, provides evidence-based screening criteria. With validation, the Postnatal Growth and ROP Study criteria could be incorporated into ROP screening guidelines to reduce the number of infants who require examinations in North America.

Postnatal weight gain and retinopathy of prematurity

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

Comparison between weight gain and Fenton preterm growth z scores in assessing the risk of retinopathy of prematurity

Several studies have shown that postnatal weight gain is a significant predictor for retinopathy of prematurity (ROP) in preterm infants. Using a cohort of 1,301 infants from a single-center ROP registry, we investigated whether incorporation of changes in Fenton preterm growth curve z scores (ie, deviation from the population average) provides improved predictive ability for developing ROP compared to weight gain alone. Three logistic regressions were fit to severe ROP: (1) baseline model that included gestational age and birth weight, (2) the baseline model adding weight gain, and (3) the baseline model adding change in z score. The area under the receiver operating characteristic curve (C index) was used to compare models. Both weight gain and change in z scores were significant predictors after adjusting for birth weight (P = 0.01) and gestational age (P < 0.01). The C indices were not significantly improved by including weight gain or z score to the baseline model; however, for a subset of subjects, change in weight z score may be a more useful measure compared to simple weight gain with regards to assessing risk for severe ROP.

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

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

The progress of prophylactic treatment in retinopathy of prematurity

Retinopathy of prematurity (ROP) is a retinal vascular disorder frequently found in premature infants. Different therapeutic strategies have been developed to treat ROP. However, there are still many children with ROP suffering by severe limitations in vision or even blindness. Recently, ROP has been suggested to be caused by abnormal development of the retinal vasculature, but not simply resulted by retinal neovascularization which takes about 4 to 6wk after birth in premature infants. Thus, instead of focusing on how to reduce retinal neovascularization, understanding the pathological changes and mechanisms that occur prior to retinal neovascularization is meaningful, which may lead to identify novel target(s) for the development of novel strategy to promote the healthy growth of retinal blood vessels rather than passively waiting for the appearance of retinal neovascularization and removing it by force. In this review, we discussed recent studies about, 1) the pathogenesis prior to retinal neovascularization in oxygen-induced retinopathy (OIR; a ROP in animal model) and in premature infants with ROP; 2) the preclinical and clinical research on preventive treatment of early OIR and ROP. We will not only highlight the importance of the mechanisms and signalling pathways in regulating early stage of ROP but also will provide guidance for actively exploring novel mechanisms and discovering novel treatments for early phase OIR and ROP prior to retinal neovascularization in the future.

Ocular complications following treatment in the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study

PURPOSE

To determine the prevalence of treatment-related ocular complications and disease progression following treatment for retinopathy of prematurity (ROP).

METHODS

This was a retrospective cohort study of eyes treated for ROP at 29 North American neonatal intensive care units in the Postnatal Growth and ROP (G-ROP) Study. Data from the time of treatment through 15 months were abstracted from medical records by certified data collectors. Treatment-related complication (cataract, hyphema, glaucoma, corneal abrasion/opacity), and disease-progression (retinal fold, dragging, or stage 4 or 5 detachment) were calculated by treatment modality. Vitreous hemorrhage was classified separately, because it can relate to treatment or disease progression.

RESULTS

Of 7,483 infants included in the study, 1,004 eyes (512 infants) underwent ROP treatment: 970 eyes received laser as initial therapy; 34 eyes received intravitreal bevacizumab (IVB). Median follow-up after treatment was 18 weeks. Overall, one or more complications occurred in 2.6% (95% CI, 1.8%-3.8%) laser treated eyes and no (0%; 95% CI, 0.0%-10.1%) IVB eyes. Disease-progression occurred in 9.2% (95% CI, 7.6%-11.2%) laser treated eyes, no (0%; 95% CI, 0.0-12.9%) IVB-only eyes. Vitreous hemorrhage occurred in 5.4% (95% CI: 4.1% - 7.0%) laser treated eyes, no IVB-only eyes.

CONCLUSIONS

Rates of complications are very low following ROP treatment with either laser or IVB. Of laser-treated eyes, 9% experienced disease progression despite treatment.

Validation of the Colorado Retinopathy of Prematurity Screening Model

Importance

The Colorado Retinopathy of Prematurity (CO-ROP) model uses birth weight, gestational age, and weight gain at the first month of life (WG-28) to predict risk of severe retinopathy of prematurity (ROP). In previous validation studies, the model performed very well, predicting virtually all cases of severe ROP and potentially reducing the number of infants who need ROP examinations, warranting validation in a larger, more diverse population.

Objective

To validate the performance of the CO-ROP model in a large multicenter cohort.

Design, Setting, Participants

This study is a secondary analysis of data from the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study, a retrospective multicenter cohort study conducted in 29 hospitals in the United States and Canada between January 2006 and June 2012 of 6351 premature infants who received ROP examinations.

Main Outcomes and Measures

Sensitivity and specificity for severe (early treatment of ROP [ETROP] type 1 or 2) ROP, and reduction in infants receiving examinations. The CO-ROP model was applied to the infants in the G-ROP data set with all 3 data points (infants would have received examinations if they met all 3 criteria: birth weight, <1501 g; gestational age, <30 weeks; and WG-28, <650 g). Infants missing WG-28 information were included in a secondary analysis in which WG-28 was considered fewer than 650 g.

Results

Of 7438 infants in the G-ROP study, 3575 (48.1%) were girls, and maternal race/ethnicity was 2310 (31.1%) African American, 3615 (48.6%) white, 233 (3.1%) Asian, 40 (0.52%) American Indian/Alaskan Native, and 93 (1.3%) Pacific Islander. In the study cohort, 747 infants (11.8%) had type 1 or 2 ROP, 2068 (32.6%) had lower-grade ROP, and 3536 (55.6%) had no ROP. The CO-ROP model had a sensitivity of 96.9% (95% CI, 95.4%-97.9%) and a specificity of 40.9% (95% CI, 39.3%-42.5%). It missed 23 (3.1%) infants who developed severe ROP. The CO-ROP model would have reduced the number of infants who received examinations by 26.1% (95% CI, 25.0%-27.2%).

Conclusions and Relevance

The CO-ROP model demonstrated high but not 100% sensitivity for severe ROP and missed infants who might require treatment in this large validation cohort. The model requires all 3 criteria to be met to signal a need for examinations, but some infants with a birth weight or gestational age above the thresholds developed severe ROP. Most of these infants who were not detected by the CO-ROP model had obvious deviation in expected weight trajectories or nonphysiologic weight gain. These findings suggest that the CO-ROP model needs to be revised before considering implementation into clinical practice.

Pathophysiology, screening and treatment of ROP: A multi-disciplinary perspective

The population of infants at risk for retinopathy of prematurity (ROP) varies by world region; in countries with well developed neonatal intensive care services, the highest risk infants are those born at less than 28 weeks gestational age (GA) and less than 1 kg at birth, while, in regions where many aspects of neonatal intensive and ophthalmological care are not routinely available, more mature infants up to 2000 g at birth and 37 weeks GA are also at risk for severe ROP. Treatment options for both groups of patients include standard retinal laser photocoagulation or, more recently, intravitreal anti-VEGF drugs. In addition to detection and treatment of ROP, this review highlights new opportunities created by telemedicine, where screening and diagnosis of ROP in remote locations can be undertaken by non-ophthalmologists using digital fundus cameras. The ophthalmological care of the ROP infant is undertaken in the wider context of neonatal care and general wellbeing of the infant. Because of this context, this review takes a multi-disciplinary perspective with contributions from retinal vascular biologists, pediatric ophthalmologists, an epidemiologist and a neonatologist. This review highlights the latest insights regarding cellular and molecular mechanisms in the formation of the retinal vasculature in the human infant, pathogenesis of ROP, detection and treatment of severe ROP, the risks and benefits of anti-VEGF therapy, the identification of new therapies over the horizon, and the optimal neonatal care regimen for best ROP outcomes, and the benefits and pitfalls of telemedicine in the remote screening and diagnosis of ROP, all of which have the potential to improve ROP outcomes.

Validation of the Children's Hospital of Philadelphia Retinopathy of Prematurity (CHOP ROP) Model

Importance

The Children's Hospital of Philadelphia Retinopathy of Prematurity (CHOP ROP) model uses birth weight (BW), gestational age at birth (GA), and weight gain rate to predict the risk of severe retinopathy of prematurity (ROP). In a model development study, it predicted all infants requiring treatment, while greatly reducing the number of examinations compared with current screening guidelines.

Objective

To validate the CHOP ROP model in a multicenter cohort that is large enough to obtain a precise estimate of the model's sensitivity for treatment-requiring ROP.

Design, Setting, and Participants

This investigation was a secondary analysis of data from the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study. The setting was 30 hospitals in the United States and Canada between January 1, 2006, and June 30, 2012. The dates of analysis were September 28 to October 5, 2015. Participants were premature infants at risk for ROP with a known ROP outcome.

Main Outcomes and Measures

Sensitivity for Early Treatment of Retinopathy of Prematurity type 1 ROP and potential reduction in the number of infants requiring examinations. In the primary analysis, the CHOP ROP model was applied weekly to predict the risk of ROP. If the risk was above a cut-point level (high risk), examinations were indicated, while low-risk infants received no examinations. In a secondary analysis, low-risk infants received fewer examinations rather than no examinations.

Results

Participants included 7483 premature infants at risk for ROP with a known ROP outcome. Their median BW was 1070 g (range, 310-3000 g), and their median GA was 28 weeks (range, 22-35 weeks). Among them, 3575 (47.8%) were female, and their race/ethnicity was 3615 white (48.3%), 2310 black (30.9%), 233 Asian (3.1%), 93 Pacific Islander (1.2%), and 40 American Indian/Alaskan native (0.5%). The original CHOP ROP model correctly predicted 452 of 459 infants who developed type 1 ROP (sensitivity, 98.5%; 95% CI, 96.9%-99.3%), reducing the number of infants requiring examinations by 34.3% if only high-risk infants received examinations. Lowering the cut point to capture all type 1 ROP cases (sensitivity, 100%; 95% CI, 99.2%-100%) resulted in only 6.8% of infants not requiring examinations. However, if low-risk infants were examined at 37 weeks' postmenstrual age and followed up only if ROP was present at that examination, all type 1 ROP cases would be captured, and the number of examinations performed among infants with GA exceeding 27 weeks would be reduced by 28.4%.

Conclusion and Relevance

The CHOP ROP model demonstrated high but not 100% sensitivity and may be better used to reduce examination frequency. The model might be used reliably to guide a modified ROP screening schedule and decrease the number of examinations performed.

A Tiered Approach to Retinopathy of Prematurity Screening (TARP) Using a Weight Gain Predictive Model and a Telemedicine System

Importance

The Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) Study telemedicine system of remote fundus image grading and The Children's Hospital of Philadelphia Retinopathy of Prematurity (CHOP-ROP) postnatal weight gain predictive model are 2 approaches for improving ROP screening efficiency. Current screening has low specificity for severe ROP.

Objective

To describe a tiered approach to ROP screening (TARP) for identifying children who develop severe ROP using telemedicine and a predictive model synergistically.

Design, Setting, and Participants

This investigation was a post hoc analysis of a cohort in the e-ROP Study (a multicenter prospective telemedicine study) and the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study (a multicenter retrospective cohort study). The setting was neonatal intensive care units at The Children's Hospital of Philadelphia and the Hospital of the University of Pennsylvania. Participants in the e-ROP Study were premature infants with a birth weight less than 1251 g and a known ROP outcome enrolled between May 25, 2011, and October 31, 2013. The G-ROP Study enrolled all infants undergoing ROP examinations with a known ROP outcome who were born between January 1, 2006, and December 31, 2011.

Main Outcomes and Measures

The mean outcomes were the sensitivity for type 1 ROP, reductions in infants requiring imaging or examinations, numbers of imaging sessions and examinations, and total clinical encounters (imaging sessions and examinations combined). The following 4 screening approaches were evaluated: ROUTINE (only diagnostic examinations by an ophthalmologist), CHOP-ROP (birth weight and gestational age, with weekly weight gain initiating examinations when the risk cut point is surpassed), e-ROP IMAGING (trained reader grading of type 1 or 2 ROP initiates diagnostic examinations), and TARP (CHOP-ROP alarm initiates imaging, and imaging finding of severe ROP initiates diagnostic examinations).

Results

A total of 242 infants were included in the study, with a median birth weight of 858 g (range, 690-1035 g). The median gestational age was 27 weeks (range, 25-29 weeks). Fifty-one percent (124 of 242) were female, and 49% (118 of 242) were male. The race/ethnicity was 27.3% (66 of 242) white, 56.2% (136 of 242) black, 2.1% (5 of 242) Native American, 1.7% (4 of 242) Asian, and 12.8% (31 of 242) other. The sensitivity for detecting type 1 ROP (32 infants) was 100% (95% CI, 89.3%-100%) with each approach. With ROUTINE, 242 infants had 877 examinations; with CHOP-ROP, 184 infants had 730 examinations; with e-ROP IMAGING, 242 infants had 532 imaging sessions, and 94 infants had 345 examinations (877 patient encounters); and with TARP, 182 infants had 412 imaging sessions, and 87 infants had 322 examinations (734 patient encounters).

Conclusions and Relevance

The tiered approach to ROP screening was associated with a reduced number of examinations and imaging sessions compared with the other approaches. Applying a postnatal growth model and telemedicine system in a tiered approach may reduce the number of clinical ROP interventions more than either approach alone.