Clinical Models and Algorithms for the Prediction of Retinopathy of Prematurity: A Report by the American Academy of Ophthalmology

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Retinopathy of Prematurity: The Role of Nutrition

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness. ROP occurs in infants who are born very preterm. In ROP, retinal blood vessel development, which is prematurely arrested in preterm infants, is altered by perinatal exposures like oxygen and inflammation. Optimizing nutritional practices for preterm infants may mitigate the risk of ROP. In this article, we review the evidence that postnatal growth, hyperglycemia, polyunsaturated fatty acids, and breast milk provision may affect ROP risk. We also outline the current management strategies for ROP and describe the vision outcomes of children affected by ROP. [Pediatr Ann. 2023;52(8):e303-e308.].

Association of inflammatory and angiogenic biomarkers in maternal plasma with retinopathy of prematurity in preterm infants

OBJECTIVE

To investigate whether various novel inflammatory and angiogenic biomarkers in maternal plasma, alone or in combination with baseline antenatal factors, could predict retinopathy of prematurity (ROP) in preterm infants.

METHODS

A retrospective cohort study was conducted on 140 premature singleton neonates born to women with preterm birth (≤32 weeks) and screened for ROP. Maternal blood obtained at the time of admission was assayed for CRP, endoglin, endostatin, IGFBP-2, IGFBP-3, IL-6, LBP, MMP-8, PlGF, S100A8/A9, TGFBI, and VEGFR-1. The primary outcome measures included severe ROP (stage 3 or higher) and type 1 ROP requiring treatment.

RESULTS

ROP was present in 25.7% (36/140) of the study population, including 20 (14.3%) cases of severe ROP and 14 (10%) with type 1 ROP. Multiple logistic regression analyses revealed significant associations between high concentrations of maternal plasma LBP and severe ROP, and between elevated plasma IL-6 and LBP levels and type 1 ROP (all P < 0.05), while adjusting for confounders (i.e., gestational age [GA] at sampling). Prenatal prediction models for severe ROP and type 1 ROP were developed by combining plasma IL-6 or LBP levels with GA at sampling, which showed good discriminatory power (area under the curve = 0.747 and 0.854, respectively).

CONCLUSIONS

IL-6 and LBP in maternal plasma were found to be independently associated with severe ROP and type 1 ROP. Prediction models based on these biomarkers along with GA at sampling may serve as good prenatal indicators for the neonatal risk of ROP progression in women at risk of preterm birth.

Early prediction of severe retinopathy of prematurity requiring laser treatment using physiological data

BACKGROUND

Early risk stratification for developing retinopathy of prematurity (ROP) is essential for tailoring screening strategies and preventing abnormal retinal development. This study aims to examine the ability of physiological data during the first postnatal month to distinguish preterm infants with and without ROP requiring laser treatment.

METHODS

In this cohort study, preterm infants with a gestational age <32 weeks and/or birth weight <1500 g, who were screened for ROP were included. Differences in the physiological data between the laser and non-laser group were identified, and tree-based classification models were trained and independently tested to predict ROP requiring laser treatment.

RESULTS

In total, 208 preterm infants were included in the analysis of whom 30 infants (14%) required laser treatment. Significant differences were identified in the level of hypoxia and hyperoxia, oxygen requirement, and skewness of heart rate. The best model had a balanced accuracy of 0.81 (0.72-0.87), a sensitivity of 0.73 (0.64-0.81), and a specificity of 0.88 (0.80-0.93) and included the SpO₂/FiO₂ ratio and baseline demographics (including gestational age and birth weight).

CONCLUSIONS

Routinely monitored physiological data from preterm infants in the first postnatal month are already predictive of later development of ROP requiring laser treatment, although validation is required in larger cohorts.

IMPACT

Routinely monitored physiological data from the first postnatal month are predictive of later development of ROP requiring laser treatment, although model performance was not significantly better than baseline characteristics (gestational age, birth weight, sex, multiple birth, prenatal glucocorticosteroids, route of delivery, and Apgar scores) alone. A balanced accuracy of 0.81 (0.72-0.87), a sensitivity of 0.73 (0.64-0.81), and a specificity of 0.88 (0.80-0.93) was achieved with a model including the SpO₂/FiO₂ ratio and baseline characteristics. Physiological data have potential to play a significant role for future ROP prediction and provide opportunities for early interventions to protect infants from abnormal retinal development.

Premature infants with gestational age less than 25 weeks require increased ophthalmology resources for retinopathy of prematurity

BACKGROUND

It is unclear how increasing survival of low gestational age (GA) infants affects ophthalmologic screening and treatment rates for retinopathy of prematurity (ROP). This study compared the examination and treatment rates of infants born at GA of <25 weeks and those born at GA of at least 25 weeks.

METHODS

This was a retrospective study of patients who met institutional ROP screening criteria and were admitted to two neonatal intensive care units (NICUs) from January 2017 to June 2020. Variables analyzed were GA, birth weight, number of ophthalmology examinations, worst stage of ROP, presence of type 1 ROP, and comorbidities associated with ROP. The χ², Fisher exact, and two-tailed t tests, as well as univariate and multivariable logistic regression, were used for statistical analysis.

RESULTS

Compared to the GA≥25 group, the GA<25 group had a higher number of total exams (10 vs 4.3 [P < 0.001]), higher average worst stage of ROP (1.4 vs 0.3 [P < 0.001]) and higher rate of type 1 ROP (21% vs 1.4% [P < 0.001]), as well as higher mortality (37% vs 8.11% [P < 0. 001]). Multivariable logistic regression analysis controlling for GA, sepsis, and number of transfusions revealed that only GA was significantly associated with developing type 1 ROP.

CONCLUSIONS

Infants with GA <25 weeks had more severe ROP and required significantly more ophthalmologic examinations than GA ≥25. It is important for ROP services to plan for this increased screening load, especially if the number of such lower-weight infants in their NICUs increases.

Diagnostic Accuracy of Wide-Field Digital Retinal Images in Retinopathy of Prematurity Detection: Systematic Review and Meta-Analysis

PURPOSE

To evaluate the diagnostic accuracy of the wide-field digital retinal imaging (WFDRI) for the detection of Retinopathy of Prematurity (ROP) in premature infants as compared to the binocular indirect ophthalmoscopy (BIO).

METHODS

This systematic review and meta-analysis included the publications searched through PubMed (Medline), EMBASE, Scopus, Web of Science, Cochrane Library databases and Clinical Trials. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2, the hierarchical summary receiver operating characteristic, meta-regression, publication bias analyses, and the GRADE methodology for the certainty of the overall evidence were conducted. The pooled effect sizes of the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) were calculated.

RESULTS

Total sixteen eligible studies from 10 articles were included with total 2,537 image interpretations from 697 premature infants. Less than 50% risk of bias and low concern were found in each domain across all articles by QUADAS-2. The pooled effect sizes showed the sensitivity of 0.77 (95% confidence interval (C.I.): 0.69-0.84), specificity of 0.96 (95% C.I.: 0.92-0.98), PLR of 20.9 (95% C.I.: 10.2-42.5), NLR of 0.23 (95% C.I.: 0.17-0.33) and DOR of 89 (95% C.I.: 43-185) as compared to BIO. The income level, setting, mean/median birth weight and gestational age contributed to the significant differences in sensitivity (p < 0.001). No publication bias was found among these 16 studies. The GRADE quality of evidence showed moderate for the pooled sensitivity and high for the pooled specificity.

CONCLUSIONS

The diagnostic accuracy based on WFDRI is substantial and comparable to BIO, supporting its application in the ROP screening programs.

Trends in Neonatal Ophthalmic Screening Methods

Neonatal ophthalmic screening should lead to early diagnosis of ocular abnormalities to reduce long-term visual impairment in selected diseases. If a treatable pathology is diagnosed within a few days after the birth, adequate therapy may be indicated to facilitate the best possible conditions for further development of visual functions. Traditional neonatal ophthalmic screening uses the red reflex test (RRT). It tests the transmittance of the light through optical media towards the retina and the general disposition of the central part of the retina. However, RRT has weaknesses, especially in posterior segment affections. Wide-field digital imaging techniques have shown promising results in detecting anterior and posterior segment pathologies. Particular attention should be paid to telemedicine and artificial intelligence. These methods can improve the specificity and sensitivity of neonatal eye screening. Both are already highly advanced in diagnosing and monitoring of retinopathy of prematurity.

The retinal vascular growth rate in babies with retinopathy of prematurity could indicate treatment need

Purpose

To analyze the weekly rate of retinal vascular growth in treatment-naïve babies with various stages of retinopathy of prematurity (ROP) and validate if this could be a predictor of treatment need.

Methods

Retrospective review of medical charts and retinal images of babies with various stages of ROP. The images were enhanced using red-green image enhancement software. Using the length of the horizontal disc diameter (DD) of each eye, the vessel growth was measured from the disc margin up to the vessel tip in fixed quadrants. The rate of vessel growth was the ratio of vessel length to the number of weeks it took to reach this length. The babies were divided into treatment warranting ROP (group 1), low-risk pre-threshold (type II) ROP (group 2,), and no-ROP (group 3) for analysis. The "no-ROP" group acted as normal control. Group 1 was further subdivided into 1A (threshold ROP), IB (aggressive posterior ROP), 1C (hybrid ROP), and ID (high-risk pre-threshold ROP).

Results

Out of 436 eyes, groups 1, 2, and 3 had 238, 108, and 90 eyes, respectively. The mean rate of vascular outgrowth along with 95% confidence interval (CI) was 0.490 [0.487,0.520], 0.612 [0.599, 0.638], and 0.719 [0.703, 0.740] DD/week, respectively, for babies with "treatment warranting," "low risk pre-threshold" and "no ROP" groups, respectively. In our estimate, more than 80% of eyes with a vessel growth rate of 0.54 DD/week or less required treatment.

Conclusion

A rate of retinal vascular growth less than 0.54 DD/week can be used to determine treatment requirements in babies with ROP.

Single-Examination Risk Prediction of Severe Retinopathy of Prematurity

BACKGROUND AND OBJECTIVES

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness. Screening and treatment reduces this risk, but requires multiple examinations of infants, most of whom will not develop severe disease. Previous work has suggested that artificial intelligence may be able to detect incident severe disease (treatment-requiring retinopathy of prematurity [TR-ROP]) before clinical diagnosis. We aimed to build a risk model that combined artificial intelligence with clinical demographics to reduce the number of examinations without missing cases of TR-ROP.

METHODS

Infants undergoing routine ROP screening examinations (1579 total eyes, 190 with TR-ROP) were recruited from 8 North American study centers. A vascular severity score (VSS) was derived from retinal fundus images obtained at 32 to 33 weeks' postmenstrual age. Seven ElasticNet logistic regression models were trained on all combinations of birth weight, gestational age, and VSS. The area under the precision-recall curve was used to identify the highest-performing model.

RESULTS

The gestational age + VSS model had the highest performance (mean ± SD area under the precision-recall curve: 0.35 ± 0.11). On 2 different test data sets (n = 444 and n = 132), sensitivity was 100% (positive predictive value: 28.1% and 22.6%) and specificity was 48.9% and 80.8% (negative predictive value: 100.0%).

CONCLUSIONS

Using a single examination, this model identified all infants who developed TR-ROP, on average, >1 month before diagnosis with moderate to high specificity. This approach could lead to earlier identification of incident severe ROP, reducing late diagnosis and treatment while simultaneously reducing the number of ROP examinations and unnecessary physiologic stress for low-risk infants.

Assessment and management of retinopathy of prematurity in the era of anti-vascular endothelial growth factor (VEGF)

The incidence of retinopathy of prematurity (ROP) continues to rise due to the improved survival of very low birth weight infants in developed countries. This epidemic is also fueled by increased survival of preterm babies with variable use of oxygen and a lack of ROP awareness and screening services in resource-limited regions. Improvements in technology and a basic understanding of the disease pathophysiology have changed the way we screen and manage ROP, educate providers and patients, and improve ROP awareness. Advancements in imaging techniques, expansion of telemedicine services, and the potential for artificial intelligence-assisted ROP screening programs have created opportunities to improve ROP care in areas with a shortage of ophthalmologists trained in ROP. To address the gap in provider knowledge regarding ROP, the Global Education Network for Retinopathy of Prematurity (GEN-ROP) created a web-based tele-education training module that can be used to educate all providers involved in ROP, including non-physician ROP screeners. Over the past 50 years, the treatment of severe ROP has evolved from limited treatment modalities to cryotherapy and laser photocoagulation. More recently, there has been growing evidence to support the use of anti-vascular endothelial growth factor (VEGF) agents for the treatment of severe ROP. However, VEGF is known to be important in organogenesis and microvascular maintenance, and given that intravitreal anti-VEGF treatment can result in systemic VEGF suppression over a period of at least 1-12 weeks, there are concerns regarding adverse effects and long-term ocular and systemic developmental consequences of anti-VEGF therapy. Future research in ophthalmology to address the growing burden of ROP should focus on cost-effective fundus imaging devices, implementation of artificial intelligence platforms, updated treatment algorithms with optimal use of anti-VEGF and careful investigation of its long-term effects, and surgical options in advanced ROP. Addressing these unmet needs will aid the global effort against the ROP epidemic and optimize our understanding and treatment of this blinding disease.

Validation of the DIGIROP-birth model in a Chinese cohort

Background

We aimed to validate the predictive performance of the DIGIROP-Birth model for identifying treatment-requiring retinopathy of prematurity (TR-ROP) in Chinese preterm infants to evaluate its generalizability across countries and races.

Methods

We retrospectively reviewed the medical records of preterm infants who were screened for retinopathy of prematurity (ROP) in a single Chinese hospital between June 2015 and August 2020. The predictive performance of the model for TR-ROP was assessed through the construction of a receiver-operating characteristic (ROC) curve and calculating the areas under the ROC curve (AUC), sensitivity, specificity, and positive and negative predictive values.

Results

Four hundred and forty-two infants (mean (SD) gestational age = 28.8 (1.3) weeks; mean (SD) birth weight = 1237.0 (236.9) g; 64.7% males) were included in the study. Analyses showed that the DIGIROP-Birth model demonstrated less satisfactory performance than previously reported in identifying infants with TR-ROP, with an area under the receiver-operating characteristic curve of 0.634 (95% confidence interval = 0.564–0.705). With a cutoff value of 0.0084, the DIGIROP-Birth model showed a sensitivity of 48/93 (51.6%), which increased to 89/93 (95.7%) after modification with the addition of postnatal risk factors. In infants with a gestational age < 28 weeks or birth weight < 1000 g, the DIGIROP-Birth model exhibited sensitivities of 36/39 (92.3%) and 20/23 (87.0%), respectively.

Conclusions

Although the predictive performance was less satisfactory in China than in developed countries, modification of the DIGIROP-Birth model with postnatal risk factors shows promise in improving its efficacy for TR-ROP. The model may also be effective in infants with a younger gestational age or with an extremely low birth weight.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01952-0.

Development and validation of a new clinical decision support tool to optimize screening for retinopathy of prematurity

BACKGROUND/AIMS

Prematurely born infants undergo costly, stressful eye examinations to uncover the small fraction with retinopathy of prematurity (ROP) that needs treatment to prevent blindness. The aim was to develop a prediction tool (DIGIROP-Screen) with 100% sensitivity and high specificity to safely reduce screening of those infants not needing treatment. DIGIROP-Screen was compared with four other ROP models based on longitudinal weights.

METHODS

Data, including infants born at 24-30 weeks of gestational age (GA), for DIGIROP-Screen development (DevGroup, N=6991) originate from the Swedish National Registry for ROP. Three international cohorts comprised the external validation groups (ValGroups, N=1241). Multivariable logistic regressions, over postnatal ages (PNAs) 6-14 weeks, were validated. Predictors were birth characteristics, status and age at first diagnosed ROP and essential interactions.

RESULTS

ROP treatment was required in 287 (4.1%)/6991 infants in DevGroup and 49 (3.9%)/1241 in ValGroups. To allow 100% sensitivity in DevGroup, specificity at birth was 53.1% and cumulatively 60.5% at PNA 8 weeks. Applying the same cut-offs in ValGroups, specificities were similar (46.3% and 53.5%). One infant with severe malformations in ValGroups was incorrectly classified as not needing screening. For all other infants, at PNA 6-14 weeks, sensitivity was 100%. In other published models, sensitivity ranged from 88.5% to 100% and specificity ranged from 9.6% to 45.2%.

CONCLUSIONS

DIGIROP-Screen, a clinical decision support tool using readily available birth and ROP screening data for infants born GA 24-30 weeks, in the European and North American populations tested can safely identify infants not needing ROP screening. DIGIROP-Screen had equal or higher sensitivity and specificity compared with other models. DIGIROP-Screen should be tested in any new cohort for validation and if not validated it can be modified using the same statistical approaches applied to a specific clinical setting.

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.

ROP Screening Tool Assessment and Validation in a Third-Level Hospital in Argentina: A Pilot Study

PURPOSE

To evaluate whether a mathematical tool that predicts severe retinopathy of prematurity (ROP) using clinical parameters at 6 weeks of life (ROPScore calculator smartphone application; PABEX Corporation) can be useful to predict severe ROP in a population of premature infants in Argentina.

METHODS

In this retrospective study, data from the clinical records of all premature infants examined between 2012 and 2018 in the ophthalmology department of a public third-level hospital in Córdoba, Argentina, were obtained. ROPScore screening was applied using a Microsoft Excel spreadsheet (Microsoft Corporation). The sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values of the algorithm were analyzed.

RESULTS

Between 2012 and 2018, a total of 2,894 pre-term infants were examined and 411 met the inclusion criteria, of whom 34% (n = 139) presented some form of ROP and 6% (n = 25) developed severe forms that required treatment. The sensitivity of the algorithm for any ROP and severe ROP was 100%. The PPV and NPV were 35.64% and 100%, respectively, for any ROP and 9.88% and 100% for severe ROP.

CONCLUSIONS

One-time only calculation of the ROPScore algorithm could identify severe cases after validation, reducing the number of screened infants by 38% in infants with a birth weight of 1,500 g or less or a gestational age of 32 weeks or younger. [J Pediatr Ophthalmol Strabismus. 2021;58(1):55-61.].

Risk Calculator for Retinopathy of Prematurity Requiring Treatment

Importance: Vascular delay that occurs early in the development of retinopathy of prematurity (ROP) is a risk factor that can be compensated by ensuring a good rate of retinal vascularization to avoid ROP that requires treatment. Background: The objective of the present study was to determine the association between ROP that requires treatment and risk factors such as the extent of the temporal avascular area of the retina and the number of days of mechanical ventilation (MV). Design: Observational retrospective case-control study. Participants: Two hundred and twenty-eight premature newborns included in the screening protocol for retinopathy of prematurity. Methods: Subjects underwent retinal examination in the 4 and 6th postnatal weeks. Main Outcome Measures: The temporal avascular area was measured in disc diameters (DD), while the MV time was measured in days of treatment. Results: Patients with a longer MV time had a higher risk of treatment (R 2: 24.7, p < 0.0001; increase in risk of 8.1% for each additional day), as did those who showed greater avascular area (R 2: 24.7, p < 0.0001; increase in risk of 111% for each additional DD). An online calculator system and a table are presented for calculating the risk of ROP requiring treatment as a function of these two risk factors. Conclusions and Relevance: The temporal avascular area of the retina and MV time must be taken into account in the first examination of the newborn to predict the need for ROP treatment.

Inflammatory and Angiogenic Mediators in Amniotic Fluid Are Associated With the Development of Retinopathy of Prematurity in Preterm Infants

Purpose

To investigate whether elevated levels of inflammatory/angiogenic and growth mediators in amniotic fluid (AF) and the presence of intra-amniotic infection are associated with the occurrence and progression of retinopathy of prematurity (ROP) in preterm infants.

Methods

This retrospective cohort study included 175 premature singleton infants who were born between 23+0 and 32+0 weeks. AF obtained via amniocentesis was cultured, and endoglin, endostatin, insulin-like growth factor-binding protein (IGFBP)-2, IGFBP-3, IGFBP-4, IL-6, IL-8, matrix metalloproteinase-8, matrix metalloproteinase-9, and vascular endothelial growth factor receptor-1 levels were assayed by ELISA. The primary outcome measures included the occurrence of any stage ROP, severe ROP (stage ≥3), and vision-threatening type 1 ROP requiring treatment.

Results

Multiple logistic regression analyses revealed that there are significant associations between elevated AF endoglin levels and ROP occurrence; between elevated AF endoglin, endostatin, and IGFBP-2 levels and severe ROP; and between high AF endoglin, IL-6, and IL-8 levels and vision-threatening ROP requiring treatment, after adjusting for potential postnatal confounders. Using stepwise regression analyses, antenatal prediction models based on these AF biomarkers and prenatal factors were developed for the ROP outcomes, which had good discriminatory power (area under the curves, 0.731-0.863). However, we found that intra-amniotic infection is not associated with ROP occurrence and progression.

Conclusions

Elevated levels of inflammatory (IL-6 and IL-8) and angiogenic (endoglin and IGFBP-2) mediators in the AF, but not the presence of intra-amniotic infection, are independently associated with the occurrence and progression of ROP in preterm infants. These findings suggest that the pathophysiologic events that predispose preterm neonates to ROP may begin before delivery.

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

OBJECTIVE

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

STUDY DESIGN

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

RESULT

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

CONCLUSION

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

Postnatal weight gain and retinopathy of prematurity

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

Prenatal and postnatal inflammation-related risk factors for retinopathy of prematurity

OBJECTIVE

To evaluate the relationship between prenatal and postnatal inflammation-related risk factors and severe retinopathy of prematurity (ROP).

STUDY DESIGN

The study included infants born <30 weeks in California from 2007 to 2011. Multivariable log-binomial regression was used to assess the association between prenatal and postnatal inflammation-related exposures and severe ROP, defined as stage 3-5 or surgery for ROP.

RESULTS

Of 14,816 infants, 10.8% developed severe ROP. Though prenatal inflammation-related risk factors were initially associated with severe ROP, after accounting for the effect of these risk factors on gestational age at birth through mediation analysis, the association was non-significant (P = 0.6). Postnatal factors associated with severe ROP included prolonged oxygen exposure, sepsis, intraventricular hemorrhage, and necrotizing enterocolitis.

CONCLUSION

Postnatal inflammation-related factors were associated with severe ROP more strongly than prenatal factors. The association between prenatal inflammation-related factors and ROP was explained by earlier gestational age in infants exposed to prenatal inflammation.

Prediction of ROP Treatment and Evaluation of Screening Criteria in VLBW Infants-a Population Based Analysis

BACKGROUND

The incidence of retinopathy of prematurity (ROP) and ROP screening criteria differ between countries. We assessed whether ROP screening could be reduced based on the local ROP incidence.

METHODS

Observational cohort study of infants born in Switzerland between 2006 and 2015 <32 0/7 weeks. Chronological and postmenstrual ages at ROP treatment were analyzed. A model to identify ROP treatment on patients born between 2006 and 2012 (training set) was developed and tested on patients born between 2013 and 2015 (validation set).

RESULTS

Of 7817 live-born infants, 1098 died within the first 5 weeks of life. The remaining 6719 infants were included into analysis. All patients requiring ROP treatment would have been identified if screening had been performed before reaching 60 days of life or 37 3/7 weeks postmenstrual age, whichever came first. The training and validation sets included 4522 and 2197 preterm infants encompassing 56 and 20 patients receiving ROP treatment, respectively. All patients would have required screening to reach 100% sensitivity. To reach a sensitivity of 95.0% and a specificity of 87.6%, we predicted a reduction in 13.2% of patients requiring screening (c-statistic = 0.916).

CONCLUSIONS

A substantial reduction of infants requiring screening seems possible, but necessitates prospective testing of new screening criteria.

The ROPScore as a Screening Algorithm for Predicting Retinopathy of Prematurity in a Brazilian Population

OBJECTIVES

To evaluate the accuracy of the ROPScore algorithm as a predictor of retinopathy of prematurity (ROP).

METHODS

A prospective cohort of 220 preterm infants with a birth weight ≤1500 g and/or gestational age ≤32 weeks was included. The ROPScore was determined in the sixth week of life in 181 infants who then survived until a corrected gestational age of 45 weeks. The sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) of the algorithm were analyzed.

RESULTS

ROP was found in 17.6% of the preterm infants. The sensitivity of this test for any stage of ROP was 87.5%, while that for severe ROP was 95.4% (21/22 cases). The PPV and NPV were 59.6% and 97%, respectively, for any stage of ROP and 44.7% and 99.25%, respectively, for severe ROP. The ROPScore could therefore hypothetically reduce the number of ophthalmologic examinations required to detect ROP by 71.8%.

CONCLUSION

The ROPScore is a useful screening tool for ROP and may optimize examinations and especially the identification of severe ROP.

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

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

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.

Factors associated with retinopathy of prematurity ophthalmology workload

OBJECTIVE

This article reports on retinopathy of prematurity (ROP) workload in the NICU related to severity of disease, gestational age at discharge, and practice variation.

STUDY DESIGN

Data analysis on 1771 patients ≤ 30 weeks of gestation at birth from a de-identified data set of 13 NICUs.

RESULTS

There was a positive relationship between the severity of ROP and (1) the number of exams per patient, (2) the severity of ROP, and (3) postmenstrual age at discharge. The progression between the stages of ROP added to exam workload and postmenstrual age at NICU discharge. The addition of plus disease did not increase the exam burden. There was significant practice variation in the number of exams performed independent of ROP severity.

CONCLUSION

The progression of the severity of ROP independent of plus disease, and practice variations both contribute to ROP workload. Addressing these factors could decrease ROP workload without compromising American Academy of Pediatrics (AAP) guidelines.

Hot Topics in Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a condition seen in premature infants that is characterized by abnormal retinal blood vessel growth incited by relative hyperoxia and followed by hypoxia. It can have severe consequences ranging from high myopia to blindness. This article reviews recent "hot" topics related to ROP, specifically the changing incidence of ROP worldwide, the advent of predictive algorithms for screening for ROP, the emerging data behind efficacy of anti-vascular endothelial growth factor treatments for ROP, and advanced retinal imaging in children who were born premature. [Pediatr Ann. 2017;46(11):e415-e422.].

Toward Achieving 100% Adherence for Retinopathy of Prematurity Screening Guidelines

PURPOSE

To report on the use of a cloud-based electronic medical record (ROP Check; Glacier Medical Software, Anchorage, AK) designed to provide American Academy of Pediatrics (AAP) guideline-adherent retinopathy of prematurity (ROP) care through the scheduling and documenting of ROP examinations.

METHODS

Data analysis on 3,155 patients from a de-identified dataset from 13 neonatal intensive care units.

RESULTS

All newborns with a gestational age of 22 to 30 weeks (N = 2,278) were entered with a documented ROP examination. Of those, 98% and 97.4% completed their initial and follow-up examinations, respectively, within AAP guidelines. All but 1 of 145 initial treatments were completed within AAP guidelines after a decision for treatment was made. Of 369 newborns older than 30 weeks' gestational age and with a birth weight of less than 1,500 grams, none progressed to treatment; four patients had stage 2 or 3 ROP. Of 508 newborns with a gestational age of 31 to 32 weeks and a birth weight of more than 1,500 grams who were entered to identify unstable newborns, 34% did not need examinations; of those who were examined, one progressed to treatment. Fourteen percent of patients were observed as outpatients before retinal maturity and 12% missed some or all outpatient appointments. A decision was made to treat at the first examination for 2 (10%) newborns with a gestational age of 22 weeks and 2 (2%) newborns with a gestational age of 23 weeks. Each patient was within the AAP guidelines for initial treatment.

CONCLUSIONS

A computerized system specifically designed with process improvement and error-free delivery of ROP care as a focus can improve adherence to AAP guidelines and achieve superior results. Such a system creates a standardized and measurable safety net for pediatric ophthalmologists, neonatologists, hospitals, and follow-up pediatricians. [J Pediatr Ophthalmol Strabismus. 2017;54(6):356-362.].

Late-onset Circulatory Collapse and Continuous Positive Airway Pressure are Useful Predictors of Treatment-requiring Retinopathy of Prematurity: A 9-year Retrospective Analysis

Visual loss caused by retinopathy of prematurity (ROP) will be prevented if treatment-requiring ROP (TR-ROP) can be predicted. In this retrospective study including 418 infants with ≤32 weeks of gestational age (GA) and/or ≤1500 grams of birthweight, we attempted to identify useful predictors. We also examined the efficiency of significant predictors compared with existing predictive models, ROPScore and CHOP model. Multivariable logistic regression analyses supported the following factors were useful for predicting TR-ROP from all infants and infants with any ROP: GA (odds ratio [OR], 0.47 and 0.48), history of late-onset circulatory collapse (LCC) (OR, 2.76 and 2.44) and use of continuous positive airway pressure (CPAP) at 35 weeks of postmenstrual age (OR, 3.78 and 4.50). The comparison of areas under receiver operating characteristic curves indicated the combination of LCC, CPAP and ROPScore was better than ROPScore to predict TR-ROP from all infants and infants with any ROP (P = 0.007 and 0.02) and the combination of LCC, CPAP and CHOP model was also better than CHOP model to predict TR-ROP from all infants and infants with any ROP (P = 0.01 and 0.02). Our results suggested infants with a history of LCC and a long CPAP support have a high incidence of TR-ROP.

Advances in understanding and management of retinopathy of prematurity

The understanding, diagnosis, and treatment of retinopathy of prematurity have changed in the 70 years since the original description of retrolental fibroplasia associated with high oxygenation. It is now recognized that retinopathy of prematurity differs in appearance worldwide and as ever smaller and younger premature infants survive. New methods are being evaluated to image the retina, diagnose severe retinopathy of prematurity, and determine windows of time for treatment to save eyes and improve visual and neural outcomes. New treatments to promote physiologic retinal vascular development, vascular repair, and inhibit vasoproliferation by regulating proteins involved in vascular endothelial growth factor, insulin-like growth factor, or erythropoietin signaling. Reducing excessive oxidative/nitrosative stress and understanding progenitor cells and neurovascular and glial vascular interactions are being studied.

Role of cytokines and treatment algorithms in retinopathy of prematurity

PURPOSE OF REVIEW

Currently, severe retinopathy of prematurity (ROP) is diagnosed by clinical evaluation and not a laboratory test. Laser is still considered standard care. However, anti-vascular endothelial growth factor (VEGF) agents are being used and there are questions whether and/or if to use them, what dose or type of agent should be considered and what agent may be most beneficial in specific cases. Also unclear are the effects of laser or anti-VEGF on severe ROP, refractive outcomes or infant development. This article reviews recent studies related to these questions and other trials for severe ROP.

RECENT FINDINGS

Imaging studies identify biomarkers of risk (plus disease, stage 3 ROP, and ROP in zone I). Intravitreal bevacizumab or ranibizumab are reported effective in treating aggressive posterior ROP in small series. Recurrences and effects on myopia vary among studies. Use of anti-VEGF agents affects cytokines in the infant blood and reduces systemic VEGF for up to 2 months, raising potential safety concerns. The effects of treatment vary based on infant size and are not comparable. Evidence for most studies is not high.

SUMMARY

Studies support experimental evidence that inhibiting VEGF reduces stage 3 ROP and peripheral avascular retina. Ongoing large-scale clinical trials may provide clarity for best treatments of severe ROP. Current guidelines hold for screening and treatment for type 1 ROP.

Colorado Retinopathy of Prematurity Screening Algorithm (CO-ROP): a validation study at a tertiary care center

PURPOSE

The Colorado Retinopathy of Prematurity Screening Algorithm (CO-ROP) recommends screening for infants meeting the following criteria for retinopathy of prematurity (ROP): gestational age ≤30 weeks, birth weight of ≤1500 g, and net weight gain of ≤650 g between birth and 4 weeks of age. This study was performed to evaluate the validity of CO-ROP in a tertiary referral county hospital.

METHODS

CO-ROP was used to retrospectively analyze the data from consecutive newborns screened for ROP using national screening guidelines at Parkland Hospital, Dallas, Texas, between April 1, 2009, to August 30, 2013. Sensitivities and specificities for identifying ROP were calculated.

RESULTS

A total of 374 infants were included, of whom 29 (7.8%) developed type 1 ROP and 12 (3.2%) developed type 2 ROP. The CO-ROP model would have decreased number of infants screened by 34% compared to current national screening criteria. CO-ROP had sensitivity of 93.1% (95% CI, 77.2-99.1) and 92.7% (95% CI, 61.5-99.8) for identifying type 1 and type 2 ROP, respectively. Of 29 patients who developed type 1 ROP, 2 were not identified using CO-ROP.

CONCLUSIONS

The CO-ROP model significantly reduced total number screened but failed to detect 2 infants with type 1 ROP, suggesting the need for further modification of the algorithm.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.