The incidence and course of retinopathy of prematurity: findings from the early treatment for retinopathy of prematurity study

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

PURPOSE

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

DESIGN

An observational case-control targeted genetic analysis.

METHODS

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

RESULTS

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

CONCLUSION

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

Airway management may influence postoperative ventilation need in preterm infants after laser eye treatment

BACKGROUND

Retinopathy of prematurity is treated with laser photocoagulation under general anaesthesia with intubation using endotracheal tube (ETT), which carries a risk for postoperative mechanical ventilation (MV). Laryngeal mask airway (LMA) may provide a safe alternative. We assessed the need for postoperative MV in preterm infants who received LMA versus ETT.

METHODS

In this single-centre, retrospective cohort study, preterm infants who underwent laser photocoagulation between 2014-2021 were enroled. For airway management, patients received either LMA (n = 224) or ETT (n = 47). The outcome was the rate of postoperative MV.

RESULTS

Patients' age were 37 [35;39] weeks of postmenstrual age, median bodyweight of Group LMA was higher than Group ETT's (2110 [1800;2780] g versus 1350 [1230;1610] g, respectively, p < 0.0001). After laser photocoagulation, 8% of Group LMA and 74% of Group ETT left the operating theatre requiring MV. Multiple logistic regression revealed that the use of LMA and every 100 g increase in bodyweight significantly decreased the odds of mechanical ventilation (OR 0.21 [95% CI 0.07-0.60], and 0.73 [95% CI 0.63-0.84], respectively). Propensity score matching confirmed that LMA decreased the odds of postoperative MV (OR 0.30 [95% CI 0.11-0.70]).

CONCLUSION

The use of LMA is associated with a reduced need for postoperative MV.

IMPACT

Using laryngeal mask airway instead of endotracheal tube for airway management in preterm infants undergoing general anaesthesia for laser photocoagulation for treating retinopathy of prematurity could significantly decrease the postoperative need for mechanical ventilation. According to our current understanding, this has been the largest study investigating the effect of laryngeal mask airway during general anaesthesia in preterm infants. Our study suggests that the use of laryngeal mask airway is a viable alternative to intubation in the vulnerable population of preterm infants in need of laser treatment.

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

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

Clinical and Growth Correlates of Retinopathy of Prematurity in Preterm Infants with Surgical Necrotizing Enterocolitis and Intestinal Perforation

OBJECTIVE

 This study aimed to identify the clinical and growth parameters associated with retinopathy of prematurity (ROP) in infants with necrotizing enterocolitis (NEC) and spontaneous ileal perforation (SIP).

STUDY DESIGN

 We conducted a retrospective cohort study that compared clinical data before and after NEC/SIP onset in neonates, categorizing by any ROP and severe ROP (type 1/2) status.

RESULTS

 The analysis included 109 infants with surgical NEC/SIP. Sixty infants (60/109, 55%) were diagnosed with any ROP, 32/109 (29.3%) infants (22% type 1 and 7.3% type 2) with severe ROP. On univariate analysis, those with severe ROP (32/109, 39.5%) were of lower median gestational age (GA, 23.8 weeks [23.4, 24.6] vs. 27.3 [26.3, 29.0], p < 0.001), lower median birth weight (625 g [512, 710] vs. 935 [700, 1,180], p < 0.001) and experienced higher exposure to clinical chorioamnionitis (22.6 vs. 2.13%, p < 0.006), and later median onset of ROP diagnosis (63.0 days [47.0, 77.2] vs. 29.0 [19.0, 41.0], p < 0.001), received Penrose drain placement more commonly (19 [59.4%] vs. 16 [34.0%], p = 0.04), retained less residual small bowel (70.0 cm [63.1, 90.8] vs. 90.8 [72.0, 101], p = 0.007) following surgery, were exposed to higher FiO2 7 days after birth (p = 0.001), received ventilation longer and exposed to higher FiO2 at 2 weeks (p < 0.05) following NEC and developed acute kidney injury (AKI) more often (25 [86.2%] vs. 20 [46.5%], p = 0.002) than those without ROP. Those with severe ROP had lower length, weight for length, and head circumference z scores. In an adjusted Firth's logistic regression, GA (adjusted odds ratio [aOR] = 0.51, 95% confidence interval [CI]: [0.35, 0.76]) and diagnosis at later age (aOR = 1.08, 95% CI: [1.03, 1.13]) was shown to be significantly associated with any ROP.

CONCLUSION

 Infants who develop severe ROP following surgical NEC/SIP are likely to be younger, smaller, have been exposed to more O2, develop AKI, and grow poorly compared with those did not develop severe ROP.

KEY POINTS

· Thirty percent of infants with NEC/SIP had severe ROP.. · Those with severe ROP had poor growth parameters before and after NEC/SIP.. · Risk factors based ROP prevention strategies are needed to have improved ophthalmic outcomes..

Multinational External Validation of Autonomous Retinopathy of Prematurity Screening

Importance

Retinopathy of prematurity (ROP) is a leading cause of blindness in children, with significant disparities in outcomes between high-income and low-income countries, due in part to insufficient access to ROP screening.

Objective

To evaluate how well autonomous artificial intelligence (AI)-based ROP screening can detect more-than-mild ROP (mtmROP) and type 1 ROP.

Design, Setting, and Participants

This diagnostic study evaluated the performance of an AI algorithm, trained and calibrated using 2530 examinations from 843 infants in the Imaging and Informatics in Retinopathy of Prematurity (i-ROP) study, on 2 external datasets (6245 examinations from 1545 infants in the Stanford University Network for Diagnosis of ROP [SUNDROP] and 5635 examinations from 2699 infants in the Aravind Eye Care Systems [AECS] telemedicine programs). Data were taken from 11 and 48 neonatal care units in the US and India, respectively. Data were collected from January 2012 to July 2021, and data were analyzed from July to December 2023.

Exposures

An imaging processing pipeline was created using deep learning to autonomously identify mtmROP and type 1 ROP in eye examinations performed via telemedicine.

Main Outcomes and Measures

The area under the receiver operating characteristics curve (AUROC) as well as sensitivity and specificity for detection of mtmROP and type 1 ROP at the eye examination and patient levels.

Results

The prevalence of mtmROP and type 1 ROP were 5.9% (91 of 1545) and 1.2% (18 of 1545), respectively, in the SUNDROP dataset and 6.2% (168 of 2699) and 2.5% (68 of 2699) in the AECS dataset. Examination-level AUROCs for mtmROP and type 1 ROP were 0.896 and 0.985, respectively, in the SUNDROP dataset and 0.920 and 0.982 in the AECS dataset. At the cross-sectional examination level, mtmROP detection had high sensitivity (SUNDROP: mtmROP, 83.5%; 95% CI, 76.6-87.7; type 1 ROP, 82.2%; 95% CI, 81.2-83.1; AECS: mtmROP, 80.8%; 95% CI, 76.2-84.9; type 1 ROP, 87.8%; 95% CI, 86.8-88.7). At the patient level, all infants who developed type 1 ROP screened positive (SUNDROP: 100%; 95% CI, 81.4-100; AECS: 100%; 95% CI, 94.7-100) prior to diagnosis.

Conclusions and Relevance

Where and when ROP telemedicine programs can be implemented, autonomous ROP screening may be an effective force multiplier for secondary prevention of ROP.

Artificial Intelligence (AI) for Early Diagnosis of Retinal Diseases

Artificial intelligence (AI) has emerged as a transformative tool in the field of ophthalmology, revolutionizing disease diagnosis and management. This paper provides a comprehensive overview of AI applications in various retinal diseases, highlighting its potential to enhance screening efficiency, facilitate early diagnosis, and improve patient outcomes. Herein, we elucidate the fundamental concepts of AI, including machine learning (ML) and deep learning (DL), and their application in ophthalmology, underscoring the significance of AI-driven solutions in addressing the complexity and variability of retinal diseases. Furthermore, we delve into the specific applications of AI in retinal diseases such as diabetic retinopathy (DR), age-related macular degeneration (AMD), Macular Neovascularization, retinopathy of prematurity (ROP), retinal vein occlusion (RVO), hypertensive retinopathy (HR), Retinitis Pigmentosa, Stargardt disease, best vitelliform macular dystrophy, and sickle cell retinopathy. We focus on the current landscape of AI technologies, including various AI models, their performance metrics, and clinical implications. Furthermore, we aim to address challenges and pitfalls associated with the integration of AI in clinical practice, including the "black box phenomenon", biases in data representation, and limitations in comprehensive patient assessment. In conclusion, this review emphasizes the collaborative role of AI alongside healthcare professionals, advocating for a synergistic approach to healthcare delivery. It highlights the importance of leveraging AI to augment, rather than replace, human expertise, thereby maximizing its potential to revolutionize healthcare delivery, mitigate healthcare disparities, and improve patient outcomes in the evolving landscape of medicine.

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

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

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.

RECENT TRENDS IN THE CUMULATIVE INCIDENCE AND INTERVENTION PATTERNS OF RETINOPATHY OF PREMATURITY IN JAPAN: A Multicenter Analysis, 2011-2020

PURPOSE

To investigate recent trends in the cumulative incidence and treatment patterns of retinopathy of prematurity (ROP) in Japan.

METHODS

A retrospective multicenter cohort was conducted from 2011 to 2020 using the Diagnosis Procedure Combination inpatient database. Preterm newborns with birth weight <2,500 g were categorized by birth weight. The cumulative incidence of ROP, treatment patterns, and association between treatment and birth weight were investigated.

RESULTS

A total of 82,683 preterm infants were identified, of whom 9,335 (11.3%) were diagnosed with ROP. The cumulative incidence of ROP increased by 15% in those with birth weight <500 g over the study period. Among the ROP infants, 20.2% received treatment, including laser photocoagulation (94.8%), intravitreal injection (3.8%), or both (1.8%). The proportion receiving laser photocoagulation decreased followed by an increase in intravitreal injection. This shift in intervention pattern was most conspicuous for those with birth weight 750 to 1,249 g. The risk ratio of receiving laser and intravitreal injection for those weighing <500 g was 24.7 (95% confidence interval, 10.5-58.2) and 28.4 (5.8-138.1), respectively, as compared with infants weighing >1,500 g.

CONCLUSION

The cumulative incidence of ROP increased in infants with birth weight <500 g. A shift from laser photocoagulation to intravitreal injection was observed in the more recent years.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prevalence of strabismus in premature infants in an age-related perspective

THE AIM

was to investigate the prevalence of strabismus in premature infants; to identify diagnostic indicators for predicting strabismus at the age of 3-8 years.

METHODS

The material was the data of 84 premature infants who underwent ophthalmological examination at the age of 6 months - 3 years and again - at 3-8 years. All children underwent ophthalmic examination for retinopathy of prematurity (ROP) in infancy.

RESULTS

An increase in the frequency of strabismus occurrence among preterm infants was observed in 3-8 years compared to the data from 6 months - 3 years - from 13.3% to 20.0% in children without ROP, from 5.9% to 23.5% in children with self-resolving ROP, from 22.7% to 45.5% in children with ROP after laser retinal photocoagulation. The presence of strabismus and structural changes of eye at ages 6 months - 3 years increase the risk of strabismus at ages 3-8 years, OR = 6.5 (95% CI 3.8-11.3), (p < 0.001); OR = 4.2 (95% CI 2.8-6.2), (p = 0.005). The increase in the risk of developing strabismus at ages 3-8 years is associated with the presence of anisometropia, (p = 0.047), amblyopia, (p < 0.05). Children with higher visual acuity at ages 3-8 years have a decreased risk of strabismus, (p < 0.05).

CONCLUSIONS

The frequency of strabismus occurrence among preterm infants has increased by ages 3-8 years. Strabismus, structural changes of eye at ages 6 months - 3 years increases the risk of strabismus at ages 3-8 years. Anisometropia and amblyopia increase in the risk of strabismus, higher visual acuity decreases risk of strabismus.

Propranolol: a new pharmacologic approach to counter retinopathy of prematurity progression

Despite the evident progress in neonatal medicine, retinopathy of prematurity (ROP) remains a serious threat to the vision of premature infants, due to a still partial understanding of the mechanisms underlying the development of this disease and the lack of drugs capable of arresting its progression. Although ROP is a multifactorial disease, retinal vascularization is strictly dependent on oxygen concentration. The exposition of the retina of a preterm newborn, still incompletely vascularized, to an atmosphere relatively hyperoxic, as the extrauterine environment, induces the downregulation of proangiogenic factors and therefore the interruption of vascularization (first ischemic phase of ROP). However, over the following weeks, the growing metabolic requirement of this ischemic retina produces a progressive hypoxia that specularly promotes the surge of proangiogenic factors, finally leading to proliferative retinopathy (second proliferative phase of ROP). The demonstration that the noradrenergic system is actively involved in the coupling between hypoxia and the induction of vasculogenesis paved the way for a pharmacologic intervention aimed at counteracting the interaction of noradrenaline with specific receptors and consequently the progression of ROP. A similar trend has been observed in infantile hemangiomas, the most common vascular lesion of childhood induced by pre-existing hypoxia, which shares similar characteristics with ROP. The fact that propranolol, an unselective antagonist of β1/2 adrenoceptors, counteracts the growth of infantile hemangiomas, suggested the idea of testing the efficacy of propranolol in infants with ROP. From preclinical studies, ongoing clinical trials demonstrated that topical administration of propranolol likely represents the optimal approach to reconcile its efficacy and maximum safety. Given the strict relationship between vessels and neurons, recovering retinal vascularization with propranolol may add further efficacy to prevent retinal dysfunction. In conclusion, the strategy of contrasting precociously the progression of the disease appears to be more advantageous than the current wait-and-see therapeutic approach, which instead is mainly focused on avoiding retinal detachment.

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

Insights into Risk: Exploring Retinopathy of Prematurity and Short-term Comorbidities in Moderate-to-Late Preterm Infants

BACKGROUND

Retinopathy of prematurity (ROP) and short-term comorbidity data moderate-to-late preterm (MLP) infants in Saudi Arabia are limited.

AIM

The present study mainly aimed to identify ROP incidence and severity in MLP infants. The secondary objective was to explore whether moderate preterm infants are more prone to systemic short-term comorbidities compared to late preterm infants.

MATERIALS AND METHODS

This retrospective study was conducted at King Abdulaziz University Hospital, a tertiary center in Jeddah, Saudi Arabia. Two-hundred and sixty-eight MLP infants born with gestational ages (GAs) of 32 to 36 + 6 weeks were included. Births were classified as moderate preterm (GA 32 to 33 + 6 weeks) and late preterm (GA 34 to 36 + 6 weeks) and the two groups were compared with an independent t-test.

RESULTS

ROP incidence was 1.5%; all cases were stage 1 and involved zone II or III. No patient had type 1 ROP requiring treatment. The short-term comorbidity incidence was high (76.1%) and included hyperbilirubinemia (n = 206, 76.7%), respiratory distress syndrome (n = 178, 66.4%), hypoglycemia (n = 32, 11.9%,), and transient tachypnea of newborn (n = 25, 9.3%). Moderate preterm infants were more likely to have lower birth weight (P < 0.001), any-stage ROP (P = 0.032), respiratory distress syndrome (P = 0.031), intraventricular hemorrhage (P = 0.038), and hyperbilirubinemia (P < 0.001) compared to the late preterm infants.

CONCLUSIONS

Any-stage ROP incidence among MLP infants was low, with no type 1 ROP cases requiring treatment. Short-term comorbidity incidence was relatively high among the moderate preterm infants. Despite the low non-type 1 ROP incidence at our center, MLP infants require proper surveillance of systemic short-term comorbidities.

Teleophthalmology and retina: a review of current tools, pathways and services

Telemedicine, the use of telecommunication and information technology to deliver healthcare remotely, has evolved beyond recognition since its inception in the 1970s. Advances in telecommunication infrastructure, the advent of the Internet, exponential growth in computing power and associated computer-aided diagnosis, and medical imaging developments have created an environment where telemedicine is more accessible and capable than ever before, particularly in the field of ophthalmology. Ever-increasing global demand for ophthalmic services due to population growth and ageing together with insufficient supply of ophthalmologists requires new models of healthcare provision integrating telemedicine to meet present day challenges, with the recent COVID-19 pandemic providing the catalyst for the widespread adoption and acceptance of teleophthalmology. In this review we discuss the history, present and future application of telemedicine within the field of ophthalmology, and specifically retinal disease. We consider the strengths and limitations of teleophthalmology, its role in screening, community and hospital management of retinal disease, patient and clinician attitudes, and barriers to its adoption.

Retinal detachment following retinopathy of prematurity in France: Screening and treatment pathways

AIM

Preterm children are highly vulnerable to sensorial impairments through Retinopathy Of Prematurity (ROP). The objective was to determine whether some cases of ROP requiring surgery could be secondary to deficiencies in care pathways.

METHODS

Descriptive study of neonatal characteristics and the screening/treatment pathways of children treated for stage ≥4A ROP from 2009 to 2020 in a referral unit in France.

RESULTS

Twenty-five preterm children (44 eyes) were included: median gestational age was 25 weeks, and median birthweight was 700 grams. Eighty-four per cent had received at least one fundus examination, 50% of which were completed on time. At the time of retinal detachment diagnosis, only 36% of the children had received laser or anti-vascular endothelial growth factor (VEGF) intra-vitreal injection. ROP stage was only reported in 8%, and the zone or type was reported in 16% of the files.

CONCLUSION

The risk of blindness and the effectiveness of laser or anti-VEGF treatment highlight the need to enhance screening and treatment practices in France.

Computer versus human-expert ranking of posterior pole vascular tortuosity and dilation using retinal vessel maps generated from bedside optical coherence tomography: a proof-of-concept study

Semiautomated computer software (ie, ROPtool) can trace and analyze optical coherence tomography (OCT)-generated retinal vessel maps for plus/pre-plus disease with high reliability and accuracy. This proof-of-concept study found that ROPtool can reliably rank OCT-generated vessel maps for tortuosity and combined tortuosity/dilation, which correlated well with human-expert rankings and clinical examination.

Oxidative stress in the eye and its role in the pathophysiology of ocular diseases

Oxidative stress occurs through an imbalance between the generation of reactive oxygen species (ROS) and the antioxidant defense mechanisms of cells. The eye is particularly exposed to oxidative stress because of its permanent exposure to light and due to several structures having high metabolic activities. The anterior part of the eye is highly exposed to ultraviolet (UV) radiation and possesses a complex antioxidant defense system to protect the retina from UV radiation. The posterior part of the eye exhibits high metabolic rates and oxygen consumption leading subsequently to a high production rate of ROS. Furthermore, inflammation, aging, genetic factors, and environmental pollution, are all elements promoting ROS generation and impairing antioxidant defense mechanisms and thereby representing risk factors leading to oxidative stress. An abnormal redox status was shown to be involved in the pathophysiology of various ocular diseases in the anterior and posterior segment of the eye. In this review, we aim to summarize the mechanisms of oxidative stress in ocular diseases to provide an updated understanding on the pathogenesis of common diseases affecting the ocular surface, the lens, the retina, and the optic nerve. Moreover, we discuss potential therapeutic approaches aimed at reducing oxidative stress in this context.

Gut Microbiome and Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a leading cause of childhood blindness worldwide, is strongly associated with gestational age and weight at birth. Yet, many extremely preterm infants never develop ROP or develop only mild ROP with spontaneous regression. In addition, a myriad of other factors play a role in the retinal pathology, one of which may include the early gut microbiome. The complications associated with early gestational age include dysbiosis of the dynamic neonatal gut microbiome, as evidenced by the development of often concomitant conditions, such as necrotizing enterocolitis. Given this, alongside growing evidence for a gut-retina axis, there is an increasing interest in how the early intestinal environment may play a role in the pathophysiology of ROP. Potential mechanisms include dysregulation of vascular endothelial growth factor and insulin-like growth factor 1. Furthermore, the gut microbiome may be impacted by other known risk factors for ROP, such as intermittent hypoxia and sepsis treated with antibiotics. This mini-review summarizes the literature supporting these proposed avenues, establishing a foundation to guide future studies.

Hypothermia and adverse outcomes during the transfer of extremely low birth weight infants

AIM

We aimed to explore whether hypothermia during the transfer of extremely low birth weight (ELBW) infants was associated with increased morbidity and mortality.

METHODS

Retrospective cohort study of transfers of ELBW infants by the London Neonatal Transfer Service between April 2015 and January 2017. Hypothermia was defined as an axillary temperature below 36.5°C.

RESULTS

Hypothermia was recorded in 36-47% of the 146 transfers depending on the time point of measurement from admission at the referring unit to admission at the receiving unit. Infants with hypothermia had a lower gestational age [25.1 (24.1-26.6) versus 26.0 (25.3-27.0) weeks, p < 0.001], birth weight [750 (600-830) versus 800 (730-885) gr, p = 0.004) and age at referral [1 (0.8-3) versus 1.5 (1-4) hours, p = 0.049] compared to infants without hypothermia. Infants with hypothermia had a longer median (IQR) duration of invasive ventilation [22(6-44) days] compared to infants without hypothermia [10 (4-21) days, p = 0.002]. Infants with hypothermia had a higher incidence of a patent ductus arteriosus and mortality before discharge from neonatal care compared to infants without hypothermia (79% vs. 27%, p = 0.043 and 29% vs. 13%, p = 0.025, respectively).

CONCLUSION

Among ELBW infants, hypothermia during transfer was common, particularly in infants of lower gestational age. Hypothermia was associated with a longer duration of ventilation and increased mortality before discharge from neonatal care.

Association of Health Insurance Status With Severity and Treatment Among Infants With Retinopathy of Prematurity

This study describes retinopathy of prematurity treatment practices using Medicaid and commercial claims databases. Infants with Medicaid tend to be sicker overall and have higher rates of retinopathy of prematurity requiring treatment than those with commercial insurance. Among patients who required treatment, those with Medicaid were more likely to receive anti-vascular endothelial growth factor than laser treatment. [J Pediatr Ophthalmol Strabismus. 2023;60(6):e75-e78.].

Prevalence and risk factors of disabilities among Egyptian preschool children: a community-based population study

BACKGROUND

Child disability has significant implications on their well-being and healthcare systems.

AIM

This survey aimed to assess the magnitude of seven types of disability among Egyptian children aged 1 < 6 years and their socio-demographic, epidemiological, and perinatal predictors.

METHODS

A national population-based cross-sectional household survey targeting 21,316 children from eight governorates was conducted. The screening questionnaire was derived from the WHO ten-question survey tool validated for identifying seven disability categories.

RESULTS

The percentage of children with at least one disability was 8.1% as follows: speech/communication (4.4%), Mobility/physical (2.5%), Seizures (2.2%), Comprehension (1.7%), Intellectual impairment (1.4%), Visual (0.3%) and Hearing (0.2%). Age was not found to affect the odds of disability except for visual disability (significantly increased with age (AOR = 1.4, 95% CI:1.1-1.7). Male sex also increased the odds of all disabilities except visual, hearing, and seizures. Convulsions after birth significantly increased the odds of disability as follows: hearing (AOR = 8.1, 95% CI: 2.2-30.5), intellectual impairment (AOR = 4.2, 95% CI: 2.5-6.9), and mobility/physical (AOR = 3.4, 95% CI: 2.3-5.0). Preterm delivery and being kept in an incubator for more than two days after birth increased the odds for visual disability (AOR = 3.7, 95% CI: 1.1-12.1 & AOR = 3.7, 95% CI: 1.7-7.9 respectively). Cyanosis increased the odds of seizures (AOR = 4.7, 95% CI: 2.2-10.3). Low birth weight also increased the odds for all disability domains except for visual and hearing. Maternal health problems during pregnancy increased the odds for all types of disability except hearing and seizures. Higher paternal education decreased the odds for all disabilities by at least 30% except for vision and hearing.

CONCLUSION

The study found a high prevalence of disability among Egyptian children aged 1-6 years. It identified a number of modifiable risk factors for disability. The practice of early screening for disability is encouraged to provide early interventions when needed.

Prevalence and risk factors of disabilities among Egyptian preschool children: a community-based population study

Background

Child disability has significant implications on their well-being and healthcare systems. Aim: This survey aimed to assess the magnitude of seven types of disability among Egyptian children aged 1 < 6 years and their socio-demographic, epidemiological, and perinatal predictors.

Methods

A national population-based cross-sectional household survey targeting 21,316 children from eight governorates was conducted. The screening questionnaire was derived from the WHO ten-question survey tool validated for identifying seven disability categories.

Results

The percentage of children with at least one disability was 8.1% as follows: speech/communication (4.4%), Mobility/physical (2.5%), Seizures (2.2%), Comprehension (1.7%), Intellectual impairment (1.4%), Visual (0.3%) and Hearing (0.2%). Age was not found to affect the odds of disability except for visual disability (significantly increased with age (AOR = 1.4, 95% CI:1.1–1.7). Male sex also increased the odds of all disabilities except visual, hearing, and seizures. Convulsions after birth significantly increased the odds of disability as follows: hearing (AOR = 8.1, 95% CI: 2.2–30.5), intellectual impairment (AOR = 4.2, 95% CI: 2.5–6.9), and mobility/physical (AOR = 3.4, 95% CI: 2.3–5.0). Preterm delivery and being kept in an incubator for more than two days after birth increased the odds for visual disability (AOR = 3.7, 95% CI: 1.1–12.1 & AOR = 3.7, 95% CI: 1.7–7.9 respectively). Cyanosis increased the odds of seizures (AOR = 4.7, 95% CI: 2.2–10.3). Low birth weight also increased the odds for all disability domains except for visual and hearing. Maternal health problems during pregnancy increased the odds for all types of disability except hearing and seizures. Higher paternal education decreased the odds for all disabilities by at least 30% except for vision and hearing.

Conclusion

The study found a high prevalence of disability among Egyptian children aged 1–6 years. It identified a number of modifiable risk factors for disability. The practice of early screening for disability is encouraged to provide early interventions when needed.

A Meta-Analysis of Neurodevelopmental Outcomes following Intravitreal Bevacizumab for the Treatment of Retinopathy of Prematurity

BACKGROUND

Retinopathy of prematurity (ROP) is the most common cause of preventable blindness in preterm infants. First-line treatments include intravitreal bevacizumab (IVB) or laser photocoagulation (LPC).

OBJECTIVES

The aim of the study was to evaluate neurodevelopmental safety of IVB compared to LPC for ROP.

METHODS

MEDLINE, Embase, and Cochrane library were searched up to September 2022. Studies were included with at least 12-month follow-up of primary outcomes such as severe neurodevelopmental impairment (sNDI), cerebral palsy (CP), and hearing impairment (HI). Secondary outcomes were moderate-to-severe neurodevelopmental impairment (msNDI), Bayley Scores of Infant Development (BSID-III), and visual impairment.

RESULTS

1,231 patients from 11 comparative studies were included. Quality of evidence was rated low for all outcomes. IVB was associated with a higher risk for sNDI (risk ratio [RR] = 1.25, 95% confidence interval [CI]: [1.01, 1.53], p = 0.04); and CP (RR = 1.40, CI: [1.08, 1.81], p = 0.01) compared to LPC. There was no significant difference between IVB and LPC for msNDI (RR = 1.15, CI: [0.98, 1.35], p = 0.08) and HI (RR = 1.43, CI: [0.86, 2.39], p = 0.17). BSID-III percentile scores were similar between IVB and LPC, with weighted mean differences of 1.51 [CI = -1.25, 4.27], 2.43 [CI = -1.36, 6.22], and 1.97 [CI = -1.06, 5.01] for cognitive, language, and motor domains, respectively (p > 0.05).

CONCLUSION

To our knowledge, this is the largest meta-analysis on neurodevelopmental outcomes and the first to rigorously examine IVB monotherapy in ROP treatment. Compared to LPC, there was a marginally increased risk for sNDI and CP with IVB but little or no difference in the risk of msNDI and HI. Further randomized studies are needed to strengthen these findings.

Improved screening of retinopathy of prematurity (ROP): development of a target product profile (TPP) for resource-limited settings

BACKGROUND

As more preterm infants survive, complications of preterm birth, including retinopathy of prematurity (ROP), become more prevalent. ROP rates and blindness from ROP are higher in low-income and middle-income countries, where exposure to risk factors can be higher and where detection and treatment of ROP are under-resourced or non-existent. Access to low-cost imaging devices would improve remote screening capabilities for ROP.

METHODS

Target product profiles (TPPs) are developed early in the medical device development process to define the setting, target user and range of product requirements. A Delphi-like process, consisting of an online survey and consensus meeting, was used to develop a TPP for an ROP imaging device, collecting feedback on a proposed set of 64 product requirements.

RESULTS

Thirty-six stakeholders from 17 countries provided feedback: clinicians (72%), product developers (14%), technicians (6%) and other (8%). Thirty-six per cent reported not currently screening for ROP, with cited barriers including cost (44%), no training (17%) and poor image quality (16%). Among those screening (n=23), 48% use more than one device, with the most common being an indirect ophthalmoscope (87%), followed by RetCam (26%) and smartphone with image capture (26%). Consensus was reached on 53 (83%) product requirements. The 11 remaining were discussed at the consensus meeting, and all but two achieved consensus.

CONCLUSIONS

This TPP process was novel in that it successfully brought together diverse stakeholders to reach consensus on the product requirements for an ROP imaging devices. The resulting TPP provides a framework from which innovators can develop prototypes.

Retinopathy of prematurity among infants admitted to two neonatal intensive care units in Ethiopia

OBJECTIVE

This study was conducted to determine the prevalence and risk factors for retinopathy of prematurity (ROP) in two neonatal intensive care units (NICUs) in Addis Ababa, Ethiopia.

METHODS AND ANALYSIS

A prospective screening survey was conducted from June 2019 to June 2020 in two level 3 public NICUs. Infants with a birth weight (BW) of ≤1500 g or gestational age (GA) of ≤32 weeks and those with a BW of >1500 g and GA of >32 weeks with an unstable clinical course were included. Data on demographic and neonatal characteristics, neonatal and maternal comorbidities, and therapeutic interventions were collected. Logistic regression analysis was used to identify predictors of ROP.

RESULTS

Two hundred and two infants were included: mean BW: 1658g (range: 700-2400 g) and mean GA: 32.4 weeks (range: 26-34 weeks). 32.2% had any stage of ROP, and 6.4% had Type 1 ROP. Lower BW, smaller GA and total days on oxygen were independent risk factors for severe ROP (Type 1 or worse). All 13 neonates with severe ROP were treated.

CONCLUSION

ROP is emerging as a concern in Ethiopia. ROP screening should include neonates with BW of <1800 g or GAs of ≤33 weeks, but further studies are needed in level 2 and private NICUs. Screening guidelines need to be developed and implemented in all hospitals with NICUs.

Clinical and Growth Correlates of Retinopathy of Prematurity in Preterm infants with Surgical Necrotizing Enterocolitis and intestinal Perforation

Background

we sought to determine the clinical and growth parameters associated with retinopathy of prematurity (ROP) in infants with necrotizing enterocolitis (NEC) and spontaneous ileal perforation (SIP).

Methods

Retrospective cohort study comparing clinical information before and following NEC/SIP onset in neonates with and without severe ROP (Type 1 and 2).

Results

Those with severe ROP (32/109, 39.5%) had lower GA, BW, chorioamnionitis, later median onset of ROP diagnosis and received Penrose drain and had higher AKI, poor weight z scores, poor linear growth, longer duration of ventilation and higher FIo2 than those without ROP following NEC/SIP. The GA and diagnosis at later age remained significant for any ROP on multi regression modelling.

Conclusion

The surgical NEC/SIP infants with severe ROP were more likely to be younger, smaller, had AKI, had higher oxygen exposure and poor weight gain and linear growth than those without severe ROP.

The impact of the COVID-19 lockdown on retinopathy of prematurity screening and management in the United States: a multicenter study

PURPOSE

To study the effect of the pandemic-related lockdown (physical distance measures and movement restrictions) on the characteristics and management of retinopathy of prematurity (ROP).

METHODS

In this controlled, multicenter cohort study, the medical records of patients born prematurely and screened for ROP in the neonatal intensive care unit during four time periods were reviewed retrospectively: (1) November 1, 2018, to March 15, 2019; (2) March 16, 2019, to August 2, 2019 (lockdown control period); (3) November 1, 2019, to March 15, 2020; and (4) March 16, 2020-August 2, 2020.

RESULTS

A total of 1,645 patients met inclusion criteria. Among the 1,633 patients with complete data, mean gestational age (GA) at birth was 28.2, 28.4, 28.0, and 28.3 weeks across time periods 1 to 4, respectively (P = 0.16). The mean birth weight of all patients was 1079.1 ± 378.60 g, with no significant variation across time periods (P = 0.08). There were fewer patients screened during the lockdown period (n = 411) compared with the period immediately before (n = 491) and the same period in the prior year (n = 533). Significantly more patients were screened using indirect ophthalmoscopy, compared to digital imaging (telemedicine), during the lockdown (P < 0.01). There were 11.7%, 7.7%, 9.0%, and 8.8% of patients requiring treatment in each time period, respectively (P = 0.42), with a median postmenstrual age at initial treatment of 37.2, 36.45, 37.1, and 36.3 weeks, respectively (P = 0.32).

CONCLUSIONS

We recorded a decrease in the number of infants meeting criteria for ROP screening during the lockdown. The GA at birth and birth weight did not differ. Significantly more infants were screened with indirect ophthalmoscopy, compared to digital imaging, during the lockdown.

Identification of clinical factors associated with timing and duration of spontaneous regression of retinopathy of prematurity not requiring treatment

OBJECTIVE

Identify clinical factors that delay or prolong spontaneous regression of retinopathy of prematurity (ROP).

STUDY DESIGN

Secondary analysis of three prospective studies with 76 infants with ROP not requiring treatment, born ≤30 weeks postmenstrual age (PMA) and ≤1500 grams. Outcomes were PMA at greatest severity of ROP (PMA MSROP), at which regression began, at time of complete vascularization (PMA CV), and regression duration. Pearson's correlation coefficients, t-tests, or analyses of variance were calculated.

RESULTS

Increased positive bacterial cultures, hyperglycemia, transfusion volume of platelets and red blood cells and severity of ROP were associated with later PMA MSROP. Positive bacterial cultures, maternal chorioamnionitis, and less iron deficiency were associated with later PMA CV and prolonged regression duration. Slower length gain was associated with later PMA CV. P < 0.05 for all.

CONCLUSIONS

Preterm infants with inflammatory exposures or linear growth impairment may require longer surveillance for ROP resolution and complete vascularization.

Association of Biomarker-Based Artificial Intelligence With Risk of Racial Bias in Retinal Images

Importance

Although race is a social construct, it is associated with variations in skin and retinal pigmentation. Image-based medical artificial intelligence (AI) algorithms that use images of these organs have the potential to learn features associated with self-reported race (SRR), which increases the risk of racially biased performance in diagnostic tasks; understanding whether this information can be removed, without affecting the performance of AI algorithms, is critical in reducing the risk of racial bias in medical AI.

Objective

To evaluate whether converting color fundus photographs to retinal vessel maps (RVMs) of infants screened for retinopathy of prematurity (ROP) removes the risk for racial bias.

Design, Setting, and Participants

The retinal fundus images (RFIs) of neonates with parent-reported Black or White race were collected for this study. A u-net, a convolutional neural network (CNN) that provides precise segmentation for biomedical images, was used to segment the major arteries and veins in RFIs into grayscale RVMs, which were subsequently thresholded, binarized, and/or skeletonized. CNNs were trained with patients' SRR labels on color RFIs, raw RVMs, and thresholded, binarized, or skeletonized RVMs. Study data were analyzed from July 1 to September 28, 2021.

Main Outcomes and Measures

Area under the precision-recall curve (AUC-PR) and area under the receiver operating characteristic curve (AUROC) at both the image and eye level for classification of SRR.

Results

A total of 4095 RFIs were collected from 245 neonates with parent-reported Black (94 [38.4%]; mean [SD] age, 27.2 [2.3] weeks; 55 majority sex [58.5%]) or White (151 [61.6%]; mean [SD] age, 27.6 [2.3] weeks, 80 majority sex [53.0%]) race. CNNs inferred SRR from RFIs nearly perfectly (image-level AUC-PR, 0.999; 95% CI, 0.999-1.000; infant-level AUC-PR, 1.000; 95% CI, 0.999-1.000). Raw RVMs were nearly as informative as color RFIs (image-level AUC-PR, 0.938; 95% CI, 0.926-0.950; infant-level AUC-PR, 0.995; 95% CI, 0.992-0.998). Ultimately, CNNs were able to learn whether RFIs or RVMs were from Black or White infants regardless of whether images contained color, vessel segmentation brightness differences were nullified, or vessel segmentation widths were uniform.

Conclusions and Relevance

Results of this diagnostic study suggest that it can be very challenging to remove information relevant to SRR from fundus photographs. As a result, AI algorithms trained on fundus photographs have the potential for biased performance in practice, even if based on biomarkers rather than raw images. Regardless of the methodology used for training AI, evaluating performance in relevant subpopulations is critical.

Retinopathy of prematurity detection: a retrospective quality improvement project before-after implementation of retinal digital imaging for screening

Screening of retinopathy of prematurity (ROP) was modified in a level-3 neonatal intensive care unit by the introduction of a wide-field retinal imaging. The aim of this study was to evaluate whether retinopathy of prematurity (ROP) diagnosis was improved or not compared to previously used binocular indirect ophthalmoscopy (BIO). This was a retrospective, uncontrolled, quality improvement project. Records of consecutive premature newborns screened for ROP over two 1-year periods were reviewed. Systemic factors potentially influencing the occurrence of ROP were investigated using uni- and multivariable linear regression followed by stepwise forward regression. ROP screening was performed by ophthalmologists using BIO in 2014, and digital wide-field retinal imaging (Panocam™ pro) in 2019. Records of N = 297 patients were analyzed (N = 159 in 2014 and N = 138 in 2019). The proportion of ROP diagnosed at any stage, over the total number of neonates screened, was significantly higher in 2019 (n = 46/138, 33.1%) compared to 2014 (n = 11/159, 6.9%) (p < 0.0001). Most neonates presented with mild forms of ROP during both 1-year periods analyzed. After adjustment for all parameters influencing ROP occurrence, the variables contributing independently to the diagnosis of any stage of ROP were birth weight (p = 0.002), duration of mechanical ventilation (p = 0.028) and wide-field fundus camera-assisted screening (p < 0.001).

CONCLUSION

After adjusting for many recognized systemic factors influencing the development of ROP, screening by wide-field digital retinal imaging was independently associated with higher ROP detection.

WHAT IS KNOWN

• No consensus has been reached to replace binocular indirect ophthalmoscopy by retinal imaging for ROP screening. • Diagnostic accuracy and high sensitivity and specificity has been reported for wide-field digital imaging.

WHAT IS NEW

• The introduction of wide-field imaging for ROP screening in at level-3 reference center was independently associated to higher ROP detection.

Coenzyme Q10 and Fish Oil Supplementation for Reducing Retinal Oxidative Stress in a Rat Model

Extremely low gestational-age neonates requiring supplemental oxygen experience intermittent hypoxia (IH) episodes, which predispose them to oxidative stress and retinopathy of prematurity. We tested the hypothesis that early supplementation with fish oil or CoQ10 confers benefits reducing the severity of IH-induced retinopathy. At birth, rat pups were exposed to two clinically relevant neonatal IH paradigms with recovery in either hyperoxia (50% O2) or room air (RA) between episodes for 14 days, during which they received daily oral fish oil, coenzyme Q10 (CoQ10) in olive oil (OO), or OO only (vehicle). At postnatal day 14 (P14), pups were allowed to recover in RA with no further treatment until P21. Retinas were examined at P14 and at P21. Both IH paradigms resulted in severe ocular oxidative stress and retinopathy regardless of recovery in hyperoxia or RA in the vehicle groups. Although early supplementation with fish oil was beneficial, CoQ10 provided superior benefits for reducing IH-induced oxidative stress and retinopathy. These effects were associated with lower retinal antioxidants and biomarkers of angiogenesis. The therapeutic benefits of CoQ10 suggest a potential treatment for IH-induced retinopathies. Further studies are needed to establish appropriate, safe, and effective doses for use in preterm infants.

Retinopathy of Prematurity in the 21st Century and the Complex Impact of Supplemental Oxygen

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness. Not only do the epidemiologic determinants and distributions of patients with ROP vary worldwide, but clinical differences have also been described. The Third Edition of the International Classification of ROP (ICROP3) acknowledges that aggressive ROP (AROP) can occur in larger preterm infants and involve areas of the more anterior retina, particularly in low-resource settings with unmonitored oxygen supplementation. As sub-specialty training programs are underway to address an epidemic of ROP in sub-Saharan Africa, recognizing characteristic retinal pathology in preterm infants exposed to unmonitored supplemental oxygen is important to proper diagnosis and treatment. This paper describes specific features associated with various ROP presentations: oxygen-induced retinopathy in animal models, traditional ROP seen in high-income countries with modern oxygen management, and ROP related to excessive oxygen supplementation in low- and middle-income countries: oxygen-associated ROP (OA-ROP).

Pathophysiology of gas exchange impairment in extreme prematurity: Insights from combining volumetric capnography and measurements of ventilation/perfusion ratio

Background

Infants born extremely preterm often suffer from respiratory disease and are invasively ventilated. We aimed to test the hypothesis that gas exchange in ventilated extremely preterm infants occurs both at the level of the alveoli and via mixing of fresh deadspace gas in the airways.

Methods

We measured the normalised slopes of phase II and phase III of volumetric capnography and related them with non-invasive measurements of ventilation to perfusion ratio (V_A/Q) and right-to-left shunt in ventilated extremely preterm infants studied at one week of life. Cardiac right-to-left shunt was excluded by concurrent echocardiography.

Results

We studied 25 infants (15 male) with a median (range) gestational age of 26.0 (22.9-27.9) weeks and birth weight of 795 (515-1,165) grams. The median (IQR) V_A/Q was 0.52 (0.46-0.56) and shunt was 8 (2-13) %. The median (IQR) normalised slope of phase II was 99.6 (82.7-116.1) mmHg and of phase III was 24.6 (16.9-35.0) mmHg. The V_A/Q was significantly related to the normalised slope of phase III (ρ = -0.573, p = 0.016) but not to the slope of phase II (ρ = 0.045, p = 0.770). The right-to-left shunt was not independently associated with either the slope of phase II or the slope of phase III after adjusting for confounding parameters.

Conclusions

Abnormal gas exchange in ventilated extremely preterm infants was associated with lung disease at the alveolar level. Abnormal gas exchange at the level of the airways was not associated with quantified indices of gas exchange impairment.

Computed Analysis of Retinal Vascular Growth After Bevacizumab Treatment of Retinopathy of Prematurity Until Age 3 Years

PURPOSE

Premature infants, after anti-vascular endothelial growth factor injections for retinopathy of prematurity, have persistent peripheral avascular retina (PAR). PAR is ablated with laser; however, physiologic growth of the retinal vasculature in the long term has not been measured. The purposes of this study were to measure retinal vessel growth after treatment with intravitreal bevacizumab (IVB) for retinopathy of prematurity, using serial fluorescein angiography (FA), until age 3 years, and to assess the timing for providing laser ablation in PAR.

METHODS

Data from an observational, longitudinal clinical study were collected. Angiographic images of eyes treated with IVB were included; imaging data from laser photocoagulation were excluded. All eyes underwent initial examination under general anesthesia with FA and photographic imaging. The retinal vessel length was measured from the temporal margin of the optic disc passing through the foveal center, and the lengths at subsequent FA were compared. To compare the changes in retinal vessel length over time in individual eyes, a paired-sample t test was performed.

FINDINGS

FA images from 70 eyes (35 infants) treated with IVB were available. A total of 150 FA images were available for review; data from 125 images of good quality were used for analysis. The mean postmenstrual ages (PMAs) at first, second, third, and fourth FA were 66.2, 100.9, 135.1, and 180.7 weeks, respectively. The mean retinal vessel length was 14.177 mm at first FA and 13.199 mm at fourth FA (PMA range, 42...234 weeks). Retinal vascular lengths of individual eyes compared over time showed no statistically significant growth from the first FA to age 3 years. The changes in retinal vessel length from first to second FA were -0.117 ± 0.79 mm (p = 0.42; n = 30); from first to third FA, +0.060 ± 0.85 mm (p = 0.79; n = 15); and first to fourth FA, -0.404 ± 1.32 mm (p = 0.45; n = 7).

IMPLICATIONS

Beyond 65 weeks' PMA, no meaningful retinal vascular growth occurred after IVB up to age 3 years, guiding the timing for physicians if laser photocoagulation is being considered. Future studies are needed to address retinal growth changes in the growing eyes of infants.

G-ROP criteria for predicting retinopathy of prematurity among neonates with different birth weight percentiles

BACKGROUND

The Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study showed that adding postnatal weight gain to birth weight and gestational age detected 100% of cases with type 1 retinopathy of prematurity (ROP) while reducing the ROP examinations by 30%. The purpose of this study was to investigate whether being small for gestational age (SGA) affects the sensitivity and specificity of the G-ROP model.

METHODS

We applied the G-ROP criteria for premature infants. The infants were classified as three subgroups: SGA, appropriate for gestational age (AGA), and large for gestational age (LGA). The performance of G-ROP criteria was assessed for each group for ROP.

RESULTS

There were 41 (10.5%) SGA, 312 (80%) AGA, and 37 (9.5%) LGA neonates. Twenty-six (6.7%) neonates were treated for ROP, and the G-ROP model identified all of them. The sensitivity of the model for treatment-requiring ROP (TR-ROP) was found to be 100% in the whole patient group and for each subgroup. The specificity for TR-ROP was 46.4% for the whole group, 50% for SGA, 44% for AGA, and 63.6% for LGA. By applying the G-ROP model, the number of ROP examinations could be reduced by 25% for the whole group, 27% for SGA, 24% for AGA, and 31% for LGA, without missing TR-ROP.

CONCLUSIONS

The sensitivity and specificity of the G-ROP model for TR-ROP in SGA infants were similar to the whole group. The model did not miss any cases of TR-ROP.

Outcomes of near confluent laser versus combined less dense laser and bevacizumab treatment of prethreshold ROP Type 1 Zone 2: a randomized controlled trial

BACKGROUND

To evaluate the results of near confluent laser therapy versus combined less dense laser and intra vitreal bevacizumab in treatment of infants with type 1 retinopathy of prematurity (ROP) in zone II.

METHODS

This is a prospective double-blinded randomized clinical trial study. Infants with Type 1 ROP in Zone 2 were randomized into case and control groups. Conventional laser therapy was executed for control group and combination of IVB and laser treatment was employed for the case group.

RESULTS

Eighty-six eyes from 43 infants were analyzed in this trial. The first group included 42 eyes from 21 infants receiving a combination of laser ablation and IVB. The second group contained 44 eyes from 22 infants who received only conventional laser therapy. The combined IVB and laser ablation group demonstrated the neovascularization regression (20 out of 21 infants) one week after the procedure. In the conventional laser therapy group, this regression was found in (12 out of 22 infants) within one week after laser therapy (P = 0.001). Plus disease regression was observed in 20 (20/21) of combined treatment group and 7 infants (7/22) of conventional laser treatment group after one week.

CONCLUSION

Combined less dense laser and bevacizumab treatment resulted in more rapid regression in comparison with the conventional laser treatment.

TRIAL REGISTRATION

IRCT20201120049450N1, 27/12/2021.

Costs associated with retinopathy of prematurity: a systematic review and meta-analysis

OBJECTIVES

To review and analyse evidence regarding costs for retinopathy of prematurity (ROP) screening, lifetime costs and resource use among infants born preterm who develop ROP, and how these costs have developed over time in different regions.

DESIGN

Systematic review and meta-analysis DATA SOURCES: PubMed and Scopus from inception to 23 June 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Included studies presented costs for ROP screening and the lifetime costs (including laser treatment and follow-up costs) and resource use among people who develop ROP. Studies not reporting on cost calculation methods or ROP-specific costs were excluded.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers screened for inclusion and extracted data, including items from a published checklist for quality assessment used for bias assessment, summary and random-effects meta-analysis for treatment costs. Included studies were further searched to identify eligible references and citations.

RESULTS

In total, 15 studies reported ROP screening costs, and 13 reported lifetime costs (either treatment and/or follow-up costs) for infants with ROP. The range for screening costs (10 studies) was US$5-US$253 per visit, or US$324-US$1072 per screened child (5 studies). Costs for treatment (11 studies) ranged from US$38 to US$6500 per child. Four studies reported healthcare follow-up costs (lifetime costs ranging from US$64 to US$2420, and 10-year costs of US$1695, respectively), and of these, three also reported lifetime costs for blindness (range US$26 686-US$224 295) using secondary cost data. Included papers largely followed the quality assessment checklist items, thus indicating a low risk of bias.

CONCLUSION

The costs of screening for and treating ROP are small compared with the societal costs of resulting blindness. However, little evidence is available for predicting the effects of changes in patient population, screening schedule or ROP treatments.

PROSPERO REGISTRATION NUMBER

CRD42020208213.

[Risk factors for recurrence after intravitreal anti-vascular endothelial growth factor injection for retinopathy of prematurity]

OBJECTIVES

To investigate the efficacy of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection in the treatment of retinopathy of prematurity (ROP) and the risk factors for recurrence.

METHODS

A retrospective analysis was performed on the medical data of 159 infants with ROP who were born in the First Affiliated Hospital of Zhengzhou University and underwent anti-VEGF treatment from January 2016 to December 2021. According to the presence or absence of recurrence within the follow-up period after initial anti-VEGF treatment, they were divided into a recurrence group with 24 infants and a non-recurrence group with 135 infants. The medical data were compared between the two groups, and a multivariate logistic regression analysis was used to investigate the risk factors for the recurrence of ROP after anti-VEGF treatment.

RESULTS

After one-time anti-VEGF treatment, all 159 infants showed regression of plus disease. Recurrence was observed in 24 infants (15.1%) after anti-VEGF treatment, with a mean interval of (8.4±2.6) weeks from treatment to recurrence. The multivariate logistic regression analysis showed that preoperative fundus hemorrhage and prolonged total oxygen supply time were risk factors for the recurrence of ROP (P<0.05), while gestational hypertension was a protective factor (P<0.05).

CONCLUSIONS

Intravitreal anti-VEGF injection is effective for ROP. Preoperative fundus hemorrhage and long duration of oxygen therapy may increase the risk of ROP recurrence, and further studies are needed to investigate the influence of gestational hypertension on the recurrence of ROP.

Cumulative hypoxia, socioeconomic deprivation and neurodevelopmental outcomes in preterm infants

BACKGROUND

Hypoxia can adversely affect cognition, while socioeconomic deprivation has also been associated with impaired neurodevelopment in the newborn. We aimed to assess the impact of hypoxia and socioeconomic deprivation on the neurodevelopmental outcomes of preterm infants.

METHODS

Retrospective cohort study at a tertiary neonatal unit between 2015 and 2018. The motor, cognitive and language domain scores of the Bayley-III assessment were recorded at 24 months of corrected gestational age. The percentage of time with pulse oximetry (SpO₂) < 75% was measured from the nursing records, from admission to 36 weeks postmenstrual age in infants born < 30 weeks gestational age. The multiple deprivation index (MDI) and the main care giver's education domain of the MDI were also recorded.

RESULTS

A total of 93,767 data points from 80 infants (34 male) with a median (IQR) gestational age of 27.9(25.9-29.0) weeks and a birth weight of 0.94(0.74-1.23) kg were analysed. The median (IQR) motor score [103(91-110)] was significantly related to the median (IQR) time with SpO₂ < 75% [1.5(0.9-3.4)%, adjusted p = 0.020]. The median (IQR) cognitive score [100(90-105)] was negatively significantly related to the time with SpO₂ < 75% (adjusted p = 0.012) and the median (IQR) education decile of the MDI [7(6-9), adjusted p = 0.011]. The median (IQR) language score [91(77-100)] was significantly positively related to the education domain of the MDI (adjusted p = 0.025).

CONCLUSIONS

Hypoxia in preterm infants exerted a negative impact on motor function and cognition and conversely, higher educational attainment had a positive impact on cognition and language.

Hematopoietic Cells Influence Vascular Development in the Retina

Hematopoietic cells play a crucial role in the adult retina in health and disease. Monocytes, macrophages, microglia and myeloid angiogenic cells (MACs) have all been implicated in retinal pathology. However, the role that hematopoietic cells play in retinal development is understudied. The temporal changes in recruitment of hematopoietic cells into the developing retina and the phenotype of the recruited cells are not well understood. In this study, we used the hematopoietic cell-specific protein Vav1 to track and investigate hematopoietic cells in the developing retina. By flow cytometry and immunohistochemistry, we show that hematopoietic cells are present in the retina as early as P0, and include microglia, monocytes and MACs. Even before the formation of retinal blood vessels, hematopoietic cells localize to the inner retina where they eventually form networks that intimately associate with the developing vasculature. Loss of Vav1 lead to a reduction in the density of medium-sized vessels and an increased inflammatory response in retinal astrocytes. When pups were subjected to oxygen-induced retinopathy, hematopoietic cells maintained a close association with the vasculature and occasionally formed 'frameworks' for the generation of new vessels. Our study provides further evidence for the underappreciated role of hematopoietic cells in retinal vasculogenesis and the formation of a healthy retina.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Propranolol ameliorates retinopathy of prematurity in mice by downregulating HIF-1α via the PI3K/Akt/ERK pathway

BACKGROUND

Retinopathy of prematurity (ROP) is the leading cause of blindness in infants, and elevation of HIF-1α through the PI3K/Akt and ERK pathways is implicated in ROP pathogenesis. The mechanism of action of propranolol in ROP remains controversial. We investigated the effect of propranolol on ROP and explored its potential mechanisms of action in an oxygen-induced retinopathy (OIR) mouse model.

METHODS

OIR mice were first treated with propranolol intraperitoneally, and the retina integrity was measured by FITC-dextran and hematoxylin-eosin staining. The expression of HIF-1α, VEGF, and key signaling pathway proteins was determined using real-time PCR and western blotting.

RESULTS

FITC-dextran staining showed that propranolol treatment reduced damage to retinal morphology in OIR mice. Mice treated with propranolol showed a reduced number of nuclei of vascular endothelial cells penetrating the inner limiting membrane of the retina, confirming the therapeutic effect of propranolol on ROP. Further analysis showed that HIF-1α and PI3K/Akt/ERK pathway protein levels were significantly elevated in OIR mice. In contrast, propranolol treatment downregulated the expression of these proteins, indicating that the PI3K/Akt/ERK/HIF-1α axis is associated with propranolol-induced ROP alleviation.

CONCLUSIONS

Propranolol has a therapeutic function against ROP, likely through the downregulation of HIF-1α via the PI3K/Akt/ERK pathway.

IMPACT

Propranolol can reduce the formation of abnormal retinal neovascularization in oxygen-induced retinopathy (OIR) models, and reduce leaking, tortuous, and abnormally expanding retinal blood vessels. Propranolol possibly improves OIR by inhibiting the activated ERK and HIF-1α pathways. Furthermore, propranolol may downregulate HIF-1α via the PI3K/Akt/ERK pathway to ameliorate retinopathy of prematurity. This study elucidated that the therapeutic effect of propranolol in OIR mice does not involve the VEGFR-2 pathway.

New Aspects on the Treatment of Retinopathy of Prematurity: Currently Available Therapies and Emerging Novel Therapeutics

Retinopathy of prematurity (ROP) is a rare proliferative ocular disorder in preterm infants. Because of the advancements in neonatal care, the incidence of ROP has increased gradually. Now, ROP is one of the leading causes of blindness in children. Preterm infants with immature retinal development are exposed to supplemental oxygen inside an incubator until their cardiopulmonary system is adequately developed. Once they are returned to room air, the relatively low oxygen level stimulates various angiogenesis factors initiating retinal neovascularization. If patients with ROP are not offered adequate and timely treatment, they can experience vision loss that may ultimately lead to permanent blindness. Although laser therapy and anti-vascular endothelial growth factor agents are widely used to treat ROP, they have limitations. Thus, it is important to identify novel therapeutics with minimal adverse effects for the treatment of ROP. To date, various pharmacologic and non-pharmacologic therapies have been assessed as treatments for ROP. In this review, the major molecular factors involved in the pathogenesis of ROP, currently offered therapies, therapies under investigation, and emerging novel therapeutics of ROP are discussed.

S, Chuluunbat T, Munkhuu B, Subramanian P, Venkatapathy N, Jonas KE, Hallak JA, Chan RP, Chiang MF, Kalpathy-Cramer J, Campbell JP. External Validation of a Retinopathy of Prematurity Screening Model Using Artificial Intelligence in 3 Low- and Middle-Income Populations

Importance

Retinopathy of prematurity (ROP) is a leading cause of preventable blindness that disproportionately affects children born in low- and middle-income countries (LMICs). In-person and telemedical screening examinations can reduce this risk but are challenging to implement in LMICs owing to the multitude of at-risk infants and lack of trained ophthalmologists.

Objective

To implement an ROP risk model using retinal images from a single baseline examination to identify infants who will develop treatment-requiring (TR)-ROP in LMIC telemedicine programs.

Design, Setting, and Participants

In this diagnostic study conducted from February 1, 2019, to June 30, 2021, retinal fundus images were collected from infants as part of an Indian ROP telemedicine screening program. An artificial intelligence (AI)-derived vascular severity score (VSS) was obtained from images from the first examination after 30 weeks' postmenstrual age. Using 5-fold cross-validation, logistic regression models were trained on 2 variables (gestational age and VSS) for prediction of TR-ROP. The model was externally validated on test data sets from India, Nepal, and Mongolia. Data were analyzed from October 20, 2021, to April 20, 2022.

Main Outcomes and Measures

Primary outcome measures included sensitivity, specificity, positive predictive value, and negative predictive value for predictions of future occurrences of TR-ROP; the number of weeks before clinical diagnosis when a prediction was made; and the potential reduction in number of examinations required.

Results

A total of 3760 infants (median [IQR] postmenstrual age, 37 [5] weeks; 1950 male infants [51.9%]) were included in the study. The diagnostic model had a sensitivity and specificity, respectively, for each of the data sets as follows: India, 100.0% (95% CI, 87.2%-100.0%) and 63.3% (95% CI, 59.7%-66.8%); Nepal, 100.0% (95% CI, 54.1%-100.0%) and 77.8% (95% CI, 72.9%-82.2%); and Mongolia, 100.0% (95% CI, 93.3%-100.0%) and 45.8% (95% CI, 39.7%-52.1%). With the AI model, infants with TR-ROP were identified a median (IQR) of 2.0 (0-11) weeks before TR-ROP diagnosis in India, 0.5 (0-2.0) weeks before TR-ROP diagnosis in Nepal, and 0 (0-5.0) weeks before TR-ROP diagnosis in Mongolia. If low-risk infants were never screened again, the population could be effectively screened with 45.0% (India, 664/1476), 38.4% (Nepal, 151/393), and 51.3% (Mongolia, 266/519) fewer examinations required.

Conclusions and Relevance

Results of this diagnostic study suggest that there were 2 advantages to implementation of this risk model: (1) the number of examinations for low-risk infants could be reduced without missing cases of TR-ROP, and (2) high-risk infants could be identified and closely monitored before development of TR-ROP.

Semi-automated vessel analysis of en face posterior pole vessel maps generated from optical coherence tomography for diagnosis of plus or pre-plus disease

En face retinal vessel maps generated from bedside optical coherence tomography (OCT) can show posterior pole vascular tortuosity and dilation (ie, plus/pre-plus disease). In this proof-of-concept study, we found that ROPtool could trace OCT-generated retinal vessel maps with high reliability and accuracy for detecting plus or pre-plus disease.

Neurosensory Alterations in Retinopathy of Prematurity: A Window to Neurological Impairments Associated to Preterm Birth

Retinopathy of prematurity (ROP) is one of the main blinding diseases affecting preterm newborns and is classically considered a vascular disorder. The premature exposure to the extrauterine environment, which is hyperoxic in respect to the intrauterine environment, triggers a cascade of events leading to retinal ischemia which, in turn, makes the retina hypoxic thus setting off angiogenic processes. However, many children with a history of ROP show persistent vision impairment, and there is evidence of an association between ROP and neurosensory disabilities. This is not surprising given the strict relationship between neuronal function and an adequate blood supply. In the present work, we revised literature data evidencing to what extent ROP can be considered a neurodegenerative disease, also taking advantage from data obtained in preclinical models of ROP. The involvement of different retinal cell populations in triggering the neuronal damage in ROP was described along with the neurological outcomes associated to ROP. The situation of ROP in Italy was assessed as well.

Celastrol inhibits pathologic neovascularization in oxygen-induced retinopathy by targeting the miR-17-5p/HIF-1α/VEGF pathway

Retinopathy of prematurity (ROP), which is characterized by retinal neovascularization (RNV), is a major cause of neonatal blindness. The primary treatment for ROP is anti-vascular endothelial growth factor (VEGF) therapy, which is costly and can rapidly lead to desensitization. Celastrol, a bioactive compound extracted from Tripterygium wilfordii Hook F. ("Thunder of God Vine"), has been shown to exert anticancer and anti-inflammatory effects. However, whether celastrol has antiangiogenic activity and can suppress inflammation to inhibit ROP progression is unclear. This was investigated in the present study in vitro as well as in vivo using a mouse model of oxygen-induced retinopathy (OIR). Our results showed that celastrol treatment reduced neovascular and avascular areas in the retina and inhibited microglia activation and inflammation in OIR mice. Celastrol also inhibited proliferation, migration, and tube formation in cultured human retinal microvascular endothelial cells, and reversed the activation of the microRNA (miR)-17-5p/hypoxia-inducible factor (HIF)-1α/VEGF pathway in the retina of OIR mice. These results indicate that celastrol alleviates pathologic RNV in the retina by protecting neuroglia and suppressing inflammation via inhibition of miR-17-5p/HIF-1α/VEGF signaling, and thus has therapeutic potential for the prevention and treatment of ROP.Abbreviations: BSA, bovine serum albumin; COX2, cyclooxygenase 2; ECM, endothelial cell medium; FBS, fetal bovine serum; HDAC, histone deacetylase; HIF-1, hypoxia-inducible factor 1; HRMEC, human retinal microvascular endothelial cell; Hsp70, heat shock protein; IB4, isolectin B4; ICAM-1, intercellular adhesion molecule 1; IL-1β/6, interleukin 1 beta/6; MAPK, mitogen-activated protein kinase; MCP-1, monocyte chemoattractant protein 1; miRNA, microRNA; MMP, matrix metalloproteinase; mTOR, mammalian target of rapamycin; NF-κB, nuclear factor-kappa B; OIR, oxygen-induced retinopathy; PBS, phosphate-buffered saline; PCNA, proliferating cell nuclear antigen; PI3K, phosphatidylinositol-3-kinase; qRT-PCR, quantitative real-time PCR; RNV, retinal neovascularization; ROP, retinopathy of prematurity; RTCA, real-time cell analyzer; RVO, retinal vaso-obliteration; TNF-α, tumor necrosis factor alpha; VCAM-1, vascular cell adhesion molecule 1; VEGF, vascular endothelial growth factor.

Synthetic Medical Images for Robust, Privacy-Preserving Training of Artificial Intelligence

Purpose

Developing robust artificial intelligence (AI) models for medical image analysis requires large quantities of diverse, well-chosen data that can prove challenging to collect because of privacy concerns, disease rarity, or diagnostic label quality. Collecting image-based datasets for retinopathy of prematurity (ROP), a potentially blinding disease, suffers from these challenges. Progressively growing generative adversarial networks (PGANs) may help, because they can synthesize highly realistic images that may increase both the size and diversity of medical datasets.

Design

Diagnostic validation study of convolutional neural networks (CNNs) for plus disease detection, a component of severe ROP, using synthetic data.

Participants

Five thousand eight hundred forty-two retinal fundus images (RFIs) collected from 963 preterm infants.

Methods

Retinal vessel maps (RVMs) were segmented from RFIs. PGANs were trained to synthesize RVMs with normal, pre-plus, or plus disease vasculature. Convolutional neural networks were trained, using real or synthetic RVMs, to detect plus disease from 2 real RVM test datasets.

Main Outcome Measures

Features of real and synthetic RVMs were evaluated using uniform manifold approximation and projection (UMAP). Similarities were evaluated at the dataset and feature level using Fréchet inception distance and Euclidean distance, respectively. CNN performance was assessed via area under the receiver operating characteristic curve (AUC); AUCs were compared via bootstrapping and Delong’s test for correlated receiver operating characteristic curves. Confusion matrices were compared using McNemar’s chi-square test and Cohen’s κ value.

Results

The CNN trained on synthetic RVMs showed a significantly higher AUC (0.971; P = 0.006 and P = 0.004) and classified plus disease more similarly to a set of 8 international experts (κ = 0.922) than the CNN trained on real RVMs (AUC = 0.934; κ = 0.701). Real and synthetic RVMs overlapped, by plus disease diagnosis, on the UMAP manifold, showing that synthetic images spanned the disease severity spectrum. Fréchet inception distance and Euclidean distances suggested that real and synthetic RVMs were more dissimilar to one another than real RVMs were to one another, further suggesting that synthetic RVMs were distinct from the training data with respect to privacy considerations.

Conclusions

Synthetic datasets may be useful for training robust medical AI models. Furthermore, PGANs may be able to synthesize realistic data for use without protected health information concerns.