Retinopathy of prematurity: Past, present and future

Retinal toxicity of heavy metals and its involvement in retinal pathology

The objective of the present review is to discuss epidemiological evidence demonstrating the association between toxic metal (Cd, Pb, Hg, As, Sn, Ti, Tl) exposure and retinal pathology, along with the potential underlying molecular mechanisms. Epidemiological studies demonstrate that Cd, and to a lesser extent Pb exposure, are associated with age-related macular degeneration (AMD), while the existing evidence on the levels of these metals in patients with diabetic retinopathy is scarce. Epidemiological data on the association between other toxic metals and metalloids including mercury (Hg) and arsenic (As), are limited. Clinical reports and laboratory in vivo studies have shown structural alterations in different layers of retina following metal exposure. Examination of retina samples demonstrate that toxic metals can accumulate in the retina, and the rate of accumulation appears to increase with age. Experimental studies in vivo and in vitro studies in APRE-19 and D407 cells demonstrate that toxic metal exposure may cause retinal damage through oxidative stress, apoptosis, DNA damage, mitochondrial dysfunction, endoplasmic reticulum stress, impaired retinogenesis, and retinal inflammation. However, further epidemiological as well as laboratory studies are required for understanding the underlying molecular mechanisms and identifying of the potential therapeutic targets and estimation of the dose-response effects.

The Royal College of Paediatrics and Child Health Retinopathy of Prematurity Screening Guidelines (2022): a series of treated infants falling outside the updated criteria

BACKGROUND/OBJECTIVES

Screening for retinopathy of prematurity (ROP) is a core healthcare intervention in premature babies to avoid preventable sight loss. A variety of screening criteria are in place globally for this purpose. The Royal College of Paediatrics and Child Health recently updated the United Kingdom ROP screening guidelines (March 2022). A key change was the reduction in the gestational age (GA) to warrant retinal screening (from 32 to 31 weeks).

SUBJECTS/METHODS

In the course of informal national surveillance during guideline development (2017-2022) and soon after, babies under our care falling outside the updated screening criteria who underwent treatment for ROP were identified. A retrospective case review was carried out.

RESULTS

Six babies were identified as having undergone screening and treatment, prior to implementation of the new guidance. Screening and treatment would have been forfeited as per the March 2022 guidelines. All six had numerous systemic risk factors for developing ROP. Specifically, all had documented poor postnatal weight gain.

CONCLUSIONS

We present this case series to bring forth an urgent discussion amongst key stakeholders as to whether the new guidance, as it stands, is safe and fit for purpose.

Comparing reactivation and retreatment for three doses of bevacizumab in type 1 retinopathy of prematurity

PURPOSE

To determine timing and rates of reactivation and retreatment of type 1 retinopathy of prematurity (ROP) after treatment with either 0.125 mg, 0.250 mg, or 0.500 mg of intravitreal bevacizumab (IVB).

METHODS

Retrospective data, including demographic information, past medical history, and ROP characteristics were analyzed for babies with type 1 ROP treated with IVB at Riley Hospital for Children for the perioed 2014-2021.

RESULTS

A total of 84 patients met inclusion criteria: 29 patients received 0.125 mg of IVB; 39, 0.250 mg; and 16, 0.500 mg. Of the 84, 67 (80%) had additional laser treatment because of late reactivation (n = 52) or persistent avascular retina (PAR) (n = 15). Subsequent laser treatment was more common with lower doses: 0.125 mg (n = 27 [93%]); 0.250 mg (n = 31 [80%]); 0.500 mg (n = 9 [57%]) (P = 0.012). There was no difference between groups with regard to reason for subsequent laser treatment (reactivation vs PAR). The 0.125 mg group required retreatment because of reactivation 3.8 weeks sooner than the other dosing groups (P = 0.047).

CONCLUSIONS

The outcomes comparing three doses of IVB for severe ROP showed a difference in the timing of secondary treatment, with the lower dosing group requiring laser for reactivation earlier.

A Narrative Review on Managing Retinopathy of Prematurity: Insights Into Pathogenesis, Screening, and Treatment Strategies

Retinopathy of prematurity (ROP) is a rare proliferative ocular condition that can happen in premature babies (born preterm <36 weeks) or who weigh <1.5 kg at birth (low birth weight babies). ROP is a major cause of childhood blindness. It is a premature disease since retina vascularization is completed only by 40 weeks of life. The survivability for preterm infants has increased owing to recent improvements in neonatal care during the past decade. As a result, the prevalence of ROP has risen concurrently. The abnormal development of blood vessels in the retina is the cause of this illness. It occurs in two phases, phases 1 and 2. Most preterm infants weighing <1.5 kg need supplemental oxygen for respiratory support at birth. This leads to the initiation of phase 1 (vasoconstrictive phase). Phase 1 is characterized by loss of maternal-fetal connection and hyperoxia due to supplemental oxygen therapy. Oxygen's vasoconstrictive and obliterative action is primarily observed in developing retinal vessels. The inhibition of vascular endothelial growth factor follows from this. Phase 2 (vasoproliferative phase) shows the dilatation and tortuosity of the bigger existing vessels together with neovascularization and proliferation of new vessels into the vitreous when the baby is shifted from respiratory support to room air. Now, the retina gets hypoxic, where the retina becomes more metabolically active but is yet minimally vascularized, leading to VEGF-induced vasoproliferation, which might result in retinal detachment. Patients with ROP face the danger of loss of vision. If correct and quick treatment is not provided, they might land into permanent blindness. Yet, ROP remains one of the most preventable causes of childhood blindness worldwide. Blindness caused by ROP can only be avoided if screening programs are readily available, pertinent, and appropriate. The initial stage in the therapy of ROP is the screening of premature neonates. Timely screening and management for ROP is important to avoid this irreversible loss of vision. The treatment is based on the severity of the disease. Management may include pharmacological interventions like intravitreal and anti-vascular endothelial growth factor and non-pharmacological interventions like laser surgery, vitrectomy, and scleral buckling. We conducted a thorough literature search of studies on pathogenesis, risk factors, classification, and various treatment options for retinopathy of prematurity in infants, using a mixture of pertinent keywords. Only those studies published in peer-reviewed journals between 2010 and 2023 and written in English were included. Duplicate studies, unavailable in full-text for free, or studies unrelated to our subject matter were excluded. After thoroughly evaluating the selected studies, the results were synthesized and presented narratively. This article sheds light on the pathogenesis of ROP, particularly its relation to oxygen use, screening, and potential therapeutic management of ROP. Today advances in screening techniques have improved the outcomes for infants with ROP. Still, ongoing research is needed to optimize management strategies and reduce the burden of this condition.

Image-free recognition of moderate ROP from mild with machine learning algorithm on plasma Raman spectrum

The retinopathy of prematurity (ROP) can cause serious clinical consequences and, fortunately, it is remediable while the time window for treatment is relatively narrow. Therefore, it is urgent to screen all premature infants and diagnose ROP degree timely, which has become a large workload for pediatric ophthalmologists. We developed a retinal image-free procedure using small amount of blood samples based on the plasma Raman spectrum with the machine learning model to automatically classify ROP cases before medical intervention was performed. Statistical differences in infrared Raman spectra of plasma samples were found among the control, mild (ZIIIS1), moderate (ZIIIS2 & ZIIS1), and advanced (ZIIS2) ROP groups. With the different wave points of Raman spectra as the inputs, the outputs of our support vector machine showed that the area under the curves in the receiver operating characteristic (AUC) were 0.763 for the pair comparisons of the control with the mild groups, 0.821 between moderate and advanced groups (ZIIS2), while more than 90% in comparisons of the other four pairs: control vs. moderate (0.981), control vs. advanced (0.963), mild vs. moderate (0.936), and mild vs. advanced (0.953), respectively. Our study could advance principally the ROP diagnosis in two dimensions: the moderate ROPs have been classified remarkably from the mild ones, which leaves more time for the medical treatments, and the procedure of Raman spectrum with a machine learning model based on blood samples can be conveniently promoted to those hospitals lacking of the pediatric ophthalmologists with experience in reading retinal images.

Prevalence and pattern of retinopathy of prematurity at two national referral hospitals in Uganda: a cross-sectional study

BACKGROUND

Retinopathy of prematurity (ROP) is a leading cause of blindness in children and an ROP epidemic is predicted this decade in sub-Saharan Africa. With the increasing survival rate of preterm babies in Uganda, and no data on ROP prevalence, there is a need to assess the burden of ROP to inform preventive strategies and targeted screening.

METHODS

We conducted a two-center cross-sectional study of preterm (< 37 weeks gestational age) infants from the neonatal units of Kawempe National Referral Hospital (KNRH) and Mulago Specialised Women and Neonatal Hospital (MSWNH) from August 2022 to October 2022. An ophthalmologist examined all participants using an indirect ophthalmoscope with a + 20D convex lens and captured digital images using a Volk iNview™ Fundus Camera. The collected data were entered into Epidata 4.2 and exported to Stata 14.0 for analysis.

RESULTS

331 preterm infants enrolled in this study. The oxygen received was unblended. The mean gestational age was 30.4 ± 2.7 weeks, and the mean birth weight was 1597 ± 509 g. 18/101 (17.8%) were found to have any ROP amongst the preterm infants recruited from MSWNH, 1/230 (0.4%) from KNRH [95% CI] had any stage of ROP (i.e. stage 5). Of these, 8 (42.1%) had stage 2 ROP. Infants with a birth weight below 1500 g were 10 times more likely to have ROP than those among infants with a birth weight more than 1500 g [AOR: 10.07 (2.71-37.44)]. Infants who were not fed exclusively on breast milk had higher odds of having ROP than those exclusively fed on breast milk [AOR: 7.82(1.92-31.82)].

CONCLUSION

6% of preterm infants born in two tertiary hospitals in Uganda were found to have ROP. Lack of exclusive feeding on breast milk and birth weight of less than 1500 g were strong predictors of ROP. The higher prevalence of ROP in MSWNH calls for cautious use of oxygen among preterms. We recommend targeted ROP screening for those at risk.

Image harmonization and deep learning automated classification of plus disease in retinopathy of prematurity

Purpose

Retinopathy of prematurity (ROP) is a retinal vascular disease affecting premature infants that can culminate in blindness within days if not monitored and treated. A disease stage for scrutiny and administration of treatment within ROP is "plus disease" characterized by increased tortuosity and dilation of posterior retinal blood vessels. The monitoring of ROP occurs via routine imaging, typically using expensive instruments ($50 to $140 K) that are unavailable in low-resource settings at the point of care.

Approach

As part of the smartphone-ROP program to enable referrals to expert physicians, fundus images are acquired using smartphone cameras and inexpensive lenses. We developed methods for artificial intelligence determination of plus disease, consisting of a preprocessing pipeline to enhance vessels and harmonize images followed by deep learning classification. A deep learning binary classifier (plus disease versus no plus disease) was developed using GoogLeNet.

Results

Vessel contrast was enhanced by 90% after preprocessing as assessed by the contrast improvement index. In an image quality evaluation, preprocessed and original images were evaluated by pediatric ophthalmologists from the US and South America with years of experience diagnosing ROP and plus disease. All participating ophthalmologists agreed or strongly agreed that vessel visibility was improved with preprocessing. Using images from various smartphones, harmonized via preprocessing (e.g., vessel enhancement and size normalization) and augmented in physically reasonable ways (e.g., image rotation), we achieved an area under the ROC curve of 0.9754 for plus disease on a limited dataset.

Conclusions

Promising results indicate the potential for developing algorithms and software to facilitate the usage of cell phone images for staging of plus disease.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Identifying novel candidate compounds for therapeutic strategies in retinopathy of prematurity via computational drug-gene association analysis

Purpose

Retinopathy of prematurity (ROP) is the leading cause of preventable childhood blindness worldwide. Although interventions such as anti-VEGF and laser have high success rates in treating severe ROP, current treatment and preventative strategies still have their limitations. Thus, we aim to identify drugs and chemicals for ROP with comprehensive safety profiles and tolerability using a computational bioinformatics approach.

Methods

We generated a list of genes associated with ROP to date by querying PubMed Gene which draws from animal models, human studies, and genomic studies in the NCBI database. Gene enrichment analysis was performed on the ROP gene list with the ToppGene program which draws from multiple drug-gene interaction databases to predict compounds with significant associations to the ROP gene list. Compounds with significant toxicities or without known clinical indications were filtered out from the final drug list.

Results

The NCBI query identified 47 ROP genes with pharmacologic annotations present in ToppGene. Enrichment analysis revealed multiple drugs and chemical compounds related to the ROP gene list. The top ten most significant compounds associated with ROP include ascorbic acid, simvastatin, acetylcysteine, niacin, castor oil, penicillamine, curcumin, losartan, capsaicin, and metformin. Antioxidants, NSAIDs, antihypertensives, and anti-diabetics are the most common top drug classes derived from this analysis, and many of these compounds have potential to be readily repurposed for ROP as new prevention and treatment strategies.

Conclusion

This bioinformatics analysis creates an unbiased approach for drug discovery by identifying compounds associated to the known genes and pathways of ROP. While predictions from bioinformatic studies require preclinical/clinical studies to validate their results, this technique could certainly guide future investigations for pathologies like ROP.

Tear-based MMP-9 detection: A rapid antigen test for ocular inflammatory disorders using vanadium disulfide nanowires assisted chemi-resistive biosensor

A sensitive, non-invasive, and biomarker detection in tear fluids for inflammation in potentially blinding eye diseases could be of great significance as a rapid diagnostic tool for quick clinical decisions. In this work, we propose a tear-based MMP-9 antigen testing platform using hydrothermally synthesized vanadium disulfide nanowires. Also, various factors contributing to baseline drifts of the chemiresistive sensor including nanowire coverage on the interdigitated microelectrode of the sensor, sensor response duration, and effect of MMP-9 protein in different matrix solutions were identified. The drifts on the sensor baseline due to nanowire coverage on the sensor were corrected using substrate thermal treatment providing a more uniform distribution of nanowires on the electrode which brought the baseline drift to 18% (coefficient of variations, CV = 18%). This biosensor exhibited sub-femto level limits of detection (LODs) of 0.1344 fg/mL (0.4933 fmoL/l) and 0.2746 fg/mL (1.008 fmoL/l) in 10 mM phosphate buffer saline (PBS) and artificial tear solution, respectively. For a practical tear MMP-9 detection, the proposed biosensor response was validated with multiplex ELISA using tear samples from five healthy controls which showed excellent precision. This label-free and non-invasive platform can serve as an efficient diagnostic tool for the early detection and monitoring of various ocular inflammatory diseases.

Serum Zinc Levels in Preterm Newborns and its Relation with Retinopathy of Prematurity

Background

With the increased survival of preterm babies, retinopathy of prematurity (ROP) has become the leading cause of preventable childhood blindness. It is caused by oxidative damage to the immature retina and zinc may help in the prevention of ROP owing to its antioxidant properties.

Objective

To measure serum zinc levels in preterm neonates and study its association with the development of ROP.

Methods

A total of 360 preterm neonates of gestational age between 28 completed weeks to <37 weeks were included in this observational cross-sectional study. Serum zinc levels of the neonates aging <24 hours of life were measured at the time of admission in NICU by spectrophotometry. Taking the reference range of serum zinc levels between 70 to 150 mcg/dL babies were arbitrarily divided into 2 groups (<70 and >70 mcg/dL). ROP screening was done at appropriate postnatal age by indirect ophthalmoscopy. The results were analyzed by the SPSS software version.

Results

The mean serum zinc level was 114.99±54.47 mcg/dL. The overall prevalence of ROP was 26%; of which, 10% of neonates had severe ROP (≥stage 3). A significant association was found between gestational age and birth weight with ROP. Oxygen supplementation, respiratory distress syndrome, surfactant use, antibiotic use >7 days, and low serum zinc levels (<70 mcg/dL) were significant risk factors on univariate analysis and after multivariate analysis, gestational age, surfactant use, and low serum zinc levels (<70 mcg/dL) came out to be independent risk factors for ROP.

Conclusion

There was a statistically significant association of low serum zinc levels with the development of ROP and it was independent of other risk factors associated with ROP.

Refractive profile of children treated with intravitreal bevacizumab for retinopathy of prematurity

Purpose

To study the refractive profile of children after they received intravitreal injection of bevacizumab for retinopathy of prematurity (ROP).

Methods

The study was conducted at a tertiary eye care hospital in South India. ROP patients of more than 1 year of age, presenting to the Pediatric Ophthalmology Clinic and Retina Clinic and having history of treatment for type I ROP with intravitreal bevacizumab (IVB) or intravitreal bevacizumab and laser photocoagulation were included in the study. Cycloplegic refraction was done, and the refractive status was evaluated. The refractive status of age-matched, full-term children with uneventful perinatal and neonatal history was also recorded and compared to the study group.

Results

Among 134 eyes of 67 study subjects, the major refractive error was myopia in 93 eyes (69.4%; spherical equivalent [SE] = -2.89 ± 3.1, range = -11.5 to -0.5 D). There were 75 eyes (56%) with low-to-moderate myopia; high myopia was seen in 13.4%, emmetropia in 18.7%, and hypermetropia in 11.9% of eyes. The majority of them (87%) had with-the-rule (WTR) astigmatism. In 134 eyes, the SE was -1.78 ± 3.2 (range = -11.5 to 4 D); the SE of the 75 eyes with low-to-moderate myopia was -1.53 ± 1.2 (range = -0.50 to -5 D). In the control group, the majority had emmetropia (91.8%). There was no significant association between the age at which IVB had been injected and the development of refractive errors (P = 0.078). The prevalence of low-to-moderate myopia was more than high myopia in patients with zone I and zone II ROP before treatment (60.0% and 54.5%, respectively).

Conclusion

Myopia was the major refractive error seen in post-IVB pediatric patients. WTR astigmatism was more commonly seen. The age at which IVB injection had been given had no effect on the development of refractive errors.

The Antiangiogenic Effect and Ocular Pharmacology of Novel Modified Nonsteroidal Anti-Inflammatory Drugs in the Treatment of Oxygen-Induced Retinopathy

Purpose: To evaluate the hypothesis that 3 novel compounds, OXT-328, Q-922, and CL-717 show efficacy in the treatment of oxygen-induced retinopathy (OIR) and whether or not their route of administration is intravitreal, topical, or systemic. Methods: The OIR mouse model, characterized by an avascular area (AVA) and a neovascular area (NVA) of the retina, was used to study retinopathy of prematurity and other retinal diseases characterized by abnormal vessel growth. We measured the effect of our compounds on both the AVA and NVA in whole mounts of mouse retinal tissue. We also evaluated their ability to prevent new vessel formation in chicken chorioallantoic membranes (CAMs). Finally, we measured the in vitro uptake and biodistribution of topically applied CL-717 in human eye explants. Results: In mice with OIR, compared to controls, a single intravitreal administration of Q-922 or OXT-328 significantly reduced both AVA and NVA. CL-717 administered as eye drops over 5 days also reduced AVA and NVA, whereas OXT-328 eye drops had no effect. Q-922 given intraperitoneal (150 mg/kg/day × 5 days) reduced AVA and NVA. Remarkably, explanted human eyes bathed in CL-717 show rapid uptake and biodistribution in ocular tissues. In the chicken CAM model, all 3 compounds reduced the formation of new blood vessels by about one-third. No side effect in mice was observed, except for mild ocular surface irritation with Q-922. Conclusions: Systemic administration of Q-922 or topical administration of CL-717 holds particular promise for a simplified treatment of proliferative retinopathies without the necessity of intravitreal injections.

The Top 100 Most Cited Manuscripts in Retinopathy of Prematurity: A Bibliometric Analysis

PURPOSE

To systematically summarize the research trends and emphases of ROP in the past decades by analyzing the characteristics of the top 100 cited ROP articles.

METHODS

The 100 most cited articles on ROP published from January 1, 1950 to December 31, 2021 were searched by Web of Science. Information such as year of publication, number of citations, journal and impact factor, type of research and topic, country of origin, institution and authorship of each article was extracted to analyze its characteristics.

RESULTS

A total of 15,928 articles were returned. These articles were published in 43 journals between 1952 and 2018, originating from 14 countries. The most widely published journal was Pediatrics (n = 19, IF = 8.109), followed by Archives of Ophthalmology (n = 15, IF = 4.399). The most cited paper (Gole et al. Archives of Ophthalmology 2005 Jul, 1614 citations) reported on the international classification of ROP. The most prevalent topic was the pathophysiology of ROP (n = 39), followed by the treatment of ROP (n = 32). Most were original research (n = 72), mainly based on research design of basic science. The most published articles were published in the United States (n = 61), and the institutions were Oregon Health & Science University, Dept Ophthalmol (n = 7).

CONCLUSIONS

These 100 most frequently cited papers reflect the significant progress and several hot topics of ROP in recent decades, and this paper will help us further understand the knowledge and progress of ROP diagnosis and treatment.

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).

Latest Trends in Retinopathy of Prematurity: Research on Risk Factors, Diagnostic Methods and Therapies

Retinopathy of prematurity (ROP) is a vasoproliferative disorder with an imminent risk of blindness, in cases where early diagnosis and treatment are not performed. The doctors' constant motivation to give these fragile beings a chance at life with optimal visual acuity has never stopped, since Terry first described this condition. Thus, throughout time, several specific advancements have been made in the management of ROP. Apart from the most known risk factors, this narrative review brings to light the latest research about new potential risk factors, such as: proteinuria, insulin-like growth factor 1 (IGF-1) and blood transfusions. Digital imaging has revolutionized the management of retinal pathologies, and it is more and more used in identifying and staging ROP, particularly in the disadvantaged regions by the means of telescreening. Moreover, optical coherence tomography (OCT) and automated diagnostic tools based on deep learning offer new perspectives on the ROP diagnosis. The new therapeutical trend based on the use of anti-VEGF agents is increasingly used in the treatment of ROP patients, and recent research sustains the theory according to which these agents do not interfere with the neurodevelopment of premature babies.

Operationalization of Retinopathy of Prematurity Screening by the Application of the Essential Public Health Services Framework

Retinopathy of prematurity (ROP) is one of the leading causes of preventable pediatric blindness worldwide. ROP screening programs have been previously implemented in multiple low- and middle-income countries. On a global scale, it is crucial that evidence-based, standardized screening criteria are utilized in the early detection and treatment of ROP. In this review article, we utilize the National Public Health Performance Standards (NPHPS) Ten Essential Public Health Services Model organized by the core functions of assessment, policy development, and assurance to evaluate the barriers and successes of existing ROP screening programs. This framework can be applied to countries facing the third epidemic of ROP and can be used to establish a generalized model for eye care and screening worldwide.

Potential Role of Bilirubin in Preventing Retinopathy of Prematurity

BACKGROUND

One of the most common problems in preterm neonates is retinopathy of prematurity (ROP). It has been shown antioxidants may be effective in preventing the development and progression of ROP. Considering the antioxidant properties of bilirubin, we decided to investigate the bilirubin level in neonates with ROP and compare it with healthy neonates.

METHODS

This case-control study was performed on VLBW neonates admitted to the NICU of Ghaem Hospital in Mashhad between 2014 and 2020 for a Jaundice evaluation. Complete neonate's characteristics, maternal history and laboratory results were collected in a questionnaire. Then the neonates were examined for ROP by a fellowship of the retina of an ophthalmologist at 32 weeks or four weeks after birth. The highest bilirubin levels during their hospitalization were also recorded.

RESULTS

Of 427 neonates examined, 121 (37.7%) had a normal eye examination, and 266 (62.3%) had ROP. The mean weight, gestational age and bilirubin were 1455.8 ± 431.4 grams, 31.6 ± 2.3 weeks and 8.8 ± 2.4 mg/dl, respectively. There was a significant difference between controls and neonates with ROP with regard to birth weight, duration of intermittent positive pressure ventilation (IPPV), duration of oxygen therapy, first and fifth minute Apgar scores, the maximum level of bilirubin and gestational age (P < 0.05). It was observed that the maximum level of bilirubin was lower in neonates with higher stages of ROP.

CONCLUSION

According to the results of this study, higher levels of bilirubin in neonates may be a protective factor against ROP. Moreover, increased levels of bilirubin are associated with reduced severity of ROP. Therefore, prophylaxis phototherapy in premature infants may need to be reconsidered.

Late Vitreoretinal Complications of Regressed Retinopathy of Prematurity: Retinal Break, Vitreous Hemorrhage, and Retinal Detachment

PURPOSE

To investigate late vitreoretinal complications and visual outcomes in patients with regressed retinopathy of prematurity (ROP) with or without prior treatment.

DESIGN

International, multicenter, noncomparative retrospective case series.

PARTICIPANTS

We analyzed 264 eyes of 238 patients from 13 centers worldwide who developed vitreoretinal complications (retinal detachment [RD], vitreous hemorrhage [VH], or retinal break) ≥ 2 years after resolution of acute ROP.

METHODS

Each participant was assigned to 1 of 3 groups (the RD, VH, and retinal break groups) according to their primary diagnosis. The average age at presentation, visual acuities, refractive error, axial length, gestational age, birth weight, acute ROP classification, prior treatments for acute ROP, postoperative visual acuity (VA), and concomitant eye conditions in the 3 groups were documented and compared.

MAIN OUTCOME MEASURES

Clinical features and visual outcomes of late vitreoretinal complications in patients with regressed ROP.

RESULTS

A total of 264 eyes of 238 patients were included. The prior acute ROP status was comparable among the 3 groups, except that the VH group had a higher proportion of patients with type 1 ROP (P = 0.03) and prior treatment (P < 0.001) than the other groups. The average age at presentation was earlier in the RD (20.3 ± 15.5 years) and VH (21.4 ± 18.9 years) groups than in the retinal break group (31.9 ± 18.2 years; P < 0.001). The retinal break group had the best presenting best-corrected VA, followed by the RD and VH groups (P < 0.001). Surgical intervention improved VA in both the RD and VH groups (both P < 0.05). The overall trend of VA was the most favorable in the retinal break group, followed by that in the VH and RD groups. Cicatricial changes in the fellow retina were observed in > 90% of patients with unilateral involvement.

CONCLUSIONS

Infants with acute ROP remain at a high risk of vision-threatening complications throughout childhood and adulthood. Continual follow-up of patients with ROP is important. When severe complications, such as RD or VH, are detected, timely surgical intervention is necessary to ensure favorable visual outcomes in these patients.

Comparison of intravitreal injection of ranibizumab versus bevacizumab for treatment of type 1 and aggressive retinopathy of prematurity in rural Egypt. A randomized clinical trial

Objective

The objective of this study is to evaluate the efficacy of intravitreal ranibizumab (IVR) monotherapy compared with intravitreal bevacizumab (IVB) monotherapy for treatment of type 1 and aggressive retinopathy of prematurity (ROP) in rural Egypt.

Methods

36 eyes of 18 infants with bilateral aggressive or type 1 ROP were recruited between September 2020 and September 2022. Mean follow-up duration was 16.53 months. IVB was injected in the right eye and IVR in the left eye, rescue injection of the same initial anti-vascular endothelial growth factor (VEGF) in case of ROP reactivation. Outcome measures included regression achieved either by single injection or multiple injections or additional laser therapy at 55 weeks’ postmenstrual age (PMA), recurrence of ROP, total retinal vascularisation time and complications.

Results

Initial regression of ROP within 1 week occurred in 11/18 eyes (61.1%) in bevacizumab group and 15/18 eyes (83.3%) in ranibizumab group (p=0.137). Primary outcome measure was achieved in 14/18 eyes (77.8%) and 16/18 eyes (88.9%) in bevacizumab and ranibizumab groups, respectively (p=0.658). Late reactivation requiring retreatment with anti-VEGF was encountered in 4/18 eyes (22.2%) and 1/18 eyes (5.6%) in bevacizumab and ranibizumab groups, respectively (p=0.338). Peripheral laser therapy on the avascular retina was done in 3/18 eyes (16.7%) in each group at mean of 55.67 weeks' PMA.

Conclusion

Bevacizumab and ranibizumab proved to be effective regarding regression of acute ROP and continuing peripheral retinal vascularisation. Higher proportion of reactivation with bevacizumab, however, clinically non-significant. Laser therapy can be postponed to reduce its complications.

Trial registration number

NCT05033106.

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.

Retinopathy of prematurity, a two-year experience at the ROP screening unit from AL-Zahraa Teaching Hospital, AL-Najaf, Iraq

This study aimed to assess the incidence of retinopathy of prematurity (ROP) in Al Najaf city, define the risk factors of ROP, and assess the performance of the newly implemented ROP screening. This retrospective study was performed in the ROP screening clinic in Al Najaf city between January 2018 and December 2019. 247 neonates were examined at the ROP screening clinic, with gestational age ≤30 weeks, weight ≤1500 g, other fetal and maternal risk factors, and older or heavier newborns with a complicated course. Out of all the neonates, 90 were enrolled in this study because all others lost contact with the ROP clinic. 62 out of 90 enrolled neonates (69%) were diagnosed with ROP. Of them, 82% had stage 1-2 ROP, and 18% had stage 3-4. We found that the higher gestational age was protective for ROP (P-value=0.012, OR=0.434, CI=0.227-0.829). CPAP carried a higher risk of ROP (P-value=0.072, OR=7.276, CI=0.834-63.441). The P-value was significant for maternal age and premature rupture of membranes (PROM) (P-value=0.028 and 0.01, respectively). This study showed the incidence of ROP in the accepted range compared to other countries with similar resources. Furthermore, there was a strong association between ROP and the following factors: decreased gestational age, CPAP, maternal age, and PROM.

Retinopathy of prematurity screening: A narrative review of current programs, teleophthalmology, and diagnostic support systems

PURPOSE

Neonatal care in middle-income countries has improved over the last decade, leading to a "third epidemic" of retinopathy of prematurity (ROP). Without concomitant improvements in ROP screening infrastructure, reduction of ROP-associated visual loss remains a challenge worldwide. The emergence of teleophthalmology screening programs and artificial intelligence (AI) technologies represents promising methods to address this growing unmet demand in ROP screening. An improved understanding of current ROP screening programs may inform the adoption of these novel technologies in ROP care.

METHODS

A critical narrative review of the literature was carried out. Publications that were representative of established or emerging ROP screening programs in high-, middle-, and low-income countries were selected for review. Screening programs were reviewed for inclusion criteria, screening frequency and duration, modality, and published sensitivity and specificity.

RESULTS

Screening inclusion criteria, including age and birth weight cutoffs, showed significant heterogeneity globally. Countries of similar income tend to have similar criteria. Three primary screening modalities including binocular indirect ophthalmoscopy (BIO), wide-field digital retinal imaging (WFDRI), and teleophthalmology were identified and reviewed. BIO has documented limitations in reduced interoperator agreement, scalability, and geographical access barriers, which are mitigated in part by WFDRI. Teleophthalmology screening may address limitations in ROP screening workforce distribution and training. Opportunities for AI technologies were identified in the context of these limitations, including interoperator reliability and possibilities for point-of-care diagnosis.

CONCLUSION

Limitations in the current ROP screening include scalability, geographical access, and high screening burden with low treatment yield. These may be addressable through increased adoption of teleophthalmology and AI technologies. As the global incidence of ROP continues to increase, implementation of these novel modalities requires greater consideration.

The U.S. National Trend for Retinopathy of Prematurity

OBJECTIVE

The use of supplemental oxygen in premature infants is essential for survival. However, its use has been associated with unintended complications. The restricted use of oxygen is associated with increased mortality and necrotizing enterocolitis (NEC), whereas its liberal use is associated with increased risk for retinopathy of prematurity (ROP). Although there is no clear consensus on the acceptable oxygen saturation range, clinicians have recently become more liberal with the use of oxygen. We aim to assess (1) the national trends for ROP in very low birth weight preterm infants, and (2) the associated trends in mortality, NEC, intraventricular hemorrhage (IVH), and length of hospital stay (LOS).

STUDY DESIGN

We analyzed deidentified patient data from the National Inpatient Sample (NIS) of the Healthcare Cost and Utilization Project (HCUP) from 2002 to 2017. All infants with gestational age ≤32 weeks and birth weight <1,500 g were included. Trends in ROP, severe ROP, mortality, NEC, IVH, severe IVH, and LOS were analyzed using Jonckheere-Terpstra test.

RESULTS

A total of 818,945 neonates were included in the study. The overall mortality was 16.2% and the prevalence of ROP was 17.5%. There was a significant trend for increased ROP over the years (p < 0.001). Severe ROP was also significantly increased (p < 0.001). This was associated with a significant trend for increased median LOS in survived infants (p < 0.001). Mortality was significantly decreased (p < 0.001), whereas NEC and severe NEC did not change over time (p = 0.222 and p = 0.412, respectively).

CONCLUSION

There is a national trend for increased ROP and severe ROP over the 16 years of the study period. This trend was associated with a significant increase in the LOS in survived infants without change in NEC.

KEY POINTS

· Prevalence of ROP and severe ROP has increased in VLBW infants over the 16-year study period.. · The prevalence of NEC did not change over the same time period.. · Increased ROP and severe ROP were consistent in all three GA and BW subgroups..

Development of myopia in laser-treated ROP infants: prematurity or laser photocoagulation?

PURPOSE

To investigate the relationship between the development of corrected 1-year-old refraction values and risk factors in preterm infants who underwent laser photocoagulation (LPC) therapy for retinopathy of prematurity (ROP).

METHODS

The ophthalmic examination findings of preterm neonates who had developed Type I ROP and received LPC therapy were evaluated retrospectively. The association between spherical equivalent (SE) values and clinical findings were analyzed by using multivariable linear regression analysis.

RESULTS

The study included 157 eyes of 80 neonates with a mean birth week of 27.1 ± 2.2 weeks (23 to 32 weeks) and a mean birth weight of 995 ± 273 g (565 to 1760 g). The treatments were administered on an average of 36.8 ± 2.7 (32 to 45 weeks) postmenstrual age. LPC treatment was applied bilaterally to 77 of the 80 neonates included in the study, and unilaterally to 3 of them. The mean ± standard deviation of the SE value was 0.31 ± 1.89 diopters (D) (- 8.00 to 4.63 D) according to the results of the 1-year corrected age refraction examination. In univariate analysis, no significant association between GA, BW, and ROP zone and SE value, while the number of laser spots (ß =  - 0.27 ± 0.00 D, p = 0.00) and stage 3 ROP (ß =  - 0.29 ± 0.37 D, p = 0.00) were significantly associated with the SE value. In multivariable linear regression analysis, a significant association between number of laser spot, stage 3 ROP and SE value (ß =  - 0.25 ± 0.00 D, p = 0.01 for number of laser spot, ß =  - 0.28 ± 0.36 D, p = 0.00 for stage 3 ROP).

CONCLUSION

In conclusion, this study supports that stage of ROP and the number of laser spots count applied in photocoagulation treatment for ROP is significantly correlated with degree of myopia (p < 0.05).

ROP-like retinopathy in full/near-term newborns: A etiology, risk factors, clinical and genetic characteristics, prognosis and management

Purpose

Retinopathy of prematurity (ROP) like retinopathy (ROPLR) could occur in full/near-term newborns. The causes and clinical features are still largely elusive. This study focused on the risk factors, clinical and genetic characteristics, treatment and outcome, and prognosis of ROPLR.

Methods

A total of 47 consecutive full/near-term newborns during 2016–2017 with ROPLR were included. The clinical and genetic characteristics, treatment and outcome, prognosis, and potential underlying etiology of ROPLR were were analyzed.

Results

91 eyes of 47 infants were found to have ROPLR. The ROPLR regressed completely in 65.9% and partially in 20.9% of eyes without any interventions. Retinal changes of family exudative vitreoretinopathy (FEVR) were allocated in 12 neonates (group A), perinatal hypoxia-ischemia were categorized in 17 neonates (group B), and the other 18 neonates were categorized in group C. Compared to those in group B/C, infants in group A had significantly more severe retinopathy (stage 4/5, p &lt; 0.001) and more treatments (p &lt; 0.00 risk factor 1).

Conclusions

Perinatal hypoxia-ischemia might be a major risk factor for ROPLR, in which spontaneous regression was common. FEVR, confirmed by positive family findings and genetic testing, might be the second risk factor of ROPLR, in which retinopathy is more severe and treatment is needed.

LncRNA TUG1 Promotes Apoptosis, Invasion, and Angiogenesis of Retinal Endothelial Cells in Retinopathy of Prematurity via MiR-145-5p

Purpose

Retinopathy of prematurity (ROP) is a common retinal vascular disease in premature neonates. In recent years, there is increasing evidence that the long non-coding RNA taurine upregulated gene 1 (TUG1) plays a regulatory role in vascular diseases, suggesting a potential role for TUG1 in vascular endothelial cells. We hypothesized that TUG1 may be associated with ROP. Our aim, therefore, was to explore the biological functions of TUG1 in aberrant retinal development.

Methods

We used the mouse oxygen-induced retinopathy (OIR) model to simulate the pathological changes of retinal in ROP. Quantitative real-time polymerase chain reaction was used to detect the expression of TUG1, miR-145-5p and cellular communication network factor 1 (CCN1). Human retinal endothelial cells (HRECs) were treated with CoCl₂ to mimic hypoxia conditions. Cellular functional changes were observed after transfection with RNA interference (RNAi)-TUG1 and miR-145-5p mimics. The apoptosis of HRECs was detected by flow cytometry, the migration ability was detected by wound healing and transwell migration assays, and the ability of angiogenesis was detected by tube formation assay. The potential binding sites between TUG1, miR-145-5p, and CCN1 were verified by dual-luciferase reporter assays. The degree of retinopathy was evaluated by staining retinal sections with hematoxylin and eosin, and the expression of CCN1, HIF-1α, VEGF, caspase-3, Bcl-2, IL-1β, and TNF-α protein was analyzed by Western blotting and immunohistochemistry.

Results

In the retina tissue of OIR mice, TUG1, miR-145-5p, and CCN1 were differentially expressed. Knocking down TUG1 attenuated apoptosis, migration, and angiogenesis induced by hypoxia on HRECs, as did miR-145-5p overexpression. Results from reporter assays indicate direct interactions between TUG1, miR-145-5p, and CCN1. Intravitreal injection of miR-145-5p mimics reduced the degree of retinopathy.

Conclusion

TUG1 acts as a molecular sponge of miR-145-5p to regulate CCN1 expression and thus regulate the development of retinal neovascularization. This regulatory mechanism may provide a new theoretical basis for the prevention and treatment of ROP.

Extending Hui-Walter framework to correlated outcomes with application to diagnosis tests of an eye disease among premature infants

Diagnostic accuracy, a measure of diagnostic tests for correctly identifying patients with or without a target disease, plays an important role in evidence-based medicine. Diagnostic accuracy of a new test ideally should be evaluated by comparing to a gold standard; however, in many medical applications it may be invasive, costly, or even unethical to obtain a gold standard for particular diseases. When the accuracy of a new candidate test under evaluation is assessed by comparison to an imperfect reference test, bias is expected to occur and result in either overestimates or underestimates of its true accuracy. In addition, diagnostic test studies often involve repeated measurements of the same patient, such as the paired eyes or multiple teeth, and generally lead to correlated and clustered data. Using the conventional statistical methods to estimate diagnostic accuracy can be biased by ignoring the within-cluster correlations. Despite numerous statistical approaches have been proposed to tackle this problem, the methodology to deal with correlated and clustered data in the absence of a gold standard is limited. In this article, we propose a method based on the composite likelihood function to derive simple and intuitive closed-form solutions for estimates of diagnostic accuracy, in terms of sensitivity and specificity. Through simulation studies, we illustrate the relative advantages of the proposed method over the existing methods that simply treat an imperfect reference test as a gold standard in correlated and clustered data. Compared with the existing methods, the proposed method can reduce not only substantial bias, but also the computational burden. Moreover, to demonstrate the utility of this approach, we apply the proposed method to the study of National-Eye-Institute-funded Telemedicine Approaches to Evaluating of Acute-Phase Retinopathy of Prematurity (e-ROP), for estimating accuracies of both the ophthalmologist examination and the image evaluation.

Update in the Treatment of Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is an alteration in the development of the immature retina vascularization that frequently occurs in premature infants and is one of the leading causes of childhood blindness worldwide. In threshold stage retinopathy, laser photocoagulation is the standard treatment, particularly in those located in zone II. However, this therapy destroys parts of the retina and can lead to significant eye complications later in life. For this reason, in the last few years, antivascular endothelial growth factor agents are being used as monotherapy or as coadjuvant with laser, especially in retinopathy located in zone I. More recently, the administration of oral propranolol has been used as prevention and/or treatment of prethreshold retinopathy with encouraging results. This review provides an overview of the current evidence on newer treatment strategies for ROP. KEY POINTS: · Laser is the standard treatment in threshold retinopathy of prematurity (ROP).. · Prethreshold stages of the ROP have no treatment.. · Propranolol may prevent the progression of ROP..

Analysis of a two-year independent screening effort for retinopathy of prematurity in rural Egypt

BACKGROUND

The third epidemic of retinopathy of prematurity (ROP) has majorly involved middle income countries in which tailored screening and local guidelines require development. The data regarding ROP prevalence and cutoff numbers for screening in Egypt are lacking.

METHODS

Retrospective analysis of an independent screening effort spanning 2 years (February 2019 to February 2021) and involving 32 neonatal care units within Sharkia governorate, Egypt. Infants of gestational age (GA) ≤ 34 weeks and/or birth weight (BW) ≤ 2000 g were included, as well as those with unstable clinical course. Two eyecare centers located in Sharkia and Cairo governorates served as referral centers for any required interventions.

RESULTS

Of the 276 screened infants, 133 (48.2%) had some form of ROP that was bilateral in 127 (95.5%) of them. Aggressive posterior ROP (AP-ROP) was detected in both eyes of 24 infants (8.7%). The median (IQR) GA of infants with ROP was 32 (30-34) weeks, and the median (IQR) BW was 1600 (1350-2000) g. Sixty-three infants (47.4%) required treatment. Of the total 84 eyes that primarily were treated, 73 (86.9%) received intravitreal ranibizumab, 8 (9.5%) underwent laser ablation therapy, and 3 eyes (3.6%) underwent surgery. Recurrence rate was 16.7% (14 eyes). Final outcome was favorable in 83 eyes (98.8%). Applying the American Academy criteria would have led to the missing of 36.8% of infants with ROP and 28.6% of those requiring treatment in our sample.

CONCLUSION

The incidence of both ROP and AP-ROP in the Egyptian rural setting appears to be in the high end of global reported rates. Prevention measures should urgently be planned and implemented.

MicroRNAs and the HIF/VEGF axis in ocular neovascular diseases

Ocular neovascular diseases, such as proliferative diabetic retinopathy, retinopathy of prematurity and neovascular age-related macular degeneration, are the leading causes of visual impairment worldwide. The hypoxia-inducible factors and vascular endothelial growth factors are key molecular promoters of ocular neovascularization. Moreover, the role of microRNAs as regulators of angiogenesis has been expanding, particularly hypoxia-associated microRNA; hypoxamiRs. This review provides a summary of hypoxamiRs that directly and specifically target HIF1A and VEGF mRNAs, thus critically involved in the regulation of ocular neovascular pathologies. The discussed microRNAs highlight putative diagnostic markers and therapeutic agents in choroidal and retinal angiogenic diseases, including proliferative diabetic retinopathy, retinopathy of prematurity and neovascular age-related macular degeneration.

Immediate Sequential Bilateral Vitrectomy Surgery for Retinopathy of Prematurity: A Single Surgeon Experience

Objectives:

We report the safety and efficacy of simultaneous bilateral vitrectomy for stage 4 and stage 5 retinopathy of prematurity (ROP).

Materials and Methods:

Babies who had immediate sequential bilateral vitrectomy surgery for stage 4 or stage 5 ROP were included in this retrospective study. Clinical history, demographic characteristics of the patients, surgical procedure details, perioperative and postoperative ophthalmic and systemic complications, and postoperative anatomical success rates were evaluated. General anesthesia features were also recorded.

Results:

Seventy eyes of 35 babies who had immediate sequential bilateral vitrectomy surgery for stage 4 or stage 5 ROP were reviewed. At the time of surgery, the mean age was 41.4±4.9 weeks. There was preoperative plus disease in 58.6% of the eyes. The mean surgery/eye ratio was 1.2. Mean anesthesia time was 95±64 minutes. The mean follow-up was 28.1 months (3 to 84 months). Anatomical success was 95.7% for stage 4A (44/46 eyes), 83.3% for stage 4B (15/18 eyes), and 50% for stage 5 (3/6 eyes) ROP. Patients with stage 5 ROP had significantly less anatomical success than stage 4A and 4B (p=0.004). None of the patients had endophthalmitis and anesthesiarelated severe complications.

Conclusion:

Immediate sequential bilateral vitrectomy surgery can be considered an option for patients with active bilateral stage 4 and stage 5 ROP. The risk of endophthalmitis should be weighed against the risks of disease progression and anesthesia-related complications.

The possible effect of pentoxifylline on development and severity of retinopathy of prematurity

BACKGROUND AND AIM

Retinopathy of prematurity (ROP) is the major ocular problem of preterm infants that occurs with abnormal proliferation of immature retinal vessels. Although pentoxifylline (PTX) was reported to inhibit vasculogenesis and neovascularization in experimental studies, there is no clinical data about the effects of PTX treatment on the development and severity of ROP. This clinical study aimed to investigate the possible effects of PTX on the development of ROP.

MATERIALS AND METHODS

A single-centre retrospective study was conducted including preterm infants who were hospitalised in the neonatal intensive care unit between 2015-2017 years. Infants were divided into two groups in terms of PTX administration for adjuvant therapy, as PTX and non-PTX groups.

RESULTS

A total of 211 infants were included in the study [gestational age 29 (27-31) weeks, birth weight 1140 (960-1340) g]. From these, 97 infants (46%) were given PTX treatment. The two groups were similar in terms of demographic data and baseline clinical characteristics. Any stage of ROP was detected in 47.4% of infants in the PTX group, which was significantly higher than those in the non-PTX group (27.2%) (p = 0.002). The incidence of advanced-stage ROP in the PTX group (10.3%) was also higher than in the non-PTX group (2.6%) (p = 0.021). Repeated usage of PTX was not found to be related to the development of ROP (p = 0.059). The time of PTX administration was similar between the ROP and no-ROP groups (median; one vs one week, p = 0.825). Surfactant therapy, duration of hospital stay, and PTX treatment were found as significant risk factors for ROP in the logistic regression analysis.

CONCLUSIONS

In contrast to the experimental studies and also promising results of PTX treatment in some neonatal morbidities, it may be associated with increased incidence and stage of ROP.

Adults Born Preterm: Long-Term Health Risks of Former Very Low Birth Weight Infants

BACKGROUND

Advances in neonatology now enable increasing numbers of very low birth weight neonates (<1500 g) to survive into early adulthood and beyond. What are the implications for their long-term care?

METHODS

Selective literature search on the outcome of very low birth weight neonates in adulthood ("adults born preterm").

RESULTS

Robust data are available on the pulmonary, metabolic, cardiovascular, renal, neurocognitive, sensory-visual, social-emotional, mental, reproductive, and musculoskeletal long-term risks. On the somatic level, elevated rates have been documented for asthma (odds Ratio [OR] 2.37), diabetes mellitus (OR 1.54), and chronic renal disease (hazard ratio [HR] 3.01), along with the cardiovascular and cerebrovascular sequelae of a tendency toward arterial hypertension. On the psychosocial level, the main findings are deficits in romantic partnerships (OR 0.72) and a lower reproduction rate (relative risk [RR] male/female 0.24/0.33). The affected women also have an elevated risk of preterm delivery.

CONCLUSION

A risk profile with both somatic and psychosocial aspects can be discerned for adults who were born prematurely, even if some of these risks are present in low absolute numbers. As the ability to compensate for latent deficits declines with age, such adults may suffer from "premature aging as the late price of premature birth." A holistic approach to care with personalized prevention strategies-which for most of them was discontinued at discharge from pediatric follow-up-therefore seems appropriate in adulthood as well.

Early Postnatal Oxygen Exposure Predicts Choroidal Thinning in Neonates

Purpose

To evaluate whether choroidal thickness (CT) using arm-mounted optical coherence tomography (OCT) in infants screened for retinopathy of prematurity (ROP) correlates with oxygen exposure in neonates.

Methods

OCT images were obtained in infants screened for ROP in a single level IV neonatal intensive care unit. CT was measured at three different locations: the subfoveal center and 1.5 mm from the fovea center in each direction. Correlation and regression analyses were performed to determine the relationship between clinical factors and CT. Clinical factors included gestational age, birth weight, presence of bronchopulmonary dysplasia (BPD), and fraction of inspired oxygen (FiO₂) at defined time points: 30 weeks postmenstrual age (PMA), 36 weeks PMA, and on day of imaging.

Results

Mean subfoveal, nasal, and temporal choroidal thicknesses CT (SFCT, NCT, and TCT, respectively) were 228.0 ± 51.4 µm, 179.7 ± 50.3 µm, and 186.4 ± 43.8 µm, respectively. SFCT was found to be significantly thicker than NCT and TCT (P < 0.0001 and P = 0.0002, respectively), but no significant difference was found between NCT and TCT (P = 0.547). Compared with infants without BPD, infants with BPD had thinner SFCT and NCT (P = 0.01 and P = 0.0008, respectively). Birth weight was positively correlated with SFCT (r = 0.39, P = 0.01) and NCT (r = 0.33, P = 0.045) but not TCT. Gestational age and ROP stage were not significantly associated with CT. SFCT was found to be significantly thinner with higher average FiO₂ supplementation levels at 30 weeks PMA (r = –0.51, P = 0.01) but not at 36 weeks PMA. Regression analysis revealed that FiO₂ at 30 weeks PMA was an independent predictor of SFCT in infants screened for ROP (P = 0.01).

Conclusions

Early postnatal exposure (<32 weeks PMA) to higher oxygen supplementation in premature neonates statistically predicts choroidal thinning.

Features of Retinal Neurogenesis as a Key Factor of Age-Related Neurodegeneration: Myth or Reality?

Age-related macular degeneration (AMD) is a complex multifactorial neurodegenerative disease that constitutes the most common cause of irreversible blindness in the elderly in the developed countries. Incomplete knowledge about its pathogenesis prevents the search for effective methods of prevention and treatment of AMD, primarily of its "dry" type which is by far the most common (90% of all AMD cases). In the recent years, AMD has become "younger": late stages of the disease are now detected in relatively young people. It is known that AMD pathogenesis-according to the age-related structural and functional changes in the retina-is linked with inflammation, hypoxia, oxidative stress, mitochondrial dysfunction, and an impairment of neurotrophic support, but the mechanisms that trigger the conversion of normal age-related changes to the pathological process as well as the reason for early AMD development remain unclear. In the adult mammalian retina, de novo neurogenesis is very limited. Therefore, the structural and functional features that arise during its maturation and formation can exert long-term effects on further ontogenesis of this tissue. The aim of this review was to discuss possible contributions of the changes/disturbances in retinal neurogenesis to the early development of AMD.

Evaluating Contrast Sensitivity in Asian Indian Pre-Term Infants With and Without Retinopathy of Prematurity

Purpose

The purpose of this study was to evaluate the contrast threshold in Asian Indian preterm infants with and without retinopathy of prematurity (ROP) using Newborn Contrast Cards measured during the first ROP screening and to correlate with final outcome and visual acuity at 3 months of corrected age.

Methods

Preterm infants born ≤ 2000 grams birth weight (BW) and/or ≤ 34 weeks gestational age (GA) undergoing ROP screening were enrolled prospectively. Visual acuity was recorded using Teller Acuity Cards. Contrast threshold was measured with Newborn Contrast Cards at first screening visit and at the end of ROP screening at 40 weeks of postmenstrual age or older.

Results

Of the 173 study infants, 134 (77.5%) did not have any stage of ROP. Of the remaining 39 (22.5%), 34 (87%) had type 2 ROP and 5 (13%) had type 1 ROP requiring treatment. The mean contrast threshold at the first visit of the no ROP type 1 and type 2 groups was 0.36 ± 0.07, 0.65 ± 0.19, and 0.46 ± 0.09, respectively (P < 0.001). Contrast threshold had a significant correlation with BW (R = −0.291, P = < 0.001) and gestational age (R = −0.47, P = < 0.001). The contrast threshold at the first visit correlated with visual acuity measured at 3 months of corrected age in logMAR (R = 0.36, P = 0.01). Other than BW and GA, no other systemic risk factors correlated with contrast threshold measured at the first screening visit.

Conclusions

Newborn Contrast Cards are a viable tool to test contrast threshold in preterm infants. The association between contrast threshold and ROP, and its correlation with visual acuity, suggest that contrast threshold measurement may help predict the clinical vision outcome among prematurely born infants.

Translational Relevance

Contrast threshold measurement may prove to be a useful tool in the estimation of visual potential in preterm infants.

Nigerian neonatologists perception and experience with retinopathy of prematurity

Background

Retinopathy of Prematurity (ROP) is an avoidable condition that affects premature infants exposed to oxygen stresses at or soon after birth. In low- and middle-income countries, like Nigeria, neonatal mortality rates are high and very few infants live to develop ROP. With recent better care, ROP is now being diagnosed.

Objective

This study aimed to characterize what Nigerian neonatologists understand about ROP.

Methods

At a joint meeting of Nigerian pediatric ophthalmologists and neonatologists in Kebbi State held 26-29 July 2018, questionnaires collected attendees' perspective and experience with ROP including causes, risk factors and experiences.

Results

Fifty-one neonatologists out of 71 returned a completed questionnaire (response rate: 71.8%). The male:female ratio was 1:1.8, and approximately 40% were aged 41-50 years (n=20, 39.22%). Only 3 (6.39%) had experience managing infants below 500g that survived. A majority managed babies with a mean weight of 913g ± 300.37 and age of 27.87 weeks ±2.37. Most had no access to oxygen monitors (n=39,78%). Most had 10 babies to one monitor and used average settings of 90-95%. One third had seen a case of ROP (n=15,29.41%). Only 5.88% (n=3) were unaware of uncontrolled oxygen use as a risk factor. Only 4 (8.89%) had a functional screening team. None were aware of local screening guidelines.

Conclusions

Regular educational programs, collaborative clinical presentations and webinars about ROP targeted at the neonatologists and parents, including establishment of screening programs across country will likely help reduce the burden of ROP blindness in Nigeria.

Flying baby optical coherence tomography alters the staging and management of advanced retinopathy of prematurity

PURPOSE

To report the use of flying baby spectral domain optical coherence tomography (SD-OCT) on infants with advanced retinopathy of prematurity (ROP), where clinical findings alone failed to differentiate between retinoschisis and retinal detachment.

METHODS

Prospective, non-interventional case-series study of three premature infants with advanced ROP of clinically uncertain stage, after examination by indirect ophthalmoscopy. To confirm the diagnosis, table-mounted SD-OCT retinal imaging was performed with the infant held in the flying baby position under topical ocular anaesthesia only. Spectral domain optical coherence tomography (SD-OCT) findings were correlated with clinical examination and ultra-widefield scanning laser ophthalmoscopy to determine disease stage and appropriate management.

RESULTS

The flying baby position was well tolerated, and SD-OCT images of central and peripheral retina were successfully obtained in all three cases. Additional information provided by the SD-OCT changed the ROP staging from 3 to 4 in one case, which subsequently required surgical treatment. In two other cases, clinical suspicion of stage 4 ROP was overruled as SD-OCT revealed tractional retinoschisis rather than full-thickness retinal detachment, thereby avoiding the need for immediate surgical intervention.

CONCLUSIONS

In this case-series study, flying baby SD-OCT provided a rapid and widely accessible imaging approach that overruled clinical findings and altered classification and management of infants with advanced ROP. The methodology was suitable for outpatient settings with no risks associated with systemic anaesthesia. The increased use of OCT imaging will make apparent how structural information is useful in management of ROP and may influence future classification of the disease.

Stable incidence but regional differences in retinopathy of prematurity in Norway from 2009 to 2017

PURPOSE

To explore the changes over time and regional differences in the incidence of retinopathy of prematurity (ROP) in a national cohort of infants born <28 weeks' gestational age (GA).

METHODS

A population-based study of infants with GA <28 weeks in Norway from 2009 to 2017. Prospectively collected data on clinical variables and outcomes were obtained from the Norwegian Neonatal Network.

RESULTS

Of 1499 live-born infants transferred to a neonatal intensive care unit, 1156 were discharged alive. Four-hundred and fifty-eight infants (39.6%) had ROP, 152 (13.1%) had severe ROP, and 110 (9.5%) were treated for ROP. Eleven hundred infants (95.2%) had complete data sets. In a model comprising region of primary care, GA [odds ratios (OR): 0.65; 95% CI: 0.55-0.77], growth velocity (OR: 1.10; 95% CI: 1.00-2.00), medically treated patent ductus arteriosus (OR: 1.80; 95% CI: 1.19-2.72), weeks of supplemental oxygen (OR: 1.07; 95% CI: 1.03 to 1.11) and region of primary care (OR: 4.95; 95% CI: 3.05-8.04 for the pair of regions with the highest estimated OR) were significantly associated with severe ROP. Additionally, institutional differences for severe ROP were found, with ORs from 0.41 (95% CI: 0.05-3.23) to 5.36 (95% CI: 3.05-9.43) using the largest institution as reference. Incidences were stable over time after adjusting for GA. A larger proportion was treated with anti-vascular endothelial growth factor after 2011.

CONCLUSIONS

The incidence of severe ROP was stable between 2009 and 2017 in Norway. Regional and institutional differences need to be explored in future studies.

MicroRNA-126 inhibits pathological retinal neovascularization via suppressing vascular endothelial growth factor expression in a rat model of retinopathy of prematurity

Vascular endothelial growth factor (VEGF) is the principal growth factor responsible for the retinal neovascularization in the pathogenesis of retinopathy of prematurity (ROP). Current therapies for ROP include laser ablation and intravitreal anti-VEGF injection. However, these treatments either destroy the peripheral retina or associate with problems of persistent peripheral avascular retina or later recurrence of ROP. In the present study we investigated a new therapeutic approach by exploring the potential role of a specific microRNA, miR-126, in regulating VEGFA expression and retinal neovascularization in a rat oxygen-induced retinopathy (OIR) model. We demonstrated that miR-126 mimic and plasmid effectively suppresses VEGFA mRNA expression in both human and rat retinal pigment epithelium cell lines, quantified with qRT-PCR. Animal experiments on rat OIR model revealed that intravitreal injection of miR-126 plasmid efficiently downregulated VEGFA expression in the intraocular fluid and retinal tissues measured by ELISA, and significantly suppressed retinal neovascularization, which was confirmed by calculating sizes of neovascularization areas on fluorescence microscopic images of flat mounted retina stained with Alexa Fluor 594-conjugated isolectin B4 to visualize blood vessels. Together, these results showed that intravitreal injection of miR-126 plasmid could inhibit retinal neovascularization by down-regulating VEGFA expression, suggesting a potential therapeutic effect for ROP.

Retinal vessel architecture in retinopathy of prematurity and healthy controls using swept-source optical coherence tomography angiography

PURPOSE

To determine microvascular changes in children with a history of retinopathy of prematurity (ROP) and in a control group of full-term children.

METHODS

In a cross-sectional study, 30 eyes of 15 children aged 6-8 years with a history of ROP were evaluated with swept-source optical coherence tomography angiography (SS-OCTA). Twenty-eight eyes of 22 age-matched full-term children served as a healthy control group. The foveal avascular zone (FAZ), vessel density (VD) and choroidal vascular flow area (VFA) were evaluated on OCTA and correlated with central retinal thickness (CRT), visual acuity (VA), birth weight (BW), gestational age (GA) and ROP stages.

RESULTS

Twenty-two eyes of 14 children with a history of ROP (stage 1-3) and 25 eyes of 19 full-term children were available for evaluation. In the ROP group, the gestational age was 27 ± 2 weeks and birth weight was 781 ± 164 g. In the ROP group, CRT was higher in the central ETDRS segment (mean difference [95% CI]: 32.8 µm [18.7; 47.0], p = 0.0002) compared to the controls. Smaller mean FAZ area (-0.12 [-0.19; -0.04], p = 0.004) and perimeter (-662 [-1228; -96], p = 0.03) was found in comparison to the control group. An oval shape of the FAZ was observed among patients with a history of ROP. The mean central VD of the superficial plexus was 28 ± 8/23 ± 8% and of the deep plexus 7 ± 7/3 ± 5% (ROP group/control group; p > 0.05). No statistically significant difference was found regarding the choroidal VFA. Only weak correlation of FAZ and VD with function was observed.

CONCLUSIONS

Swept-source optical coherence tomography angiography imaging revealed significant microvascular anomalies in children with a history of ROP indicating disturbance of early morphological development of the central retina.

Quantitatively comparing weekly changes in retinal vascular characteristics of eyes eventually treated versus not treated for retinopathy of prematurity

PURPOSE

To quantitatively compare retinal vascular characteristics over time in eyes eventually treated versus not treated for retinopathy of prematurity (ROP), using ROPtool analysis of narrow-field retinal images.

METHODS

This longitudinal study used prospectively collected narrow-field retinal images of infants screened for ROP, prior to treatment, if needed. Images were analyzed using a methodology that combines quadrant-level measures from several images of the same eye. For the longitudinal analysis, one examination per postmenstrual age (PMA) was included per eye. We compared the following ROPtool indices and their change per week between eyes eventually treated versus not treated for ROP: tortuosity index (TI), dilation index (DI), sum of adjusted indices (SAI), and tortuosity-weighted plus (TWP). Analysis was performed on three levels: eye (mean value/eye), quadrant (highest quadrant value/eye), and blood vessel (highest blood vessel value/eye).

RESULTS

Of 832 examinations (99 infants), 745 images (89.5%) had 3-4 quadrants analyzable by ROPtool. On the eye level, ROPtool indices differed between eyes eventually treated versus not treated at PMA of 33-35 and 37 weeks for TI, SAI, and TWP, and at PMA of 33-34 and 37 weeks for DI (P ≤ 0.0014), and change per week differed between eyes eventually treated versus not treated only for SAI at PMA of 32 weeks (P < 0.001).

CONCLUSIONS

Quantitative analysis of retinal vascular characteristics using ROPtool can help predict eventual need for treatment for ROP as early as 32 weeks PMA. ROPtool index values were more useful than change in these indices to predict eyes that would eventually need treatment for ROP.

Three-dimensional Imaging Coupled with Topological Quantification Uncovers Retinal Vascular Plexuses Undergoing Obliteration

Introduction: Murine models provide microvascular insights into the 3-D network disarray seen in retinopathy and cardiovascular diseases. Light-sheet fluorescence microscopy (LSFM) has emerged to capture retinal vasculature in 3-D, allowing for assessment of the progression of retinopathy and the potential to screen new therapeutic targets in mice. We hereby coupled LSFM, also known as selective plane illumination microscopy, with topological quantification, to characterize the retinal vascular plexuses undergoing preferential obliteration. Method and Result: In postnatal mice, we revealed the 3-D retinal microvascular network in which the vertical sprouts bridge the primary (inner) and secondary (outer) plexuses, whereas, in an oxygen-induced retinopathy (OIR) mouse model, we demonstrated preferential obliteration of the secondary plexus and bridging vessels with a relatively unscathed primary plexus. Using clustering coefficients and Euler numbers, we computed the local versus global vascular connectivity. While local connectivity was preserved (p > 0.05, n = 5 vs. normoxia), the global vascular connectivity in hyperoxia-exposed retinas was significantly reduced (p < 0.05, n = 5 vs. normoxia). Applying principal component analysis (PCA) for auto-segmentation of the vertical sprouts, we corroborated the obliteration of the vertical sprouts bridging the secondary plexuses, as evidenced by impaired vascular branching and connectivity, and reduction in vessel volumes and lengths (p < 0.05, n = 5 vs. normoxia). Conclusion: Coupling 3-D LSFM with topological quantification uncovered the retinal vasculature undergoing hyperoxia-induced obliteration from the secondary (outer) plexus to the vertical sprouts. The use of clustering coefficients, Euler's number, and PCA provided new network insights into OIR-associated vascular obliteration, with translational significance for investigating therapeutic interventions to prevent visual impairment.

Rate and Treatment of Retinopathy of Prematurity in Extremely Low Birth Weight Infants with Gestational Age ≤28 Weeks in Eastern China

Purpose

To investigate the incidence and clinical characteristics of ROP in extremely preterm (EP) and extremely low birth weight (ELBW) infants in eastern China.

Patients and Methods

This retrospective study included 104 infants with a birth weight (BW) ≤ 1000 g and gestational age (GA) ≤ 28 weeks, who were admitted to the Eye and ENT Hospital of Fudan University over 10 years. The infants were examined for ROP with RetCam. Infants with type 1 ROP and aggressive posterior ROP (AP-ROP) were treated. The risk factors evaluated were GA and BW.

Results

Mean GA was 26.63 ± 0.88 weeks and mean BW was 892.39 ± 108.06 g. Of the 104 infants, 83 (79.8%) developed ROP, three (2.9%) had AP-ROP, 14 (13.5%) had type 1 ROP, and 10 (9.6%) had type 2 ROP. The proportions of infants with BW ≤750 g and 751-1000 g were 8.7% and 91.3%, respectively, and the incidences of severe ROP in these infants were 22.2% and 15.8%, respectively. The infants with severe ROP had a mean GA of 26.56 ± 0.68 weeks and mean BW of 860.00 ± 163.48 g, and 47.1% of severe ROP occurred in infants with a GA of 26 weeks. However, multivariate logistic regression showed that the severity of ROP was not directly inversely related to GA or BW in this study population.

Conclusion

In EP and ELBW Chinese infants, who were admitted to the Eye and ENT Hospital of Fudan University, the development of ROP was more frequent and the incidence of severe ROP that progressed to the stage that required treatment was high.

Risk factors for myopia at 1-year corrected age following laser photocoagulation for retinopathy of prematurity

BACKGROUND/OBJECTIVES

The prevalence of myopia is higher in preterm infants who underwent laser photocoagulation (LPC) for retinopathy of prematurity (ROP). The aim of this study was to investigate factors associated with myopia in preterm infants who undergo LPC for ROP.

SUBJECTS/METHODS

We retrospectively analysed the medical records of preterm infants born at Kyushu University Hospital (October 2008-March 2018) at ≤32 weeks of gestational age or with birth weight ≤1500 g. We evaluated the associations between nine clinical factors and the spherical equivalent at 1-year corrected age by performing multivariable linear regression in LPC-treated ROP patients.

RESULTS

Among the 485 infants enroled, 76 developed ROP requiring treatment. Of these, 71 underwent LPC, which was provided to 63 infants as the primary treatment (LPC alone or the combination therapy of LPC and intravitreal injection of bevacizumab [IVB]) and to eight infants as additional LPC after IVB monotherapy. The results of a refractive examination at 1-year corrected age were available for 110 eyes of 56 infants (78.9%). The mean ± standard deviation of the SE value was -0.5 ± 3.0 dioptres (D). Multivariable linear regression analysis revealed a significant association between laser spot count and SE value (ß = -0.081 ± 0.040 D per 100 spots [mean ± standard error], p = 0.045).

CONCLUSIONS

Our results suggest that an increased laser spot count observed during ROP treatment associates with myopia.

An inhibitor of endothelial ETS transcription factors promotes physiologic and therapeutic vessel regression

During the progression of ocular diseases such as retinopathy of prematurity and diabetic retinopathy, overgrowth of retinal blood vessels results in the formation of pathological neovascular tufts that impair vision. Current therapeutic options for treating these diseases include antiangiogenic strategies that can lead to the undesirable inhibition of normal vascular development. Therefore, strategies that eliminate pathological neovascular tufts while sparing normal blood vessels are needed. In this study we exploited the hyaloid vascular network in murine eyes, which naturally undergoes regression after birth, to gain mechanistic insights that could be therapeutically adapted for driving neovessel regression in ocular diseases. We found that endothelial cells of regressing hyaloid vessels underwent down-regulation of two structurally related E-26 transformation-specific (ETS) transcription factors, ETS-related gene (ERG) and Friend leukemia integration 1 (FLI1), prior to apoptosis. Moreover, the small molecule YK-4-279, which inhibits the transcriptional and biological activity of ETS factors, enhanced hyaloid regression in vivo and drove Human Umbilical Vein Endothelial Cells (HUVEC) tube regression and apoptosis in vitro. Importantly, exposure of HUVECs to sheer stress inhibited YK-4-279-induced apoptosis, indicating that low-flow vessels may be uniquely susceptible to YK-4-279-mediated regression. We tested this hypothesis by administering YK-4-279 to mice in an oxygen-induced retinopathy model that generates disorganized and poorly perfused neovascular tufts that mimic human ocular diseases. YK-4-279 treatment significantly reduced neovascular tufts while sparing healthy retinal vessels, thereby demonstrating the therapeutic potential of this inhibitor.