Evolving Concepts in the Management of Retinopathy of Prematurity

Twelve-year outcomes of bedside laser photocoagulation for severe retinopathy of prematurity

Purpose

The purpose of this study is to evaluate the 12-year outcomes of bedside laser photocoagulation (LP) for severe retinopathy of prematurity (ROP) under sedation combined with ocular surface anesthesia in neonatal intensive care units (NICU).

Design

The study is a retrospective case series.

Methods

Infants treated with bedside LP for severe ROP from April 2009 to September 2021 were included. All LP treatments were performed under sedation and surface anesthesia at the bedside in NICU. Data were recorded for clinical and demographic characteristics, total laser spots, duration of treatment, proportion of total regression of ROP, proportion of recurrence, and adverse events.

Results

A total of 364 infants (715 eyes) were included, with a mean gestational age of 28.6 ± 2.4 weeks (range: 22.6-36.6 weeks) and a mean birth weight of 1,156.0 ± 339.0 g (range: 480-2,200 g). The mean number of laser spots was 832 ± 469, and the mean duration of treatment was 23.5 ± 5.3 min per eye. Of all the eyes, 98.3% responded to LP with complete regression of ROP. ROP recurred in 15 (2.1%) eyes after the initial LP. Additional LP was performed in seven (1.0%) eyes. No patient exhibited mistaken LP of other ocular tissues, and there were no serious ocular adverse effects. None of them needed endotracheal intubation.

Conclusions

Bedside LP treatment is effective and safe for premature infants with severe ROP under sedation and surface anesthesia in NICU, especially for infants whose general condition is unstable and not suitable for transport.

Comparative Analysis Reveals Novel Changes in Plasma Metabolites and Metabolomic Networks of Infants With Retinopathy of Prematurity

Purpose

Advances in mass spectrometry have provided new insights into the role of metabolomics in the etiology of several diseases. Studies on retinopathy of prematurity (ROP), for example, overlooked the role of metabolic alterations in disease development. We employed comprehensive metabolic profiling and gold-standard metabolic analysis to explore major metabolites and metabolic pathways, which were significantly affected in early stages of pathogenesis toward ROP.

Methods

This was a multicenter, retrospective, matched-pair, case-control study. We collected plasma from 57 ROP cases and 57 strictly matched non-ROP controls. Non-targeted ultra-high-performance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) was used to detect the metabolites. Machine learning was employed to reveal the most affected metabolites and pathways in ROP development.

Results

Compared with non-ROP controls, we found a significant metabolic perturbation in the plasma of ROP cases, which featured an increase in the levels of lipids, nucleotides, and carbohydrate metabolites and lower levels of peptides. Machine leaning enabled us to distinguish a cluster of metabolic pathways (glycometabolism, redox homeostasis, lipid metabolism, and arginine pathway) were strongly correlated with the development of ROP. Moreover, the severity of ROP was associated with the levels of creatinine and ribitol; also, overactivity of aerobic glycolysis and lipid metabolism was noted in the metabolic profile of ROP.

Conclusions

The results suggest a strong correlation between metabolic profiling and retinal neovascularization in ROP pathogenesis. These findings provide an insight into the identification of novel metabolic biomarkers for the diagnosis and prevention of ROP, but the clinical significance requires further validation.

Socioeconomics of retinopathy of prematurity screening and treatment in the United States

BACKGROUND

Retinopathy of prematurity (ROP) screening, an integral part of pediatric ophthalmology, can be time consuming and resource intensive. The purpose of this study was to evaluate the economic landscape of ROP screening and treatment among pediatric ophthalmologists in the United States.

METHODS

An online survey was distributed to US pediatric ophthalmologists through a pediatric ophthalmology email listserv. Survey results were compiled, and responses were deidentified and analyzed, with particular focus on factors affecting financial compensation.

RESULTS

A total of 97 responses were collected. Almost half of respondents worked in private practice settings. Over 80% of respondents had a formal contract to perform ROP care, but only 26% enlisted the assistance of an attorney to negotiate their contract. Just over half of respondents believed themselves adequately compensated for their services. Respondents that had retained an attorney for contractual negotiations were more likely to have a higher mean annual compensation rate ($126,545 ± $145,133 vs $70,214 ± $50,671; P = 0.05). Physicians who believed themselves adequately compensated were more likely to be in academic practice settings (78% academic vs 55% combo/other vs 24% private; P < 0.001) and were more likely to have contracts to perform ROP care (68% with contracts vs 15% without; P = 0.001). Average annual compensation was $82,968 ± $84,132, approximately $24,000 higher than reported in 2013.

CONCLUSIONS

More pediatric ophthalmologists among our respondents obtained contracts for their services, and compensation rates have increased since 2013. Nevertheless, concerns regarding under-compensation and time commitment persist, raising concerns about the long-term sustainability of current models for providing ROP services.

Hypertension in neonates treated with intravitreal bevacizumab for retinopathy of prematurity

OBJECTIVE

To investigate if preterm neonates developed systemic hypertension after intravitreal bevacizumab for retinopathy of prematurity.

METHODS

Patients who received treatment between January 1, 2011 and January 31, 2019 were eligible for inclusion. Patients with pre-existing hypertension, congenital eye disease, or who were discharged within 72 h of treatment were excluded. Charts were reviewed for baseline data, co-morbidities, and the development of systemic hypertension within 4 weeks post treatment.

RESULTS

After exclusions, 64 patients were analyzed. New-onset systemic hypertension was identified in 44 (69%) infants. There were no statistical differences in the demographic characteristics or presence of co-morbidities between the hypertensive and non-hypertensive groups. Of those who developed hypertension, the majority presented within the first week post treatment (55%).

CONCLUSIONS

The majority of infants who received intravitreal bevacizumab developed new-onset systemic hypertension after treatment. Further studies may explore hypertension as a potential side effect of bevacizumab in the neonatal population.

Update on Anti-Vascular Endothelial Growth Factor Safety for Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a neovascular retinal disorder that occurs in infants born prematurely. Nowadays, ROP constitutes a leading cause of childhood blindness worldwide and for decades the standard of care has involved peripheral retinal ablation. However, this type of treatment requires the use of specialized equipment by well-trained physicians, has been associated with poor structural and visual outcomes in some preterm infants, and despite its adequate application, some cases of ROP may continue to progress. Therefore, the need for simpler and more efficient strategies made anti-vascular endothelial growth factor (anti-VEGF) medications an appealing option for treatment. Recently, the use of anti-VEGF agents for ROP has increased worldwide; nevertheless, this practice remains off-label, and there is a lack of information regarding its safety profile and the possibility of unfavorable long-term outcomes causes the utmost concern. This review updates the recent evidence regarding the systemic and ocular safety of anti-VEGF treatment for ROP.

Soluble epoxide hydrolase promotes astrocyte survival in retinopathy of prematurity

Polyunsaturated fatty acids such as docosahexaenoic acid (DHA) positively affect the outcome of retinopathy of prematurity (ROP). Given that DHA metabolism by cytochrome P450 and soluble epoxide hydrolase (sEH) enzymes affects retinal angiogenesis and vascular stability, we investigated the role of sEH in a mouse model of ROP. In WT mice, hyperoxia elicited tyrosine nitration and inhibition of sEH and decreased generation of the DHA-derived diol 19,20-dihydroxydocosapentaenoic acid (19,20-DHDP). Correspondingly, in a murine model of ROP, sEH-/- mice developed a larger central avascular zone and peripheral pathological vascular tuft formation than did their WT littermates. Astrocytes were the cells most affected by sEH deletion, and hyperoxia increased astrocyte apoptosis. In rescue experiments, 19,20-DHDP prevented astrocyte loss by targeting the mitochondrial membrane to prevent the hyperoxia-induced dissociation of presenilin-1 and presenilin-1-associated protein to attenuate poly ADP-ribose polymerase activation and mitochondrial DNA damage. Therapeutic intravitreal administration of 19,20-DHDP not only suppressed astrocyte loss, but also reduced pathological vascular tuft formation in sEH-/- mice. Our data indicate that sEH activity is required for mitochondrial integrity and retinal astrocyte survival in ROP. Moreover, 19,20-DHDP may be more effective than DHA as a nutritional supplement for preventing retinopathy in preterm infants.

Current management of retinopathy of prematurity in sub-Saharan Africa

PURPOSE

To survey current oxygen management, screening criteria, and methods for treating retinopathy of prematurity (ROP) in sub-Saharan Africa.

METHODS

An online survey was sent to ophthalmologists and neonatologists practicing in sub-Saharan Africa.

RESULTS

Ophthalmologists and neonatologists from 15 of 49 countries (31%) in sub-Saharan Africa responded. Neonatologists reported treating a median of 15 infants with supplemental oxygen per week but only had a median of 3.5 oxygen-measuring devices and a median of zero oxygen blenders in their units. Ophthalmologists reported screening a median of 5 infants per week for ROP and treating 2 infants each month for ROP. Most ophthalmologists (24/27 [89%]) had access to anti-vascular endothelial growth factor drugs to treat ROP, but only 13 of 27 (48%) had access to a laser.

CONCLUSIONS

Survey results reveal an urgent need for additional oxygen- management equipment in hospitals in sub-Saharan Africa.

Targeted Blood Metabolomic Study on Retinopathy of Prematurity

Purpose

This study aims at exploring alterations of major metabolites and metabolic pathways in retinopathy of prematurity (ROP) infants and identifying biomarkers that may merit early diagnosis of ROP.

Methods

We analyzed targeted metabolites from 81 premature infants (<34 weeks of gestational age), including 40 ROP cases (15 males and 25 females, birth weight 1.263 ± 0. 345 kg, gestational age 31.20 ± 4.62 weeks) and 41 cases (30 males, 11 females, birth weight 1.220 ± 0.293 kg, gestational age 30.96 ± 4.17 weeks) of well-matched non-ROP controls. Metabolites were measured by ultra-performance liquid chromatography-tandem mass spectrometry. Standard multivariate and univariate analysis was performed to interpret metabolomic results.

Results

Glycine, glutamate, leucine, serine, piperidine, valine, tryptophan, citrulline, malonyl carnitine (C3DC), and homocysteine were identified as the top discriminant metabolites. In particular, discriminant concentrations of C3DC and glycine were also confirmed by univariate analysis as statistically significant different between ROP and non-ROP infants.

Conclusions

This study gained an insight into the metabolomic aspects of ROP development. We suggest that higher blood levels of C3DC and glycine can be promising biomarkers to predict the occurrence, but not the severity of ROP.

Hypertension and Neuroimaging Changes After Bevacizumab for Retinopathy of Prematurity

Bevacizumab is a human monoclonal immunoglobulin G1 antibody to vascular endothelial growth factor indicated in several adult diseases. Emerging literature and expert opinion support the off-label use of intravitreal bevacizumab in the treatment of retinopathy of prematurity (ROP), a common disease process seen in premature neonates. One of the most common side effects of systemic therapy in adults is hypertension; however, this has not been well described in infants receiving bevacizumab for ROP. In this report, we review a case of a former 25-week premature infant treated for stage 3 ROP with administration of intravitreal bevacizumab. The immediate posttreatment course was uncomplicated; however, at 10 days posttreatment, he developed new-onset systemic hypertension. In addition, neuroimaging revealed new areas of vasogenic edema, which improved over time. To the best of our knowledge and after a review of the literature, neither of these effects has been described in neonates after intravitreal bevacizumab for ROP.

Role of cytochrome P450-derived, polyunsaturated fatty acid mediators in diabetes and the metabolic syndrome

Over the last decade, cases of metabolic syndrome and type II diabetes have increased exponentially. Exercise and ω-3 polyunsaturated fatty acid (PUFA)-enriched diets are usually prescribed but no therapy is effectively able to restore the impaired glucose metabolism, hypertension, and atherogenic dyslipidemia encountered by diabetic patients. PUFAs are metabolized by different enzymes into bioactive metabolites with anti- or pro-inflammatory activity. One important class of PUFA metabolizing enzymes are the cytochrome P450 (CYP) enzymes that can generate a series of bioactive products, many of which have been attributed protective/anti-inflammatory and insulin-sensitizing effects in animal models. PUFA epoxides are, however, further metabolized by the soluble epoxide hydrolase (sEH) to fatty acid diols. The biological actions of the latter are less well understood but while low concentrations may be biologically important, higher concentrations of diols derived from linoleic acid and docosahexaenoic acid have been linked with inflammation. One potential application for sEH inhibitors is in the treatment of diabetic retinopathy where sEH expression and activity is elevated as are levels of a diol of docosahexaenoic acid that can induce the destabilization of the retina vasculature.

A new approach to neonatal medical management that could transform the prevention of retinopathy of prematurity: Theoretical considerations

Retinopathy of prematurity (ROP) is a disease of the immature retina and is the leading global cause of blindness in children. Two postnatal phases of the disease are distinguished, the first phase is thought to be caused by hyperoxia. One of the most relevant ROP risk factor in routine clinical practice is blood transfusion which leads to the introduction into the neonatal circulation of 'non-physiological' adult haemoglobin (HbA) rather than the physiological foetal haemoglobin (HbF). Due to their different affinities for oxygen, HbA will release into retina more oxygen than HbF. It can be expected that this much greater influx of oxygen from HbA may be sensed by the relevant retinal receptors as hyperoxia. Based on the above considerations, I propose that the introduction of non-physiological HbA from adult donors during blood transfusion for anaemia is of key importance in the development and progression of ROP. This hypothesis predicts that there is an HbA limit, beyond which the sequence of events described in the pathogenesis of ROP is triggered. To prevent ROP, I propose launching a new medical field: neonatal transfusion medicine. This system would involve the collection and preparation of umbilical cord blood from the placenta of healthy newborns (containing almost 100% HbF), which would then be administered to premature newborns (who are at risk of ROP) instead of adult blood.

Analysis of Anti-Vascular Endothelial Growth Factor Injection Claims Data in US Medicare Part B Beneficiaries From 2012 to 2015

Importance

The frequency of anti-vascular endothelial growth factor (VEGF) injections has grown exponentially with the introduction of bevacizumab, ranibizumab, and most recently aflibercept. The cost associated with these medications has garnered significant national attention, warranting a granular analysis of their use.

Objective

To analyze trends in anti-VEGF injections for US Medicare Part B beneficiaries from 2012 to 2015.

Design, Setting, and Participants

This observational cohort study used 2012-2015 data from the Centers for Medicare & Medicaid Services Medicare Part B Provider Utilization Files to analyze trends in intravitreal injections of anti-VEGF medications among Medicare Part B beneficiaries and their health care professionals.

Main Outcomes and Measures

The primary outcome measure was distribution of and change over time in the number of anti-VEGF injections performed for ranibizumab, aflibercept, and bevacizumab.

Results

A total of 2 574 124 intravitreal injections were performed by 3348 ophthalmologists in the outpatient setting for Medicare Part B beneficiaries during the 2015 calendar year; 100 ophthalmologists (3.0%) performed the highest volume of intravitreal injections. The total number of intravitreal injections administered in 2015 was 870 843 for aflibercept, 697 412 for ranibizumab, and 1 147 432 for bevacizumab. Ranibizumab injections decreased by 7.1% from 2012 to 2015 and bevacizumab injections decreased by 17.1%. From 2013 to 2015, aflibercept injections increased by 69.4%. The 100 ophthalmologists performing the highest volume of ranibizumab injections, as gauged by number of injections administered, accounted for 31.0% (95% CI, 30.994%-30.997%) of all ranibizumab injections nationally. The 100 ophthalmologists performing the highest volume of aflibercept injections accounted for 17.6% (95% CI, 17.638%-17.641%) of all aflibercept injections and the 100 ophthalmologists performing the highest volume of bevacizumab injections accounted for 19.6% (95% CI, 19.649%-19.653%) of all bevacizumab injections administered nationally to Medicare Part B beneficiaries. The highest number of injections per 1000 Medicare Part B beneficiaries occurred in Nebraska (aflibercept), Tennessee (ranibizumab), and South Dakota (bevacizumab).

Conclusions and Relevance

A total of 3.0% of ophthalmologists account for 17.6% to 31.0% of the total number of anti-VEGF injections administered nationally in the Medicare Part B population. Overall, bevacizumab and ranibizumab injections have decreased, coinciding with a 69.4% increase in aflibercept injections.

New Lipid Mediators in Retinal Angiogenesis and Retinopathy

Retinal diseases associated with vascular destabilization and the inappropriate proliferation of retinal endothelial cells have major consequences on the retinal vascular network. In extreme cases, the development of hypoxia, the upregulation of growth factors, and the hyper-proliferation of unstable capillaries can result in bleeding and vision loss. While anti-vascular endothelial growth factor therapy and laser retinal photocoagulation can be used to treat the symptoms of late stage disease, there is currently no treatment available that can prevent disease progression. Cytochrome P450 enzymes metabolize endogenous substrates (polyunsaturated fatty acids) to bioactive fatty acid epoxides that demonstrate biological activity with generally protective/anti-inflammatory and insulin-sensitizing effects. These epoxides are further metabolized by the soluble epoxide hydrolase (sEH) to fatty acid diols, high concentrations of which have vascular destabilizing effects. Recent studies have identified increased sEH expression and activity and the subsequent generation of the docosahexaenoic acid-derived diol; 19,20-dihydroxydocosapentaenoic acid, as playing a major role in the development of diabetic retinopathy. This review summarizes current understanding of the roles of cytochrome P450 enzyme and sEH–derived PUFA mediators in retinal disease.

Ophthalmic Insert versus Eye Drops for Mydriasis in Neonates: A Randomized Clinical Trial

BACKGROUND

Eye drop treatment routinely used to obtain mydriasis prior to fundoscopy in neonates requires repeated instillations of mydriatic agents that can lead to systemic side effects.

OBJECTIVES

The aim of this study was to compare the mydriatic efficacy and tolerance of administration of phenylephrine and tropicamide via the ophthalmic insert Mydriasert® versus standard eye drop treatment in neonates.

METHODS

In this prospective, single-blinded, noninferiority study, 80 hospitalized neonates (age < 18 months) requiring bilateral fundus examination were randomized to receive eye drops (repeated instillations of 2.5% phenylephrine and 0.5% tropicamide) or the insert. The primary outcome was mydriasis suitable for fundoscopy 75 min after mydriatic agent introduction (T75).

RESULTS

Mydriasis was successfully achieved in both eyes at T75 in 97.5% (n = 39/40) of the insert group patients versus 90% (n = 36/40) receiving eye drops (between-group difference 7.5%, demonstrating noninferiority). Mydriasis remained stable in 60.0% of patients (n = 24/40) in the insert group versus 15% (n = 6/40) in the eye drop group (p < 0.0001). The insert group required fewer nursing interventions than the eye drop group (p = 0.0001). Mean blood pressure were significantly higher in the insert versus the eye drop group (p < 0.0001 and p = 0.0003, respectively); mean heart rate was not significantly different between the groups (p = 0.37). In the insert group, 2 patients reported an adverse event (bradycardia, n = 1, and gastroesophageal reflux, n = 1; both appeared to be related to neonate pathology).

CONCLUSIONS

The degree of mydriasis achieved with Mydriasert® was noninferior to that obtained with eye drops. The insert appears to be safe to use in neonates without a history of increased vagal tone or gastrointestinal reflux.

Time trends, disease patterns and gender imbalance in the top 100 most cited articles in ophthalmology

We analysed the 100 top cited articles in ophthalmology to identify and characterise the most influential articles of the past four decades. Two independent investigators searched the Scopus database to determine the 100 most frequently cited articles in ophthalmology (T100-Eye) and general non-ophthalmology journals (T100-Gen) published from 1975 to December 2017. The T100-Eye list consisted of 83 original articles and 17 reviews, and the number of citations ranged from 582 to 2833. Seventy-eight of these articles were published in three journals alone (impact factor (IF): 5.05-8.2), led by the Archives of Ophthalmology The T100-Gen list consisted of 84 original articles and 16 reviews and the number of citations ranged from 358 to 3272. Forty-five of these articles were published in four journals alone (IF: 9.66-72.41). In both lists, majority of the first authors were from the USA (T100-Eye, n=80; T100-Gen, n=66), and were men (n=76 in T100-Eye; n=72 in T100-Gen). With regard to the article type, in the T100-Eye, among the 83 original research articles, most were randomised controlled trials (n=26) or clinical observational studies related to description of a new condition or new management (n=26). In the T100-Gen, of the 84 original research articles, many were clinical observational studies (n=27) or basic science research (n=26). In both lists, the most frequently examined diseases were age-related macular degeneration, diabetic retinopathy and glaucoma. Our analysis reveals landmark articles, trends and medical advancements in ophthalmology over the past four decades. It also highlights gender disparity and influence of the USA in seminal ophthalmic research.