Increased incidence of retinopathy of prematurity and evolving treatment modalities at a Canadian tertiary centre

Systemic exposure to aflibercept after intravitreal injection in premature neonates with retinopathy of prematurity: results from the FIREFLEYE randomized phase 3 study

BACKGROUND

There are no data on pharmacokinetics, pharmacodynamics, and immunogenicity of intravitreal aflibercept in preterm infants with retinopathy of prematurity (ROP). FIREFLEYE compared aflibercept 0.4 mg/eye and laser photocoagulation in infants with acute-phase ROP requiring treatment.

METHODS

Infants (gestational age ≤32 weeks or birthweight ≤1500 g) with treatment-requiring ROP in ≥1 eye were randomized 2:1 to receive aflibercept 0.4 mg or laser photocoagulation at baseline in this 24-week, randomized, open-label, noninferiority, phase 3 study. Endpoints include concentrations of free and adjusted bound aflibercept in plasma, pharmacokinetic/pharmacodynamic exploration of systemic anti-vascular endothelial growth factor effects, and immunogenicity.

RESULTS

Of 113 treated infants, 75 received aflibercept 0.4 mg per eye at baseline (mean chronological age: 10.4 weeks), mostly bilaterally (71 infants), and with 1 injection/eye (120/146 eyes). Concentrations of free aflibercept were highly variable, with maximum concentration at day 1, declining thereafter. Plasma concentrations of adjusted bound (pharmacologically inactive) aflibercept increased from day 1 to week 4, decreasing up to week 24. Six infants experienced treatment-emergent serious adverse events within 30 days of treatment; aflibercept concentrations were within the range observed in other infants. There was no pattern between free and adjusted bound aflibercept concentrations and blood pressure changes up to week 4. A low-titer (1:30), non-neutralizing, treatment-emergent anti-drug antibody response was reported in 1 infant, though was not clinically relevant.

CONCLUSIONS

24-week data suggest intravitreal aflibercept for treatment of acute-phase ROP is not associated with clinically relevant effects on blood pressure, further systemic adverse events, or immunogenicity.

CLINICALTRIALS

GOV IDENTIFIER

NCT04004208.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Nailfold Capillaroscopy: A Promising, Noninvasive Approach to Predict Retinopathy of Prematurity

OBJECTIVE

To test the hypothesis that nailfold capillaroscopy can noninvasively detect dysregulated retinal angiogenesis and predict retinopathy of prematurity (ROP) in infants born premature before its development.

METHODS

In a cohort of 32 infants born <33 weeks of gestation, 1386 nailfold capillary network images of the 3 middle fingers of each hand were taken during the first month of life. From these, 25 infants had paired data taken 2 weeks apart during the first month of life. Images were analyzed for metrics of peripheral microvascular density using a machine learning-based segmentation approach and a previously validated microvascular quantification platform (REAVER vascular analysis). Results were correlated with subsequent development of ROP based on a published consensus ROP severity scale.

RESULTS

In total, 18 of 32 (56%) (entire cohort) and 13 of 25 (52%) (2-time point subgroup) developed ROP. Peripheral vascular density decreased significantly during the first month of life. In the paired time point analysis, vessel length density, a key metric of peripheral vascular density, was significantly greater at both time points among infants who later developed ROP (15 563 and 11 996 μm/mm2, respectively) compared with infants who did not (12 252 and 8845 μm/mm2, respectively) (P < .001, both time points). A vessel length density cutoff of >15 100 at T1 or at T2 correctly detected 3 of 3 infants requiring ROP therapy. In a mixed-effects linear regression model, peripheral vascular density metrics were significantly correlated with ROP severity.

CONCLUSIONS

Nailfold microvascular density assessed during the first month of life is a promising, noninvasive biomarker to identify premature infants at highest risk for ROP before detection on eye exam.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The time and financial ramifications of providing services for retinopathy of prematurity at a single inner-city institution in the United States: a pilot study

BACKGROUND

Retinopathy of prematurity (ROP) is a sight-threatening disease that requires strict, scheduled screening and timely treatment. Examining infants in the neonatal intensive care unit (NICU) confers an added burden for ophthalmologists whose practices are predominantly outpatient. We sought to evaluate the time required for ROP services and to approximate compensation to better understand the implications of providing this crucial service.

METHODS

The ROP coordinator tracked the time ophthalmologists spent providing ROP services at two NICUs (2018-2020). Estimated revenue was calculated using Medicaid Current Procedural Terminology codes. Total ophthalmologist time was from NICU arrival to departure; travel time was estimated as 45 minutes.

RESULTS

The ophthalmologists cumulatively spent on average 98 and 108 hours yearly for screening only (SO) and screening plus treatment (ST), respectively; this increased to 164 and 181 hours yearly with travel time, respectively. Estimated annual Medicaid physician reimbursements were $15,246 ($156/hour) for SO and $19,184 for ST ($177/hour). Actual annual physician reimbursements were $39,655 ($405/hour) for SO and $53,385 for ST ($492/hour). With travel time, reimbursements decreased by about 40%. A hypothetical full-time ROP practice would generate annual physician salaries of $204,732 for SO and $232,807 for ST. With travel time, this decreases to $122,452 and $139,379, respectively.

CONCLUSIONS

Performing ROP services requires substantial time, especially when including travel among facilities. This study highlights the extensive requirements for the critical task of decreasing ROP blindness.

Demographic Risk Factors of Retinopathy of Prematurity: A Systematic Review of Population-Based Studies

INTRODUCTION

Current national guidelines use gestational age (GA) and birth weight (BW) as their basis for retinopathy of prematurity (ROP) screening. The strength of association of these and other demographic risk factors is inconsistent across studies. This review aims to evaluate the strength of association of documented risk factors for ROP in large sample, population-based studies.

METHODS

MEDLINE, EMBASE, and Cochrane Library were searched from January 2010 to May 2020. Original studies reporting the risk of ROP in a region and demographic risk factors were included.

RESULTS

Eighteen studies comprising 342,005 infants were included. The overall risk of ROP in preterm infants was 18.8%. For every week decrease in GA, there was a median adjusted odds ratio (aOR) of 1.4 times (range 1.2-1.9) of developing ROP. For every 100-g decrease in BW, the median aOR was 1.8 times (range 1.2-2.7). Higher risk was found in infants with neonatal sepsis and bronchopulmonary dysplasia. The risk of any, severe, and treatment-requiring ROP was highest for 23 weeks GA, which was 66.5, 40.3, and 39.4%, respectively. Regions with higher neonatal mortality rates had the highest mean GA of infants with ROP.

CONCLUSION

For every week decrease in GA and every 100-g decrease in BW, there was a median of 1.4 times and 1.8 times the odds of developing ROP, respectively. Further research is required to clarify the role of additional risk factors.

Strategies to Prevent Severe Retinopathy of Prematurity: A 2020 Update and Meta-analysis

The incidence of retinopathy of prematurity (ROP) is showing an increasing trend in the United States. This may be because of increasing survival rates among extremely preterm infants (<25 weeks' gestation) and targeting higher oxygen saturation. Five randomized clinical trials of low versus high oxygen saturation target ranges found increased mortality in the low oxygen saturation target group and an increased incidence of ROP in the high oxygen saturation target group. The American Academy of Pediatrics recommends using an oxygen saturation target range of 90% to 95% in extremely low-birthweight infants. The change of practice to target this higher oxygen saturation range, from admission until discharge, may be contributing to the increasing incidence of ROP in extremely preterm infants. To decrease the incidence of ROP without increasing mortality, 2 new cohort trials suggest gradually increasing oxygen saturation targets as preterm infants mature. There is evidence that human milk, vitamin A, and omega-3 fatty acids can help, in addition to continuous oxygen saturation monitoring, to decrease the risk of ROP. We review this literature and provide a meta-analysis to evaluate the evidence.

Intravitreal antivascular endothelial growth factor injection versus laser photocoagulation for retinopathy of prematurity: A meta-analysis of 3,701 eyes

We investigate the efficacy and safety of intravitreal injection (IVI) of antivascular endothelial growth factor agents and laser photocoagulation (LPC) for retinopathy of prematurity. We performed a systematic search of Ovid MEDLINE, EMBASE, and Cochrane CENTRAL (2005-2019). Comparative studies reporting on ocular efficacy and/or safety outcomes after IVIs and LPC for retinopathy of prematurity were included. The primary outcome was the regression rate, whereas secondary endpoints included the likelihood of requiring additional treatment, visual and refractive outcomes, and complications. Overall, 777 publications were identified. Twenty-four articles were included, with 1,289 eyes receiving IVI and 2,412 eyes undergoing LPC. There was no significant difference in the regression rate between IVI and LPC (P = 0.68); however, eyes that underwent IVI were associated with a significantly higher likelihood of requiring additional treatment (risk ratio = 2.16, 95% confidence interval (CI) = [1.26, 3.73], P = 0.005) and longer time from treatment to retreatment or recurrence (weighted mean difference = 6.43 weeks, 95% CI = [2.36, 10.51], P = 0.002). Eyes receiving IVI required surgical intervention significantly less often (risk ratio = 0.45, 95% CI = [0.23, 0.89], P = 0.02). Astigmatism was significantly lower after IVI relative to LPC (weighted mean difference = -0.25 D, 95% CI = [-0.45, -0.06], P = 0.01), and there was a lower proportion of emmetropic eyes at last follow-up after LPC (risk ratio = 0.51, 95% CI = [0.27, 0.99], P = 0.05). There were no differences in visual and safety outcomes between IVI and LPC. LPC had a lower likelihood of requiring additional treatment, whereas IVIs were associated with a longer interval from treatment to retreatment or recurrence, reduced risk of surgical intervention and superior refractive outcomes. All other outcomes were comparable between IVIs and LPC.

Screening and novel therapies for retinopathy of prematurity - A review

With current screening for sight threatening retinopathy of prematurity (ROP) <10% of screened infants need treatment. Prediction models based on birth characteristics, postnatal weight gain and other factors have been developed to reduce examinations in low-risk infants. A model based on advanced statistics using data from >7000 infants registered in the Swedish ROP registry is being developed. Based on birth characteristics only, it appears to predict total risk of ROP-treatment as well as models including weight measurements. Treatment risk peaked at 12 weeks of age. Laser therapy is the method of choice for severe ROP. Anti-VEGF therapies are implemented worldwide despite insufficient knowledge of choice of drug, dosage and long term systemic effects. Prevention of ROP may be achieved through oxygen control and provision of the mother's breastmilk. Other interventions such as supplementation with long chain polyunsaturated fatty acids and preservation of fetal haemoglobin are investigated.