Structural, visual and refractive outcomes of intravitreal aflibercept injection in high-risk prethreshold type 1 retinopathy of prematurity

FLUORESCEIN ANGIOGRAPHY EVALUATION OF CHILDREN PREVIOUSLY TREATED WITH ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR MONOTHERAPY FOR RETINOPATHY OF PREMATURITY

PURPOSE

To determine the level of vascularization and peripheral vascular findings by fluorescence angiography in patients with aggressive retinopathy of prematurity or Type 1 retinopathy of prematurity treated with a single dose of anti-vascular endothelial growth factor.

METHODS

Data of patients referred to the authors' clinic for fluorescence angiography examination between June 2016 and September 2021 were retrospectively analyzed. Patients who had their first fluorescence angiography examination at the age of 1 year or older were included in the study.

RESULTS

A total of 486 eyes of 250 patients were included. Of these, 83 eyes (17.1%) had vascular termination in Zone II and 403 eyes (82.9%) in Zone III. In 62.7% of eyes, the distance from the vascular terminals to the temporal ora serrata was less than two disk diameters, and in 20.2%, it was more than two disk diameters. Abnormal vascular findings were noted, including circumferential vessels (41.2%), finger-like projection anomaly (36.2%), hyperfluorescence (16.9%), fine branching and blunt termination (15%), and arteriovenous shunt (9.9%).

CONCLUSION

Fluorescence angiography performed late in the course of treatment can clearly define the vascular termini and detect abnormalities that cannot be detected by indirect ophthalmoscopy. Follow-up with fluorescence angiography can help prevent complications that can lead to vision loss.

Comparison of Bevacizumab and Aflibercept for Suppression of Angiogenesis in Human Retinal Microvascular Endothelial Cells

Bevacizumab (Avastin) is a vascular endothelial growth factor (VEGF) inhibitor that is widely used for aggressive posterior retinopathy of prematurity (APROP). Its use is associated with multiple adverse effects. Aflibercept (Eylea) is a VEGFR-1 analogue that is approved for ocular use, but its efficacy for APROP is less studied. We tested the hypothesis that Eylea is as effective as Avastin for suppression of intermittent hypoxia (IH)-induced angiogenesis. Human retinal microvascular endothelial cells (HRECs) were treated with Avastin and low- or high-dose Eylea and exposed to normoxia, hyperoxia (50% O₂), or neonatal IH for 24, 48, or 72 h. Cells were assessed for migration and tube formation capacities, as well as biomarkers of angiogenesis and oxidative stress. Both doses of Eylea suppressed migration and tube formation in all oxygen environments, although the effect was not as robust as Avastin. Furthermore, the lower dose of Eylea appeared to be more effective than the higher dose. Eylea induced soluble VEGFR-1 (sVEGFR-1) coincident with high IGF-I levels and decreased Notch/Jagged-1, demonstrating a functional association. Given the role of VEGFR-1 and Notch as guidance cues for vascular sprouting, these data suggest that Eylea may promote normal vascular patterning in a dose-dependent manner.

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

PURPOSE

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

METHODS

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

FINDINGS

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

IMPLICATIONS

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

Progress on the application of growth factor-related drugs in ophthalmology

Vascular endothelial growth factor（VEGF）, fibroblast growth factor（FGF）, nerve growth factor（NGF）, epidermal growth factor and interferon are important endogenous proteins that regulate cell proliferation, differentiation and regeneration. Biological products targeting growth factors are used in the treatment of ocular diseases such as wet age-related macular degeneration, corneal injury and neurotrophic keratitis. Anti-VEGF drugs can regulate the proliferation of vascular endothelia, reduce the edema and exudation of retinal tissue，which are the main therapeutic agents for wet age-related macular degeneration and diabetic retinopathy. The basic FGF (b-FGF) can promote the proliferation, differentiation, and migration of corneal epithelial cells, accelerating the healing of the corneal injury and reduces corneal inflammation；and bovine b-FGF has been approved for the treatment of corneal injuries. The NGF promotes the growth, development, and differentiation of central and peripheral neurons, thus accelerating the repair of nerve damage；and the European Medicines Agency approved the use of nerve growth factor for the treatment of neurotrophic keratitis in 2017. Recent clinical studies show that patients with moderate or severe neurotrophic keratitis achieved complete corneal healing following 8 weeks of NGF therapy. Epidermal growth factor derivative eye drops have been approved for the treatment of corneal epithelial injuries. Recombinant human interferon has been clinically used in the treatment of ocular viral infections. This article reviews the research progress in the development of new cell growth factor drugs for the treatment of ophthalmic diseases, to provide insights for expanding the application of cell growth factors in ophthalmology.

Incontinentia pigmenti and the eye

PURPOSE OF REVIEW

Incontinentia pigmenti (IP) is a rare X-linked dominant phakomatosis that predominately presents with dermatologic manifestations but can also cause central nervous system and ocular abnormalities. Awareness of the ocular complications of IP is crucial to identify ocular abnormalities early and prevent permanent vision loss.

RECENT FINDINGS

There have been significant recent advances in ocular diagnostic imaging in IP. Optical coherence tomography (OCT) has helped characterize outer plexiform layer abnormalities in the macula, which can help explain central vision loss in IP patients. OCT angiography (OCT-A) also identifies macular vascular changes that induce these foveal structural abnormalities and may supplement fluorescein angiography, the current standard of care to identify peripheral retinal ischemia and neovascularization for infants with IP. Additionally, recent studies have presented excellent anatomic outcomes years after laser photocoagulation to ischemic retina. Early data indicates that antivascular endothelial growth factor therapy can induce retinal revascularization, but runs the risk of late recurrent neovascularization and requires long-term monitoring.

SUMMARY

Ophthalmic imaging is evolving in the evaluation of IP and is increasingly guiding treatment modalities. A particular focus on the ocular manifestations of IP has been the ideal treatment for retinopathy in this disorder.

The Male to Female Ratio in Treatment-Warranted Retinopathy of Prematurity: A Systematic Review and Meta-analysis

Importance

Literature and anecdotal evidence suggest a relationship between male sex and retinopathy of prematurity (ROP). It is not known whether a difference, if present, is sex-related pathophysiologic predisposition or sex difference in meeting ROP screening criteria.

Objective

To evaluate the association of sex with the development of treatment-warranted ROP.

Data Sources

PubMed, Embase, and Web of Science databases were searched from 2000 to 2022. The search strategy used keywords including retinopathy of prematurity or ROP or retrolental fibroplasia and treatment or anti-VEGF or bevacizumab or ranibizumab or aflibercept or conbercept or laser or cryotherapy and gender or sex or male or female and medical subject headings terms.

Study Selection

All studies reporting on treatment with anti-vascular endothelial growth factor, laser photocoagulation, and/or cryotherapy for ROP were identified. Studies reporting sex distribution in the treatment group were included in the meta-analysis. Exclusion criteria included case reports, case series of fewer than 10 treated patients, systematic reviews, conference abstracts, letters to the editor, animal studies, and non-English records.

Data Extraction and Synthesis

Two reviewers independently screened and extracted the data following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The proportions of treated male and female infants were combined using random-effects meta-analysis.

Main Outcomes and Measures

Numbers and percentages of male and female infants treated for ROP.

Results

Of 11 368 identified studies, 316 met inclusion criteria, yielding a total of 31 026 treated patients. A higher percentage of male infants were treated for ROP (55% [95% CI, 0.54%-0.55%]), with low heterogeneity between studies (I2 = 34%; P < .001). Thirty-eight studies reported sex distribution in the screened population (170 053 patients; 92 612 [53%] male vs 77 441 [47%] female). There was no significant difference in the odds of receiving treatment between screened male and female infants (pooled odds ratio, 1.04 [95% CI, 0.91-1.18]; P = .67).

Conclusions and Relevance

More male infants are treated for ROP than female infants. This could be due to a known relative pathophysiological fragility of preterm male infants in addition to a difference in ROP screening rates, with more male infants meeting the criteria than female infants. These findings have implications for future studies and may prompt more careful clinical monitoring of male neonates.

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

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

Using real-world data in pediatric clinical trials: Lessons learned and future applications in studies of persistent pulmonary hypertension of the newborn

Persistent pulmonary hypertension of the newborn (PPHN) is a complication of term birth, characterized by persistent hypoxemia secondary to failure of normal postnatal reduction in pulmonary vascular resistance, with potential for short- and long-term morbidity and mortality. The primary pharmacologic goal for this condition is reduction of the neonate's elevated pulmonary vascular resistance with inhaled nitric oxide, the only approved treatment option. Various adjunctive, unapproved therapeutics have been trialed with mixed results, likely related to challenges with recruiting the full, intended patient population into clinical studies. Recently, real-world data and subsequent derived evidence have been utilized to improve the efficiency of various pediatric clinical trials. We aim to provide recent perspectives regarding the use of real-world data in the planning and execution of pediatric clinical trials and how this may facilitate more streamlined assessment of future therapeutics for the treatment of PPHN and other neonatal conditions.

Effect of Intravitreal Aflibercept vs Laser Photocoagulation on Treatment Success of Retinopathy of Prematurity: The FIREFLEYE Randomized Clinical Trial

IMPORTANCE

Laser photocoagulation, which is the standard treatment for retinopathy of prematurity (ROP), can have adverse events. Studies of anti-vascular endothelial growth factor injections have suggested efficacy in the treatment of ROP, but few studies have directly compared them with laser treatments.

OBJECTIVE

To compare intravitreal aflibercept vs laser photocoagulation in infants with ROP requiring treatment.

DESIGN, SETTING, AND PARTICIPANTS

This noninferiority, phase 3, 24-week, randomized clinical trial was conducted in 27 countries (64 hospital sites) throughout Asia, Europe, and South America. Overall, 118 infants (gestational age ≤32 weeks at birth or birth weight ≤1500 g) with ROP severity (zone I stage 1+ [stage 1 plus increased disease activity], zone I stage 2+, zone I stage 3, zone I stage 3+, zone II stage 2+, or zone II stage 3+) requiring treatment or with aggressive posterior ROP in at least 1 eye were enrolled between September 25, 2019, and August 28, 2020 (the last visit occurred on February 12, 2021).

INTERVENTIONS

Infants were randomized 2:1 to receive a 0.4-mg dose of intravitreal aflibercept (n = 75) or laser photocoagulation (n = 43) at baseline. Additional treatment was allowed as prespecified.

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of infants without active ROP and unfavorable structural outcomes 24 weeks after starting treatment (assessed by investigators). The requirement for rescue treatment was considered treatment failure. Intravitreal aflibercept was deemed noninferior if the lower limit of the 1-sided 95% bayesian credible interval for the treatment difference was greater than -5%.

RESULTS

Among 118 infants randomized, 113 were treated (mean gestational age, 26.3 [SD, 1.9] weeks; 53 [46.9%] were female; 16.8% had aggressive posterior ROP, 19.5% had zone I ROP, and 63.7% had zone II ROP) and 104 completed the study. Treatment (intravitreal aflibercept: n = 75; laser photocoagulation: n = 38) was mostly bilateral (92.9%), and 82.2% of eyes in the intravitreal aflibercept group received 1 injection per eye. Treatment success was 85.5% with intravitreal aflibercept vs 82.1% with laser photocoagulation (between-group difference, 3.4% [1-sided 95% credible interval, -8.0% to ∞]). Rescue treatment was required in 4.8% (95% CI, 1.9% to 9.6%) of eyes in the intravitreal aflibercept group vs 11.1% (95% CI, 4.9% to 20.7%) of eyes in the laser photocoagulation group. The serious adverse event rates were 13.3% (ocular) and 24.0% (systemic) in the intravitreal aflibercept group compared with 7.9% and 36.8%, respectively, in the laser photocoagulation group. Three deaths, which occurred 4 to 9 weeks after intravitreal aflibercept treatment, were considered unrelated to aflibercept by the investigators.

CONCLUSIONS AND RELEVANCE

Among infants with ROP, intravitreal aflibercept compared with laser photocoagulation did not meet criteria for noninferiority with respect to the primary outcome of the proportion of infants achieving treatment success at week 24. Further data would be required for more definitive conclusions regarding the comparative effects of intravitreal aflibercept and laser photocoagulation in this population.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04004208.

RNA-Seq Provides Insights into VEGF-Induced Signaling in Human Retinal Microvascular Endothelial Cells: Implications in Retinopathy of Prematurity

The pathophysiology of retinopathy of prematurity (ROP) is postulated to first involve delayed intraretinal vascularization, followed by intravitreal neovascularization (IVNV). Although intravitreal agents that reduce the bioactivity of vascular endothelial growth factor (VEGF) are used to treat IVNV, concerns exist regarding their effects on intraretinal vascularization. In an experimental ROP model, VEGF receptor 2 (VEGFR2) knockdown in retinal endothelial cells reduced IVNV and promoted intraretinal vascularization, whereas knockdown of a downstream effector, signal transducer and activator of transcription 3 (STAT3) in retinal endothelial cells only reduced IVNV. In this study, we tested the hypothesis that the different pathways involved in VEGF-triggered VEGFR2 signaling and VEGF-triggered STAT3 signaling in retinal endothelial cells would allow us to delineate signaling pathways involved in IVNV from those involved in intraretinal vascularization in ROP. To address our hypothesis, we used RNA-sequencing and pathway enrichment analysis to determine changes in the transcriptome of cultured human retinal microvascular endothelial cells (HRMECs). Of the enriched pathways, inactivation of oncostatin M signaling was predicted by either KDR or STAT3 knockdown in the presence of VEGF. Activation of kinetochore metaphase signaling was predicted by KDR knockdown, whereas inactivation was predicted by STAT3 knockdown in the presence of VEGF. Inactivation of signaling by the Rho family of GTPases was predicted by KDR knockdown, but activation was predicted by STAT3 knockdown in the presence of VEGF. Taken together, our data identified unique signaling pathway differences between VEGF-triggered VEGFR2 and VEGF-triggered STAT3 in HRMECs that might have implications in ROP.

Plasma Levels of Bevacizumab and Vascular Endothelial Growth Factor After Low-Dose Bevacizumab Treatment for Retinopathy of Prematurity in Infants

Importance

Intravitreal bevacizumab effectively treats severe retinopathy of prematurity (ROP), but it enters the bloodstream and may reduce serum vascular endothelial growth factor (VEGF), potentially causing detrimental effects on developing organs in the premature infant.

Objective

To evaluate the association of intravitreal bevacizumab with plasma bevacizumab and VEGF concentrations at 2 and 4 weeks after predefined, de-escalating doses of intravitreal bevacizumab were administered to infants with severe ROP.

Design, Setting, and Participants

This phase 1 dose de-escalation case series study was conducted at 10 US hospitals of ophthalmology institutions from May 21, 2015, to May 7, 2019. Blood samples were collected 2 and 4 weeks after intravitreal bevacizumab injection. Participants included 83 premature infants with type 1 ROP in 1 or both eyes and no previous ROP treatment. Data were analyzed from April 2017 to August 2021.

Interventions

Study eyes received a single bevacizumab injection of 0.250 mg, 0.125 mg, 0.063 mg, 0.031 mg, 0.016 mg, 0.008 mg, 0.004 mg, or 0.002 mg. When the fellow eye required treatment, one dose higher was administered. Total dose administered at baseline was defined as the sum of doses given to each eye within 3 days of initial study-eye injection.

Main Outcomes and Measures

Plasma bevacizumab concentration at 2 and 4 weeks after injection and the percentage change in plasma VEGF concentrations from pretreatment levels.

Results

A total of 83 infants (mean [SD] age, 25 [2] weeks; 48 boys [58%]) were included in this study. Higher doses of bevacizumab administered at baseline were associated with higher plasma bevacizumab concentrations at 2 weeks (ρ, 0.53; 95% CI, 0.31-0.70) and 4 weeks (ρ, 0.44; 95% CI, 0.18-0.64). Plasma VEGF concentrations decreased by 50% or more from pretreatment levels in 40 of 66 infants (61%) at 2 weeks and 31 of 61 infants (51%) at 4 weeks, but no association was observed between the total dose of bevacizumab administered at baseline and percentage change in plasma VEGF concentrations 2 weeks (ρ, -0.04; 95% CI, -0.28 to 0.20) or 4 weeks (ρ, -0.17; 95% CI, -0.41 to 0.08) after injection.

Conclusions and Relevance

Results of this phase 1 dose de-escalation case series study revealed that bevacizumab doses as low as 0.002 mg were associated with reduced plasma VEGF levels for most infants at 2 and 4 weeks after intravitreal administration; however, no association was observed between total bevacizumab dose administered and reductions in plasma VEGF levels from preinjection to 2 weeks or 4 weeks. Additional studies are needed to evaluate the long-term effects of low-dose bevacizumab on neurodevelopment and retinal structure.

New trends in intravitreal anti-VEGF therapy for ROP

Retinopathy of Prematurity (ROP) affects premature newborns, and it can cause childhood blindness and visual impairment if untreated. The understanding of the pathogenetic role of Vascular Endothelial Growth Factor (VEGF) has led to development of therapeutic strategies such as intravitreal anti-VEGF drugs. We reported drug efficacy and ROP recurrence rates, extrapolated from the reviewed studies. Association of Pegabtanib and laser photocoagulation confers efficacy in the regression of ROP stage 3 plus in zone I / II in 89.7% of treated eyes, reducing the recurrence rate to 14.6% compared to 50% of laser therapy alone. Irrespective of the dose, Ranibizumab demonstrated average efficacy greater than 75% on regression of active disease with the highest rates of the dose of 0.1 mg (92.5%). The recurrence, on the other hand, is the highest among this new anti-VEGF agents and is around an average of 41.5%, which records the highest values in the case of Aggressive Posterior Rop (APROP). Aflibercept at a dose of 1 mg demonstrated average efficacy of about 81.9% of treated infants, analyzing significantly fewer studies than Ranibizumab. The recurrence rate stands at an average of 28.9%, especially in the later forms of ROP. Using a dose of 0.25 mg of Conbercept, the disease regression rate is currently on average 83%, with an average recurrence rate of 15.24%, the peak of which was observed in cases of ROP in zone I. Further studies are needed to prove safety at long term, because,at the moment, only short-term data are available.

Comparison of Clinical Outcomes of Intravitreal Bevacizumab and Aflibercept in Type 1 Prethreshold Retinopathy of Prematurity in Posterior Zone II

Purpose

To evaluate the efficacy and safety of intravitreal injection (IVI) of bevacizumab (IVB) versus aflibercept (IVA) in premature infants with type 1 prethreshold retinopathy of prematurity (ROP) in the posterior Zone II.

Methods

The study was a multicenter, historical cohort of premature newborns diagnosed with type 1 prethreshold ROP in the posterior Zone II, treated with IVB or IVA. Demographic features, complications, and treatment outcomes were then compared between the two groups.

Results

Seventy-six patients received aflibercept (the IVA group), and 210 received bevacizumab (the IVB group). The two groups were not significantly different in terms of postmenstrual age (PMA) at the time of ROP diagnosis and other known risk factors for ROP development and progression. All eyes in both the groups responded to IVI; however, recurrence was observed in four eyes (1.9%) in the IVB group and 12 (15.8%) in the IVA group (P = 0.001). Recurrence occurred 9.1 ± 0.83 (5-12) and 15.5 ± 0.98 (12-18) weeks after primary treatment in the IVB and IVA groups, respectively (P = 0.000). In the IVA group, retinal vascularization was completed in 38.18 ± 6.5 weeks (21-48) after IVI, and it happened in 23.86 ± 9.3 weeks (13-60) in the IVB group (P = 0.009). Furthermore, vascularization reached the peripheral retina in 73.25 ± 6.5 (56-84) and 58.75 ± 8.8 (45-93) weeks, PMA in the IVA and IVB groups, respectively (P = 0.03). No acute postoperative complications were observed in the treated eyes in either group.

Conclusion

This study shows that both IVA and IVB are effective and well tolerated for the management of type 1 prethreshold ROP in the posterior Zone II; however, IVA needs a significantly longer time for vascularization completion and has a higher recurrence rate compared with IVB.

Aflibercept for Retinopathy of Prematurity: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

To determine the effectiveness of aflibercept in retinopathy of prematurity (ROP).

PATIENTS AND METHODS

We performed a systematic review and meta-analysis of proportions from the literature in PubMed and Cochrane Library using search terms related to the use of aflibercept in ROP. Studies in non-preterm infants or that did not use aflibercept as the initial treatment were excluded. Risk of bias was assessed by the ROBINS-I (Risk Of Bias in Non-randomized Studies of Interventions) tool.

RESULTS

We identified six case series. Collectively, 218 eyes were treated with aflibercept for ROP. We found an average 97% (95% confidence interval [CI], 93% to 99%) regression rate with aflibercept and an average 16% (95% CI, 5% to 41%) recurrence rate. With the exception of one outlier study, these numbers are similar to previous reports using anti-vascular endothelial growth factor (VEGF) agents in ROP.

CONCLUSIONS

Aflibercept holds promise for use in ROP and has been demonstrated to be efficacious in six case series. Randomized, controlled clinical trials appear warranted to compare aflibercept with other anti-VEGF agents. [Ophthalmic Surg Lasers Imaging. 2021;52:673-681.].

Comparison of aflibercept and bevacizumab in the treatment of type 1 retinopathy of prematurity

Background

To evaluate the outcome of intravitreal bevacizumab (IVB) and aflibercept (IVA) injection for patients with retinopathy of prematurity (ROP).

Methods

In this single-center retrospective cohort, the recorded medical data of the infants who had been undergone intravitreal injection with either bevacizumab or aflibercept for type 1 ROP were reviewed. The infants were allocated into two groups. IVB group included patients who were treated with bevacizumab as initial treatment and the IVA group included patients who were treated with aflibercept as initial treatment. The rate and time of complete regression, as well as the recurrence rates, were compared between the groups.

Results

A total of 889 eyes of 453 infants were enrolled in the study. There were 865 eyes of 441 infants in the IVB group and 24 eyes of 12 infants in the IVA group. Follow-up time was 289 ± 257 days in the IVB group and 143 ± 25 days in the IVA group (p < 0.001). The difference in the ROP zone was not statistically significant between the 2 treatment groups (p = 0.328). All eyes in the IVA group showed initial regression of ROP after the intravitreal injections. These regressions were achieved in 830 (96.0%) eyes that were injected with IVB (p = 0.023). The median observed regression time was 10 days and 16 days in eyes treated with bevacizumab and aflibercept respectively. Recurrence was noted in 3.9% of eyes (34/865) in the IVB group and 58.3% of eyes (14/24) in the IVA group (p < 0.001).

Conclusion

While the regression rate in the IVA group was significantly higher than in the IVB group, the recurrence rate was significantly more in the IVA group, which may be attributed to differences in the pharmacokinetics of these drugs in the vitreous body.

VEGFR1 signaling in retinal angiogenesis and microinflammation

Five vascular endothelial growth factor receptor (VEGFR) ligands (VEGF-A, -B, -C, -D, and placental growth factor [PlGF]) constitute the VEGF family. VEGF-A binds VEGF receptors 1 and 2 (VEGFR1/2), whereas VEGF-B and PlGF only bind VEGFR1. Although much research has been conducted on VEGFR2 to elucidate its key role in retinal diseases, recent efforts have shown the importance and involvement of VEGFR1 and its family of ligands in angiogenesis, vascular permeability, and microinflammatory cascades within the retina. Expression of VEGFR1 depends on the microenvironment, is differentially regulated under hypoxic and inflammatory conditions, and it has been detected in retinal and choroidal endothelial cells, pericytes, retinal and choroidal mononuclear phagocytes (including microglia), Müller cells, photoreceptor cells, and the retinal pigment epithelium. Whilst the VEGF-A decoy function of VEGFR1 is well established, consequences of its direct signaling are less clear. VEGFR1 activation can affect vascular permeability and induce macrophage and microglia production of proinflammatory and proangiogenic mediators. However the ability of the VEGFR1 ligands (VEGF-A, PlGF, and VEGF-B) to compete against each other for receptor binding and to heterodimerize complicates our understanding of the relative contribution of VEGFR1 signaling alone toward the pathologic processes seen in diabetic retinopathy, retinal vascular occlusions, retinopathy of prematurity, and age-related macular degeneration. Clinically, anti-VEGF drugs have proven transformational in these pathologies and their impact on modulation of VEGFR1 signaling is still an opportunity-rich field for further research.

Comparison of two different doses of intravitreal aflibercept in the treatment of retinopathy of prematurity

PURPOSE

To compare the effectiveness of 0.4 mg/0.01 ml ("low dose") and 1 mg/0.025 ml ("standard dose") intravitreal aflibercept (IVA) in the treatment of retinopathy of prematurity (ROP).

METHODS

The medical records of patients treated with the lower dose (low-dose group) or the more commonly used dose (standard-dose group) of IVA for type 1 or aggressive posterior retinopathy of prematurity (AP-ROP) were evaluated retrospectively. The clinical features, regression and recurrence rates, additional treatments, retinal detachment rates and border of vascularization at last examination were analyzed.

RESULTS

A total of 32 eyes of 16 patients in the low-dose group and 42 eyes of 21 patients in the standard-dose group were included. At the time of the initial treatment, vascularization was in zone I in 26 eyes (81%) in the low-dose group and in 14 eyes (33%) in the standard-dose group (P = 0.000). The regression rate was 94% and 100%, respectively (P = 0.184). Retinal detachment occurred in 1 unresponsive eye in the low-dose group and 2 eyes after reactivation in the standard-dose group. Recurrence was observed in 9 (28%) eyes in the low-dose group and 10 (24%) eyes in the standard-dose group after the complete regression of the disease with treatment (P = 0.845). At 6 months, vascularization had entered zone III in 12 eyes (38%) in the low-dose group and in 24 eyes (57%) in the standard-dose group (P = 0.017).

CONCLUSIONS

Although the difference between groups was not statistically significant, eyes with lack of response were present only in the low-dose group.

Preclinical Efficacy and Safety of VEGF-Grab, a Novel Anti-VEGF Drug, and Its Comparison to Aflibercept

Purpose

VEGF-Grab is a novel anti-vascular endothelial growth factor (VEGF) candidate drug with higher affinity to both VEGF and placental growth factor (PlGF) compared to aflibercept. We investigated the preclinical efficacy of VEGF-Grab for ophthalmic therapy and compared it to that of aflibercept.

Methods

The in vitro anti-VEGF efficacy of VEGF-Grab was determined using VEGF-induced cell proliferation/migration and tube formation assays. The in vivo antiangiogenic efficacy of intravitreal injection of either VEGF-Grab or aflibercept was evaluated using murine models of ocular angiogenesis: mouse oxygen-induced retinopathy (OIR) and rat laser-induced choroidal neovascularization (CNV). The in vivo retinal toxicity in the mouse eye resulting from the injection of either drug was evaluated with light and electron microscopy.

Results

VEGF-Grab showed greater inhibition of VEGF-induced cell proliferation/migration than aflibercept, but it showed comparable inhibition of tube formation in vitro. In the in vivo OIR model, VEGF-Grab showed a comparable suppression of retinal neovascularization compared to aflibercept. Additionally, VEGF-Grab showed an efficacy similar to that of aflibercept in terms of CNV inhibition in the laser-induced CNV model. Histology and transmission electron microscopy showed no significant signs of toxicity in the mouse retina at 7 and 30 days following the intravitreal injection of VEGF-Grab or aflibercept.

Conclusions

Compared to aflibercept, VEGF-Grab presented comparable in vivo antiangiogenic efficacy and superior in vitro anti-VEGF activity. The retinal safety profiles were comparable for the two drugs. Considering its known higher binding affinity to VEGF and PlGF compared to aflibercept, VEGF-Grab could be a potential candidate drug for neovascular retinal diseases and an alternative to aflibercept.

Hypertension and Ischemic Stroke After Aflibercept for Retinopathy of Prematurity

Background

Retinopathy of prematurity is the leading cause of preterm infants' blindness. The preferred method for the management of aggressive posterior ROP is the anti-vascular endothelial growth factor (anti-VEGF). However, systemic and ocular adverse effects of anti-VEGF drugs remain a concern.

Case Presentation

A case report of a preterm infant with a history of hypertension underwent intravitreal injection of aflibercept at the 50-week postmenstrual age because of aggressive posterior retinopathy of prematurity (ROP) in both eyes. Seven days after the intravitreal administration of aflibercept, he has a hypertension crisis and an ischemic stroke. Serial fundoscopies implied complete arrest of vascularization till seven months after receiving treatment.

Conclusion

We report a case of an infant, with a history of hypertension, had an ischemic stroke just one week after the intravitreal injection of aflibercept for aggressive posterior ROP. We can conclude that in cases of preterm infants with systemic comorbidities, like uncontrolled hypertension, that predispose patients to thromboembolic events, we should be cautious about the potential increase in the risk of thromboembolic events after administration of anti-vascular endothelial growth factor agents (anti-VEGF), especially those with a longer half-life, like aflibercept.

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.

Comparison of the Efficacy Between Intravitreal Aflibercept and Laser Photocoagulation in the Treatment of Retinopathy of Prematurity

PURPOSE

To compare the efficacy of intravitreal aflibercept and laser photocoagulation in the treatment of retinopathy of prematurity (ROP).

METHODS

The files of patients who were diagnosed as having type 1 ROP or aggressive posterior ROP (APROP) and treated with laser photocoagulation and 1 mg/0.025 mL of intravitreal aflibercept were retrospectively analyzed. The patients' birth weight, gestational age, detection week of the disease, zone, stage, presence of plus disease and rubeosis, regression of ROP, re-treatments administered during the follow-up, and spherical equivalent values obtained at the corrected sixth month were recorded.

RESULTS

The study included 27 eyes of 15 patients who underwent laser photocoagulation and 24 eyes of 12 patients who received intravitreal aflibercept. Retinal vascularization was in zone II in all eyes in the laser photocoagulation group and zone 1 in 22 eyes (91.7%) in the intravitreal aflibercept group (P < .05). In the laser photocoagulation group, 25 eyes (92.6%) had stage 3 ROP and 2 eyes (7.4%) had stage 2 ROP. In the intravitreal aflibercept group, 14 eyes (58.3%) had stage 3 ROP and 10 eyes (41.7%) had APROP (P < .05). Treatment was established at a postmenstrual age of 37.6 ± 2.5 weeks in the laser photocoagulation group and 34.2 ± 2.4 weeks in the intravitreal aflibercept group (P < .05). The regression rates after treatment were 92.6% and 100%, respectively (P > .05). In the intravitreal aflibercept group, laser photocoagulation was performed on 10 eyes (41.6%) during follow-up visits. Spherical equivalents were measured as +1.10 ± 2.30 and +1.50 ± 2.41 diopters, respectively (P < .05) at the corrected sixth month.

CONCLUSIONS

Intravitreal aflibercept is an effective treatment for ROP. However, it requires more additional treatments than laser photocoagulation during the follow-up visits. [J Pediatr Ophthalmol Strabismus. 2020;57(1):54-60.].

Fluorescein Angiographic Findings of Peripheral Retinal Vasculature after Intravitreal Conbercept versus Ranibizumab for Retinopathy of Prematurity

PURPOSE

To evaluate angiographic findings of peripheral retina vasculature in retinopathy of prematurity (ROP) neonates who received intravitreal conbercept (IVC) or ranibizumab (IVR).

METHODS

Fluorescein angiography (FA) findings were retrospectively evaluated for ROP neonates who received IVC or IVR. Outcome measures included peripheral avascular zone, vascular leakage, vascular blunting, vascular loops, vascular dilatation, arteriovenous shunt, and capillary dropout.

RESULTS

Fifty-four eyes (28 patients) with ROP were included. Twenty-nine eyes (15 patients) received IVC, and 25 eyes (13 patients) received IVR. For infants of the IVC group, the mean gestational age, birth weight, and postmenstrual age (PMA) at the initial treatment were 28.96 ± 2.36 weeks, 1168.8 ± 344.5 g, and 41.22 ± 4.39 weeks, respectively. For the IVR group, they were 28.83 ± 2.34 weeks, 1255.0 ± 356.9 g, and 39.42 ± 2.77 weeks, respectively (P=0.817, 0.522, and 0.075). For the IVC group, FA performed at 71.29-115.43 weeks PMA showed 96.55% of eyes had avascular zone; vascular leakage was found in 24.14% eyes; vascular blunting, vascular dilation, vascular loops, arteriovenous shunt, and capillary dropout were found in 96.55%, 72.41%, 79.31%, 48.28%, and 68.97% eyes, respectively. For the IVR group, FA performed at 65.57-133.71 weeks PMA showed 92.0% of eyes had avascular zone; vascular leakage was found in 40.0% eyes; vascular blunting, dilatation, loops, arteriovenous shunt, and capillary dropout were found in 100%, 60.0%, 64.0%, 36.0%, and 68.0% eyes, respectively.

CONCLUSION

No significant difference can be observed between the IVC group and IVR group for peripheral vascular structure anomalies with FA evidence. FA studies should be considered to assess the status of the peripheral retinal vasculature to determine therapeutic outcomes and potential functional outcomes.

Development of refractive error in children treated for retinopathy of prematurity with anti-vascular endothelial growth factor (anti-VEGF) agents: A meta-analysis and systematic review

Objective

To investigate refractive error development in preterm children with severe retinopathy of prematurity (ROP) treated with anti-vascular endothelial growth factor (anti-VEGF) agents and laser photocoagulation.

Methods

Selection criteria were comparative studies that compared the refractive errors in children, birthweights ≤1500 grams and gestational ages ≤30 weeks, and treatments for Type I ROP with intravitreal bevacizumab (IVB) versus laser photocoagulation. Studies were identified using PubMed, Google Scholar, and published reviews. Meta-analyses were performed on the post-treatment outcomes of spherical equivalent (SEQ), cylindrical power, and prevalence of high myopia. Longitudinal development of refractive error in IVB, or in laser-treated children, or in normal full-term children was visually summarized.

Results

Two randomized controlled trials and 5 non-randomized studies, including a total of 272 eyes treated by IVB and 247 eyes treated by laser, were included in this study. Compared with laser-treated children, IVB-treated children have less myopic refractive error (P<0.001), lower prevalence of high myopia (P<0.05), and less astigmatism (P = 0.02).

Conclusions

Treatment with IVB is associated with less myopia and astigmatism than laser treatment for infants with severe ROP. Given the complexity of ROP and the variability of dosing, our review supports close monitoring of refractive error outcomes in children treated with IVB.

Comparison of Vascular Outgrowth Rate and Retinal Vascular Development Border after Intravitreal Injection of Aflibercept or Bevacizumab to Treat Retinopathy of Prematurity

PURPOSE

It is aimed to evaluate vascular outgrowth rate (VOR) of retinal vessels and retinal vascular development border (RVDB) after intravitreal injections of aflibercept or bevacizumab (IVA or IVB) monotherapy, which have been used to treat retinopathy of prematurity.

METHODS

In this study, patients were followed by two sequential fluorescein angiography (FA) examinations (Ret-Cam III Imaging System Clarity Medical Systems, Pleasanton, CA, USA) after anti-VEGF monotherapy. RVDB was determined by the ratio between DB (the distance from the center of the disk to the RVDB) and DM (the distance from the center of the disk to the center of the macula). On the other hand, VOR was calculated by the following novel formula: VOR = (DB/DM on the second FA) - (DB/DM on the first FA)/time between two FA examinations.

RESULTS

Fifty-one eyes of 27 infants who received aflibercept were included as group 1; 38 eyes of 19 patients who received bevacizumab were included in group 2. There were no significant differences between these groups in terms of demographic variables, percentages of disease at zone 1 and posterior zone 2 (p = 0.260), as well as stage 2+ and stage 3+ disease (p = 1.0) at the time of anti-VEGF injections. VORs, which had been measured in between two sequential follow-up FAs, were estimated to be significantly higher in group 1, both in nasal (p = 0.042) and temporal sides (p = 0.033). However, DB/DM ratios were significantly higher in group 2 in the first FA (p = 0.001 at nasal and temporal sides) and the second FA examinations (p = 0.007 and p = 0.004 at nasal and temporal sides, respectively).

CONCLUSION

VOR was found to be significantly higher in patients who were treated with IVA monotherapy. Paradoxically, RVDB was farther in patients receiving IVB monotherapy despite a slower VOR in these patients.

Intravitreal aflibercept injection in Indian eyes with retinopathy of prematurity

Purpose:

To study the efficacy of intravitreal Aflibercept, an anti Vascular Endothelial Growth factor, (anti-VEGF) in Retinopathy of Prematurity (ROP).

Methods:

This was a retrospective, interventional consecutive case series of 46 Indian eyes which received intravitreal injection of Aflibercept for High risk Prethreshold ROP, Threshold ROP, and Aggressive-Posterior ROP (AP-ROP).

Results:

Aflibercept was effective in achieving the primary endpoint, namely regression of ROP following the injection in all 46 eyes (100%) at one week following the injection. 32.6% (15/46) of eyes achieved secondary endpoint namely complete vascularization, with no recurrence of ROP at varying time intervals: as early as 15 weeks to as late as 29 weeks after injection, at intervals ranging from 49 to 64 weeks PCA.

Conclusion:

Intravitreal Aflibercept was effective in inducing complete regression of all types of ROP in all the eyes in our series. In addition, 32.6% of cases did not need a secondary intervention, with no recurrence of ROP and complete vascularization of the retina. In 81.8% of Zone I ROP eyes, Aflibercept facilitated continuation of retinal vascular development following regression of ROP, resulting in less extensive laser during treatment of ROP recurrence. This is the largest series of Aflibercept in ROP, till date as per MEDLINE search.

Optimizing Measurement of Vascular Endothelial Growth Factor in Small Blood Samples of Premature Infants

To establish a method that allows for the reliable assessment of vascular endothelial growth factor (VEGF-A) concentrations in very small blood samples of preterm infants. Systemic VEGF measurements are important in view of the most appropriate Anti-VEGF drug to be used for the treatment of acute retinopathy of prematurity (ROP). Cord blood samples from preterm (n = 6) infants, blood samples from preterm infants with treatment requiring ROP (n = 12), and blood samples from healthy adults (n = 10) were collected. Serum, citrate plasma, and serum from recalcified citrate blood were obtained. Levels of VEGF-A and platelet factor-4 (PF-4) were quantified by ELISA or AlphaLISA immunoassay. VEGF-A levels could be detected by both assays, with the AlphaLISA generating slightly lower levels in healthy adults, but not in cord blood of preterm infants. In plasma samples, VEGF levels ranged from non detectable to 181 pg/ml. PF-4 concentrations were between 0.16–3.88 µg/ml. Values of VEGF-A and PF-4 in serum and recalcified serum were significantly higher compared to plasma through the release of these cytokines after platelet activation. In plasma samples of infants with ROP, VEGF-A could always be detected and its values ranged from 19.50 to 245.91 pg/ml and PF-4 concentrations were between 0.1 and 3.3 µg/ml. Using the AlphaLISA kit, we were able to detect VEGF in small sample volumes (5 µl plasma or serum/well) in premature infants with treatment requiring ROP and to monitor platelet activation by PF-4 detection. Minimal blood probe volumes reduce phlebotomy losses avoiding the risk of iatrogenic anemia, thus allowing close monitoring of the cytokine levels in these very fragile infants.

Efficacy of intravitreal aflibercept monotherapy in retinopathy of prematurity evaluated by periodic fluorescence angiography and optical coherence tomography

PURPOSE

To evaluate the efficacy of intravitreal aflibercept (IVA) in vascular and macular maturation in neonates with type 1 retinopathy of prematurity (ROP) and aggressive posterior retinopathy of prematurity (APROP).

MATERIALS AND METHODS

Thirty-six eyes of 18 patients with type 1 ROP or APROP in zone I or posterior zone II were enrolled in our study. At baseline, only fluorescein angiography (FA) was performed. After IVA injection, both FA and optical coherence tomography (OCT) were performed after 6.8 ± 0.8 (range 6-8) and 19 ± 0.9 (range 18-20) weeks to follow vascular and macular changes.

RESULTS

Both diffuse flat neovascularization with leakage and abnormal vascular branching at the small arteriolar level were detected in all eyes (100%) at baseline FA. Regression of the disease was observed in 34 eyes (94.4%) in the first week with binocular indirect ophthalmoscopy. Early unresponsiveness in remaining two eyes of an infant required an IVA re-treatment. Late reactivation was detected only in 19.4% of eyes, none of which required treatment during 12 months of follow-up. The most common feature after IVA injection was abnormal branching at capillary level, which was noted in 100% in the first post-injection FA and 50.0% of all eyes in the second FA. Meanwhile, the end limit of vascularization was observed in zone III in 83.3% of eyes. No vascular abnormality was also detected in 27.3% of eyes. The OCT examination at a mean postmenstrual age of 43.4 weeks revealed cystoid macular changes in four eyes of two infants (11.1%), normal foveal contour in 30 eyes of 15 infants (83.3%) and matured ellipsoid zone at the foveal center in 28 eyes of 14 infants (77.8%). Macular maturation was complete in all eyes in the last OCT analyses.

CONCLUSION

Intravitreal aflibercept monotherapy has been an effective treatment in type I ROP and APROP with much lower early and late re-treatment rates because of early unresponsiveness and late reactivation, respectively. In most of the eyes, rapid vascular outgrowth beyond zone III together with normal macular maturation was observed more precisely by periodic FA and OCT.

Different effects of various anti-angiogenic treatments in an experimental mouse model of retinopathy of prematurity

BACKGROUND

Anti-vascular endothelial growth factor (VEGF) drugs are an option for the treatment of retinopathy of prematurity (ROP). Blocking of other angiogenic factors is also of interest. We therefore investigated in which effects would result blocking of placental growth factor (PlGF).

METHODS

C57BL/6 mice were exposed to 75% oxygen from P7 to P12. Intravitreal injections were performed at P12. Mice of control groups remained untouched after oxygen treatment, or phosphate buffered saline or neutral IgG molecules were injected. In the treatment groups, antibodies against VEGF or PlGF, a mixture of anti-VEGF and anti-PlGF, aflibercept or sunitinib were injected. On P17, electroretinographic (ERG) measurements were performed. Avascular zones and neovascularization were evaluated in retinal flat-mounts. Results are expressed as percent of total retinal area (median with median absolute deviation, MAD).

RESULTS

Eyes of control groups showed similar neovascularization (1.4-3.3%, MAD 0.4-0.9%). Neovascularization was significantly less (0.5-0.7%, MAD 0.1-0.3%) in all treatment groups. Avascular zones in the retinas of control groups showed similar values (18.3-25.7%, MAD 4.8-8.8%). Avascular zones were significantly reduced down to 3.6 ± 1.3% after anti-VEGF injection, but they were not reduced significantly in the other treatment groups (13.3-22%, MAD 3.6-6.1%). ERG measurements did not reveal significant differences between the controls and the treatment groups.

CONCLUSIONS

Blocking of PlGF or injection of sunitinib results in a similar inhibition of neovascularization as by anti-VEGF treatment in the mouse model of ROP. However, physiological angiogenesis that occurs after anti-VEGF treatment is blocked by anti-PlGF or sunitinib treatment, indicating that pathological neovascularization may follow different pathways than physiological angiogenesis.

SHORT-TERM OUTCOMES AFTER INTRAVITREAL INJECTIONS OF CONBERCEPT VERSUS RANIBIZUMAB FOR THE TREATMENT OF RETINOPATHY OF PREMATURITY

PURPOSE

Intravitreal injection of conbercept (IVC) is the latest applied treatment that could be used in retinopathy of prematurity (ROP) patients. The structural outcomes and recurrence of ROP among patients treated with IVC or intravitreal injection of ranibizumab (IVR) were compared.

METHODS

A consecutive case series of ROP treated with IVC or IVR were retrospectively studied. The primary outcome was treatment success defined as regression of plus disease. The secondary outcomes were recurrence of plus, times of injection, and the final regression of disease.

RESULTS

A total of 48 eyes (24 patients) with ROP were included. Twenty eyes (10 patients) received IVC, and 28 eyes (14 patients) received IVR. For the IVC group, 18 eyes had Zone II 3+ ROP and 2 eyes had aggressive posterior ROP. Among the 28 eyes treated with IVR, 6 eyes had Zone I 2/3+ ROP, 6 eyes had aggressive posterior ROP, and 16 eyes had Zone II 3+ ROP. For the IVC group, the mean gestational age, birth weight, postmenstrual age at initial treatment, and follow-up period for the infants were 29.49 ± 1.37 weeks, 1,369.0 ± 161.9 g, 38.47 ± 2.72 weeks, and 52.6 ± 21.4 weeks, respectively. And for the infants who received IVR, these were 28.35 ± 1.62 weeks, 1,171.4 ± 279.9 g, 38.53 ± 3.54 weeks, and 42.9 ± 9.8 weeks, respectively. For the IVC group, 17 (85%) of 20 eyes received the injection only once, and the regression of plus disease occurred 4.3 ± 2.08 weeks later. Three eyes (15%) did not healed with one injection received a second IVC, and the regression of plus disease occurred within 3 weeks. For the IVR group, 15/28 (53.6%) eyes received a second IVR. Among them, 10 recurrent eyes and 5 eyes did not recover with one injection. No retinal detachment was observed in both group infants.

CONCLUSION

Both conbercept and ranibizumab are effective choice for the treatment of ROP. Conbercept is a novel effective treatment strategy for ROP providing a new treatment option for ophthalmologists.

Efficacy of intravitreal conbercept injection in the treatment of retinopathy of prematurity

BACKGROUND

To evaluate the safety and efficacy of intravitreal conbercept (IVC) injection in the treatment of retinopathy of prematurity (ROP).

METHODS

Patients with ROP who underwent IVC injection in Zhujiang Hospital from June 2015 to July 2016 were studied retrospectively. The primary outcome was defined as the regression of plus disease. The secondary outcomes were defined as the presence of recurrence, number of injections and the final regression of disease.

RESULTS

A total of 48 eyes of 24 patients with ROP were included. Among them, 9 eyes of 5 patients had zone I ROP, 35 eyes of 18 patients had zone II ROP and 4 eyes of 2 patients had aggressive posterior ROP. The mean gestational age was 28.5±1.6 weeks, the mean birth weight was 1209.6±228.6 g, the mean postmenstrual age of first injection was 34.2±1.9 weeks and the mean follow-up period was 31.0±4.7 weeks. Forty of 48 eyes (83.3%) received IVC only once, and the regression of plus disease occurred at an average of 3.5±1.5 weeks after the first injection of conbercept. For eight recurrent eyes (16.7%), four eyes received a second IVC and the remaining four eyes received laser photocoagulation, and the regression of plus disease occurred in 3 weeks. No lens opacity, vitreous haemorrhage, entophthalmia or retinal detachment was observed during follow-up.

CONCLUSION

IVC injection is an effective treatment for ROP.

A Dosing Study of Bevacizumab for Retinopathy of Prematurity: Late Recurrences and Additional Treatments

PURPOSE

Intravitreal bevacizumab is increasingly used to treat severe retinopathy of prematurity (ROP), but it enters the bloodstream, and there is concern that it may alter development of other organs. Previously we reported short-term outcomes of 61 infants enrolled in a dose de-escalation study, and we report the late recurrences and additional treatments.

DESIGN

Masked, multicenter, dose de-escalation study.

PARTICIPANTS

A total of 61 premature infants with type 1 ROP.

METHODS

If type 1 ROP was bilateral at enrollment, then the study eye was randomly selected. In the study eye, bevacizumab intravitreal injections were given at de-escalating doses of 0.25 mg, 0.125 mg, 0.063 mg, or 0.031 mg; if needed, fellow eyes received 1 dose level higher: 0.625 mg, 0.25 mg, 0.125 mg, or 0.063 mg, respectively. After 4 weeks, additional treatment was at the discretion of the investigator.

MAIN OUTCOME MEASURES

Early and late ROP recurrences, additional treatments, and structural outcomes after 6 months.

RESULTS

Of 61 study eyes, 25 (41%; 95% confidence interval [CI], 29%-54%) received additional treatment: 3 (5%; 95% CI, 1%-14%) for early failure (within 4 weeks), 11 (18%; 95% CI, 9%-30%) for late recurrence of ROP (after 4 weeks), and 11 (18%; 95% CI, 9%-30%) for persistent avascular retina. Re-treatment for early failure or late recurrence occurred in 2 of 11 eyes (18%; 95% CI, 2%-52%) treated with 0.25 mg, 4 of 16 eyes (25%; 95% CI, 7%-52%) treated with 0.125 mg, 8 of 24 eyes (33%; 95% CI, 16%-55%) treated with 0.063 mg, and 0 (0%; 95% CI, 0%-31%) of 10 eyes treated with 0.031 mg. By 6 months corrected age, 56 of 61 study eyes had regression of ROP with normal posterior poles, 1 study eye had developed a Stage 5 retinal detachment, and 4 infants had died of preexisting medical conditions.

CONCLUSIONS

Retinal structural outcomes are very good after low-dose bevacizumab treatment for ROP, although many eyes received additional treatment.

Anti-VEGF for ROP and Pediatric Retinal Diseases

Vascular endothelial growth factor (VEGF) is an important mediator of the pathological neovascularization and vascular permeability of the eye. The increasing use of intravitreal therapies targeting VEGF has revolutionized the treatment of pediatric vitreoretinal diseases. In retinopathy of prematurity (ROP), the role of VEGF in pathogenesis has been well recognized and the use of anti-VEGF treatment in phase 2 ROP has demonstrated promising results, particularly in severe cases of posterior disease. This has made VEGF an established target in the treatment of pediatric retinal diseases known to have abnormal vascular activity. However, questions remain about late systemic and neurodevelopmental effects after anti-VEGF therapy for children because intravitreal injection of anti-VEGF may result in systemic circulation of anti-VEGF agent and a corresponding suppression of systemic VEGF. We do not currently know whether the short-term suppression of systemic VEGF affects long-term neurodevelopmental outcomes because VEGF is a vital supporting factor during neurodevelopment. This review article focuses on the evidence for the use of anti-VEGF treatment in certain pediatric ocular diseases, including ROP, Coats disease, and retinoblastoma. More extensive and prospective studies are warranted to further elucidate the role of anti-VEGF therapy in these diseases and illustrate how we can optimally use these agents in pediatric patients.

Changes in systemic vascular endothelial growth factor levels after intravitreal injection of aflibercept in infants with retinopathy of prematurity

BACKGROUND

To investigate the levels of VEGF in the systemic circulation of patients with type 1 ROP who received intravitreal injections of 1 mg (0.025 mL) aflibercept (IVA) or 0.625 mg (0.025 mL) bevacizumab (IVB).

METHODS

Patients who had type 1 ROP and received either IVA or IVB were enrolled in this prospective study. Serum and plasma samples were collected prior to and up to 12 weeks after IVB or IVA treatment. The serum and plasma VEGF levels were measured using enzyme-linked immunosorbent assays (ELISAs), and the platelet levels in the blood were also quantified. The serum and plasma levels of VEGF, as well as the ratio of VEGF to platelet count (VEGF/PLT) were measured prior to and up to 12 weeks after anti-VEGF treatment.

RESULTS

In total, 14 patients with type 1 ROP were enrolled in this study; five patients received IVA, and nine patients received IVB. Following either IVA or IVB treatment, all the eyes (100%) showed complete resolution of ROP-induced abnormal neovascularization and presented continued vascularization toward the peripheral retina. Compared to baseline, the serum VEGF levels were significantly reduced in the ROP patients up to 12 weeks after either IVA or IVB treatments (all P < 0.05). At 2, 4, and 8 weeks after intravitreal injection, the serum VEGF levels were more suppressed in the IVB group than in the IVA group (P = 0.039, P = 0.004, and P = 0.003, respectively). The serum VEGF/PLT ratio after IVA or IVB showed similar reductions and trends as the serum VEGF data. Changes in the plasma VEGF levels could not be properly assessed because some of the samples had VEGF levels below the detection limit of the ELISA.

CONCLUSIONS

Serum VEGF levels and the VEGF/PLT ratio in patients with type 1 ROP were suppressed for 3 months after treatment with either IVA or IVB, but the suppression of systemic VEGF was more pronounced in patients treated with IVB than those treated with IVA.

Systemic Inflammation-Associated Proteins and Retinopathy of Prematurity in Infants Born Before the 28th Week of Gestation

Purpose

To assess the association between systemic levels of inflammation-associated proteins and severe retinopathy of prematurity (ROP) in extremely preterm infants.

Methods

We collected whole blood on filter paper on postnatal days 1, 7, 14, 21, and 28 from 1205 infants born before the 28th week of gestation, and measured the concentrations of 27 inflammation-associated, angiogenic, and neurotrophic proteins. We calculated odds ratios with 95% confidence intervals for the association between top quartile concentrations of each protein and prethreshold ROP.

Results

During the first three weeks after birth, high concentrations of VEGF-R1, myeloperoxidase (MPO), IL-8, intercellular adhesion molecule (ICAM)-1, matrix metalloproteinase 9, erythropoietin, TNF-α, and basic fibroblast growth factor were associated with an increased risk for prethreshold ROP. On day 28, high levels of serum amyloid A, MPO, IL-6, TNF-α, TNF-R1/-R2, IL-8, and ICAM-1 were associated with an increased risk. Top quartile concentrations of the proinflammatory cytokines TNF-α and IL-6 were associated with increased risks of ROP when levels of neuroprotective proteins and growth factors, including BDNF, insulin-like growth factor 1, IGFBP-1, VEGFR-1 and -2, ANG-1 and PlGF, were not in the top quartile. In contrast, high concentrations of NT-4 and BDNF appeared protective only in infants without elevated inflammatory mediators.

Conclusions

Systemic inflammation during the first postnatal month was associated with an increased risk of prethreshold ROP. Elevated concentrations of growth factors, angiogenic proteins, and neurotrophins appeared to modulate this risk, and were capable of reducing the risk even in the absence of systemic inflammation.

Retinopathy of prematurity: inflammation, choroidal degeneration, and novel promising therapeutic strategies

Retinopathy of prematurity (ROP) is an important cause of childhood blindness globally, and the incidence is rising. The disease is characterized by initial arrested retinal vascularization followed by neovascularization and ensuing retinal detachment causing permanent visual loss. Although neovascularization can be effectively treated via retinal laser ablation, it is unknown which children are at risk of entering this vision-threatening phase of the disease. Laser ablation may itself induce visual field deficits, and there is therefore a need to identify targets for novel and less destructive treatments of ROP. Inflammation is considered a key contributor to the pathogenesis of ROP. A large proportion of preterm infants with ROP will have residual visual loss linked to loss of photoreceptor (PR) and the integrity of the retinal pigment epithelium (RPE) in the macular region. Recent studies using animal models of ROP suggest that choroidal degeneration may be associated with a loss of integrity of the outer retina, a phenomenon so far largely undescribed in ROP pathogenesis. In this review, we highlight inflammatory and neuron-derived factors related to ROP progression, as well, potential targets for new treatment strategies. We also introduce choroidal degeneration as a significant cause of residual visual loss following ROP. We propose that ROP should no longer be considered an inner retinal vasculopathy only, but also a disease of choroidal degeneration affecting both retinal pigment epithelium and photoreceptor integrity.

Effect of Intravitreal Aflibercept on Central Retinal Arterial Blood Flow in Type 1 Retinopathy of Prematurity

Purpose

To evaluate the blood flow changes of the central retinal artery measured with color Doppler imaging (CDI) in infants receiving intravitreal aflibercept (IVA) for treatment of type 1 retinopathy of prematurity (ROP).

Methods

Patients with type 1 ROP were assessed prospectively by CDI following IVA. Color Doppler imaging was used to measure the peak systolic velocity, end diastolic velocity (EDV), pulsatility index (PI), and resistivity index (RI) of the central retinal artery (CRA) before IVA injection and 1 hour, 1 week, and 1 month after injection.

Results

A total of 29 eyes of 15 infants were included in this study. The mean gestational age at birth was 28.62 ± 2.48 weeks and the mean birthweight was 1,198.62 ± 348.99 g. All treated eyes showed complete regression of ROP and peripheral retinal vascularization continued. Measurements of EDV-CRA, RI-CRA, and PI-CRA showed significant changes after IVA treatment.

Conclusions

This study showed that IVA is an effective treatment for type 1 ROP. After IVA treatment, vascular resistance increases, ocular blood flow decreases, and changes in hemodynamic parameters of CRA may remain for a month. Further studies are needed to evaluate the effect of anti-vascular endothelial growth factor agents on ocular hemodynamics in infants with ROP.

Intravitreal anti-VEGF treatment for retinopathy of prematurity in infants with active adenoviral keratoconjunctivitis

PURPOSE

To evaluate the results of intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment for retinopathy of prematurity (ROP) in infants with active adenoviral keratoconjunctivitis (AKC).

MATERIAL AND METHODS

A retrospective analysis was performed using the medical records of all infants treated with intravitreal injections of anti-VEGF agents during an AKC outbreak previously reported in the literature at a tertiary center for treatment of ROP. The infants were divided into two groups. Group 1 included nine infants (18 eyes) with AKC, while Group 2 included 13 infants (26 eyes) without AKC.

RESULTS

During the AKC outbreak, 22 infants were treated with anti-VEGF agents for treatment-requiring ROP. In all patients in both groups, the ROP and plus disease displayed a significant regression within 2 days after the intravitreal injections. Moreover, no serious complications such as endophthalmitis, retinal detachment, cataract or intravitreal hemorrhage were observed after the treatment and there were no statistically significant differences between the groups in terms of postoperative complications.

CONCLUSION

Immediate and appropriate intervention is very important in cases of treatment-requiring ROP otherwise it can result in blindness. However, laser treatment for ROP is technically difficult in infants with active AKC. The results of this study showed that favorable outcomes without serious ocular complications could be obtained via intravitreal injections of anti-VEGF agents in infants with active AKC.

Review of the mechanisms and therapeutic avenues for retinal and choroidal vascular dysfunctions in retinopathy of prematurity

Retinopathy of prematurity (ROP) is a multifactorial disease and the main cause of visual impairment and blindness in premature neonates. The inner retina has been considered the primary region affected in ROP, but choroidal vascular degeneration and progressive outer retinal dysfunctions have also been observed. This review focuses on observations regarding neurovascular dysfunctions in both the inner and outer immature retina, the mechanisms and the neuronal-derived factors implicated in the development of ROP, as well potential therapeutic avenues for this disorder.

CONCLUSION

Alterations in the neurovascular integrity of the inner and outer retina contribute to the development of ROP.

Review of effects of anti-VEGF treatment on refractive error

To examine the effect of anti-vascular endothelial growth factor (anti-VEGF) agents on refractive error in the setting of retinopathy of prematurity (ROP) through a review of the literature, a PubMed search was performed of appropriate search terms, and the results of all relevant studies were extracted and compiled. Eleven relevant articles were identified in the literature, totaling 466 eyes, treated with varied anti-VEGF agents (bevacizumab, ranibizumab, and aflibercept) with mean spherical equivalent refractions ranging from +0.75 D to −3.57 D, with prevalence of high myopia ranging from 0 to 35%. Anti-VEGF monotherapy for ROP leads to low levels of myopia, and there may be a differential effect of specific anti-VEGF agents utilized on refractive outcomes.

Neurodevelopmental Outcomes Following Bevacizumab Injections for Retinopathy of Prematurity

BACKGROUND AND OBJECTIVE

Bevacizumab intravitreal injection, a vascular endothelial growth factor inhibitor, is used to treat retinopathy of prematurity (ROP). However, concerns have been raised regarding its systemic absorption and effect on developing tissues including brain. This study compared neurodevelopment at 18 months' corrected age in preterm infants of <29 weeks' gestation treated with bevacizumab versus laser ablation.

METHODS

Data from the Canadian Neonatal Network and the Canadian Neonatal Follow-Up Network databases were retrospectively reviewed. Infants born at <29 weeks' in 2010-2011 with treated ROP were studied. Neurodevelopmental outcome at 18 months was assessed by using neurologic examination and the Bayley Scales of Infant and Toddler Development Third Edition. Regression analyses were performed.

RESULTS

Of 125 treated infants, 27 received bevacizumab and 98 laser. The bevacizumab group, compared with laser, obtained a median Bayley Scales of Infant and Toddler Development Third Edition motor composite score of 81 (interquartile range, 70-91) versus 88 (79-97), a language composite score of 79 (65-97) versus 89 (74-97), and a cognitive score of 90 (80-100) versus 90 (85-100). Difference was detected on the motor score only (P = .02). Odds of severe neurodevelopmental disabilities (Bayley scores <70, severe cerebral palsy, hearing aids, or bilateral blindness) was 3.1 times higher (95% confidence interval: 1.2-8.4) in infants treated with bevacizumab versus laser after adjusting for gestational age, gender, maternal education, Score for Neonatal Acute Physiology-II score, bronchopulmonary dysplasia, sepsis, and severe brain injury.

CONCLUSIONS

Preterm infants treated with bevacizumab versus laser had higher odds of severe neurodevelopmental disabilities. Further investigation on the long-term safety of antivascular endothelial growth factor treatment of ROP is needed.

Retinopathy of prematurity: Past, present and future

Retinopathy of prematurity (ROP) is a vasoproliferative disorder of the retina occurring principally in new born preterm infants. It is an avoidable cause of childhood blindness. With the increase in the survival of preterm babies, ROP has become the leading cause of preventable childhood blindness throughout the world. A simple screening test done within a few weeks after birth by an ophthalmologist can avoid this preventable blindness. Although screening guidelines and protocols are strictly followed in the developed nations, it lacks in developing economies like India and China, which have the highest number of preterm deliveries in the world. The burden of this blindness in these countries is set to increase tremendously in the future, if corrective steps are not taken immediately. ROP first emerged in 1940s and 1950s, when it was called retrolental fibroplasia. Several epidemics of this disease were and are still occurring in different regions of the world and since then a lot of research has been done on this disease. However, till date very few comprehensive review articles covering all the aspects of ROP are published. This review highlights the past, present and future strategies in managing this disease. It would help the pediatricians to update their current knowledge on ROP.