Bevacizumab (Avastin) for retinopathy of prematurity: wrong dose, wrong drug, or both?

Respiratory outcomes in preterm infants following intravitreal bevacizumab for retinopathy of prematurity-a 10-year matched case study

OBJECTIVES

To evaluate respiratory outcomes in preterm infants with retinopathy of prematurity (ROP) following intravitreal bevacizumab injection (IVB).

METHODS

This single-centre study enroled preterm infants with a gestational age (GA) < 34 weeks or a birth weight (BW) < 1500 g with bilateral type 1 ROP who received a single IVB, and a treatment-free control group matched by GA, postmenstrual age, and respiratory status at the time of the IVB. The primary outcome was serial respiratory changes in mean airway pressure (MAP), fraction of inspired oxygen (FiO2), and respiratory severity score (RSS, MAP x FiO2) during the 28-day post-IVB/matching period and overall respiratory improvement at day 28 and at discharge. The duration of supplemental oxygen therapy following IVB/matching was documented.

RESULTS

A total of 5578 infants were included. Seventy-eight infants were enroled in the IVB group, and another 78 infants were matched as the control group. Both groups had downward trends in the MAP, FiO2, and RSS over the study period (all P < 0.001), but there were no between-group differences in these measures. The percentage of overall respiratory improvement was similar between the IVB and control groups, so was the duration of invasive and in-hospital oxygen ventilation. A lower percentage of oxygen dependence at discharge in the IVB group (P = 0.03) remained significant after adjusting for GA and BW.

CONCLUSIONS

This is a matched case study to evaluate respiratory outcomes in preterm infants following IVB for ROP. We found that the IVBs did not compromise respiratory outcomes in preterm infants during the 28-day post-IVB period and at discharge.

Primary and additional treatment preference in aggressive retinopathy of prematurity and type 1 retinopathy of prematurity

Objective

This study aimed to evaluate the preference for antivascular endothelial growth factor (anti-VEGF) versus laser ablation therapy as primary and additional treatment in aggressive retinopathy of prematurity (ROP) and type 1 ROP.

Methods

This multicentre retrospective study was conducted at nine medical centres across South Korea. A total of 94 preterm infants with ROP who underwent primary treatment between January 2020 and December 2021 were enrolled. All eyes were classified as having type 1 ROP or aggressive ROP. Data on the zone, primary treatment chosen, injection dose, presence of reactivation and additional treatment were collected and analysed.

Results

Seventy infants (131 eyes) with type 1 ROP and 24 infants (45 eyes) with aggressive ROP were included. Anti-VEGF injection was selected as the primary treatment in 74.05% of the infants with type 1 ROP and 88.89% with aggressive ROP. Anti-VEGF injection was selected as the ROP was located in zone I or posterior zone II, and laser ablation was selected when it was located in zone II. The anti-VEGF injection doses varied and tended to be higher in the aggressive ROP group. Infants with aggressive ROP were 2.08 times more likely to require additional treatment than those with type 1 ROP. When ROP reactivation occurred, laser therapy was preferred as an additional treatment.

Conclusion

In Korea, the preference for anti-VEGF therapy or laser therapy differed according to ROP subtype, zone and primary or secondary treatment. These findings suggest that ROP treatment are considered according to ROP subtype, location and reactivation.

Appropriate dose of intravitreal ranibizumab for ROP: a retrospective study

Objective

To compare the recurrence rate of retinopathy of prematurity (ROP) after treatment with 0.3 mg vs. 0.25 mg ranibizumab.

Subjects

All patients with ROP who underwent intravitreal injection of ranibizumab in Hainan General Hospital between January 2014 and May 2020 were included in this retrospective study.

Methods

Eighty-two cases (146 eyes) who received intravitreal injection of 0.25 mg ranibizumab were included in the conventional-dose group, and 59 cases (108 eyes) who received intravitreal injection of 0.3 mg ranibizumab were included in the high-dose group. The two groups were further divided into the 25-28-week, 29-31-week, 32-34-week, and 35-36-week GA subgroups. The differences between the conventional-dose group and the high-dose group in gestational age (GA), birth weight (BW), age at initial injection (weeks), incidence of systemic diseases, the recurrence rate of ROP, and age at retinal vascularization completed (weeks) were analyzed.

Results

GA, BW, age at initial injection, and the incidence of systemic diseases were not significantly different between the conventional-dose group and the high-dose group (p > 0.05). The recurrence rates of ROP were significantly lower in the 25-28-week, 29-31-week, and 32-34-week subgroups of the high-dose group than in the same subgroups of the conventional-dose group (p < 0.05). Within the conventional-dose group, the recurrence rate of ROP was significantly lower in the 32-34-week and 35-36-week subgroups than in the 25-28-week and 29-31-week subgroups (p < 0.05). Within the high-dose group, the recurrence rate of ROP was not significantly different between the four subgroups (p > 0.05). Retinal vascularization was completed at a later age in the 32-34-week subgroup of the high-dose group than in the 32-34-week subgroup of the conventional-dose group (p < 0.05) but was not significantly different between the two groups at any other GA range (p > 0.05). No severe ocular or systemic complications occurred in any patient.

Conclusion

Treatment with 0.3 mg ranibizumab can reduce the recurrence rate of ROP without prolonging retinal vascularization or causing serious systemic complications. Therefore, this dose may be an appropriate therapeutic dose for ROP.

Treatment outcomes of combination of anti-vascular endothelial growth factor injection and laser photocoagulation in Type 1 ROP and APROP

PURPOSE

To study treatment outcomes of combination treatment of intravitreal anti-vascular endothelial growth factor (VEGF) injection and laser photocoagulation in Type 1 Retinopathy of Prematurity (ROP) and Aggressive Posterior ROP (APROP).

METHODS

This is a retrospective observational study of 87 eyes of 48 premature babies who presented with Type I ROP or APROP and were treated with combination of laser and anti-VEGF therapy. Retrospective evaluation of case records was done to collect data on gestational age, birth weight, age at intervention, anterior segment and fundus findings, intervention with laser and anti-VEGF and response to treatment. Outcome measure was defined as attached retina at posterior pole at last follow-up.

RESULTS

Mean gestational age was 29.1 weeks, and mean birth weight was 1226.9 gms. Sixty-six (75.8%) eyes had Type I ROP and 21 (24.1%) eyes had APROP at presentation. Five eyes (3 patients) were lost to follow-up after treatment. Of 82 eyes, 80.5% (66 eyes) showed regression of ROP following combination treatment and 19.5% (16 eyes) needed surgery. Of these, 15 underwent surgery and 12 had successful outcome. Mean follow-up duration of patients was 52 weeks. Finally, 95.1% (78 eyes) had attached retina at posterior pole and 4.9% (4 eyes) had detached retina.

CONCLUSION

We conclude that combination therapy is an effective and safe treatment strategy for Type I ROP and APROP.

Update on the Use of Anti-VEGF Drugs in the Treatment of Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is one of the many significant consequences of premature birth and remains one of the leading causes of visual impairment in infants. Originally, cryotherapy was used to prevent the complications of vitreous hemorrhage and retinal detachment. Subsequently, laser photocoagulation, which is at least as effective and possibly safer than cryoretinopexy, was adopted as the primary treatment for type 1 ROP (stage 2 or 3 disease in zone II with plus disease or any stage disease in zone I with plus disease or stage 3 disease in zone I without plus disease). Laser therapy has been proven effective, and has a degree of permanence that is yet to be matched by alternative treatments, but can be associated with significant ocular side effects such as myopia. Treatment of type 1 ROP with anti-vascular endothelial growth factor (VEGF) agents seems to have fewer ocular side effects than laser ablation of the retina, particularly if used to treat type 1 ROP in zone I. However, ROP recurrence is a real threat after anti-VEGF therapy and long-term systemic side effects of this therapy remain under evaluation. This review focuses on the ophthalmic and systemic benefits and risks of anti-VEGF therapies for ROP as compared to retinal photocoagulation. Anti-VEGF therapies have dramatically altered the management of ROP and have also been shown to be beneficial with regard to the visual prognosis of patients with ROP, but patients so treated require frequent short- and long-term follow-up to detect and manage potential complications associated with this form of treatment. Such information also will allow clinicians to characterize the efficacy, side effect profile, and utility of intravitreal anti-VEGF agents for this condition. Prospective studies are needed to identify the optimum anti-VEGF drug and dose. [J Pediatr Ophthalmol Strabismus. 2020;57(6):351-362.].

Soluble Tei2 fusion protein inhibits retinopathy of prematurity occurrence via regulation of the Ang/Tie2 pathway

The aim of the present study was to investigate the potential mechanism of retinopathy of prematurity (ROP) using an oxygen-induced retinopathy (OIR) mouse model. For experiments, mice were divided into either the OIR group or control group. Fluorescein isothiocyanate-dextran cardiac perfusion and stretched retina preparation were performed. The total retina area, area of instillation, density of microvascular network, area of new blood vessels, vein width and the tortuosity of arteries were measured. Next, mice were randomly assigned into the PBS, soluble TEK receptor tyrosine kinase (sTie2)-fusion protein (Fc), angiopoietin 1 (Ang1), ranibizumab, ranibizumab + sTie2-Fc and ranibizumab + Ang1 treatment groups. Following housing for 5 days, the body weight of each mouse was recorded. Mice in the OIR group presented smaller total retina area and larger area of instillation, larger area of new blood vessels, and higher microvascular network density compared with the control PBS group. Obvious retinal vein dilatation and arterial tortuosity were identified in the OIR group. The amount of endotheliocyte nuclei of new vessels beyond the inner limiting membrane was larger in the OIR group compared with the control group. Furthermore in the next set of experiments, a larger area of instillation, smaller area of new blood vessels and decreased amount of endotheliocyte nuclei of new vessels were observed in the sTie2-Fc group, Ang1 group, ranibizumab group, ranibizumab + sTie2-Fc group and ranibizumab + Ang1 group compared with the PBS group. Specifically, the ranibizumab + sTie2-Fc group and ranibizumab + Ang1 group demonstrated markedly reduced retina instillation area and microvascular network density in the instillation area. Total retina area and body weight following 10 days of the experiment for the ranibizumab group were significantly lower compared with other groups. In conclusion, the combined regulation of the Ang/Tie2 and the vascular endothelial growth factor (VEGF)/VEGF receptor pathways markedly increased the efficacy of treatment with retinal neovascularization (RNV). Regulation of these pathways has a potential for treating RNV, in particular ROP.

Intravitreal bevacizumab versus ranibizumab: Effects on the vessels of the fellow non-treated eye

Purpose

To evaluate the effects of anti-vascular endothelial growth factors (anti-VEGF) on the vessels of the non-treated eyes following intravitreal injections.

Methods

In this prospective, non-randomized trial, a total of 38 patients were recruited. 21 patients received ranibizumab, and 17 patients received bevacizumab. Fundus photography was carried out at baseline immediately before injection and at 3 days, 7 days, and one month after the injections. Using image analysis software, measurements were summarized as the central retinal artery equivalent (CRAE) and central retinal vein equivalent.

Results

In non-treated eyes, CRAE decreased significantly from 153.23 ± 15.20 μm before injection to 148.77 ± 17.21 μm 3 days after intravitreal bevacizumab (P = 0.004). There was no significant difference in CRAE, between the pre-injection baseline, one week, and one month after intravitreal bevacizumab injection in non-treated eyes (P > 0.05). No significant difference was noted in CRAE in the non-treated eyes of the ranibizumab group at any post-injection visit (P = 0.1).

Conclusion

A significant transient narrowing effect of bevacizumab on retinal arterioles in the fellow non-treated eyes on the third day after intravitreal injection may show that plasma concentrations of these drugs are sufficient to spread the effect to the other eye.

Inhibitory Effects On Retinal Neovascularization by Ranibizumab and sTie2-Fc in An Oxygen-Induced Retinopathy Mouse Model

PURPOSE

To study retinal neovascularization (RNV) inhibition by intravitreal injections (IVs) of ranibizumab, sTie2 fusion protein (sTie2-Fc), and a combined therapy in an oxygen-induced retinopathy (OIR) model.

MATERIALS AND METHODS

An OIR mouse model was used to simulate RNV in retinopathy of prematurity (ROP); and the effect of blocking the angiopoietin (Ang) and its receptor (Tie2) and the vascular endothelial growth factor (VEGF) and its receptor (VEGFR) signaling pathways was compared using an IV of sTie2-Fc (Ang inhibitor) and/or ranibizumab (aVEGF antagonist). The effects were assessed using fluorescein isothiocyanate (FITC)-dextran cardiac perfusion, isolectin B4 (IB4) staining with whole retinal mounting, and hematoxylin and eosin (HE) staining to count the endothelial cells (ECs) that broke through the internal limiting membrane (ILM). The mRNA and protein levels of VEGF-A, VEGFR-2, Ang1, Ang2, and Tie2 were also determined by reverse transcriptase polymerase chain reaction (RT-PCR) and western blot analysis.

RESULTS

Compared with the control group injected with phosphate-buffered saline (PBS), all three experimental groups, ranibizumab, sTie2-Fc, and ranibizumab + sTie2-Fc, had a significant decrease in micro-vessel densities and neovascular clusters, and fewer ECs broke through the ILM (all p < 0.05). The non-perfusion areas decreased in both mono-treated groups, although the combined therapy had larger non-perfusion areas. All three treatments decreased the mRNA and protein levels of VEGFA, Ang1, and Tie2.

CONCLUSION

In this study, it was confirmed that blocking the Ang/Tie2 and/or VEGF/VEGFR pathways could inhibit RNV and decrease abnormal micro-vessel density; and the mono-blockage of Ang/Tie2 might cause a smaller non-perfusion area.

Comparing Alternative Ranibizumab Dosages for Safety and Efficacy in Retinopathy of Prematurity: A Randomized Clinical Trial

IMPORTANCE

Anti-vascular endothelial growth factor (VEGF) therapies are a novel treatment option in retinopathy of prematurity (ROP). Data on dosing, efficacy, and safety are insufficient.

OBJECTIVE

To investigate lower doses of anti-VEGF therapy with ranibizumab, a substance with a significantly shorter systemic half-life than the standard treatment, bevacizumab.

DESIGN, SETTING, AND PARTICIPANTS

This randomized, multicenter, double-blind, investigator-initiated trial at 9 academic medical centers in Germany compared ranibizumab doses of 0.12 mg vs 0.20 mg in infants with bilateral aggressive posterior ROP; ROP stage 1 with plus disease, 2 with plus disease, or 3 with or without plus disease in zone I; or ROP stage 3 with plus disease in posterior zone II. Patients were recruited between September 2014 and August 2016. Twenty infants were screened and 19 were randomized.

INTERVENTIONS

All infants received 1 baseline ranibizumab injection per eye. Reinjections were allowed in case of ROP recurrence after at least 28 days.

MAIN OUTCOMES AND MEASURES

The primary end point was the number of infants who did not require rescue therapy at 24 weeks. Key secondary end points included time-to-event analyses, progression of physiologic vascularization, and plasma VEGF levels. Stages of ROP were photodocumented and reviewed by an expert committee.

RESULTS

Nineteen infants with ROP were enrolled (9 [47.4%] female; median [range] postmenstrual age at first treatment, 36.4 [34.7-39.7] weeks), 3 of whom died during the study (1 in the 0.12-mg group and 2 in the 0.20-mg group). Of the surviving infants, 8 (88.9%) (17 eyes [94.4%]) in the 0.12-mg group and 6 (85.7%) (13 eyes [92.9%]) in the 0.20-mg group did not require rescue therapy. Both ranibizumab doses were equally successful in controlling acute ROP (Cochran-Mantel-Haenszel analysis; odds ratio, 1.88; 95% CI, 0.26-13.49; P = .53). Physiologic intraretinal vascularization was superior in the 0.12-mg group. The VEGF plasma levels were not systematically altered in either group.

CONCLUSIONS AND RELEVANCE

This pilot study demonstrates that ranibizumab is effective in controlling acute ROP and that 24% of the standard adult dose (0.12 mg) appears equally effective as 40% (0.20 mg). Superior vascularization of the peripheral retina with 0.12 mg of ranibizumab indicates that the lower dose may be favorable. Unchanged plasma VEGF levels point toward a limited systemic drug exposure after ranibizumab.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02134457 and clinicaltrialsregister.eu Identifier: 2013-002539-13.

SYSTEMIC PHARMACOKINETICS AND PHARMACODYNAMICS OF INTRAVITREAL AFLIBERCEPT, BEVACIZUMAB, AND RANIBIZUMAB

After monthly intravitreal injections, the systemic exposures of aflibercept, bevacizumab, and ranibizumab were distinct and correlated with different reductions in plasma free–vascular endothelial growth factor, which could provide biologic plausibility for potential differences in systemic adverse events.

Purpose:

To evaluate the systemic pharmacokinetics (PKs) of aflibercept, bevacizumab, and ranibizumab in patients with neovascular age-related macular degeneration (AMD), diabetic macular edema (DME), or retinal vein occlusion (RVO).

Methods:

Prospective, open-label, nonrandomized clinical trial of patients with AMD, DME, or RVO who were antivascular endothelial growth factor (VEGF) naïve or had not received anti-VEGF for ≥4 months. Patients received 3 monthly intravitreal injections of aflibercept 2.0 mg, bevacizumab 1.25 mg, or ranibizumab (0.5 mg for AMD/RVO, 0.3 mg for DME). The main outcome measures were serum PKs and plasma free-VEGF concentrations after the first and third injections.

Results:

A total of 151 patients were included. In AMD/DME/RVO, systemic exposure to each drug was highest with bevacizumab, then aflibercept, and lowest with ranibizumab. Ranibizumab cleared from the bloodstream more quickly than bevacizumab or aflibercept. Aflibercept treatment resulted in the greatest reductions in plasma free-VEGF relative to baseline levels, whereas ranibizumab treatment resulted in the smallest decreases in plasma free-VEGF.

Conclusion:

The three anti-VEGF treatments examined in this analysis demonstrated notable differences in systemic PKs. Generally, the reduction in plasma free-VEGF levels correlated with elevated levels of circulating anti-VEGF agents, with the reduction in free-VEGF levels greatest with aflibercept and least with ranibizumab.

Comparison of efficacy between anti-vascular endothelial growth factor (VEGF) and laser treatment in Type-1 and threshold retinopathy of prematurity (ROP)

Background

Retinopathy of Prematurity (ROP) is one of the most common causes of childhood blindness worldwide. Comparisons of anti-VEGF and laser treatments in ROP are relatively lacking, and the data are scattered and limited. The objective of this meta-analysis is to compare the efficacy of both treatments in type-1 and threshold ROP.

Methods

A comprehensive literature search on ROP treatment was conducted using PubMed and Embase up to March 2017 in all languages. Major evaluation indexes were extracted from the included studies by two authors. The fixed-effects and random-effects models were used to measure the pooled estimates. The test of heterogeneity was performed using the Q statistic.

Results

Ten studies were included in this meta-analysis. Retreatment incidence was significantly increased for anti-VEGF (OR 2.52; 95% CI 1.37 to 4.66; P = 0.003) compared to the laser treatment, while the incidences of eye complications (OR 0.29; 95% CI 0.10 to 0.82; P = 0.02) and myopia were significantly decreased with anti-VEGF compared to the laser treatment. However, there was no difference in the recurrence incidence (OR 1.86; 95% CI 0.37 to 9.40; P = 0.45) and time between treatment and retreatment (WMD 7.54 weeks; 95% CI 2.00 to 17.08; P = 0.12).

Conclusion

This meta-analysis indicates that laser treatment may be more efficacious than anti-VEGF treatment. However, the results of this meta-analysis also suggest that laser treatment may cause more eye complications and increase myopia. Large-scale prospective RCTs should be performed to assess the efficacy and safety of anti-VEGF versus laser treatment in the future.

Electronic supplementary material

The online version of this article (10.1186/s12886-018-0685-6) contains supplementary material, which is available to authorized users.

Management of Retinopathy of Prematurity--Use of Anti-VEGF Therapy

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness worldwide. Although laser photocoagulation re-mains the gold standard for treating threshold and prethreshold disease (type 1 ROP), the off-label use of anti‒vascular endothelial growth factor (anti-VEGF) therapy to treat ROP is increasing. Benefits include acute regression of ROP, growth of retinal vasculature beyond the demarcation line, lesser degree of myopia and peripheral visual field loss, and avoidance of sedation and intubation required for laser. However, controversies regarding anti-VEGF in this vulnerable population persist including choice of anti-VEGF agent, dosing, systemic absorption, safety, and late recurrence. This review updates recent evidence regarding the use of anti-VEGF therapy in the management of ROP.

Vascular Safety of Ranibizumab in Patients With Diabetic Macular Edema: A Pooled Analysis of Patient-Level Data From Randomized Clinical Trials

Importance

Patients with diabetic macular edema (DME) are at high risk of vascular complications, including stroke and myocardial infarction (MI). Concerns have been raised that intravitreal dosing of vascular endothelial growth factor inhibitors in DME could be associated with an increase in cardiovascular and cerebrovascular adverse events.

Objective

To evaluate the cardiovascular and cerebrovascular safety of ranibizumab, 0.5 mg and 0.3 mg, compared with sham with and without laser in DME.

Data Sources

Patient-level data from 6 randomized, double-masked, sham- and laser-controlled clinical trials.

Study Selection

Company-sponsored (Genentech or Novartis) studies in DME completed as of December 31, 2013.

Data Extraction and Synthesis

Pairwise comparisons (ranibizumab, 0.5 mg, vs sham and laser; ranibizumab, 0.3 mg, vs sham) were performed using Cox proportional hazard regression (hazard ratios, 95% CIs) and rates per 100 person-years. Data analysis was conducted from June 1 to July 15, 2015.

Main Outcomes and Measures

Standardized Medical Dictionary for Regulatory Activities queries and extended searches were prospectively defined to identify relevant safety end points, including arterial thromboembolic events, MI, stroke or transient ischemic attack, vascular deaths, and major vascular events as defined by the Antiplatelet Trialists' Collaboration (APTC).

Results

Overall, 936 patients were treated with ranibizumab, 0.5 mg; 250 patients with ranibizumab, 0.3 mg; and 581 patients with sham/laser. The hazard ratios associated with all pairwise comparisons included 1 for all key cardiovascular and cerebrovascular safety end points. For ranibizumab, 0.5 mg, vs sham/laser and ranibizumab, 0.3 mg, vs sham, the hazard ratios were, respectively, arterial thromboembolic events, 1.05 (95% CI, 0.66-1.68) and 0.78 (95% CI, 0.43-1.40); MI, 0.84 (95% CI, 0.41-1.72) and 0.94 (95% CI, 0.43-2.06); stroke or transient ischemic attack, 0.94 (95% CI, 0.44-1.99) and 0.53 (95% CI, 0.19-1.42); stroke (excluding transient ischemic attack), 1.63 (95% CI, 0.65-4.07) and 0.59 (95% CI, 0.14-2.46); vascular death, 2.17 (95% CI, 0.57-8.29) and 2.51 (95% CI, 0.49-12.94); and APTC-defined events, 1.09 (95% CI, 0.63-1.88) and 1.00 (95% CI, 0.51-1.96).

Conclusions and Relevance

This pooled analysis includes 1 of the largest patient-level data sets on treatment of DME with ranibizumab. Although still underpowered to detect small differences for infrequent events, such as stroke, the findings suggest that intravitreous ranibizumab does not increase the risk of systemic vascular events. However, uncertainty remains for patients with DME who are at high risk for vascular disease and were not included in these trials.

Targeting VEGF in canine oxygen-induced retinopathy - a model for human retinopathy of prematurity

Development of the dog superficial retinal vasculature is similar to the mechanism of human retinal vasculature development; they both develop by vasculogenesis, differentiation, and assembly of vascular precursors called angioblasts. Canine oxygen-induced retinopathy (OIR) was first developed by Arnall Patz in an effort to experimentally determine the effects of hyperoxia on the development of the retinal vasculature. The canine OIR model has many characteristics in common with human retinopathy of prematurity. Exposure of 1-day-old dogs to hyperoxia for 4 days causes a vaso-obliteration throughout the retina. Vasoproliferation, after the animals have returned to room air, is robust. The initial small preretinal neovascular formations anastomose to form large preretinal membranes that eventually cause tractional retinal folds. The end-stage pathology of the canine model is similar to stage IV human retinopathy of prematurity. Therefore, canine OIR is an excellent forum to evaluate the response to drugs targeting VEGF and its receptors. Evaluation of an antibody to VEGF-R2 and the VEGF-Trap demonstrated that doses should be titered down so that preretinal neovascularization is inhibited but retinal revascularization is able to proceed, vascularizing peripheral retina and preventing it from being a source of VEGF.

Advances in understanding and management of retinopathy of prematurity

The understanding, diagnosis, and treatment of retinopathy of prematurity have changed in the 70 years since the original description of retrolental fibroplasia associated with high oxygenation. It is now recognized that retinopathy of prematurity differs in appearance worldwide and as ever smaller and younger premature infants survive. New methods are being evaluated to image the retina, diagnose severe retinopathy of prematurity, and determine windows of time for treatment to save eyes and improve visual and neural outcomes. New treatments to promote physiologic retinal vascular development, vascular repair, and inhibit vasoproliferation by regulating proteins involved in vascular endothelial growth factor, insulin-like growth factor, or erythropoietin signaling. Reducing excessive oxidative/nitrosative stress and understanding progenitor cells and neurovascular and glial vascular interactions are being studied.

The German ROP Registry: data from 90 infants treated for retinopathy of prematurity

PURPOSE

The German retinopathy of prematurity (ROP) Registry collects data on treated ROP in a multicentre approach to analyse epidemiology and treatment patterns of severe ROP.

METHODS

Nine centres entered data from 90 treated ROP infants (born between January 2011 and December 2013) into a central database. Analysis included incidence rate of severe ROP, demographic data, stage of ROP, treatment patterns, recurrence rates, relevant comorbidities and ophthalmological or systemic complications associated with treatment.

RESULTS

Treatment rate for ROP was 3.2% of the screened population. The most frequent ROP stage at time of treatment was zone II, stage 3 +  (137 eyes). Treatment was bilateral in 97% of infants. Treatment patterns changed over time from 7% anti-vascular endothelial growth factor (VEGF) monotherapy in 2011 to 32% in 2014. Overall, laser treatment was the predominant treatment. However, all infants with zone I disease received anti-VEGF treatment. About 19% of infants required retreatment (16% of laser-treated and 21% of anti-VEGF treated infants). Mean time between first and second treatment was 3.8 weeks (± 11 days) for laser-treated and 10.4 weeks (± 60 days) for anti-VEGF-treated infants.

CONCLUSION

This study is the first multicentre analysis of severe ROP in Germany. The identified treatment patterns find laser as the most prevalent form of therapy, with an increasing use of anti-VEGF therapy over recent years. Recurrence rates were relatively high overall with slightly higher recurrence rates and later recurrence times in the anti-VEGF group. Anti-VEGF was predominantly used for high-risk stages like AP-ROP and zone I disease.

Fzd4 Haploinsufficiency Delays Retinal Revascularization in the Mouse Model of Oxygen Induced Retinopathy

Mutations in genes that code for components of the Norrin-FZD4 ligand-receptor complex cause the inherited childhood blinding disorder familial exudative vitreoretinopathy (FEVR). Statistical evidence from studies of patients at risk for the acquired disease retinopathy of prematurity (ROP) suggest that rare polymorphisms in these same genes increase the risk of developing severe ROP, implying that decreased Norrin-FZD4 activity predisposes patients to more severe ROP. To test this hypothesis, we measured the development and recovery of retinopathy in wild type and Fzd4 heterozygous mice in the absence or presence of ocular ischemic retinopathy (OIR) treatment. Avascular and total retinal vascular areas and patterning were determined, and vessel number and caliber were quantified. In room air, there was a small delay in retinal vascularization in Fzd4 heterozygous mice that resolved as mice reached maturity suggestive of a slight defect in retinal vascular development. Subsequent to OIR treatment there was no difference between wild type and Fzd4 heterozygous mice in the vaso-obliterated area following exposure to high oxygen. Importantly, after return of Fzd4 heterozygous mice to room air subsequent to OIR treatment, there was a substantial delay in retinal revascularization of the avascular area surrounding the optic nerve, as well as delayed vascularization toward the periphery of the retina. Our study demonstrates that a small decrease in Norrin-Fzd4 dependent retinal vascular development lengthens the period during which complications from OIR could occur.

Pharmacologic interventions for the prevention and treatment of retinopathy of prematurity

Retinopathy of prematurity (ROP), a significant morbidity in prematurely born infants, is the most common cause of visual impairment and blindness in children and persists till adulthood. Strict control of oxygen therapy and prevention of intermittent hypoxia are the keys in the prevention of ROP, but pharmacologic interventions have decreased risk of ROP. Various drug classes such as methylxanthines (caffeine), VEGF inhibitors, antioxidants, and others have decreased ROP occurrence. The timing of pharmacologic intervention remains unsettled, but early prevention rather than controlling disease progression may be preferred. These drugs act through different mechanisms, and synergistic approaches should be considered to maximize efficacy and safety.

Outcomes and Prognostic Factors of Intravitreal Bevacizumab Monotherapy in Zone I Stage 3+ and Aggressive Posterior Retinopathy of Prematurity

Purpose. This study aims to evaluate the regression of retinopathy of prematurity (ROP) after one intravitreal injection of bevacizumab and the factors that influenced it. Methods. This retrospective case series was carried out at the “Iuliu Hațieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania. It includes all the consecutive infants treated for ROP with one intravitreal bevacizumab injection, from January 1, 2009, throughout July 31, 2013. The follow-up continued for 60 weeks after injection. We recorded ROP classification, regression, gender, gestational age, birth weight, postnatal age and postmenstrual age at treatment, and pregnancy type. Regression was analyzed according to each of the abovementioned factors, with the program IBM SPSS 20 (Chicago, Illinois, USA). Results. This study includes 74 eyes of 37 infants of which 52 had aggressive posterior ROP (70.27%) and 22 had zone I stage 3+ ROP (29.72%). One week after the bevacizumab injection, ROP regressed in 63 eyes (85.13%), with a statistically significant higher rate in zone I stage 3+ ROP (100%), as compared with aggressive posterior ROP (78.84%) (P = 0.03). We recorded no complications subsequent to the intravitreal injections of bevacizumab. We identified no late retinal detachment. Conclusion. ROP regression rate after one intravitreal bevacizumab injection was 85.13%. This trial is registered with trial registration number IRCT2014101618966N2.

Intravitreally Injected Anti-VEGF Antibody Reduces Brown Fat in Neonatal Mice

Anti-vascular endothelial growth factor (VEGF) agents are the mainstay treatment for various angiogenesis-related retinal diseases. Currently, bevacizumab, a recombinant humanized anti-VEGF antibody, is trailed in retinopathy of prematurity, a vasoproliferative retinal disorder in premature infants. However, the risks of systemic complications after intravitreal injection of anti-VEGF antibody in infants are not well understood. In this study, we show that intravitreally injected anti-VEGF antibody is transported into the systemic circulation into the periphery where it reduces brown fat in neonatal C57BL/6 mice. A considerable amount of anti-VEGF antibody was detected in serum after intravitreal injection. Furthermore, in interscapular brown adipose tissue, we found lipid droplet accumulation, decreased VEGF levels, loss of vascular network, and decreased expression of mitochondria-related genes, Ppargc1a and Ucp1, all of which are characteristics of "whitening" of brown fat. With increasing age and body weight, brown fat restored its morphology and vascularity. Our results show that there is a transient, but significant impact of intravitreally administered anti-VEGF antibody on brown adipose tissue in neonatal mice. We suggest that more attention should be focused on the metabolic and developmental significance of brown adipose tissue in bevacizumab treated retinopathy of prematurity infants.

Spectral-Domain OCT Analyses of Macular Changes After Ranibizumab Therapy for Type 1 Retinopathy of Prematurity

PURPOSE

To investigate the clinical and macular spectral-domain optical coherence tomography (SD-OCT) findings after intravitreal ranibizumab treatment for type 1 retinopathy of prematurity (ROP).

METHODS

Eighteen eyes of 10 premature infants with type 1 ROP were retrospectively studied. All eyes were treated with intravitreal ranibizumab as monotherapy. Macular SD-OCT was performed before and after intravitreal ranibizumab therapy using a portable SD-OCT machine; the follow-up images were taken 1 day, 1 week, 1 month, and 2 months after therapy.

RESULTS

Among the 10 infants, there were six males and four females. Mean central foveal thickness before and 2 months after intravitreal ranibizumab was 292.5 ± 61.4 and 171.6 ± 21.7 µm, respectively. Differences were statistically significant (P = .01). Sixteen eyes of eight patients had macular edema before treatment. Two eyes of two patients developed a crack in the outer hyperreflective line on SD-OCT corresponding with retinal pigment epithelium with serous retinal detachment 1 day after treatment. Macular edema regressed in all patients 2 months after intravitreal ranibizumab therapy. Mean follow-up time was 11.4 ± 1.5 months. No recurrence was seen except in both eyes of one patient treated with intravitreal ranibizumab monotherapy.

CONCLUSIONS

Intravitreal ranibizumab injection is effective for the treatment of type 1 ROP as a monotherapy agent; however, macular changes not seen with indirect ophthalmoscope may develop.

Intravitreal anti-VEGF therapy as a treatment for retinopathy of prematurity: what we know after 7 years

The authors review published clinical case reports, case series, and clinical trials evaluating the use of anti-vascular endothelial growth factor (VEGF) medications for the primary or adjunctive treatment of retinopathy of prematurity (ROP). A literature search of peer reviewed reports on PubMed was performed. More than 50 pertinent peer-reviewed publications between 2006 and 2014 were selected to be included in this review and are summarized in this report. There is a growing body of literature on the use of anti-VEGF therapy as a treatment for ROP, predominately in the form of case reports and small case series. Adverse effects from anti-VEGF treatment for ROP have been reported, but with limited follow-up time. The use of anti-VEGF as a treatment for ROP remains off-label.

Local acting Sticky-trap inhibits vascular endothelial growth factor dependent pathological angiogenesis in the eye

Current therapeutic antiangiogenic biologics used for the treatment of pathological ocular angiogenesis could have serious side effects due to their interference with normal blood vessel physiology. Here, we report the generation of novel antivascular endothelial growth factor-A (VEGF) biologics, termed VEGF “Sticky-traps,” with unique properties that allow for local inhibition of angiogenesis without detectable systemic side effects. Using genetic and pharmacological approaches, we demonstrated that Sticky-traps could locally inhibit angiogenesis to at least the same extent as the original VEGF-trap that also gains whole-body access. Sticky-traps did not cause systemic effects, as shown by uncompromised wound healing and normal tracheal vessel density. Moreover, if injected intravitreally, recombinant Sticky-trap remained localized to various regions of the eye, such as the inner-limiting membrane and ciliary body, for prolonged time periods, without gaining access either to the photoreceptors/choriocapillaris area or the circulation. These unique pharmacological characteristics of Sticky-trap could allow for safe treatment of pathological angiogenesis in patients with diabetic retinopathy and retinopathy of pre-maturity.

Insulin-like growth factor-1 and anti-vascular endothelial growth factor in retinopathy of prematurity: has the time come?

Treatment of retinopathy of prematurity (ROP) is currently evolving. Novel therapeutic options are emerging that have the potential to complement existing therapies and improve treatment outcomes. However, any new therapeutic option must be thoroughly evaluated before existing (and successful) treatment paradigms can be amended. This is particularly so when switching from locally effective therapies like photoablative laser therapy to systemic pharmacological treatments, which may have hitherto unknown widespread side effects. This review compiles the current knowledge of where and when the two most advanced pharmacological treatment options for ROP, insulin-like growth factor-1 supplementation and anti-vascular endothelial growth factor treatment, may have their place in future therapy regimens for ROP. The requirement for clinical studies is emphasized: these are needed to address safety considerations before any of these interventions can achieve the status of standard clinical care in the very vulnerable population of ROP infants.

What is the evidence for systemic effects of intravitreal anti-VEGF agents, and should we be concerned?

Anti-vascular endothelial growth factor (VEGF) therapy has revolutionised the treatment of retinal disease, and appears to be very safe. Nevertheless, there are several lines of evidence that imply that small doses of these agents could potentially have a systemic effect. The clinical significance of these systemic effects remains unclear, but further study is indicated.

Incidence of choroidal neovascularization in the fellow eye in the comparison of age-related macular degeneration treatments trials

OBJECTIVE

To assess the influence of drug; dosing regimen; and traditional, nontraditional, and genetic risk factors on the incidence of choroidal neovascularization (CNV) in the fellow eye of patients treated for CNV with ranibizumab or bevacizumab.

DESIGN

Cohort study of patients enrolled in a multicenter, randomized clinical trial.

PARTICIPANTS

Patients with no CNV in the fellow eye at the time of enrollment in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT).

METHODS

Eligibility criteria for the clinical trial required that study eyes have evidence on fluorescein angiography and optical coherence tomography of CNV secondary to age-related macular degeneration (AMD) and visual acuity between 20/25 and 20/320. Treatment for the study eye was assigned randomly to either ranibizumab or bevacizumab and to 3 different regimens for dosing over a 2-year period. The genotypes for 4 single nucleotide polymorphisms (SNPs) associated with risk of AMD were determined. Only patients without CNV in the fellow eye at baseline were considered at risk. The CATT ophthalmologists examined patients every 4 weeks through 2 years and recorded treatment for CNV in the fellow eye.

MAIN OUTCOME MEASURES

Development of CNV in the fellow eye.

RESULTS

Among 1185 CATT participants, 727 (61%) had no CNV in the fellow eye at enrollment. At 2 years, CNV had developed in 75 (20.6%) of 365 patients treated with ranibizumab and in 60 (16.6%) of 362 patients treated with bevacizumab (absolute difference, 4.0%; 95% confidence interval [CI], -1.7% to 9.6%; P = 0.17). The risk ratio for pro re nata dosing relative to monthly dosing was 1.1 (95% CI, 0.8-1.6). Greater elevation of the retinal pigment epithelium and fluid in the foveal center of the study eye were associated with increased incidence of CNV in the fellow eye. Incidence was not associated with genotype on rs1061170 (CFH), rs10490924 (ARMS2), rs11200638 (HTRA1), and rs2230199 (C3; P>0.35).

CONCLUSIONS

Through 2 years, there was no statistically significant difference between ranibizumab and bevacizumab in incidence of CNV in the fellow eye. Genotype on 4 SNPs previously found to be associated with AMD did not affect the risk of CNV in the fellow eye among CATT patients.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Educational paper: do we need neonatal clinical pharmacologists?

Effective and safe drug administration in young infants should be based on integrated knowledge concerning the evolving physiological characteristics of the infant who will receive the drug and the pharmacokinetic and pharmacodynamic characteristics of a given drug. Consequently, clinical pharmacology in neonates is as dynamic and diverse as the neonates we are entitled to take care of. Even more than median estimates, covariates of variability within the population are of clinical relevance. We aim to illustrate the complexity and the need for neonatal clinical pharmacology based on the gap between current and likely best clinical practice for two commonly administered compounds (aminoglycosides for infection and ibuprofen for patent ductus arteriosus) and one new compound (bevacizumab, to treat threshold retinopathy of prematurity). Progression has been made to render pharmacokinetic studies child size, e.g., low volume samples, optimal study design, and population pharmacokinetics. Challenges to further improve clinical pharmacology in neonates include, when appropriate, the validation of off-patent drug dosing regimens and of infant-tailored formulations. Knowledge integration, i.e., the use of available data to improve current drug use and to predict pharmacokinetics/pharmacodynamics for similar compounds is needed. Development of clinical research networks is helpful to achieve these goals.

An evidence-based review of vascular endothelial growth factor inhibition in pediatric retinal diseases: part 2. Coats' disease, best disease, and uveitis with childhood neovascularization

Vascular endothelial growth factor (VEGF) is an important factor in the pathogenesis of multiple retinal neovascular disorders. This report focuses on the quality and depth of new evidence for the use of VEGF inhibitors in selected pediatric ocular diseases, including Coats' disease, Best disease, and childhood uveitis. Because much of the literature comprises case reports and retrospective case series, the level of evidence supporting its use as a primary treatment option, or even as adjuvant therapy, is low. The standard of care is treatment of the underlying disorder to prevent neovascularization (retinal or subretinal), vitreous hemorrhage, or subsequent retinal detachment. However, these complications may not present until late in the disease course. It may then be useful to treat with these agents. Prospective studies are warranted to further elucidate the role of anti-VEGF therapy in these diseases.

An evidence-based meta-analysis of vascular endothelial growth factor inhibition in pediatric retinal diseases: part 1. Retinopathy of prematurity

Recently there has been interest in the novel, off-label use of anti-vascular endothelial growth factor (anti-VEGF) agents for various stages of retinopathy of prematurity (ROP). The authors report on the quality and depth of new evidence published from 2009 to 2011 concerning the treatment of retinopathy of prematurity (ROP) with bevacizumab (Avastin; Genentech Inc., South San Francisco, CA) as either primary or adjunctive treatment for ROP. There is significant variability in the evidence, quality, and design of the studies available in the literature. There has been a trend in the scientific literature of the past 2 years toward larger, multi-center, randomized studies investigating the role of bevacizumab in the treatment of ROP. More recent evidence suggests that monotherapy with intravitreal bevacizumab may be a viable first-line treatment for select cases of zone I ROP and possibly for posterior zone II disease. Adjunctive treatment with bevacizumab may enhance outcomes in patients treated with laser photocoagulation or pars plana vitrectomy. However, there are significant concerns regarding its long-term safety profile. Further prospective studies are warranted to more fully determine the role of anti-VEGF therapy in this disease.

Combination of intravitreal ranibizumab and laser photocoagulation for aggressive posterior retinopathy of prematurity

Purpose

To report on 2 cases of aggressive posterior retinopathy of prematurity (ROP) treated with intravitreal ranibizumab (Lucentis^®) and laser photocoagulation.

Methods

Two premature females, born at 25 and 26 weeks’ gestation with a birth weight of 530 and 550 g, respectively, with aggressive posterior ROP received combined treatment with laser photocoagulation and intravitreal ranibizumab (0.3 mg [30 µl]) to each eye. Structural outcomes were evaluated by indirect ophthalmoscopy and documented by retinography.

Results

An intravitreal injection was made at 34 weeks of postmenstrual age in the first case, followed by laser photocoagulation 1 week later. There was a partial regression of ROP with treatment. Five weeks later, neovascularization regrowth with bleeding in both eyes (intraretinal and subhyaloid) occurred and retreatment with combined therapy was performed. In the second case, single therapy with laser photocoagulation was made at 34 weeks of postmenstrual age. In spite of the confluent photocoagulation in the avascular area, progression to 4A ROP stage occurred 1 week later. Both eyes were retreated 1 week later with intravitreal ranibizumab and laser photocoagulation. Treatment resulted in ROP regression in both cases. There were no signs of systemic or ocular adverse side effects.

Conclusion

The cases presented show that combination therapy of indirect laser photocoagulation and intravitreal ranibizumab can be effective in the management of aggressive posterior ROP. Further investigation on anti-VEGF safety in premature infants is necessary. Additional studies are needed to define the role of anti-VEGF in ROP treatment.