A lower dose of intravitreal conbercept effectively treats retinopathy of prematurity

Comparison of different agents and doses of anti-vascular endothelial growth factors (aflibercept, bevacizumab, conbercept, ranibizumab) versus laser for retinopathy of prematurity: A network meta-analysis

Laser photocoagulation (LPC) and/or intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections constitute the current standard treatment for retinopathy of prematurity (ROP). This network meta-analysis focus on whether a ranking of interventions may be established for different dose levels of intravitreal injection of anti-VEGF agents (aflibercept, bevacizumab, conbercept, ranibizumab) as primary treatments for ROP versus laser in terms of retreatment rate as primary outcome, and time to retreatment and refractive error as secondary endpoints, since best anti-VEGF dosage remains under debate. Sixty-eight studies (15 randomized control trials and 53 nonrandomized studies) of 12,356 eyes of 6445 infants were retrieved from databases (2005 Jan. - 2023 June). Studies were evaluated for model fit, risk of bias and confidence of evidence in Network Meta-Analysis (CINeMA). Bayesian NMA showed that anti-VEGF drugs were not inferior to laser in terms of retreatment rate. For intravitreal bevacizumab (IVB), doses half of the conventional infant dose showed a low risk of retreatment rate (risk ratio (RR) of 1.43; 95% credible interval (CrI): 0.508, 4.03). On probability ranking as surface under the cumulative ranking curve (SUCRA) plot, half dose of bevacizumab had a better position than conventional and augmented (1.2-2 times the regular dose) doses. A similar probability trend was observed for half vs. conventional doses of aflibercept and ranibizumab. Conventional infant dose of conbercept showed the lowest risk for retreatment (RR 0.846; 95% CrI: 0.245, 2.91). For secondary endpoints, lower doses of anti-VEGF agents were associated with shorter times to retreatment. The largest changes were noted for the augmented doses of bevacizumab and ranibizumab (0.3 mg) with means of 14.1 weeks (95% CrI: 6.65, 21.6) and 12.8 weeks (95% CrI: 3.19, 20.9), respectively. Finally, NMA demonstrated better refractive profile for anti-VEGF than laser therapy, especially for the conventional infant doses of bevacizumab and ranibizumab which exhibited a significantly better refractive profile than LPC, with mean differences of 1.67 (spherical equivalent - diopters) (95% CrI: 0.705, 2.67) and 2.19 (95% CrI: 0.782, 3.59), respectively. In the SUCRA plots, LPC had a markedly different position with a higher probability for myopia. Further clinical trials comparing different intravitreal doses of anti-VEGF agents are needed, but our findings suggest that low doses of these drugs retain efficacy and may reduce ocular and systemic undesired events.

Systemic Cytokines in Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a vasoproliferative vitreoretinal disorder, is the leading cause of childhood blindness worldwide. Although angiogenic pathways have been the main focus, cytokine-mediated inflammation is also involved in ROP etiology. Herein, we illustrate the characteristics and actions of all cytokines involved in ROP pathogenesis. The two-phase (vaso-obliteration followed by vasoproliferation) theory outlines the evaluation of cytokines in a time-dependent manner. Levels of cytokines may even differ between the blood and the vitreous. Data from animal models of oxygen-induced retinopathy are also valuable. Although conventional cryotherapy and laser photocoagulation are well established and anti-vascular endothelial growth factor agents are available, less destructive novel therapeutics that can precisely target the signaling pathways are required. Linking the cytokines involved in ROP to other maternal and neonatal diseases and conditions provides insights into the management of ROP. Suppressing disordered retinal angiogenesis via the modulation of hypoxia-inducible factor, supplementation of insulin-like growth factor (IGF)-1/IGF-binding protein 3 complex, erythropoietin, and its derivatives, polyunsaturated fatty acids, and inhibition of secretogranin III have attracted the attention of researchers. Recently, gut microbiota modulation, non-coding RNAs, and gene therapies have shown promise in regulating ROP. These emerging therapeutics can be used to treat preterm infants with ROP.

Retinopathy of prematurity: Metabolic risk factors

At preterm birth, the retina is incompletely vascularized. Retinopathy of prematurity (ROP) is initiated by the postnatal suppression of physiological retinal vascular development that would normally occur in utero. As the neural retina slowly matures, increasing metabolic demand including in the peripheral avascular retina, leads to signals for compensatory but pathological neovascularization. Currently, only late neovascular ROP is treated. ROP could be prevented by promoting normal vascular growth. Early perinatal metabolic dysregulation is a strong but understudied risk factor for ROP and other long-term sequelae of preterm birth. We will discuss the metabolic and oxygen needs of retina, current treatments, and potential interventions to promote normal vessel growth including control of postnatal hyperglycemia, dyslipidemia and hyperoxia-induced retinal metabolic alterations. Early supplementation of missing nutrients and growth factors and control of supplemental oxygen promotes physiological retinal development. We will discuss the current knowledge gap in retinal metabolism after preterm birth.

Anti-vascular endothelial growth factor therapy in retinopathy of prematurity: An updated literature review

Laser photocoagulation can still be considered the gold standard for treatment for retinopathy of prematurity (ROP). However, anti-vascular endothelial growth factor (anti-VEGF) therapy has increasingly become an important option that plays a significant role in the treatment of ROP. Major clinical trials have been published regarding the anti-VEGF use in ROP, along with multiple other studies looking into the different agents, doses, techniques, and possible complications. Anti-VEGF therapies can be considered as a safe and effective option for managing ROP. More longitudinal randomized clinical trials are necessary to evaluate the preferred treatment agent, the appropriate dose, best follow-up protocol, and the long-term ocular and systemic outcomes following treatment.

The role of anti-vascular endothelial growth factor in treatment of retinopathy of prematurity-a current review

The review aims to evaluate the uses of conventional laser therapy and intravitreal injection of various anti-VEGF in terms of efficacy and side effects for the treatment of retinopathy of prematurity. A literature search of the publication, concerning conventional laser treatment and intravitreal injection of anti-VEGF for ROP. A total of 40 articles were reviewed after curation by the authors for relevance. Intravitreal anti-VEGF showed better ocular efficacy in zone I ROP while laser therapy had a lower recurrence rate in zone II. Comparing the two mainstay anti-VEGF agents, bevacizumab showed lower ROP recurrence rate than ranibizumab. Anti-VEGF has a higher chance in developing persistent peripheral avascularisation compared to conventional laser therapy, but a lower chance of developing high myopia. Ranibizumab has a lower systemic absorption than bevacizumab, despite having no difference in the incidence of persistent peripheral avascularisation. In conclusion, it is advised that intravitreal anti-VEGF should be used as the first-line treatment for zone I ROP while laser therapy should be the mainstay for zone II ROP owing to the different pathogenetic mechanisms. In patients with recurrence after initial anti-VEGF injection, that given ranibizumab may opt to repeat the injection while that given bevacizumab should consider supplement laser ablative treatment.

Comparison of Intravitreal Anti-VEGF Agents With Laser Photocoagulation for Retinopathy of Prematurity of 1,627 Eyes in China

Purpose

To compare the efficacies and treatment outcomes of intravitreal anti-VEGF agents and laser therapy in retinopathy of prematurity (ROP).

Methods

A retrospective, non-randomized, comparative study of patients diagnosed with type 1 ROP or aggressive posterior ROP (A-ROP) treated with intravitreal anti-VEGF agents or laser therapy as primary treatment at the People's Hospital of Peking University.

Results

A total of 1,627 eyes of 862 patients were included. In Group 1, 399 eyes of 204 patients were diagnosed with A-ROP or zone I type 1 ROP. The initial regression of the anti-VEGF subgroup was better than that of the laser subgroup, and the reactivation rate and rate of progression to retinal detachment were lower than those of the laser subgroup. In Group 2, 1,228 eyes of 658 patients were diagnosed with zone II type 1 ROP. The reactivation rate of the laser subgroup was lower than that of the anti-VEGF subgroup. No significant differences were found in the initial regression and the probability of developing retinal detachment. Among the anti-VEGF agents, the reactivation rate in eyes treated with conbercept was much lower than that in eyes treated with ranibizumab. The spherical power and spherical equivalents of eyes treated with laser were significantly higher than those of eyes treated with anti-VEGF agents 1 year after initial treatment.

Conclusions

In contrast to laser therapy, anti-VEGF agents as primary treatments have potential advantages for eyes with zone I type 1 ROP and A-ROP. For eyes with zone II type 1 ROP, laser photocoagulation and anti-VEGF agents therapy showed similar efficacy; however, the rate of reactivation with laser therapy was significantly lower than that with anti-VEGF agents. Among the anti-VEGF agents, the reactivation rate was much lower in eyes treated with conbercept than in eyes treated with ranibizumab. Compared to anti-VEGF agents, laser treated eyes had greater trend to myopia.

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.

Assessment and management of retinopathy of prematurity in the era of anti-vascular endothelial growth factor (VEGF)

The incidence of retinopathy of prematurity (ROP) continues to rise due to the improved survival of very low birth weight infants in developed countries. This epidemic is also fueled by increased survival of preterm babies with variable use of oxygen and a lack of ROP awareness and screening services in resource-limited regions. Improvements in technology and a basic understanding of the disease pathophysiology have changed the way we screen and manage ROP, educate providers and patients, and improve ROP awareness. Advancements in imaging techniques, expansion of telemedicine services, and the potential for artificial intelligence-assisted ROP screening programs have created opportunities to improve ROP care in areas with a shortage of ophthalmologists trained in ROP. To address the gap in provider knowledge regarding ROP, the Global Education Network for Retinopathy of Prematurity (GEN-ROP) created a web-based tele-education training module that can be used to educate all providers involved in ROP, including non-physician ROP screeners. Over the past 50 years, the treatment of severe ROP has evolved from limited treatment modalities to cryotherapy and laser photocoagulation. More recently, there has been growing evidence to support the use of anti-vascular endothelial growth factor (VEGF) agents for the treatment of severe ROP. However, VEGF is known to be important in organogenesis and microvascular maintenance, and given that intravitreal anti-VEGF treatment can result in systemic VEGF suppression over a period of at least 1-12 weeks, there are concerns regarding adverse effects and long-term ocular and systemic developmental consequences of anti-VEGF therapy. Future research in ophthalmology to address the growing burden of ROP should focus on cost-effective fundus imaging devices, implementation of artificial intelligence platforms, updated treatment algorithms with optimal use of anti-VEGF and careful investigation of its long-term effects, and surgical options in advanced ROP. Addressing these unmet needs will aid the global effort against the ROP epidemic and optimize our understanding and treatment of this blinding disease.

Comparison of clinical outcomes of conbercept versus ranibizumab treatment for retinopathy of prematurity: a multicentral prospective randomised controlled trial

Purpose

To compare the recurrence rate and surgical complications of retinopathy of prematurity (ROP) between patients treated with intravitreal injection of conbercept (IVC) and intravitreal injection of ranibizumab (IVR) within 6 months.

Methods

A multicentral prospective, randomised controlled trial was applied from May 2017 to February 2019 for the infants diagnosed as aggressive posterior-ROP, zone I or posterior zone II treatment-requiring ROP by binocular indirect ophthalmoscope and RetCam3. These infants were assigned to randomly receive either intravitreal injection of 0.25 mg conbercept or 0.25 mg ranibizumab. The recurrence rate, fundus fluorescence angiography (FFA) and surgical complications were examined during the follow-up period of 6 months. Recurrent eyes were retreated by laser or another intravitreal injection within the 72 hours.

Results

A total of 30 infant patients (60 eyes) underwent IVC and 30 patients (60 eyes) underwent IVR. A total of 10 eyes (16.67%) in the IVC group and 14 eyes (23.34%) in the IVR group developed recurrence. There was no significant statistical difference in the recurrence rate between the two groups (χ²=0.83, p=0.36). The postmenstrual age (PMA) at first injection was (34.60±3.47) weeks in IVC and (35.14±1.76) in IVR group. In recurrent cases, the mean PMA at second treatment were (43.31±3.85) and (43.43±3.89) weeks in the IVC and IVR group, respectively. The period between two treatments was (8.71±6.62) for the IVC and (8.29±2.56) weeks for the IVR group. All these results showed no significant statistical difference between these two groups. The fluorescein leakage were observed in the eyes of recurrent infants by FFA. There were no other complications in the two groups except for complicated cataract in three eyes.

Conclusion

Both IVC and IVR are effective therapies for the treatment of ROP. Conbercept is a new option for treating ROP.

Comparison of the effectiveness of conbercept and ranibizumab treatment for retinopathy of prematurity

PURPOSE

To compare the effectiveness of intravitreal conbercept and ranibizumab treatment for retinopathy of prematurity (ROP).

METHODS

In this retrospective study, the date of patients with ROP treated with intravitreal conbercept or ranibizumab from July 2012 to March 2018 with at least 12 months of follow-up at the Eye Center in People's Hospital of Peking University were analysed. Regression, progression or recurrence and peripheral retina vascularization were evaluated.

RESULTS

In total, 283 eyes (145 infants) with conbercept treatment and 916 eyes (480 infants) with ranibizumab treatment were enrolled. In zone I ROP and aggressive posterior ROP (APROP), the recurrence prevalence was 49.09% (108/220 eyes) and 28.57% (10/33 eyes), and the recurrence interval was 7.87 ± 0.65 (5.5-9.5) weeks and 10.6 ± 1.53 (10.5-13) weeks in the ranibizumab and conbercept groups, respectively. In zone II ROP disease, the recurrence prevalence was 23.56% (164/696 eyes) and 13.31% (33/248 eyes), and the interval of recurrence was 8.40 ± 0.88 (6-10.5) weeks and 11.4 ± 1.35 (11-13.5) weeks in the ranibizumab and conbercept groups, respectively. The recurrence prevalence was significantly higher with ranibizumab in Zone I ROP and APROP (p = 0.006) and Zone II ROP (p < 0.001), and the recurrence interval was significantly longer in the conbercept group than that in the ranibizumab (p < 0.001). There was no significant difference in the rate of retinal vascularization (p = 0.441).

CONCLUSION

Conbercept and ranibizumab are effective for treating ROP. Compared with ranibizumab, conbercept resulted in less recurrence and longer treatment intervals.

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.].

Serum levels of cytokines in infants treated with conbercept for retinopathy of prematurity

Intravitreal anti-vascular endothelial growth factor (VEGF) agents have revolutionized the treatment of retinopathy of prematurity (ROP); however, there are concerns regarding the potential systemic complications caused by those treatments. This study aimed to determine the serum concentrations of cytokines in infants with ROP and to evaluate the changes in serum VEGF concentrations after intravitreal conbercept (IVC). Sixty infants with ROP treated with IVC 0.25 mg were included. Blood samples were collected before treatment as well as 1 week and 4 weeks after treatment. Serum levels of 45 types of cytokines were measured by a multiplex bead assay. We observed that IVC 0.25 mg in ROP patients suppressed the circulating levels of VEGF-A and VEGF-D as of 1 week after injection, and these growth factor levels returned to baseline at 4 weeks. No significant differences were observed in the serum levels of the other cytokines between baseline and 1 or 4 weeks after IVC.

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.

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.