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

Recurrence of Retinopathy of Prematurity Following Anti-vascular Endothelial Growth Factor (Anti-VEGF) Therapy: A Systematic Review and Meta-Analysis

Retinopathy of prematurity (ROP) is a neovascular disorder which affects premature infants and can lead to childhood blindness. Treatment includes laser photocoagulation and intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections, both effective options. However, laser photocoagulation can lead to refractive errors, while anti-VEGF therapy can result in disease recurrence. Our systematic review aimed to evaluate the recurrence rates of ROP following treatment with anti-VEGF agents compared to other anti-VEGF agents and laser photocoagulation. We also aimed to measure the retreatment intervals and assess successful retreatment rates to identify the most effective treatment modality. Our review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and included both randomized controlled trials (RCTs) and non-randomized comparative studies (NCS). A thorough search of MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) databases was performed. Studies were assessed using the Cochrane Risk of Bias (RoB2) tool and the Newcastle-Ottawa Scale (NOS). Random-effects and fixed-effects models were used to measure pooled estimates. The outcomes were reported as risk ratios (RR) and standardized mean differences (SMD). A total of 21 studies (six RCTs and 15 NCS) with 6,152 eyes were included. Overall, anti-VEGF agents showed a higher risk of recurrence compared to laser photocoagulation (RR=2.14, 95% CI: 1.06-4.33, p=0.03). Conbercept demonstrated a significantly lower risk of recurrence than laser photocoagulation and ranibizumab (RR=0.47, 95% CI: 0.39-0.58, p<0.00001), while aflibercept showed a higher recurrence risk compared to bevacizumab (RR=12.61, 95% CI: 6.43-24.73, p<0.00001). Bevacizumab was associated with a longer retreatment interval than laser photocoagulation (SMD=0.89, 95% CI: 0.61-1.17, p<0.00001). No significant differences in retreatment success rates between bevacizumab and laser photocoagulation were observed. Anti-VEGF therapy is effective in the treatment of ROP; however, it is associated with a higher risk of recurrence compared to laser photocoagulation. Conbercept shows greater efficacy in reducing recurrence risk and prolonging the retreatment interval compared to ranibizumab. Aflibercept demonstrated inconsistent outcomes. No significant difference in recurrence rates was observed between bevacizumab and ranibizumab. Recurrences occurred significantly later when anti-VEGF therapy was used compared to laser photocoagulation. Successful retreatment rates between bevacizumab and laser photocoagulation were similar.

Efficacy and Safety of Aflibercept and Ranibizumab in the Treatment of Retinopathy of Prematurity

PURPOSE

To compare the efficacy, recurrence rate, and recurrence interval of intravitreal injection of aflibercept (IVA) and ranibizumab (IVR) in patients with retinopathy of prematurity (ROP).

METHODS

This is a single-center retrospective study of neonates hospitalized from January 2018 to March 2023 in the Department of Neonatology of the First Affiliated Hospital of Zhengzhou University who received intravitreal injection of anti-vascular endothelial growth factor owing to type 1 prethreshold ROP, threshold ROP, or aggressive posterior ROP. Clinical data were collected to record the cure, recurrence, number of injections, and side effects of ROP.

FINDINGS

A total of 224 neonates (444 eyes) were enrolled in this study, of which 121 (241 eyes) received IVA and 103 (203 eyes) received IVR. There were no significant differences in the general characteristics of infants between the two groups (P > 0.05). The corrected gestational age of the first injection was 37.27 ± 3.07 weeks in the IVA group and 37.20 ± 4.89 weeks in the IVR group (P = 0.582). The recurrence rate was 15.8% in the IVA group and 14.9% in the IVR group (P = 0.841). For relapsed infants, the postmenstrual age (PMA) was 34.89 ± 3.49 weeks in the IVA group and 35.28 ± 4.43 weeks in the IVR group at the first treatment. The PMA was 43.69 ± 4.57 and 40.96 ± 4.98 weeks at the second treatment in the IVA and IVR groups, respectively (P = 0.185). There were two children in the IVA group that required a third treatment, with PMAs of 58.71 and 57.29 weeks at the time of surgery, and one child in the IVR group, with a PMA of 43.14 weeks at the time of injection (P = 0.221). No complications were recorded in either group.

IMPLICATIONS

The efficacies of aflibercept and ranibizumab in treating ROP are similar, and the safety of the medications was good. Further research should be conducted in large-scale, prospective clinical trials, providing ophthalmologists with new options for the treatment of ROP.

The AAV2.7m8 capsid packages a higher degree of heterogeneous vector genomes than AAV2

Recombinant adeno-associated virus (rAAV) vectors are currently the only proven vehicles for treating ophthalmological diseases through gene therapy. A wide range of gene therapy programs that target ocular diseases are currently being pursued. Nearly 20 years of research have gone into enhancing the efficacy of targeting retinal tissues and improving transgene delivery to specific cell types. The engineered AAV capsid, AAV2.7m8 is currently among the best capsids for transducing the retina following intravitreal (IVT) injection. However, adverse effects, including intraocular inflammation, have been reported following retinal administration of AAV2.7m8 vectors in clinical trials. Furthermore, we have consistently observed that AAV2.7m8 exhibits low packaging titers irrespective of the vector construct design. In this report, we found that AAV2.7m8 packages vector genomes with a higher degree of heterogeneity than AAV2. We also found that genome-loaded AAV2.7m8 stimulated the infiltration of microglia in mouse retinas following IVT administration, while the response to genome-loaded AAV2 and empty AAV2.7m8 capsids produced much milder responses. This finding suggests that IVT administration of AAV2.7m8 vectors may stimulate retinal immune responses in part because of its penchant to package and deliver non-unit length genomes.

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.

Efficacy comparison of anti-vascular endothelial growth factor drugs for the treatment of type 1 retinopathy of prematurity: A network meta-analysis of randomised controlled trials

PURPOSE

To compare the efficacy of different anti-vascular endothelial growth factor (VEGF) agents for the treatment of retinopathy of prematurity (ROP) in preterm infants.

METHODS

Seven databases were searched for eligible literature up to February 22, 2023. Studies were included if they were randomised controlled trials (RCTs) investigating the efficacy of anti-VEGF agents for ROP in infants. A network meta-analysis (NMA) was performed. We also conducted subgroup analyses to determine the efficacy ranking of regimens used in different regions. The odds ratio (OR), standardised mean difference (SMD), and surface under the cumulative ranking curve (SUCRA) were calculated for each outcome.

RESULTS

Thirteen RCTs of 10 different regimens, involving 1196 infants (2388 eyes), were identified. Bevacizumab (0.625 mg; OR = 0.16, 95% confidence interval [CI] 0.06-0.40, SUCRA = 80.6%) and conbercept (0.15 mg; OR = 0.08, 95% CI 0.02-0.30, SUCRA = 96.0%) were the most effective regimens in reducing the risk of ROP recurrence requiring retreatment in Western countries and China, respectively. Compared with laser therapy, bevacizumab (0.625 mg; SMD = 1.54, 95% CI 0.06-3.02) achieved significantly longer intervals between treatment and recurrence. No significant difference in the risk of retinal detachment was detected between any anti-VEGF agent and laser (p > 0.05).

CONCLUSIONS

Bevacizumab (0.625 mg) and conbercept (0.15 mg) appeared to be the most effective therapies for ROP in Western countries and China, respectively. More high-quality RCTs are warranted to evaluate the efficacy and long-term safety of anti-VEGF drugs for the management of ROP.

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 clinical effectiveness of conbercept and ranibizumab for treating retinopathy of prematurity: a meta-analysis

BACKGOUND

Conbercept and ranibizumab have been used to treat retinopathy of prematurity (ROP). However, the clinical effectiveness of conbercept and ranibizumab remains controversial.

AIM

This meta-analysis aimed to compare the effectiveness of conbercept and ranibizumab for treating ROP.

METHOD

We systematically searched Pubmed, Web of Science, Embase, the Cochrane Library, Ovid, Scopus, China National Knowledge Infrastructure, Wanfang Database, CQVIP, Duxiu Database, SinoMed, and X-MOL to screen relevant studies up to November 2022. Retrospective cohort studies and randomized controlled trials (RCTs) evaluating the effectiveness of conbercept and ranibizumab in treating patients with ROP were selected. The outcomes assessed were the rates of primary cure, ROP recurrence, and retreatment. Statistical analysis was performed using Stata.

RESULTS

Seven studies (n = 989) were selected in the meta-analysis. There were 303 cases (594 eyes) treated with conbercept and 686 patients (1,318 eyes) treated with ranibizumab. Three studies reported the primary cure rate. Compared to ranibizumab, conbercept had a significantly higher primary cure rate (odds ratio [OR] 1.91, 95% confidence interval [CI] 1.05-3.49, P < 0.05). Five studies reported the rate of ROP recurrence, and there were no significant differences between conbercept and ranibizumab (OR 0.62, 95% CI 0.28-1.38, P > 0.05). Three studies reported the rate of retreatment, and the rates were not significantly different between conbercept and ranibizumab (OR 0.78, 95% CI 0.21-2.93, P > 0.05).

CONCLUSION

Conbercept had a higher rate of primary cure in ROP patients. More RCTs are needed to compare the efficacy of conbercept and ranibizumab in treating ROP.

The efficacy and ocular safety following aflibercept, conbercept, ranibizumab, bevacizumab, and laser for retinopathy of prematurity: a systematic review and meta-analysis

BACKGROUND

Retinopathy of prematurity (ROP) is typically treated with laser photocoagulation and/or intravitreal anti-vascular endothelial growth factor (anti-VEGF). To the best of our knowledge, most systematic reviews have focused on comparing anti-VEGF against laser treatment while comparisons between different anti-VEGF agents are lacking. Thus, we conducted this meta-analysis to compare the efficacy and safety of different anti-VEGF agents or laser after primary ROP therapy.

METHODS

We conducted a comprehensive search across multiple databases up to November 2022. We included studies that used anti-VEGF or laser for ROP with comparable cohorts.

RESULTS

Overall, 44 studies were included in this meta-analysis. When comparing anti-VGEF with laser, we found that the anti-VEGF group had a significantly higher retreatment rate (RR = 1.56, 95%CI = [1.06, 2.31], p = 0.03), a longer time from treatment to retreatment (WMD = 5.99 weeks, 95%CI = [4.03, 7.95], p < 0.001), a lower retinal detachment rate (RR = 0.55, 95%CI = [0.30, 0.91], p = 0.02), higher spherical equivalent (WMD = 1.69D, 95%CI = [0.61, 2.77], p = 0.002), lower myopia rate (RR = 0.69, 95%CI = [0.50, 0.97], p = 0.03) and lower anisometropia rate (RR = 0.44, 95%CI = [0.29, 0.67], p = 0.0001). In comparisons between ranibizumab and bevacizumab, the intravitreal ranibizumab (IVR) group was associated with higher recurrence rate (RR = 2.02, 95%CI = [1.49, 2.73], p < 0.0001), higher retreatment rate (RR = 1.70, 95%CI = [1.17, 2.47], p = 0.0006), and lower high myopia rate (RR = 0.31, 95%CI = [0.12, 0.77], p = 0.01). Similarly, when compared to aflibercept and conbercept, the IVR cohort also demonstrated higher recurrence and retreatment rates. While no significant differences were observed in any of the variables included in the statistical analysis in the comparison between bevacizumab and aflibercept.

CONCLUSIONS

Anti-VEGF was associated with higher retreatment and lesser incidence of myopia as compared to laser. Laser therapy was linked to more complications like retinal detachment and myopia. Ranibizumab exhibited higher recurrence and retreatment rates compared to bevacizumab, aflibercept, and conbercept.

Combined Anti-Angiogenic and Anti-Inflammatory Nanoformulation for Effective Treatment of Ocular Vascular Diseases

Background

Ocular vascular diseases are the major causes of visual impairment, which are characterized by retinal vascular dysfunction and robust inflammatory responses. Traditional anti-angiogenic or anti-inflammatory drugs still have limitations due to the short-acting effects. To improve the anti-angiogenic or anti-inflammatory efficiency, a dual-drug nanocomposite formulation was proposed for combined anti-angiogenic and anti-inflammatory treatment of ocular vascular diseases.

Methods 

CBC-MCC@hMSN(SM) complex nanoformulation was prepared by integrating conbercept (CBC, an anti-angiogenic drug) and MCC950 (MCC, an inhibitor of inflammation) into the surface-modified hollow mesoporous silica nanoparticles (hMSN(SM)). CBC-MCC@hMSN(SM) complex nanoformulation was then characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, zeta potentials, and nitrogen adsorption-desorption measurement. CBC and MCC release profile, cytotoxicity, tissue toxicity, anti-angiogenic effects, and anti-inflammatory effects of CBC-MCC@hMSN(SM) were estimated using the in vitro and in vivo experiments.

Results

 CBC-MCC@hMSN(SM) complex had no obvious cytotoxicity and tissue toxicity and did not cause a detectable ocular inflammatory responses. CBC-MCC@hMSN(SM) complex was more effective than free CBC or MCC in suppressing endothelial angiogenic effects and inflammatory responses in vitro. A single intraocular injection of CBC-MCC@hMSN(SM) complex potently suppressed diabetes-induced retinal vascular dysfunction, choroidal neovascularization, and inflammatory responses for up to 6 months.

Conclusion 

Combined CBC and MCC nanoformulation provides a promising strategy for sustained suppression of pathological angiogenesis and inflammatory responses to improve the treatment outcomes of ocular vascular diseases.

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.

Treatment for Retinopathy of Prematurity in Twins: The Small Twin without High Birth Weight Discordant Is Not at Increased Risk

Purpose: As common retinopathy is observed in low-birth infants, the characteristics of ROP in twins are worth exploring. The present study tried to demonstrate the risk factors of treatment for retinopathy of prematurity (ROP) in twins both diagnosed with ROP. Methods: A retrospective, institution-based cohort study of 62 premature ROP twin pairs with a mean gestational age (GA) younger than 35 weeks and a birth weight (BW) lower than 2500 g. Only infants with a follow-up period longer than 6 months and complete treatment records were included. The demographic data, treatment requirements and further rescue treatments were all collected and analyzed for all infants according to whether they accepted treatments. Moreover, all twin infants were divided into small and large twin groups according to birth weight, and they were also categorized as three groups according to the treatment requirement including both twins receiving treatment (BT group), one of the twins receiving treatment (ST group) and none of the twins receiving treatment (NT group). Comparisons of demographic data, treatment requirements and further rescue treatments were all conducted according to the different grouping methods. Results: The mean GA of the enrolled infants was (29.29 ± 2.45) weeks with a mean BW of (1335.77 ± 390.36) grams. Among them, 110 infants were mechanically ventilated. Fifty-one of the infants did not receive any treatment and 73 infants received laser or intravitreal injection of anti-VEGF agents. In total, 64 infants only underwent intravitreal injection of anti-VEGF agents or laser treatment, while the other nine infants received scleral buckling or vitrectomy as a necessary treatment when the retinal detachment was observed. No significantly different mechanical ventilation or treatment requirements could be observed between the small twin group and the large twin group (p = 0.73, 0.94). The twins in the BT groups showed the lowest BW, while the NT group infants had the highest BW. The GA for the BT, ST and NT groups were (27.86 ± 1.87) weeks, (29.60 ± 1.52) weeks and (31.33 ± 2.39) weeks, respectively, and showed significant differences as well (p < 0.001). Conclusion: Being a small twin in twin-paired ROP without a high BW discordant will not increase the risk for treatment requirement or additional surgery necessity with a much more severe stage of ROP.

Different Types of Hyperfluorescence Observed in Post Anti-VEGF Fluorescein Angiographic Patterns in Retinopathy of Prematurity Patients

Purpose

To demonstrate that the demographic and treatment characteristics of retinopathy of prematurity (ROP) eyes showed different types of hyperfluorescence in fluorescein angiography (FA) initially treated with anti-vascular endothelial growth factor (VEGF) agents.

Methods

A consecutive case series of ROP treated with anti-VEGF agents was retrospectively studied. All the patients underwent FA examinations at least 6 months later after treatment. The demographic and treatment characteristics of eyes with or without hyperfluorescence in FA were analyzed. The different types of hyperfluorescence were divided into three groups, including vascular leakage, fibrous membrane, and vascular abnormality.

Results

Two hundred and forty-two eyes of 123 patients with treatment-required ROP were included. Hyperfluorescence was defined in 51/242 eyes, and 2.08 ± 1.11 injections were performed for them, while the eyes without hyperfluorescence received 1.65 ± 0.80 injections (P = 0.013). Vascular leakage was defined in 26/51 hyperfluorescence eyes. The postmenstrual age (PMA) of first injection for the hyperfluorescence group was 38.56 ± 3.24 weeks, which is earlier than that of infants without hyperfluorescence (P = 0.011). More additional treatments were performed in eyes with hyperfluorescence (23.53 vs. 3.66%, P = 0.000). Among them, the eyes with vascular leakage required more additional treatment than eyes without vascular leakage (42.31 vs. 4.00%, P = 0.004). For the 26 eyes with vascular leakage, 11 eyes of 8 patients received further treatments during further follow-up. No significant difference of refractive errors can be defined between different groups.

Conclusion

Eyes with persistent hyperfluorescencein FA after treatment required more anti-VEGF and additional treatments, including laser and PPV. Not all hyperfluorescences were vascular leakage and required additional treatment.

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.

Efficacious, safe, and stable inhibition of corneal neovascularization by AAV-vectored anti-VEGF therapeutics

Corneal neovascularization (CoNV) leads to visual impairment, affecting over 1.4 million people in the United States per year. It is caused by a variety of pathologies, such as inflammation, hypoxia, and limbal barrier dysfunction. Injection of the anti-vascular endothelial growth factor (VEGF) drug KH902 (conbercept) can inhibit CoNV but requires repeated dosing that produces associated side effects, such as cornea scar. To explore more efficacious and long-lasting treatment of CoNV, we employed recombinant adeno-associated virus (rAAV)2 and rAAV8 vectors to mediate KH902 expression via a single intrastromal injection and investigated its anti-angiogenic effects and safety in both alkali-burn- and suture-induced CoNV mouse models. Our results showed that rAAV-mediated KH902 mRNA expression in the cornea was sustained for at least 3 months after a single intrastromal injection. Moreover, the expression level of rAAV8-KH902 far exceeded that of rAAV2-KH902. A single-dose rAAV8-KH902 treatment at 8 × 10⁸ genome copies (GCs) per cornea dramatically inhibited CoNV for an extended period of time in mouse CoNV models without adverse events, whereas the inhibition of CoNV by a single intrastromal administration of the conbercept drug lasted for only 10−14 days. Overall, our study demonstrated that the treatment of CoNV with a single dose of rAAV8-KH902 via intrastromal administration was safe, effective, and long lasting, representing a novel therapeutic strategy for CoNV.

Description and management of retinopathy of prematurity reactivation after intravitreal antivascular endothelial growth factor therapy

PURPOSE OF REVIEW

To review the literature regarding reactivation of retinopathy of prematurity (ROP) after treatment with antivascular endothelial growth factor (anti-VEGF) agents.

RECENT FINDINGS

Reactivation can occur after anti-VEGF or laser. Risk factors for reactivation include patient and disease-related factors. Various studies are evaluating the use of different anti-VEGF agents and reactivation rates. However, the definition of reactivation varies between studies.

SUMMARY

The literature has varied definitions of reactivation, which is often used interchangeably with recurrence. It is important to recognize features of reactivation of ROP to appropriately manage patients and conduct clinical trials. The International Classification of ROP 3rd edition has established a consensus guideline regarding terminology describing reactivation.

The Role of Intravitreal Anti-VEGF Agents in Rabbit Eye Model of Open-Globe Injury

Purpose

To evaluate the effects of intravitreal anti-VEGF agents in a rabbit model of open-globe injury (OGI).

Methods

OGI was induced in the right eyes of 75 Belgian rabbits by making 5 mm circumferential incision placed 6 mm behind the limbus. The rabbits were divided into 4 groups: control (n = 5), OGI group (n = 40), and intravitreal Ranibizumab and Conbercept (n = 15 each). Ranibizumab or Conbercept was injected into the vitreous at 0.5 hours, 3 days, or 7 days. Vitreous fluid was collected, and levels of growth factors and cytokines were measured by enzyme-linked immunosorbent assay (ELISA). On day 28 after OGI, B scan examination and histological examination were performed to evaluate intravitreal proliferation and formation of epiretinal fibrosis.

Results

Vitreous levels of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-β), and plasminogen activator inhibitor-1 (PAI-1) were significantly increased in rabbit eyes after OGI. Compared to eyes in OGI group, anti-VEGF treatments significantly reduced these growth factors and cytokines. Among the 7 eyes examined from each group for intravitreal proliferative changes, they were found in 7 of 7 (100%) in OGI group and were decreased by Ranibizumab and Conbercept to 5 of 7 (71.4%) and 4 of 7 (57.1%), respectively. Both Ranibizumab and Conbercept inhibited epiretinal scar formation at the wound site, with Conbercept showing the greatest effect (maximal length of scar (L), L_OGI = 503 ± 82.44 μm, L_Ranibizumab = 355 ± 43.66 μm, and L_Conbercept = 250.33 ± 36.02 μm).

Conclusion

Anti-VEGF treatments after OGI significantly attenuated the upregulation of growth factors and cytokines in the vitreous and prevented intravitreal proliferation and epiretinal scar formation and thus may protect against the development of posttraumatic complications such as proliferative vitreoretinopathy (PVR).

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.

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.

Hyperreflective foci in OCT image as a biomarker of poor prognosis in diabetic macular edema patients treating with Conbercept in China

Purpose

To investigate the dynamic changes of hyperreflective foci (HF) in diabetic macular edema (DME) patients during the intravitreal Conbercept treatment in China.

Methods

DME Patients receiving intravitreal Conbercept (IVC) injections during the year 2016–2017 were retrospectively investigated. Thirteen patients (26 eyes) were recruited in this study. They received IVC once a month for 3 consecutive months. The number and location of HFs, the best-corrected visual acuity (BCVA) and central macular thickness (CMT) at each visit were analyzed and compared.

Results

After the first injection, BCVA (LogMAR) was increased from 0.75 ± 0.48 to 0.43 ± 0.24 (p < 0.05), CMT improved from 575.9 ± 191.9 to 388.2 ± 198.5 μm (p = 0.014). However, the BCVA and CMT had no statistical difference after the second and third injection as compared with those after the first injection respectively. The baseline number of HFs was 5.39 ± 4.24, 5.15 ± 5.17 and 0.88 ± 1.90 in the inner retinal, outer retinal and subretinal layer respectively. The number of HFs in these three retinal layers decreased significantly after the first injection (p = 0.0045, p < 0.0001 and p = 0.0045, respectively). However, after the second injection, only the number of HFs in the inner retinal layer experienced a further decrease. After the third injection, no statistically significant HFs changes was observed in each retinal layers. Correlation analysis showed that there was a positive significant correlation between the baseline number of HFs in the inner retina, outer retina, subretina and final BCVA (r = 0.571, p = 0.002; r = 0.464, p = 0.017; r = 0.405, p = 0.04 respectively). There was also a significant positive correlation between outer retinal HFs reduction, total retinal HFs reduction and increase of BCVA (r = 0.40, p = 0.043 and r = 0.393, p = 0.04 respectively).

There were no severe ocular adverse reactions or systemic adverse events.

Conclusions

Conbercept is effective and safe in the treatment of DME. HFs can act as a biomarker of poor final visual outcome.

Intravitreal ranibizumab or conbercept for retinal arterial macroaneurysm: a case series

BACKGROUND

There is no consensus for the standard treatment of retinal arterial macroaneurysm (RAM). Intravitreal anti-vascular endothelium growth factor (anti-VEGF) is an alternative treatment option for RAM. The purpose of this study is to describe the clinical efficacy of intravitreal ranibizumab or intravitreal conbercept for retinal arterial macroaneurysm.

CASE PRESENTATION

Three cases that presented with symptomatic RAM were treated with intravitreal anti-VEGF agents. Two eyes received two intravitreal ranibizumab injections with a time interval of one month and completed a one-year follow-up, while one eye only received one intravitreal conbercept injection and was followed up for six months. Both the retinal thickness and the visual acuity were significantly improved at the final clinic visit. The macular hemorrhage and edema were resolved. There were no ocular or systemic side effects.

CONCLUSIONS

Intravitreal ranibizumab or conbercept might be used as a therapeutic option for symptomatic retinal arterial macroaneurysm patients. Anti-VEGF therapy should be further investigated in a larger series with longer follow-up for this disease profile.

A Multinational Comparison of Anti-Vascular Endothelial Growth Factor Use: The United States, the United Kingdom, and Asia-Pacific

PURPOSE

A comparison of anti-vascular endothelial growth factor (anti-VEGF) medication use across multiple countries.

CLINICAL RELEVANCE

Anti-VEGF medication use is now considered first-line treatment for numerous retinal diseases globally. Exploring medication choices, costs within each healthcare system, policy challenges, emerging treatments, and patient access all provide insight into a newly recognized and major public health issue.

METHODS

All data presented in this review are available through the published English literature in PubMed, non-peer-reviewed trade publications, and reported surveys. The following search terms were used: anti-VEGF OR bevacizumab OR ranibizumab OR aflibercept OR pegaptanib OR conbercept AND trends OR survey OR cost OR patterns OR preference. Countries with large populations and available data included the United States, United Kingdom, China, India, Korea, Singapore, and Australia. Population and economic statistics were obtained from published reports from the World Bank, World Health Organization, and Commonwealth Fund.

RESULTS

Anti-VEGF medication use and costs are significant aspects of patient and healthcare system expenditures in each nation and may have an especially large potential economic burden in India and China. Bevacizumab use comprises the majority of anti-VEGF medication use in the United States and Singapore, although aflibercept use is growing rapidly. Paradoxically, data demonstrate that there is a significant trend in medication choice toward ranibizumab and aflibercept among practice settings outside of the United States, such as the United Kingdom, China, South Korea, and Australia. The price of anti-VEGF medications ranged from US $30 (ziv-aflibercept) to US $1950 (ranibizumab and aflibercept). Ranibizumab's price ranged from US $240 in India to US $1950 in the United States. Conbercept in China costs approximately US $1150 per dose.

CONCLUSIONS

Outside of the United States, many nations are using a majority of more expensive anti-VEGF medications, which may lead to increased costs and decreased access. Increasing the availability of safely compounded anti-VEGF medications will likely improve access, create patient/provider choice, and decrease relative healthcare costs for the growing burden of retinal diseases globally.

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 lower dose of intravitreal conbercept effectively treats retinopathy of prematurity

Intravitreal Conbercept (IVC) is the latest applied and effective treatment for the management of retinopathy of prematurity (ROP). However, conbercept escapes from the vitreous into the general circulation and reduce systemic VEGF concentrations. Thus, there are concerns about systemic complications, in these premature infants who are developing vital organ systems. This study is to determine whether a low dosage (0.15 mg/0.015 mL) of IVC is effective in the treatment of Zone II Stage 2/3 + ROP. A total of 38 eyes of 20 infants were analyzed retrospectively. We identified treatment effectiveness as complete regression of retinopathy and retinal vascularisation to zone III. The mean gestational age (GA), postmenstrual age (PMA) at treatment and birth weights (BW) were 28.6 ± 2.2 weeks, 39.3 ± 3.0 weeks and 1297.5 ± 429.2 g respectively. Primary effectiveness (react to IVC 0.15 mg alone) was found in 32/38 eyes (84.2%). Secondary effectiveness (a second IVC was required) was found in 6/38 eyes (15.8%). Follow-up continued until 90 weeks’ postmenstrual age and showed no recurrences of plus disease or neovascularization. The study suggests 0.15 mg IVC is effective for Zone II Stage 2/3 + ROP, and there is no adverse ocular outcomes during the follow-up period.

PDGF-C and PDGF-D in ocular diseases

PDGFs and their receptors are critical regulators of numerous tissues and organs, including the eye. Extensive studies have shown that PDGFs and their receptors play critical roles in many ocular neovascular diseases, such as neovascular age-related macular degeneration, retinopathy of prematurity, and proliferative vitreoretinopathy. In addition, PDGFs and PDGFRs are also important players in ocular diseases involving the degeneration of retinal neuronal and vascular cells, such as glaucoma and retinitis pigmentosa. Due to their critical roles in the pathogenesis of many blinding ocular diseases, the PDGFs and PDGFRs have been considered as important target molecules for the treatment of eye diseases. PDGF-C and PDGF-D are relatively new members of the PDGF family and are potent angiogenic and survival factors. Recent studies have demonstrated their important roles in different types of eye diseases. Thus, modulating PDGF-C and PDGF-D activities may have therapeutic values for the treatment of ocular neovascular and degenerative diseases. This review mainly summarizes the recent advances on PDGF-C and PDGF-D biology in relationship to some major ocular diseases.