Retinal Detachment after Treatment of Retinopathy of Prematurity with Laser versus Intravitreal Anti-Vascular Endothelial Growth Factor

Recent Advances in Nanomedicine for Ocular Fundus Neovascularization Disease Management

As an indispensable part of the human sensory system, visual acuity may be impaired and even develop into irreversible blindness due to various ocular pathologies. Among ocular diseases, fundus neovascularization diseases (FNDs) are prominent etiologies of visual impairment worldwide. Intravitreal injection of anti-vascular endothelial growth factor drugs remains the primary therapy but is hurdled by common complications and incomplete potency. To renovate the current therapeutic modalities, nanomedicine emerged as the times required, which is endowed with advanced capabilities, able to fulfill the effective ocular fundus drug delivery and achieve precise drug release control, thus further improving the therapeutic effect. This review provides a comprehensive summary of advances in nanomedicine for FND management from state-of-the-art studies. First, the current therapeutic modalities for FNDs are thoroughly introduced, focusing on the key challenges of ocular fundus drug delivery. Second, nanocarriers are comprehensively reviewed for ocular posterior drug delivery based on the nanostructures: polymer-based nanocarriers, lipid-based nanocarriers, and inorganic nanoparticles. Thirdly, the characteristics of the fundus microenvironment, their pathological changes during FNDs, and corresponding strategies for constructing smart nanocarriers are elaborated. Furthermore, the challenges and prospects of nanomedicine for FND management are thoroughly discussed.

Comparison of Intravitreal Ranibizumab and Laser Photocoagulation in the Treatment of Type I Retinopathy of Prematurity in Malaysia: A One-Year Follow-Up Study

PURPOSE

This study aimed to evaluate the treatment efficacy, anatomical outcomes, and refractive outcomes of laser photocoagulation (LPC) and intravitreal ranibizumab (IVR) in the treatment of type I retinopathy of prematurity (ROP) at one-year follow-up.

METHODS

This is a retrospective study on the treatment of type I ROP and aggressive ROP (A-ROP) using LPC or IVR in three Malaysian hospitals providing pediatric ophthalmology services from January 2019 to December 2021. Information on gestational age, birth weight, ROP zone and stage, and underlying comorbidities was collected. Parameters for evaluating treatment efficacy include the time taken to achieve complete regression, the regression rate, and the reactivation rate. The anatomical and refractive outcomes were evaluated at one year of adjusted age.

RESULTS

This study included 92 eyes from 46 infants. Of these, 42 eyes received LPC as the initial treatment, while 50 eyes underwent IVR. A higher percentage of infants with cardiovascular disease were treated with IVR (66.7%) compared to LPC (40%) (p<0.05). However, there were no significant differences in gestational age, birth weight, respiratory distress syndrome, sepsis, or intraventricular hemorrhage between the two treatment groups (p>0.05). Infants treated with LPC had a higher regression rate than those treated with IVR, but they were also significantly more myopic and had worse best-corrected visual acuity (BCVA). Conversely, infants treated with IVR experienced a significantly higher reactivation rate compared to those treated with LPC. Logistic regression analysis showed no significant associations between gestational age, birth weight, plus disease, zone 1 ROP, and the choice of initial treatment with the reactivation of ROP.

CONCLUSIONS

Both LPC and IVR effectively treat type I ROP in infants, with IVR yielding superior anatomical and refractive outcomes and LPC offering a lower reactivation rate. Understanding individual patient characteristics is crucial for treatment selection.

Treated Cases of Retinopathy of Prematurity in Germany: 10-Year Data from the Retina.net Retinopathy of Prematurity Registry

PURPOSE

To analyze changes in demographic parameters and retreatment patterns over a 10-year period in a clinical routine setting of infants with retinopathy of prematurity (ROP) requiring treatment documented in the German Retina.net ROP registry.

DESIGN

Multicenter, noninterventional, observational registry study recruiting patients treated for ROP.

SUBJECTS

A total of 692 eyes of 353 infants treated for ROP were documented in the Retina.net ROP registry over a 10-year period between 2011 and 2020. These cases cover about 15% of all infants treated for ROP in Germany.

METHODS

The Retina.net ROP registry was established in 2012 to jointly collect information on infants treated for ROP. The database collects information on demographic parameters (gestational age [GA], birth weight, neonatal comorbidities) as well as treatment parameters (type of treatment, weight and age at treatment, and stage of ROP). A total of 19 centers contributed to the analysis. This is the 10-year analysis of data from 2011 to 2020, in which we focus on changes over time regarding the respective parameters.

MAIN OUTCOME MEASURES

Changes over time in demographic parameters and treatment patterns for ROP in Germany.

RESULTS

The overall incidence of treatment requiring ROP was 3.5% of all infants screened for ROP at participating centers. Gestational age, weight at birth, and weight at treatment remained stable over the 10-year period, whereas postmenstrual and postnatal age at treatment increased moderately but statistically significantly over the years. The most prevalent ROP severity stage at treatment was stage 3+ in zone II (76.6% of all treated eyes). Treatment patterns changed considerably from predominantly laser treatments in 2011 (75% of all treated eyes) to predominantly ranibizumab treatments in 2020 (60.9% of all treated eyes). The overall retreatment rate was 15.6%. Retreatment rates differed between initial treatment modalities (14.1% after laser coagulation, 12% after bevacizumab and 24.5% after ranibizumab). Treatment-associated systemic or ophthalmic complications were rare.

CONCLUSIONS

This data analysis represents one of the largest documented cohorts of infants treated for ROP. The data on demographic parameters and treatment patterns provide useful information for further improvement of ROP management.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Propranolol: a new pharmacologic approach to counter retinopathy of prematurity progression

Despite the evident progress in neonatal medicine, retinopathy of prematurity (ROP) remains a serious threat to the vision of premature infants, due to a still partial understanding of the mechanisms underlying the development of this disease and the lack of drugs capable of arresting its progression. Although ROP is a multifactorial disease, retinal vascularization is strictly dependent on oxygen concentration. The exposition of the retina of a preterm newborn, still incompletely vascularized, to an atmosphere relatively hyperoxic, as the extrauterine environment, induces the downregulation of proangiogenic factors and therefore the interruption of vascularization (first ischemic phase of ROP). However, over the following weeks, the growing metabolic requirement of this ischemic retina produces a progressive hypoxia that specularly promotes the surge of proangiogenic factors, finally leading to proliferative retinopathy (second proliferative phase of ROP). The demonstration that the noradrenergic system is actively involved in the coupling between hypoxia and the induction of vasculogenesis paved the way for a pharmacologic intervention aimed at counteracting the interaction of noradrenaline with specific receptors and consequently the progression of ROP. A similar trend has been observed in infantile hemangiomas, the most common vascular lesion of childhood induced by pre-existing hypoxia, which shares similar characteristics with ROP. The fact that propranolol, an unselective antagonist of β1/2 adrenoceptors, counteracts the growth of infantile hemangiomas, suggested the idea of testing the efficacy of propranolol in infants with ROP. From preclinical studies, ongoing clinical trials demonstrated that topical administration of propranolol likely represents the optimal approach to reconcile its efficacy and maximum safety. Given the strict relationship between vessels and neurons, recovering retinal vascularization with propranolol may add further efficacy to prevent retinal dysfunction. In conclusion, the strategy of contrasting precociously the progression of the disease appears to be more advantageous than the current wait-and-see therapeutic approach, which instead is mainly focused on avoiding retinal detachment.

A meta-analysis of adverse effects of retinopathy of prematurity on neurodevelopment in preterm infants

BACKGROUND

Retinopathy of prematurity (ROP) increases with the survival of late preterm infants, but its relationship with neurodevelopmental outcomes in preterm infants remains controversial. To investigate the relationship between ROP and its severity and adverse neurodevelopmental outcomes in preterm infants.

METHODS

We conducted a meta-analysis. All relevant literature before November 2022 were retrieved from PubMed, Embase, Cochrane Library Web of Science, CNKI, CBM, Wan fang Data, and VIP Database. According to the inclusion criteria and exclusion criteria, eligible literature were included to conduct clinical trial quality assessment, and the Newcastle-Ottawa scale was used to evaluate the quality of evidence. Meta-analysis was performed using RevMan5.3. Data extraction, quality assessment, and meta-analysis were performed independently by 2 people. Mean difference or standardized mean difference of motor, language and cognitive scores (Bayley III or Bayley II) were used as effect sizes for continuous data analysis, all of which were represented by 95% CI. For heterogeneity (I2 ≥ 50% or P < .10), a random effects model was used, otherwise a fixed effects model was used.

RESULTS

A total of 6 literature were included. The results of the ROP group for motor (comprehensive motor, proportional motor, and fine motor), language and cognitive scores were -5.57 (95%CI, -1.43 to 0.04), -0.95 (95%CI, 1.4-0.50), -1.34 (95% CI, 1.77-0.92), -1.75 (95% CI, 2.26-1.24) and -5.56 (95% CI, 9.56-1.57). Additionally, the results of severe ROP group for motor (comprehensive motor, proportional motor, fine motor), language and cognitive scores were -8.32 (95%CI, -8.91 to 7.74), -1.10 (95%CI, -1.83 to -0.36), -1.08 (95%CI, -1.75 to -0.41), -7.03 (95%CI, -7.71 to 6.35), and -7.96 (95%CI, -8.5 to -7.42).

CONCLUSIONS

The Bayley Scale scores of the ROP group were lower than those of the not ROP group, and the scores of the severe ROP were significantly lower than those of the not severe ROP group. These findings suggest that ROP can indeed delay motor, language and cognitive, especially in severe cases.

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.

IMI-Management and Investigation of High Myopia in Infants and Young Children

Purpose

The purpose of this study was to evaluate the epidemiology, etiology, clinical assessment, investigation, management, and visual consequences of high myopia (≤-6 diopters [D]) in infants and young children.

Findings

High myopia is rare in pre-school children with a prevalence less than 1%. The etiology of myopia in such children is different than in older children, with a high rate of secondary myopia associated with prematurity or genetic causes. The priority following the diagnosis of high myopia in childhood is to determine whether there is an associated medical diagnosis that may be of greater overall importance to the health of the child through a clinical evaluation that targets the commonest features associated with syndromic forms of myopia. Biometric evaluation (including axial length and corneal curvature) is important to distinguishing axial myopia from refractive myopia associated with abnormal development of the anterior segment. Additional investigation includes ocular imaging, electrophysiological tests, genetic testing, and involvement of pediatricians and clinical geneticists is often warranted. Following investigation, optical correction is essential, but this may be more challenging and complex than in older children. Application of myopia control interventions in this group of children requires a case-by-case approach due to the lack of evidence of efficacy and clinical heterogeneity of high myopia in young children.

Conclusions

High myopia in infants and young children is a rare condition with a different pattern of etiology to that seen in older children. The clinical management of such children, in terms of investigation, optical correction, and use of myopia control treatments, is a complex and often multidisciplinary process.

An Update on Anti-Vascular Endothelial Growth Factor Treatment for Retinopathy of Prematurity

Purpose

To present updated information on the role of anti-vascular endothelial growth factor (anti-VEGF) therapy for treating retinopathy of prematurity (ROP).

Methods

We searched through PubMed and Scopus databases using the keywords of this article and gathered relevant published articles from the year 2005 to December 2022. The selected articles were classified and summarized, and reasonable conclusions were made accordingly.

Results

Considering the current evidence, anti-VEGF agents are superior to laser therapy for the initial treatment of type 1 ROP in zone 1 or posterior zone 2. However, there is a substantial risk of reactivation or persistent avascular retina after solo treatment with anti-VEGFs, and many cases may require laser therapy within the following weeks or months. Thus, vigilant follow-up examinations are mandatory.

Conclusions

The role of anti-VEGF agents in the treatment of ROP is indispensable. However, future studies are required to improve indications and dosage and determine long-term ocular and systemic safety.

Intravitreal Bevacizumab Is Associated With Prolonged Ventilatory Support in Preterm Infants With Bronchopulmonary Dysplasia

BACKGROUND

Intravitreal bevacizumab (IVB), an anti-vascular endothelial growth factor (VEGF) antibody, is a widely adopted treatment for retinopathy of prematurity (ROP). Although animal studies have demonstrated that IVB inhibits alveologenesis in neonatal rat lung, the clinical influence of IVB on respiratory outcomes has not been studied.

RESEARCH QUESTION

Does IVB affect the respiratory outcome in preterm infants with bronchopulmonary dysplasia?

STUDY DESIGN AND METHODS

We retrospectively assessed very low birth weight (VLBW) preterm infants admitted to our neonatal ICU between January 2016 and June 2021. Furthermore, we evaluated the short-term respiratory outcomes after IVB therapy in VLBW preterm infants requiring ventilatory support at 36 weeks' postmenstrual age (PMA).

RESULTS

One hundred seventy-four VLBW preterm infants with bronchopulmonary dysplasia were recruited. Eighty-eight infants showed ROP onset before being ventilator free, and 78 infants received a diagnosis of the most severe ROP before being ventilator free. Among them, 32 received a diagnosis with type 1 ROP and received IVB treatment. After adjusting for gestational age, birth body weight, and baseline respiratory status, we discovered that IVB is associated significantly with prolonged ventilatory support and a lower likelihood of becoming ventilator free (hazard ratio, 0.53; P = .03).

INTERPRETATION

IVB may have a short-term respiratory adverse effect in patients requiring ventilatory support at 36 weeks' PMA. Therefore, long-term follow-up for respiratory outcomes may be considered in VLBW infants who receive IVB treatment.

Pulmonary Hypertension in Preterm Infants Treated With Laser vs Anti-Vascular Endothelial Growth Factor Therapy for Retinopathy of Prematurity

Importance

Anti-vascular endothelial growth factor (VEGF) therapy for retinopathy of prematurity (ROP) has potential ocular and systemic advantages compared with laser, but we believe the systemic risks of anti-VEGF therapy in preterm infants are poorly quantified.

Objective

To determine whether there was an association with increased risk of pulmonary hypertension (PH) in preterm infants with ROP following treatment with anti-VEGF therapy as compared with laser treatment.

Design, Setting, and Participants

This multicenter retrospective cohort study took place at neonatal intensive care units of 48 children's hospitals in the US in the Pediatric Health Information System database from 2010 to 2020. Participants included preterm infants with gestational age at birth 22 0/7 to 31 6/7 weeks who had ROP treated with anti-VEGF therapy or laser photocoagulation.

Exposures

Anti-VEGF therapy vs laser photocoagulation.

Main Outcomes and Measures

New receipt of pulmonary vasodilators at least 7 days after ROP therapy was compared between exposure groups, matched using propensity scores generated from preexposure variables, and adjusted for birth year and hospital. The odds of receiving an echocardiogram after 30 days of age was also included to adjust for secular trends and interhospital variation in PH screening.

Results

Among 1577 patients (55.9% male) meeting inclusion criteria, 689 received laser photocoagulation and 888 received anti-VEGF treatment (95% bevacizumab, 5% ranibizumab). Patients were first treated for ROP at median 36.4 weeks' postmenstrual age (IQR, 34.6-38.7). A total of 982 patients (491 in each group) were propensity score matched. Good covariate balance was achieved, as indicated by a model variance ratio of 1.15. More infants who received anti-VEGF therapy were treated for PH, but when adjusted for hospital and year, this was no longer statistically significant (6.7%; 95% CI, 2.6-6.9 vs 4.3% 95% CI, 4.4-10.2; adjusted odds ratio, 1.62; 95% CI, 0.90-2.89; P = .10).

Conclusions and Relevance

Anti-VEGF therapy was not associated with greater use of pulmonary vasodilators after adjustment for hospital and year. Our findings suggest exposure to anti-VEGF may be associated with PH, although we cannot exclude the possibility of residual confounding based on systemic comorbidities or hospital variation in practice. Future studies investigating this possible adverse effect seem warranted.

Effect of ranibizumab on retinopathy of prematurity: A meta-analysis

The primary objective of this study was to systematically evaluate the clinical efficacy of intravitreal ranibizumab injection in the treatment for retinopathy of prematurity (ROP) in infants. The MEDLINE (PubMed), Embase, China Biology Medicine disc, Cochrane Library, Web of Science, WanFang Data, CNKI, and CQVIP databases were searched to collect randomized controlled trials (RCTs) comparing the efficacy of ranibizumab with laser treatment in ROP. The retrieval time was from 2007, on which ranibizumab was approved until 12 January 2022. Data were extracted based on predetermined inclusion and exclusion criteria. Two investigators employed QUADAS-2 to independently assess the quality of all eligible original studies. Following quality evaluation, we also performed a meta-analysis using STATA v 15.1 and RevMan v 5.4 and funnel plots were used to detect publication bias. A total of five RCTs were included in the meta-analysis. In this study, the regression rate of retinal neovascularization was used as the index of therapeutic effectiveness. According to the results, the retinal neovascularization regression rate of the intravitreal ranibizumab injection group was statistically higher than that of the laser therapy group [risk ratio (RR) = 1.26, 95% confidence interval (CI): 1.18–1.35]; however, the incidence of adverse events, including recurrence and complications, was not different between them (RR = 0.73, 95%CI: 0.19–2.80). Therefore, intravitreal ranibizumab injection may be more clinically effective than laser therapy in the treatment for ROP. The safety and efficacy of ranibizumab in the long-term treatment for ROP needs further investigation.

Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, CRD42022296387

Evaluation of segmental scleral buckling surgery for stage 4A retinopathy of prematurity in China

Aims

To describe the long-term effect of scleral buckling (SB) surgery for stage 4A retinopathy of prematurity (ROP).

Methods

A retrospective chart review was conducted for patients with a diagnosis of stage 4A ROP who underwent SB between October 2010 and October 2021. Basic data were collected from patient charts, including gender, birth weight, gestational age at birth, disease stage, presence of plus disease, preoperative treatment [laser photocoagulation, intravitreal anti-vascular endothelial growth factor (VEGF) agent therapy, or a combination of both] and complications (vitreous hemorrhages), postmenstrual age at surgery, intraoperative combined treatment, and total length of follow-up. Retinal attachment status after surgery, postoperative complications (glaucoma, cataract), date and type of subsequent retinal surgeries (if performed), and refractive status 1 year after surgery were evaluated. The follow-up time after the first procedure was over 1 year.

Results

Six-two eyes from forty-eight patients met the inclusion criteria for this study. The initial reattachment rate was 93.5% (58/62 eyes), and the final reattachment rate was 100% after two procedures at the end of follow-up. The incidence of cataracts was 3.2% (2/62), with no eye subsequently needing lensectomy surgery. None of the patients developed glaucoma during the follow-up time. The average spherical equivalent refraction value for patients was −3.00 ± 2.51 D (−7.60 D to +2.75 D) 1 year after surgery.

Conclusion

SB, especially segmental buckling, which induces less myopia and does not require buckle removal, has the potential to provide a significant positive impact in the treatment of stage 4A ROP.

A comparison of primary laser versus laser after anti-vascular endothelial growth factor for type 1 retinopathy of prematurity

PURPOSE

To compare characteristics of laser treatment for high-risk type 1 retinopathy of prematurity (ROP) in eyes treated with primary laser versus laser after an initial treatment with intravitreal anti-vascular endothelial growth factor (anti-VEGF).

METHODS

The medical records of consecutive patients at a single academic institution treated for type 1 ROP before 36 weeks' postmenstrual age with primary laser versus laser after initial treatment with anti-VEGF were reviewed retrospectively. Outcome measures were laser spot number, mean laser power, total laser energy (Joules), and retinal vascularization to the nasal ora at time of laser treatment.

RESULTS

Compared with the 46 eyes treated with primary laser, the 46 eyes treated with laser after anti-VEGF required fewer spots (mean, 775 vs 1418 [P < 0.01]), less power (182 vs 223 mW [P < 0.01]), and less total energy (27 vs 61 Joules [P < 0.01]), and showed greater vascularization to the nasal ora at the time of laser treatment (47.8% vs 6.5% [P < 0.01]).

CONCLUSIONS

In our study cohort, laser after initial anti-VEGF treatment may have allowed for greater retinal vascularization and been less destructive than primary laser for high-risk type 1 ROP.

Neurosensory Alterations in Retinopathy of Prematurity: A Window to Neurological Impairments Associated to Preterm Birth

Retinopathy of prematurity (ROP) is one of the main blinding diseases affecting preterm newborns and is classically considered a vascular disorder. The premature exposure to the extrauterine environment, which is hyperoxic in respect to the intrauterine environment, triggers a cascade of events leading to retinal ischemia which, in turn, makes the retina hypoxic thus setting off angiogenic processes. However, many children with a history of ROP show persistent vision impairment, and there is evidence of an association between ROP and neurosensory disabilities. This is not surprising given the strict relationship between neuronal function and an adequate blood supply. In the present work, we revised literature data evidencing to what extent ROP can be considered a neurodegenerative disease, also taking advantage from data obtained in preclinical models of ROP. The involvement of different retinal cell populations in triggering the neuronal damage in ROP was described along with the neurological outcomes associated to ROP. The situation of ROP in Italy was assessed as well.

Decoupling Oxygen Tension From Retinal Vascularization as a New Perspective for Management of Retinopathy of Prematurity. New Opportunities From β-adrenoceptors

Retinopathy of prematurity (ROP) is an evolutive and potentially blinding eye disease that affects preterm newborns. Unfortunately, until now no conservative therapy of active ROP with proven efficacy is available. Although ROP is a multifactorial disease, premature exposition to oxygen concentrations higher than those intrauterine, represents the initial pathogenetic trigger. The increase of oxygenation in a retina still incompletely vascularized promotes the downregulation of proangiogenic factors and finally the interruption of vascularization (ischemic phase). However, the increasing metabolic requirement of the ischemic retina induces, over the following weeks, a progressive hypoxia that specularly increases the levels of proangiogenic factors finally leading to proliferative retinopathy (proliferative phase). Considering non-modifiable the coupling between oxygen levels and vascularization, so far, neonatologists and ophthalmologists have "played defense", meticulously searching the minimum necessary concentration of oxygen for individual newborns, refining their diagnostic ability, adopting a careful monitoring policy, ready to decisively intervene only in a very advanced stage of disease progression. However, recent advances have demonstrated the possibility to pharmacologically modulate the relationship between oxygen and vascularization, opening thus the perspective for new therapeutic or preventive opportunities. The perspective of a shift from a defensive towards an attack strategy is now at hand.

The emerging role of extracellular vesicles in retinal diseases

As a type of nanosized membranous vesicles secreted by living cells, extracellular vesicles (EVs) mediate intercellular communications with excellent physicochemical stability and biocompatibility. By delivering biologically active molecules including proteins, nucleic acids and lipids, EVs participate in many physiological and pathological processes. Increasing studies have suggested that EVs may be biomarkers for liquid biopsy of retinal diseases due to the ability to transfer through the blood-retinal barrier. EVs also represent a novel cell-free strategy to repair tissue damage in regenerative medicine. Evidence has indicated that EVs can be engineered and modified to enhance their efficacy. In this review, an overview of the characteristics, isolation, and identification of EVs is provided. Moreover, recent advances with EVs in the diagnosis and treatment of retinal diseases and the engineering approaches to elevate their effects are introduced, and opportunities and challenges for clinical application are discussed.

Complications of retinopathy of prematurity treatment

PURPOSE OF REVIEW

The purpose of this review is to summarize complications of treatment for retinopathy of prematurity (ROP) and to compare complications of laser and intravitreal antivascular endothelial growth factor (VEGF) injections.

RECENT FINDINGS

Poor structural outcomes and myopia are more common with laser for severe ROP than with anti-VEGF. Clinical trial data show unfavourable outcomes in 9.1-9.5% of laser treated, and 1.4-3.6% of anti-VEGF treated eyes. Additional randomized trial data show risk for very high myopia (≥-8.00D) to be 3.8 and 51.4% for zone I eyes treated with bevacizumab and laser, respectively. However, anti-VEGF may be complicated by late recurrence and is more likely to require retreatment than laser. Laser often necessitates general anaesthesia with its attendant risks, including worse short-term respiratory outcomes. Neurodevelopmental complications have been reported with anti-VEGF, but existing studies are subject to bias.

SUMMARY

Treatment complications are substantially different for the two modalities in common use today. In more severe cases, risk of poor structural outcome and myopia favour treatment with anti-VEGF. In less severe ROP, risk of recurrence and the need for additional treatments may favour laser. Additional data are needed to establish comparative risks of neurodevelopmental complications.

CM082, a novel VEGF receptor tyrosine kinase inhibitor, can inhibit angiogenesis in vitro and in vivo

The goal of this study was to evaluate the effects of CM082, a novel vascular endothelial growth factor (VEGF) receptor-2 tyrosine kinase inhibitor, on human umbilical vein endothelial cells (HUVECs), and oxygen-induced retinopathy (OIR) mice. HUVECs were stimulated with rHuVEGF165 and then treated with CM082 to assess the antiangiogenic effects of CM082; subsequently, proliferation, wound-healing migration, Transwell invasion, tube formation assays, and Western blotting were performed in vitro. Retinal neovascularization tufts, avascular area, and TUNEL assays were estimated for OIR mice after intraperitoneal injection with CM082. CM082 significantly inhibited proliferation, migration, invasion, and tube formation induced by stimulation of HUVECs with rHuVEGF165; this inhibitory effect was mediated by blocking VEGFR2 activation. CM082 significantly inhibited retinal neovascularization and avascular area and did not increase apoptosis in the retina of OIR mice. The findings demonstrated that CM082 exhibits highly antiangiogenic effects in HUVECs and OIR mice. Thus, it may serve as an alternative treatment for neovascular eye disease in the future.

Systemic conbercept pharmacokinetics and VEGF pharmacodynamics following intravitreal injections of conbercept in patients with retinopathy of prematurity

BACKGROUND

Data on serum vascular endothelial growth factor (VEGF) and drug levels in patients with retinopathy of prematurity (ROP) following intravitreal injections of conbercept (IVC) are lacking.

METHODS

Multicentre, prospective, non-randomised study of patients with aggressive posterior retinopathy of prematurity (APROP) or type 1 ROP who had not received other treatment. All infants received therapy in both eyes plus intravitreal IVC 0.25 mg/0.025 mL in one eye and had at least 6 months of follow-up. Blood samples were collected before and 1 week and 4 weeks after IVC. The main outcome measures were serum conbercept and VEGF concentrations.

RESULTS

Forty infants with APROP or type 1 ROP were enrolled. The mean serum VEGF at baseline and 1 week and 4 weeks after a total of 0.25 mg of IVC was 953.35±311.90 pg/mL, 303.46±181.89 pg/mL and 883.12±303.89 pg/mL, respectively. Serum VEGF 1 week after IVC was significantly lower (p<0.05) than baseline, and at 4 weeks after IVC, it was significantly higher (p<0.05) than at 1 week. There was no significant difference (p>0.05) between baseline and 4 weeks. Serum conbercept was below the limit of quantitation (BLOQ) at baseline and 4 weeks and was 19.81±7.60 ng/mL at 1 week.

CONCLUSION

Serum VEGF 1 week after IVC was significantly lower than baseline but returned to baseline at 4 weeks. Serum conbercept increased at 1 week and was BLOQ at 4 weeks.