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

RhoA/ROCK Signaling Is Involved in Pathological Retinal Neovascularization

OBJECTIVE

The aim of the study was to evaluate the effect of the RhoA/ROCK inhibitor Fasudil on retinal neovascularization (NV) in vivo and angiogenesis in vitro.

METHODS

C57BL/6 was used to establish an OIR model. First, RhoA/ROCK expression was first examined and compared between OIR and healthy controls. Then, we evaluated the effect of Fasudil on pathological retinal NV. Whole-mount retinal staining was performed. The percentage of NV area, the number of neovascular tufts (NVT), and branch points (BP) were quantified. Finally, human umbilical vein endothelial cells (HUVECs) were used to investigate the effect of Fasudil on angiogenesis.

RESULTS

Real-time PCR and Western blotting showed that ROCK expression in retinal tissue was statistically upregulated in OIR. Furthermore, we found that Fasudil attenuated the percentage of NV area, the number of NVT, and BP significantly. In addition, Fasudil could suppress the proliferation and migration of HUVECs induced by VEGF.

CONCLUSIONS

RhoA/ROCK might be involved in the pathogenesis of OIR. And its inhibitor Fasudil could suppress retinal NV in vivo and angiogenesis in vitro. Fasudil may be a potential treatment strategy for retinal vascular diseases.

Twelve-year outcomes of bedside laser photocoagulation for severe retinopathy of prematurity

Purpose

The purpose of this study is to evaluate the 12-year outcomes of bedside laser photocoagulation (LP) for severe retinopathy of prematurity (ROP) under sedation combined with ocular surface anesthesia in neonatal intensive care units (NICU).

Design

The study is a retrospective case series.

Methods

Infants treated with bedside LP for severe ROP from April 2009 to September 2021 were included. All LP treatments were performed under sedation and surface anesthesia at the bedside in NICU. Data were recorded for clinical and demographic characteristics, total laser spots, duration of treatment, proportion of total regression of ROP, proportion of recurrence, and adverse events.

Results

A total of 364 infants (715 eyes) were included, with a mean gestational age of 28.6 ± 2.4 weeks (range: 22.6-36.6 weeks) and a mean birth weight of 1,156.0 ± 339.0 g (range: 480-2,200 g). The mean number of laser spots was 832 ± 469, and the mean duration of treatment was 23.5 ± 5.3 min per eye. Of all the eyes, 98.3% responded to LP with complete regression of ROP. ROP recurred in 15 (2.1%) eyes after the initial LP. Additional LP was performed in seven (1.0%) eyes. No patient exhibited mistaken LP of other ocular tissues, and there were no serious ocular adverse effects. None of them needed endotracheal intubation.

Conclusions

Bedside LP treatment is effective and safe for premature infants with severe ROP under sedation and surface anesthesia in NICU, especially for infants whose general condition is unstable and not suitable for transport.

Role of Anti-Vascular Endothelial Growth Factor (Anti-VEGF) in the Treatment of Retinopathy of Prematurity: A Narrative Review in the Context of Middle-Income Countries

The rise in preterm births and higher survival rates of premature infants have led to a global increase in retinopathy of prematurity (ROP), a vasoproliferative retinal disorder common in premature infants. ROP is one of the leading causes of childhood blindness. Clinical manifestation of ROP ranges from mild abnormal retinal neovascularization to bilateral retinal detachment and vision loss. The incidence of ROP is higher in middle income countries, including India, which has the highest number of global preterm births. Low birth weight and low gestational age are the primary risk factors for ROP; however, anemia, cardiac defects, blood transfusion, apnea, sepsis, respiratory distress syndrome, high exposure to oxygen and poor postnatal weight gain may also contribute to its development. India has stringent ROP screening guidelines revised in 2018, and screening of infants with either birth weight <2000 grams or gestational age <34 weeks is mandated. With an improved understanding of the pathogenesis of ROP in the past decades and advances in clinical research, treatment for ROP has evolved from cryotherapy to laser retinal ablation. Most recently, anti-vascular endothelial growth factor (anti-VEGF) drugs have emerged as a favorable treatment option for zone-I and II ROP. This article reviews the current approaches for ROP treatment in India with a particular focus on anti-VEGF drugs. The article also integrates the understanding of safety and risk-benefit evaluation of the current approaches in ROP management. The review concluded that there is a need to increase the ROP screening not only for preterm and low birth weight but also for optimal gestational age infants with healthy birth weight. Anti-VEGF therapies have shown improved efficacy, although studies are required to establish the long-term safety.

[Telemedical support of feto-neonatal care in one region - Part II: Structural requirements and areas of application in neonatology]

Telemedical infrastructure for patient assessment, care and follow-up as well as interdisciplinary exchange can contribute to ensuring patient care that is close to home and meets the highest quality standards, even outside specialised centres. In neonatology, synchronous audio-visual communication across institutions has been used for many years, especially in the Anglo-American countries. Areas of application include extended neonatal primary care and resuscitation, specific diagnostic applications, e.g. ROP screening and echocardiography, as well as parental care, regular telemedical ward rounds and further training of medical staff, especially using simulation training. For the implementation of such telemedical infrastructures, certain organisational, medical-legal and technical requirements for hardware, software and structural and process organisation must be met. The concrete realisation of a telemedical infrastructure currently being implemented for the region of Eastern Saxony is demonstrated here using the example of the Saxony Center for feto/neonatal Health (SCFNH). Within the framework of feto-neonatal competence networks such as the SCFNH, the quality of medical care, patient safety and satisfaction in a region can be increased by means of a comprehensive, well-structured and established telemedical infrastructure.

Applying Lucentis for the treatment of retinopathy of prematurity

Purpose: to evaluate the efficacy of Lucentis for the treatment of retinopathy of prematurity (ROP). Material and methods. 51 infants (102 eyes) with the gestational age between 24 and 33 weeks were given intravitreal injections of Lucentis, All patients selected had ROP stages I+, II+, III or III+ in zone 1, stage III+ in zone 2, or aggressive posterior ROP. The procedure was performed under general anesthesia; the dose, technique and the number of Lucentis injections conformed with the recommendations given in Lucentis instruction for use. If indicated, retinal laser photocoagulation was given after intravitreal injections using Supra (Quantel Medical, France) and Lachta-Mylon (Russia, Lasermedservis) laser equipment. Results. Clinical efficacy of intravitreal administration of Ranibizumab in infants with aggressive posterior ROP, zone 1 ROP, Stage III of zone 2 ROP was determined at 86.3 % (with no more than two injections). If ROP remains active after two injections, a change of therapy is recommended. Vascularization was noted to be complete in 51 % of cases. Conclusion. To achieve a maximum treatment effect of ROP with Lucentis, strict observation of indications criteria must take place.

Lysophosphatidylcholine Offsets the Protective Effects of Bone Marrow Mesenchymal Stem Cells on Inflammatory Response and Oxidative Stress Injury of Retinal Endothelial Cells via TLR4/NF-κB Signaling

Diabetic retinopathy (DR), as a major cause of blindness worldwide, is one common complication of diabetes mellitus. Inflammatory response and oxidative stress injury of endothelial cells play significant roles in the pathogenesis of DR. The study is aimed at investigating the effects of lysophosphatidylcholine (LPC) on the dysfunction of high glucose- (HG-) treated human retinal microvascular endothelial cells (HRMECs) after being cocultured with bone marrow mesenchymal stem cells (BMSCs) and the underlying regulatory mechanism. Coculture of BMSCs and HRMECs was performed in transwell chambers. The activities of antioxidant-related enzymes and molecules of oxidative stress injury and the contents of inflammatory cytokines were measured by ELISA. Flow cytometry analyzed the apoptosis of treated HRMECs. HRMECs were further treated with 10-50 μg/ml LPC to investigate the effect of LPC on the dysfunction of HRMECs. Western blotting was conducted to evaluate levels of TLR4 and p-NF-κB proteins. We found that BMSCs alleviated HG-induced inflammatory response and oxidative stress injury of HRMECs. Importantly, LPC offsets the protective effects of BMSCs on inflammatory response and oxidative stress injury of HRMECs. Furthermore, LPC upregulated the protein levels of TLR4 and p-NF-κB, activating the TLR4/NF-κB signaling pathway. Overall, our study demonstrated that LPC offsets the protective effects of BMSCs on inflammatory response and oxidative stress injury of HRMECs via TLR4/NF-κB signaling.

Galectins in the Pathogenesis of Common Retinal Disease

Diseases of the retina are major causes of visual impairment and blindness in developed countries and, due to an ageing population, their prevalence is continually rising. The lack of effective therapies and the limitations of those currently in use highlight the importance of continued research into the pathogenesis of these diseases. Vascular endothelial growth factor (VEGF) plays a major role in driving vascular dysfunction in retinal disease and has therefore become a key therapeutic target. Recent evidence also points to a potentially similarly important role of galectins, a family of β-galactoside-binding proteins. Indeed, they have been implicated in regulating fundamental processes, including vascular hyperpermeability, angiogenesis, neuroinflammation, and oxidative stress, all of which also play a prominent role in retinopathies. Here, we review direct evidence for pathological roles of galectins in retinal disease. In addition, we extrapolate potential roles of galectins in the retina from evidence in cancer, immune and neuro-biology. We conclude that there is value in increasing understanding of galectin function in retinal biology, in particular in the context of the retinal vasculature and microglia. With greater insight, recent clinical developments of galectin-targeting drugs could potentially also be of benefit to the clinical management of many blinding diseases.

Mesenchymal stem cell-derived secretomes for therapeutic potential of premature infant diseases

Preterm birth is a complex syndrome and remains a substantial public health problem globally. Its common complications include periventricular leukomalacia (PVL), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC) and retinopathy of prematurity (ROP). Despite great advances in the comprehension of the pathogenesis and improvements in neonatal intensive care and associated medicine, preterm birth-related diseases remain essentially without adequate treatment and can lead to high morbidity and mortality. The therapeutic potential of mesenchymal stem/stromal cells (MSCs) appears promising as evidenced by their efficacy in preclinical models of pathologies relevant to premature infant complications. MSC-based therapeutic efficacy is closely associated with MSC secretomes and a subsequent paracrine action response to tissue injuries, which are complex and abundant in response to the local microenvironment. In the current review, we summarize the paracrine mechanisms of MSC secretomes underlying diverse preterm birth-related diseases, including PVL, BPD, NEC and ROP, are summarized, and focus is placed on MSC-conditioned media (CM) and MSC-derived extracellular vesicles (EVs) as key mediators of modulatory action, thereby providing new insights for future therapies in newborn medicine.

Refractive outcomes after intravitreal injection of antivascular endothelial growth factor versus laser photocoagulation for retinopathy of prematurity: a meta-analysis

OBJECTIVE

To determine the effects of the intraocular injection of antivascular endothelial growth factor (anti-VEGF) drugs on the refractive status of infants with retinopathy of prematurity (ROP).

DESIGN

Systematic review and meta-analysis of the refractive status of infants with ROP who receive anti-VEGF drugs.

DATA SOURCES

The PubMed, Web of Science and Embase databases and the ClinicalTrials.gov website were searched up to June 2020.

ELIGIBILITY CRITERIA WHEN SELECTING STUDIES

We included randomised controlled trials (RCTs) and observational studies that compared refractive errors between anti-VEGF drug and laser therapies.

DATA EXTRACTION AND SYNTHESIS

Data extraction and risk-of-bias assessments were conducted by two independent reviewers. We used a random-effect model to pool outcomes. The outcome measures were the spherical equivalents, axial length (AL), anterior chamber depth (ACD) and lens thickness (LT).

RESULTS

Thirteen studies involving 1850 eyes were assessed: 914 in the anti-VEGF drug group, and 936 in the control (laser) group. Children who received anti-VEGF drug treatment had less myopia than those who received laser therapy (mean difference=1.80 D, 95% CI 0.97 to 2.63, p＜0.0001, I²=78%). The AL, ACD and LT did not reach statistical significance difference between the two groups. The current evidence indicates that the refractive safety in children with ROP is better for anti-VEGF drug treatment than for laser therapy.

CONCLUSIONS

This meta-analysis indicates that anti-VEGF drug therapy results in less myopia compared with laser therapy. However, there are relatively few published articles on refractive errors in ROP, and so high-quality and powerful RCTs are needed in the future.

PROSPERO REGISTRATION NUMBER

CRD42020160673.

Neovascular Macular Degeneration: A Review of Etiology, Risk Factors, and Recent Advances in Research and Therapy

Neovascular age-related macular degeneration (exudative or wet AMD) is a prevalent, progressive retinal degenerative macular disease that is characterized by neovascularization of the choroid, mainly affecting the elderly population causing gradual vision impairment. Risk factors such as age, race, genetics, iris color, smoking, drinking, BMI, and diet all play a part in nvAMD's progression, with anti-vascular endothelial growth factor (anti-VEGF) therapy being the mainstay of treatment. Current therapeutic advancements slow the progression of the disease but do not cure or reverse its course. Newer therapies such as gene therapies, Rho-kinase inhibitors, and levodopa offer potential new targets for treatment.

Oxidative Stress Markers and the Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a leading cause of potentially preventable blindness in low birth weight preterm infants. Several perinatal and postnatal factors contribute to the incomplete maturation of retinal vascularization, leading to oxidative stress damage. Literature data suggest that the lack of equilibrium between pro-oxidants and anti-oxidants plays a key role. In the last decade, there has been an increasing interest in identifying the antecedents of ROP and the relevant pathogenic mechanisms involved. In this context, a panel of biomarkers was investigated in order to achieve early detection of oxidative stress occurrence and to prevent retinal damage. Several nutritional elements have been found to play a relevant role in ROP prevention. At this stage, no conclusive data have been shown to support the usefulness of one biomarker over another. Recently, the Food and Drugs Administration, the European Medicine Agency, and the National Institute of Health proposed a series of criteria in order to promote the inclusion of new biomarkers in perinatal clinical guidelines and daily practice. The aim of the present review is to offer an update on a panel of biomarkers, currently investigated as potential predictors of ROP, highlighting their strengths and weaknesses.

Exosomes from Microglia Attenuate Photoreceptor Injury and Neovascularization in an Animal Model of Retinopathy of Prematurity

The role of microglia in the pathophysiology of ischemic retinal diseases has been studied extensively. Exosomes from microglial cells exert protective effects during several nervous system diseases, but their roles in hypoxia-induced retinopathy remain unclear. In our study, exosomes derived from microglial cells were injected into the vitreous body of mice with oxygen-induced retinopathy (OIR). Results showed that exosome-treated OIR mice exhibited smaller avascular areas and fewer neovascular tufts in addition to decreased vascular endothelial growth factor (VEGF) and transforming growth factor β (TGF-β) expression. Moreover, photoreceptor apoptosis was suppressed by exosome injection. Mechanistically, exosomes from microglial cells were incorporated into photoreceptors in vitro and inhibited the inositol-requiring enzyme 1α (IRE1α)-X-box binding protein 1 (XBP1) cascade, which contributes to hypoxia-induced photoreceptor apoptosis. Furthermore, the exosomes also downregulated the mRNA and protein levels of VEGF and TGF-β in hypoxia-exposed photoreceptors. A microRNA assay showed that microRNA-24-3p (miR-24-3p) levels were extremely high in exosomes from microglial cells, suggesting that this could be the key molecule that inhibits the hypoxia-induced expression of IRE1α in photoreceptors. These findings delineate a novel exosome-mediated mechanism of microglial cell-photoreceptor crosstalk that facilitates normal angiogenesis and visual function in OIR mice; thus, our results also suggest a potential therapeutic approach for retinopathy of prematurity.

Effects of LY294002 on the function of retinal endothelial cell in vitro

AIM

To study the effects of LY294002 [phosphatidylinositol 3-kinase (PI3K) inhibitor] on the function and mechanisms of retinal endothelial cells (RECs) in vitro.

METHODS

RECs were randomly divided into control group and LY294002 treatment group. RECs in the control group were placed the incubator for hypoxic exposure in vitro. RECs in the LY294002 treatment group were pretreated with LY294002 (40 µmol/L) under hypoxic condition. The expression of matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial growth factor (VEGF), and apoptosis and proliferation of RECs were evaluated with Western blot, real-time reverse transcription-polymerase chain reaction (RT-PCR), and flow cytometric analysis, correspondently.

RESULTS

Compared with the control group, treating the RECs with LY294002 was able to remarkably inhibit cell proliferation rates (t_1d=2.13, t_2d=2.65, t_3d=2.36, t_4d=2.06, all P<0.05). Flow cytometric analysis indicated that a moderate increase in apoptosis in the LY294002 treatment group compared to the control group (t=2.51, P<0.05). The expression of MMP-2, MMP-9 and VEGF were downregulated in the LY294002 treatment group by Western blot and real-time RT-PCR (all P<0.05).

CONCLUSION

LY294002 regulates the function of RECs by reducing the expression of MMP-2, MMP-9, and VEGF in vitro. LY294002 may provide an effective method for preventing pathological angiogenesis.