Recent advancements in diabetic retinopathy treatment from the Diabetic Retinopathy Clinical Research Network

The role of inflammation in immune system of diabetic retinopathy: Molecular mechanisms, pathogenetic role and therapeutic implications

Diabetic retinopathy is one of the most common complications of diabetes mellitus and the leading cause of low vision and blindness worldwide. Mounting evidence demonstrates that inflammation is a key mechanism driving diabetes-associated retinal disturbance, yet the pathophysiological process and molecular mechanisms of inflammation underlying diabetic retinopathy are not fully understood. Cytokines, chemokines, and adhesion molecules interact with each other to form a complex molecular network that propagates the inflammatory and pathological cascade of diabetic retinopathy. Therefore, it is important to understand and elucidate inflammation-related mechanisms behind diabetic retinopathy progression. Here, we review the current understanding of the pathology and pathogenesis of inflammation in diabetic retinopathy. In addition, we also summarize the relevant clinical trials to further suggest inflammation-targeted therapeutics for prevention and management of diabetic retinopathy.

Proteomic changes of aqueous humor in proliferative diabetic retinopathy patients treated with different intravitreal anti-VEGF agents

Anti-VEGF-based treatment have been regularly used in recent years in proliferative diabetic retinopathy (PDR) patients. However, some of these patients fail to respond effectively to anti-VEGF. Given that VEGF is not the sole factor influencing PDR pathogenesis and that different anti-VEGF pharmaceuticals are likely to differentially impact these underlying pathophysiological processes, we performed a prospective analysis of the protein profiles of the aqueous humor (AH) in PDR patients before and after treatment with three intravitreal anti-VEGF drugs (ranibizumab, aflibercept, and conbercept) to assess and compare the short-term impacts of these agents. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomic methods were used to evaluate the AH protein profiles of PDR patients using paired pre- and 7 days post-anti-VEGF treatment samples (ranibizumab [IVR]: n = 10; conbercept [IVC]: n = 10; aflibercept [IVA]: n = 5). Gene ontology (GO) annotation, KEGG pathway analyses, and protein-protein interaction (PPI) networks were then used to explore the functional relevance of proteins that were differentially expressed between groups. Here, a total of 874 proteins from 25 patients (50 AH samples) were identified in the three patient groups. Different and common clusters of regulated proteins for each group were identified. We identified RARRES1, ALDH3A1, and RBP4 as being specifically regulated following treatment with all three tested anti-VEGF agents. We further found that VEGFR1, VEGFR2, APOM, hornerin, and HSP90B1 were differentially expressed in different anti-VEGF agent groups. In summary, we discovered that ALDH3A1 was a previously unreported protein that was related to angiogenesis and was differentially expressed in the three anti-VEGF treatment groups, suggesting that it may be a new target for PDR therapy. The described proteomic changes in the AH of PDR patients treated with different anti-VEGF agents provide novel targets which may explain the heterogeneity of anti-VEGF treatment responses in these patients, providing a robust foundation for future studies of PDR pathogenesis.

Application of 5G Technology to Conduct Real-Time Teleretinal Laser Photocoagulation for the Treatment of Diabetic Retinopathy

Question

How feasible is fifth-generation (5G) real-time telemedicine-mediated laser photocoagulation as a treatment for diabetic retinopathy?

Findings

In this study, a retinal specialist in Beijing, China, performed an online 5G real-time navigated retinal laser photocoagulation procedure on 6 participants (9 eyes) with diabetic retinopathy located in Huzhou, China. All procedures were able to be completed without noticeable delay, and no safety issues were identified.

Meaning

The combination of a 5G high-speed network and navigated retinal laser photocoagulation may enable a novel teleophthalmology paradigm that can provide essential remote health care to patients with diabetic retinopathy.

Importance

Interest in teleophthalmology has been growing, especially during the COVID-19 pandemic. The advent of fifth-generation (5G) wireless systems has the potential to revolutionize teleophthalmology, but these systems have not previously been leveraged to conduct therapeutic telemedicine in the ophthalmology field.

Objective

To assess the feasibility of 5G real-time laser photocoagulation as a telemedicine-based treatment for diabetic retinopathy (DR).

Design, Setting, and Participants

This was a prospective study involving a retinal specialist from the Peking Union Medical College Hospital in Beijing, China, who performed online 5G real-time navigated retinal laser photocoagulation to treat participants with proliferative or severe nonproliferative DR who had been recruited in the Huzhou First People’s Hospital in Zhejiang Province, China, located 1200 km from Beijing from October 2019 to July 2020.

Interventions

These teleretinal DR and laser management procedures were conducted using a teleophthalmology platform that used the videoconference platform for teleconsultation, after which telelaser planning and intervention were conducted with a laser system and a platform for remote computer control, which were connected via 5G networks.

Main Outcomes and Measures

Diabetic eye prognosis and the real-time laser therapy transmission speed were evaluated.

Results

A total of 6 participants (9 eyes) were included. Six eyes were treated via panretinal photocoagulation alone, while 1 eye underwent focal/grid photocoagulation and 2 eyes underwent both panretinal photocoagulation and focal/grid photocoagulation. The mean (SD) age was 53.7 (13.6) years (range, 32-67 years). The mean (SD) duration of diabetes was 14.3 (6.4) years (range, 3-20 years). The mean (SD) logMAR at baseline was 0.32 (0.20) (20/30 Snellen equivalent). Retinal telephotocoagulation operations were performed on all eyes without any noticeable delay during treatment. The mean (SD) number of panretinal photocoagulation laser spots per eye in 1 session was 913 (243).

Conclusions and Relevance

This study introduces a novel teleophthalmology paradigm to treat DR at a distance. Applying novel technologies may continue to ensure that remote patients with DR and other conditions have access to essential health care. Further studies will be needed to compare this approach with the current standard of care to determine whether visual acuity or safety outcomes differ.

Stability study over time of clinical solutions of ziv-aflibercept prepared in infusion bags using a proper combination of physicochemical and functional strategies

A range of biopharmaceutical products are used to target Vascular Endothelial Growth Factor (VEGF), including Eylea® (aflibercept, AFL) and Zaltrap® (ziv-aflibercept, ziv-AFL). The first is indicated for ophthalmological diseases such as neovascular (wet) age-related macular degeneration, while the second is used in the treatment of metastatic colorectal cancer. The stability of AFL in prefilled syringes has been widely studied; however, no research has yet been done on the stability of ziv-AFL in polyolefin infusion bags. Therefore, the purpose of the present research is to evaluate the stability of ziv-AFL (Zaltrap®) clinical solutions prepared under aseptic conditions in polyolefin infusion bags at two different concentrations, i.e. 4.0 and 0.6 mg/mL, and stored refrigerated in darkness at 2-8 °C for 14 days. With that aim, the ziv-AFL clinical solutions were assessed by analysing changes in its physicochemical and functional properties. The distribution of the particulates was studied over a range of 0.001-10 μm by Dynamic Light Scattering (DLS); oligomers were analysed by Size-Exclusion High-Performance Chromatography with Diode Array Detection (SE/HLPC-DAD); the secondary structure of the protein was studied by far UV Circular Dichroism (CD) and the tertiary structure by Intrinsic Tryptophan Fluorescence (IT-F) and Intrinsic Protein Fluorescence (IP-F); charge variants were assessed by Strong Cation Exchange Ultra-High-Performance Chromatography with UV detection (SCX/UHPLC-UV); functionality was evaluated by ELISA by measuring the biological activity as manifested in the extension of the immunological reaction of the ziv-AFL with its antigen (VEGF). Neither aggregation nor oligomerization were detected by the techniques mentioned above. Secondary and tertiary structures remained unchanged over the 14-day period, as did charge variants. The functionality observed initially was maintained along time. Therefore, it could be proposed that the ziv-AFL clinical solutions studied showed great physicochemical and functional stability over a period of two weeks, regardless of the concentration, i.e. 4 or 0.6 mg/mL.

Efficacy and Safety of TangWang Prescription for Type 2 Non-Proliferative Diabetic Retinopathy: A Study Protocol for a Randomized Controlled Trial

Background: Diabetic retinopathy (DR) is one of the most common and severe microvascular complications of diabetes mellitus (DM), which results in blindness among adults worldwide. Presently, the efficacy of drug treatments for diabetic retinopathy (DR) is not satisfactory, thus urgently necessitating effective drug treatment measures. TangWang prescription (TWP) has been found to have retinal protection effects in previous clinical and basic research. However, there is a lack of rigorous, randomized, and controlled studies. This study aims to evaluate the efficacy and safety of TWP in delaying the development of DR.

Methods: This study is a randomized, double-blind, placebo-controlled, parallel-group, multicenter clinical trial, consisting of 384 participants to be randomized in a 1:1 ratio in the treatment and control groups. Furthermore, the treatment and control groups will be administered the TangWang prescription and the placebo, respectively, each at a dose of one bag twice a day. The study period will last for 48 weeks. The primary outcome measure will be the changes in the degree of retinal microvascular lesions before and after treatment. The secondary outcome will be changes in the degree of hemangioma, microvascular bleeding, microvascular leakage, macular edema, and vision. All statistical tests will be two-sided, and a p < 0.05 will be considered statistically significant.

Discussion: We hypothesize that the patients with DR will benefit from TangWang prescription, and in addition to the central random system and platform of dynamic information collection, the patients’ conditions will be monitored, and the data collected for analysis. If successful, this study will provide evidence that the TWP formulation delays in the progression of DR.

Trial registration: The design of this trial has been registered with the ClinicalTrials.gov (NCT03025399).

Predictors for 2-Year Functional and Morphological Outcomes of a Treat-and-Extend Regimen with Ranibizumab in Patients with Diabetic Macular Edema

PURPOSE

The purpose of the study was to investigate longer term functional and morphological outcomes and their predictors in diabetic macular edema (DME) following a treat-and-extend regimen (TER) without loading dose under ranibizumab.

METHODS

Patient data were reviewed and analyzed retrospectively over a period of 24 months after initiation of TER. Best-corrected visual acuity (BCVA), treatment frequency, and quantitative and qualitative spectral-domain optical coherence tomography parameters were assessed.

RESULTS

118 eyes of 87 patients were included. A mean of 9.74 ± 2.13 injections in the first and 7.63 ± 2.29 in the second year were applied. There were significant gains of BCVA and reductions in central retinal thickness from baseline to 12 and 24 months (all p < 0.001). Percentage of eyes with an intact inner segment/outer segment (IS/OS) junction increased from 15.3% at baseline to 42.1% at 24 months (p < 0.001). An intact IS/OS junction at baseline increased the probability of having a dry retina after 12 months by 79.3% (p = 0.017) and after 24 months by 88.1% (p = 0.040). Less IS/OS disruption at baseline predicted longer maximum recurrence-free treatment intervals at 2 years (r = -0.345, p < 0.001) and better BCVA at 1 year (r = -0.347, p < 0.001). Baseline bigger intraretinal cysts were associated with more IS/OS disruption at 24 months (r = 0.305, p = 0.007). Younger age and lower BCVA at baseline were predictive for a higher BCVA gain at 24 months (p = 0.046, p < 0.001).

CONCLUSION

Ranibizumab applied in a TER without loading dose in DME significantly improves visual acuity and retinal anatomical structure throughout 2 years. The evaluated predictors might help guide routine clinical treatment in DME.

Clinical Characteristics, Preventive Care and Attitude to Telemedicine among Patients with Diabetic Retinopathy: A Cross-Sectional Study

Diabetic retinopathy (DR) is the most frequent and one of the most severe complications of both types of diabetes. Despite the development of versatile diabetes management programs in most developed countries, many patients remain at increased risk for developing this life-limiting and life-threatening condition. This cross-sectional analysis objective was to examine and compare the prevalence of diabetic retinopathy and comorbidities, as well as the clinical characteristics, prevention patterns, and attitude to telemedicine in patients with diabetes. We found that, when compared to the non-DR group, patients with DR significantly more often utilize clinical preventive services and counseling; however, there is still a significant gap in the receipt of preventative care. Moreover, in the DR subgroup, inadequate diabetic control and the presence of various signs and symptoms of diseases were observed. Although less than a fifth of all patients use mobile applications to monitor their health status, the patients indicate their willingness to use telemedical technology, particularly if it is recommended by the physician and provided without additional costs. The evolution of telemedicine offers a possibility of inexpensive, continuous monitoring of the disease that could improve treatment outcomes. Our observations emphasize DR's perception as a complex disease in which education and continuous monitoring, particularly with telemedicine methods, are critical for further improvement in chronic care.

Clinical features of ocular toxocariasis: a comparison between ultra-wide-field and conventional camera imaging

PURPOSE

The purpose of this study is to compare the lesion detection rates of ocular toxocariasis (OT) between ultra-wide-field scanning laser ophthalmoscopy (UWF-SLO) and conventional fundus photography (CFP), and to evaluate the potential diagnostic ability of UWF-SLO in OT.

METHODS

A total of 56 patients with serological/immunological confirmed unilateral OT were enrolled. The presence of OT characteristic features included the posterior granuloma (postG), peripheral granuloma (periG), tractional retinal detachment (TRD), retinal folds (RF), and vitreous strands (VS) and was analyzed in 36 patients with UWF-SLO and 56 patients with CFP. Diagnostic tests were employed using the clinical examination as gold standard.

RESULTS

In total of the 56 OT eyes, granulomas were identified in 91.1% (51/56) of eyes, including postG in 46.4% (26/56) of eyes, periG in 41.1% (23/56) of eyes, and combined granulomas in 3.6% (2/56) of eyes. TRD, RF, and VS were found in 28.6% (16/56), 51.8% (29/56), and 83.9% (47/56) of patients, respectively. Although the specificities of the diagnosis in clinical features were similar by the diagnostic tests, the sensitivities of postG, periG, TRD, RF, and VS using UWF-SLO were 100%, 100%, 66.7%, 95%, and 81.8%, respectively, which were significantly higher those of CFP (72.2%, 31.3%, 11.1%, 55%, and 48.5%). Additionally, the extent of vitreous haze was milder graded by UWF-SLO compared to CFP (p = 0.0099).

CONCLUSIONS

The diagnostic ability of UWF-SLO was superior to CFP using clinical examination as gold standard for the ascertainment of the characteristic manifestations of OT, especially for granulomas and RF.

Intravitreal conbercept improves outcome of proliferative diabetic retinopathy through inhibiting inflammation and oxidative stress

Conbercept is a newly-developed anti-vascular endothelial growth factor (VEGF) drug. This study aimed to evaluate the effects of conbercept on inflammation and oxidative response in proliferative diabetic retinopathy (PDR). Morphology changes in retinal microvasculature of PDR patients were determined by optical coherence tomographic angiography (OCTA). The mice were injected with streptozocin (STZ) for 20 weeks to induced PDR, then the changes in inflammatory factors, oxidative response and histological analysis were examined with Elisa assay, real time-PCR and commercial kits analysis. Conbercept treatment significantly alleviated the retinal pathological changes and significantly reduced intercellular cell adhesion molecule-1 (ICAM-1), macrophage inflammatory protein-1 (MIP-1), IL-1β, IL-6 and TNF-α protein levels but not prostaglandin E1 (PGE1), prostaglandin E2 (PGE2) and prostaglandin F2a (PGF2a) levels, all of which were remarkably elevated in aqueous fluid of PDR patients compared with non-PDR subjects. Meanwhile the inhibitory effects of conbercept on these inflammatory factors were proved by RT-PCR assays in mice experiments. And the inflammatory signal such as p-IKBα and p-p65 was correspondingly inhibited by conbercept in STZ-treated mice. Conbercept treatment significantly elevated the aqueous glutathione level of PDR patients and inhibited NOX-1, NOX-4 and ph22phox mRNA expressions and ROS production of PDR mice. Ki67 immunofluorescence staining showed that conbercept inhibited endothelial cell proliferation in retina of PDR mice. In conclusion, conbercept significantly inhibited the angiogenesis, inflammation and oxidative response in PDR mice, and these findings further reveals the molecular mechanisms of conbercept in treating PDR.

NEI-Supported Age-Related Macular Degeneration Research: Past, Present, and Future

Purpose

To review past and current National Eye Institute (NEI)–supported age-related macular degeneration (AMD) activities and initiatives and preview upcoming coordinated efforts for studying AMD.

Methods

We conducted and summarized a portfolio analysis and literature review of NEI intramural and extramural AMD activities.

Results

The NEI supports a broad range of AMD research, both by individual independent investigators as well as through networks and consortia. The International AMD Genomics Consortium, Age-Related Eye Disease Study, Age-Related Eye Disease Study 2 (AREDS2), and Comparison of AMD Treatments Trial legacy work probed the complex genetics, clinical presentation, and standards of patient care, respectively. The NEI AMD Pathobiology Working Group identified gaps and opportunities for future research efforts. The AMD Ryan Initiative Study and clinical trials testing the efficacies of minocycline to modulate retinal microglia activity and induced pluripotent stem cells–derived retinal pigmented epithelium (RPE) patch implants to rescue photoreceptor cell death are among the future directions for NEI-supported AMD research. Finally, NEI commissioned the creation of AREDS2 participant-derived induced pluripotent stem cell (iPSC) lines linked to their associated genomic and phenotypic datasets. These datasets will also be linked to the data obtained using their associated iPSC-derived cells (RPE, retina, choroid) and made publicly available.

Conclusions

Investments by NEI for AMD research will continue to provide invaluable resources to investigators committed to addressing this complex blinding disease and other retinal degenerative diseases.

Translational Relevance

NEI now stands poised to expand the resources available to clinical investigators to uncover disease mechanisms and move experimental therapies into clinical trials.

Choroidal Thickness After Dexamethasone Implant or Aflibercept in Patients with Diabetic Macular Edema Persistent to Ranibizumab

Purpose: This study aims to compare subfoveal choroidal thicknesses (SFCTs) after intravitreal dexamethasone (IVD) or intravitreal aflibercept (IVA) treatment in patients with persistent diabetic macular edema (DME) unresponsive to intravitreal ranibizumab (IVR). Methods: The study consisted of patients with DME unresponsive to IVR treatment in which 37 were administered 1 dose IVD (group A) and 34 patients who were administered 3 doses of IVA (group B), as well as 35 healthy individuals (group C). Detailed ophthalmological examination and optical coherence tomography parameters of group A and group B, including central retinal thickness and SFCT, were retrospectively evaluated before and after treatment. Results from preinjection, and 1, 2, and 3 months after injection were analyzed. Results of group A and group B were compared within themselves and also compared with group C. Results: SFCT measurements were compared within group A and group B (1 = preinjection; 2 = 1 month postinjection; 3 = 2 months postinjection; 4 = 3 months postinjection). There was significant thinning in SFCT between 1-2, 1-3, 1-4, 2-3, 2-4, and 3-4 time intervals within both group A and group B (both P < 0.001). Comparison of SFCT measurements showed preinjection, 1-, and 2-month values of group A were significantly thicker than those of group C (P < 0.001), whereas there was no significant difference between 3-month values (P = 0.09). Preinjection, 1-, and 2-month values of group B were significantly thicker than those of group C (P < 0.001), whereas there was no significant difference between 3-month values (P = 0.06). Conclusions: Three month follow-up showed thinning in SFCT measurements in patients with persistent DME unresponsive to IVR who were applied IVD or IVA treatment.

Rebound Phenomenon after Intravitreal Injection of Triamcinolone Acetonide for Macular Edema

INTRODUCTION

The aim of this article was to report on a rebound phenomenon after intravitreal triamcinolone acetonide (IVTA) injection for macular edema secondary to diabetic retinopathy (DR) and central or branch retinal vein occlusion (CRVO/BRVO).

METHODS

The data were analyzed retrospectively. Complete ophthalmic examinations, including spectral domain optical coherence tomography, were performed before and 2 months after IVTA injection. The incidence of a rebound phenomenon was defined as an increase in central retinal thickness of >10% from baseline at 2 months after IVTA injection.

RESULTS

This retrospective study included 211 consecutive patients (268 eyes). One hundred ninety (71.2%), 39 (14.6%), and 39 (14.6%) eyes had macular edema (ME) due to DR, CRVO, and BRVO. In total, 9.7% of the eyes showed a rebound phenomenon (DR: 9.5%, CRVO: 5.2%, BRVO: 15.4%). The mean number of prior injections of vascular endothelial growth factor inhibitor or corticosteroid agent was statistically significantly higher in the rebound group (6.8 vs. 5.3) than in the nonrebound group (p = 0.01).

CONCLUSION

Our study shows that 9.7% of the eyes with ME secondary to DR and RVO developed a rebound phenomenon following IVTA injection, limiting its therapeutic effect. We found an increased number of prior intravitreal pharmacotherapy to be a risk factor for a rebound phenomenon.

Comparison of aqueous humor levels of PlGF and VEGF in proliferative diabetic retinopathy before and after intravitreal conbercept injection

AIMS

The aim of this paper is to observe the change of aqueous humor levels of placenta growth factor (PlGF) and vascular endothelial growth factor (VEGF) in proliferative diabetic retinopathy (PDR) patients before and one week after intravitreal conbercept injection.

METHODS

A prospective case series study was conducted in 24 active PDR patients (24 eyes). All the patients had received 0.5 mg of intravitreal conbercept followed by vitrectomy one week later. The aqueous humor was collected before conbercept injection and at the beginning of vitrectomy.

RESULTS

Before conbercept injection, the aqueous humor median levels of VEGF-A, VEGF-B and PlGF were457.0pg/mL(IQRfrom392.9to860.6pg/mL), 43.6pg/mL(IQRfrom33.6to81.6pg/mL), 37.5pg/mL(IQRfrom25.0to53.6pg/mL), respectively. One week after conbercept injection, the aqueous humor levels of VEGF-A, VEGF-B and PiGF decreased significantly. The aqueous humor VEGF-A levels in PDR patients with fibrovascular membranes were lower than those without them. There was positive correlation between aqueous humor VEGF-B and PiGF levels (P = 0.007). No significant correlation was found between VEGF-A and PiGF levels. No ocular and systemic adverse events were observed.

CONCLUSIONS

The aqueous humor levels of PlGF was correlated with VEGF-B, and levels of VEGF-A, VEGF-B, and PlGF decreased after intravitreal conbercept injection in active PDR patients.

Comprehensive biophysical and functional study of ziv-aflibercept: characterization and forced degradation

Aflibercept (AFL) is an Fc fusion protein used in the treatment of colorectal cancers and different ophthalmological diseases. There are two medicines in which AFL is the active substance: Zaltrap and Eylea, referred as ziv-AFL and AFL respectively. No proper accelerated degradation studies were published on either AFL or ziv-AFL. These studies are essential during research, development and manufacturing stages. Here, we characterized ziv-AFL and submitted it to different stress conditions: light, 60 °C, freeze-thaw cycles, changes in pH, high hypertonic solution and strong denaturing conditions. We used an array of techniques to detect aggregation (SE-HPLC/DAD and DLS), changes in secondary structure (Far-UV circular dichroism), changes in conformation or tertiary structure (Intrinsic tryptophan fluorescence) and alterations in functionality (ELISA). Results indicate that aggregation is common degradation pathway. Two different types of aggregates were detected: dimers and high molecular weight aggregates attributed to β-amyloid-like structures. Secondary structure was maintained in most of the stress tests, while conformation was altered by almost all the tests except for the freeze-thaw cycles. Functionality, evaluated by its immunochemical reaction with VEGF, was found to be stable but with decrease when exposed to light and with likely partial inactivation of the drug when pH was altered.

New imaging systems in diabetic retinopathy

Various imaging modalities are of significant utility in the screening, grading, treatment, and follow-up of the different stages of diabetic retinopathy (DR) and diabetic macular edema. Color stereographic photography, fluorescein angiography, and optical coherence tomography (OCT) have been the gold standard for DR imaging for years. Besides these tools, newer technologies are gaining validation and popularity, such as fundus autofluorescence and OCT angiography. Furthermore, widefield retinography and ultra-widefield retinography have been introduced for a more comprehensive evaluation of the medium-far and very-far retinal peripheries, which is crucial for the assessment of the diverse manifestations of the disease. The aim of this review is to illustrate the recent advancements of the imaging systems for diagnosing DR, with a focus on the newest and noninvasive diagnostic tools.

Baicalin protects human retinal pigment epithelial cell lines against high glucose-induced cell injury by up-regulation of microRNA-145

BACKGROUND

Diabetic retinopathy (DR) is a common complication of diabetes mellitus, which is a major reason of blindness. Baicalin (BAI) is a flavonoid extracted from Scutellaria baicalensis, whose pharmacological characterizes have been widely reported in various diseases. However, it remains unclear the effect of BAI on DR. The study aimed to confirm the protective effect of BAI on DR.

METHODS

ARPE-19 cells and HRMECs were exposed to the high glucose (HG) environment to construct a cell injury model. After treatment with HG and BAI, cell viability, apoptosis, inflammatory cytokines and ROS generations were determined in ARPE-19 cells and HRMECs. Subsequently, microRNA-145 (miR-145) inhibitor and its negative control were transfected into ARPE-19 cells, and the regulatory effects on HG-and BAI-co-treated cells were detected. NF-κB and p38MAPK signaling pathways were finally examined to state the underling mechanisms.

RESULTS

HG treatment significantly induced ARPE-19 cells and HRMECs injury in vitro. BAI significantly promoted cell proliferation, reduced apoptosis, as well as inhibited the release of IL-1β, IL-6, IL-8 and ROS level in HG-injured ARPE-19 cells and HRMECs. Additionally, the expression level of miR-145 was up-regulated in HG-and BAI-co-treated cells. More importantly, miR-145 inhibition reversed the protective effect of BAI on HG-injured ARPE-19 cells. Besides, we observed that BAI inhibited the activations of NF-κB and p38MAPK pathways by up-regulating miR-145.

CONCLUSIONS

Results demonstrated that BAI exhibited the protective effect against HG-induced cell injury by up-regulation of miR-145.

An outline for the pharmacological effect of icariin in the nervous system

Icariin is a major active component of the traditional herb Epimedium, also known as Horny Goat Weed. It has been extensively studied throughout the past several years and is known to exert anti-oxidative, anti-neuroinflammatory, and anti-apoptotic effects. It is now being considered as a potential therapeutic agent for a wide variety of disorders, ranging from neoplasm to cardiovascular disease. More recent studies have shown that icariin exhibits potential preventive and/or therapeutic effects in the nervous system. For example, icariin can prevent the production of amyloid β (1-42) and inhibit the expression of amyloid precursor protein (APP) and β-site APP cleaving enzyme 1 (BACE-1) in animal models of Alzheimer's disease (AD). Icariin has been shown to mitigate pro-inflammatory responses of microglia in culture and in animal models of cerebral ischemia, depression, Parkinson's disease (PD), and multiple sclerosis (MS). Icariin also prevents the neurotoxicity induced by hydrogen peroxide (H₂O₂), endoplasmic reticulum (ER) stress, ibotenic acid, and homocysteine. In addition, icariin is implicated in facilitating learning and memory in both normal aging animals and disease models. To date, we still have no consolidated source of knowledge about the pharmacological effects of icariin in the nervous system, though its roles in other tissues have been reviewed in recent years. Here, we summarize the pharmacological development of icariin as well as its possible mechanisms in prevention and/or therapy of disorders afflicting the nervous system in hope of expanding the knowledge about the preventive and/or therapeutic effect of icariin in brain disorders.

The route of administration influences the therapeutic index of an anti-proNGF neutralizing mAb for experimental treatment of Diabetic Retinopathy

Many neurodegenerative retinal diseases are treated with monoclonal antibodies (mAb) delivered by invasive intravitreal injection (IVT). In Diabetic Retinopathy there is a scarcity of effective agents that can be delivered using non-invasive methods, and there are significant challenges in the validation of novel therapeutic targets. ProNGF represents a potential novel target, and IVT administration of a function-blocking anti-proNGF mAb is therapeutic in a mouse model of DR. We therefore compared invasive IVT to less invasive systemic intravenous (IV) and local subconjunctival (SCJ) administration, for therapy of Diabetic Retinopathy. The IV and SCJ routes are safe, afford sustained pharmacokinetics and tissue penetration of anti-proNGF mAb, and result in long–term therapeutic efficacy that blocks retinal inflammation, edema, and neuronal death. SCJ may be a more convenient and less-invasive approach for ophthalmic use and may enable reduced frequency of intervention for the treatment of retinal pathologies.

Intravitreal Injection of Anti-vascular Endothelial Growth Factor Agents for Ocular Vascular Diseases: Clinical Practice Guideline

PURPOSE

To provide the clinical recommendations for the administration of intravitreal anti-vascular endothelial growth factor (VEGF) drugs especially bavacizumab for ocular vascular diseases including diabetic macular edema, neovascular age-related macular degeneration, myopic choroidal neovascularization, retinal vein occlusion and central serous chorioretinopathy.

METHODS

Twenty clinical questions were developed by the guideline technical committee. Relevant websites and databases were searched to find out the pertinent clinical practice guidelines to answer the questions. The technical committee provided possible answers (scenarios) according to the available evidences for each question. All scenarios along with their levels of evidence and the supported articles were sent to the experts for external review. If the experts did not agree on any of the scenarios for one particular clinical question, the technical committee reviewed all scenarios and their pertinent evidences and made the necessary decision. After that, the experts were asked to score them again. All confirmed scenarios were gathered as the final recommendations.

RESULTS

All the experts agreed on at least one of the scenarios. The technical committee extracted the agreed scenario for each clinical question as the final recommendation. Finally, 56 recommendations were developed for the procedure of intravitreal anti-VEGF injection and their applications in the management of ocular vascular diseases.

CONCLUSION

The implementation of this guideline can standardize the management of the common ocular vascular diseases by intravitreal injection of anti-VEGF agents. It can lead to better policy-making and evidence-based clinical decision by ophthalmologists and optimal evidence based eye care for patients.

Observation of optic disc neovascularization using OCT angiography in proliferative diabetic retinopathy after intravitreal conbercept injections

This study reports the short-term efficacy and safety of intravitreal conbercept injections for neovascularization at the disc (NVD) in patients with proliferative diabetic retinopathy (PDR). Conbercept is a recombinant fusion protein with a high affinity for all isoforms of vascular endothelial growth factor (VEGF)-A, placental growth factor and VEGF-B. A prospective case series study was conducted in 15 patients (15 eyes). Patients had complete ocular examinations and received a 0.5 mg intravitreal conbercept injection followed by supplemental pan-retinal photocoagulation (PRP). Optical coherence tomography angiography (OCTA) was performed before and after treatment. Before treatment, the mean NVD area was 1.05 ± 0.33 mm², and it decreased to 0.56 ± 0.17 mm² after an interval of 7.5 d (p = 0.000). One eye required vitrectomy during follow-up. Recurrent NVD was observed in 2 eyes, which resolved after repeated injections. The remaining 12 eyes were stable over a mean follow-up period of 8.3 months. The mean area of the NVD in 14 patients without vitrectomy was 0.22 ± 0.11 mm² (p = 0.000) at the last visit. Intravitreal conbercept injections combined with intensive PRP are an effective and safe treatment for PDR with NVD. Quantitative information on NVD can be obtained with OCTA, which may be clinically useful in evaluating the therapeutic effect.

Pharmaceutical compounding of aflibercept in prefilled syringes does not affect structural integrity, stability or VEGF and Fc binding properties

Macular edema due to neovascular age-related macular degeneration, diabetes or retinal vein occlusion can cause central vision loss. Intravitreal treatment with antibody-based biopharmaceutical compounds designed to neutralize vascular endothelial growth factor (VEGF) has proven to be an efficient strategy to ameliorate macular edema and restore visual acuity. At the same time, the use of anti-VEGF drugs places an economic burden on the health care system; the drugs are expensive, and repeated injections are usually required to maintain the therapeutic effect. Thus, there is an unmet need for more cost-effective procedures. We here describe how the most recently approved anti-VEGF drug, aflibercept, can be compounded into prefilled sterile syringes and stored for up to 4 weeks without compromising its quality, stability or functional properties, including VEGF and neonatal Fc receptor (FcRn) binding. The novel compounding method for repackaging of aflibercept in sterile plastic syringes can greatly reduce both cost and time spent per patient in the injection room.

Efficacy of intravitreal bevacizumab combined with pan retinal photocoagulation versus panretinal photocoagulation alone in treatment of proliferative diabetic retinopathy

Objective:

To compare effectiveness of pan-retinal photocoagulation alone versus panretinal photocoagulation combined with intravitreal bevacizumab on visual acuity and central macular thickness in patients presenting with proliferative diabetic retinopathy.

Methods:

This Randomized controlled trial was carried out at Armed Forces Institute of ophthalmology, Pakistan from Jan 2016 to Aug 2016. Seventy six eyes of 50 patients having proliferative diabetic retinopathy and diabetic macular edema were included in the study. All the patients were subjected to detailed clinical examination that included Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), slit lamp examination of anterior and posterior segments. Optical coherence tomography (OCT) and fundus fluorescein angiography (FFA) were carried out and patients were divided in two groups (GP and GI). Three monthly sessions of Pan retinal photocoagulation (PRP) using Pattern Scan Laser (PASCAL) alone was performed in group GP while PRP along with three monthly intravitreal bevacizumab (IVB) was performed in group GI. BCVA and CMT was recorded 04 weeks after the third PRP session in both the groups.

Results:

Seventy six eyes of 50 patients (38 in each group) were treated with three sessions of PRP alone and PRP with IVB in Group GP and GI respectively. Mean age of the patient in group GP was 57.47± 6.08 years while that in group GI was 55.69 ±6.58. The magnitude of induced change in BCVA was 0.09 ± 0.15 in GP while 0.22 + 0.04 in GI groups while mean induced change in CMT after treatment was 77.44 ± 92.30 um and 117.50 ± 93.82 um in group GP and GI.

Conclusion:

Laser PRP combined with IVB has superior visual and anatomical outcome than PRP alone in patients with combined presentation of PDR and DME.

Vascular endothelial growth factor: a neurovascular target in neurological diseases

Brain function critically relies on blood vessels to supply oxygen and nutrients, to establish a barrier for neurotoxic substances, and to clear waste products. The archetypal vascular endothelial growth factor, VEGF, arose in evolution as a signal affecting neural cells, but was later co-opted by blood vessels to regulate vascular function. Consequently, VEGF represents an attractive target to modulate brain function at the neurovascular interface. On the one hand, VEGF is neuroprotective, through direct effects on neural cells and their progenitors and indirect effects on brain perfusion. In accordance, preclinical studies show beneficial effects of VEGF administration in neurodegenerative diseases, peripheral neuropathies and epilepsy. On the other hand, pathologically elevated VEGF levels enhance vessel permeability and leakage, and disrupt blood-brain barrier integrity, as in demyelinating diseases, for which blockade of VEGF may be beneficial. Here, we summarize current knowledge on the role and therapeutic potential of VEGF in neurological diseases.

Oral Delivery of Protein Drugs Bioencapsulated in Plant Cells

Plants cells are now approved by the FDA for cost-effective production of protein drugs (PDs) in large-scale current Good Manufacturing Practice (cGMP) hydroponic growth facilities. In lyophilized plant cells, PDs are stable at ambient temperature for several years, maintaining their folding and efficacy. Upon oral delivery, PDs bioencapsulated in plant cells are protected in the stomach from acids and enzymes but are subsequently released into the gut lumen by microbes that digest the plant cell wall. The large mucosal area of the human intestine offers an ideal system for oral drug delivery. When tags (receptor-binding proteins or cell-penetrating peptides) are fused to PDs, they efficiently cross the intestinal epithelium and are delivered to the circulatory or immune system. Unique tags to deliver PDs to human immune or nonimmune cells have been developed recently. After crossing the epithelium, ubiquitous proteases cleave off tags at engineered sites. PDs are also delivered to the brain or retina by crossing the blood–brain or retinal barriers. This review highlights recent advances in PD delivery to treat Alzheimer's disease, diabetes, hypertension, Gaucher's or ocular diseases, as well as the development of affordable drugs by eliminating prohibitively expensive purification, cold chain and sterile delivery.