Recent advances in the management and understanding of diabetic retinopathy

MiR-124-3p Suppresses the Dysfunction of High Glucose-Stimulated Endothelial Cells by Targeting G3BP2

Background: Diabetic retinopathy (DR) is the most important manifestation of diabetic microangiopathy. MicroRNAs (miRNAs), members of non-coding RNAs, have been frequently reported to regulate various diseases including DR. MiR-124-3p is involved in DR based on bioinformatics. The current study aimed to investigate the role of miR-124-3p in high glucose (HG)-treated human retinal microvascular endothelial cells (HRMECs), an in vitro model of DR.

Methods: Bioinformatics analysis was applied to reveal the targets downstream miR-124-3p. A series of assays including CCK-8, luciferase reporter, western blot, and tube formation assays were used to explore the function and mechanism of miR-124-3p in HG-stimulated HRMECs.

Results: We found out that miR-124-3p was downregulated in HG-stimulated HRMECs. Functionally, miR-124-3p overexpression restrained the HG-induced cell injury of HRMECs. Mechanistically, we predicted 5 potential target mRNAs of miR-124-3p. G3BP stress granule assembly factor 2 (G3BP2) was validated to bind with miR-124-3p. Rescue assays showed that miR-124-3p suppressed cell injury of HG-stimulated HRMECs through G3BP2. In addition, miR-124-3p regulated the p38MAPK signaling pathway by G3BP2, and G3BP2 promoted injury of HG-treated HRMECs through the activation of the p38MAPK signaling pathway.

Conclusion: MiR-124-3p suppressed the dysfunctions of HG-treated HRMECs by targeting G3BP2 and activating the p38MAPK signaling. This new discovery provided a potential biomarker for DR treatment.

Glucose metabolomic profile during embryogenesis in the tick Rhipicephalus microplus

INTRODUCTION

Metabolomic approaches can assess the actual state of an organism's energy metabolism during a specific morphological event, providing a more accurate insight into the correlations between physiology and metabolic regulation.

METHODS

The study of the metabolomic profile aim to identify the largest possible number of biomolecules in a certain organism or specific structures. For this purpose, mass spectrometry (MS) and chromatography have been used in the present study.

OBJECTIVES

In this context, the aim of the present work is to evaluate the glucose metabolomic profile during embryogenesis in Rhipicephalus microplus tick, investigating the dynamics of nutrient utilization during tick embryo formation, as well as the control of glucose metabolism.

RESULTS

We show that glycogen reserves are preferentially mobilized to sustain the energy-intensive process of embryogenesis. Subsequently, the increase in concentration of specific amino acids indicates that protein degradation would provide carbons to fuel gluconeogenesis, supplying the embryo with sufficient glucose and glycogen during development.

CONCLUSION

Altogether, these results demonstrated the presence of a very refined catabolic and anabolic control during embryogenesis in R. microplus tick, suggesting the pronounced gluconeogenesis as a strategy to secure embryo development. Moreover, this research contributes to the understanding of the mechanisms that control glucose metabolism during tick embryogenesis and may aid the identification of putative targets for novel chemical or immunological control methods, which are essential to improve the prevention of tick infestations.

Visualizing the intellectual structure and recent research trends of diabetic retinopathy

AIM

To analyze the intellectual structure and recent research trends in diabetic retinopathy (DR) and unearth potential knowledge.

METHODS

English DR publication included in this study was exported from the Web of Science Core Collection, and Chinese DR publication was exported from China National Knowledge Infrastructure from the establishment time of the database to 2019. CiteSpace and Microsoft Excel were used to visually analyze DR research, including analysis of the number of publications, highly cited publication analysis, spatial distribution analysis, and keyword co-occurrence analysis.

RESULTS

A total of 23 795 English studies and 11 577 Chinese studies, including 2089 studies related to traditional Chinese medicine (TCM), were obtained. The data suggested the following: 1) The number of English and Chinese DR publications increased over time, and the growth rate of English publications was relatively fast. 2) The distribution of international scholars and institutions was close, while the distribution was scattered in China. Shanghai Jiao Tong University has the largest number of publications. Tien-Yin Wong was the core author with the largest number of publications. England and the United States are the core of international DR research cooperation. 3) Optical coherence tomography and risk factors are recent international research hot spots and trends. The difference is that TCM is a recent research trend under DR in China.

CONCLUSION

DR has drawn an increasing amount of attention worldwide. The focus of research in this field has shifted from tertiary type DR treatment to secondary prevention strategies which focus on the screening and monitoring of disease progression. The advantages of TCM in the prevention of DR have attracted attention, and it is worth incorporating this with Western medicine to address this challenge.

Anti-VEGF crunch syndrome in proliferative diabetic retinopathy: A review

Anti-vascular endothelial growth factor (anti-VEGF) crunch syndrome describes the progression to tractional retinal detachment following intravitreal anti-VEGF therapy in an eye with proliferative diabetic retinopathy . We reviewed the literature on the anti-VEGF crunch using the PubMed and Cochrane databases. Anti-VEGF crunch typically manifests as sudden vision loss in the affected eye between 1 and 6 weeks following intravitreal anti-VEGF injection, with a mean onset of 13 days. Risk factors for crunch development include the use of a higher anti-VEGF dose and increased severity of diabetic retinopathy with fibrosis. Our review found that intravitreal anti-VEGF, in particular bevacizumab, should be used with caution when treating patients with severe proliferative diabetic retinopathy and pre-existing intraocular fibrosis. In patients where anti-VEGF is used before a planned vitrectomy, we recommend close monitoring for crunch symptoms and proceeding promptly with surgery if there is new or progression of tractional retinal detachment. For eyes with minimal preexisting traction that develop crunch after anti-VEGF treatment, surgeons should proceed to vitrectomy within 7 days. The existing literature on the anti-VEGF crunch is limited by heterogeneity in the way crunch is documented and characterized and the presence of panretinal photocoagulation as a confounding factor. Because of these methodological flaws, the relative frequency of the anti-VEGF crunch cannot be accurately estimated.

RELATIONSHIP BETWEEN STAGES OF DIABETIC RETINOPATHY AND LEVELS OF BRAIN-DERIVED NEUROTROPHIC FACTOR IN AQUEOUS HUMOR AND SERUM

PURPOSE

The aim of the study was to determine aqueous humor and serum levels of brain-derived neurotrophic factor (BDNF) in diabetic patients with and without retinopathy.

METHODS

The study included diabetic patients with or without retinopathy, who had an indication for cataract surgery. The study groups were diabetic patients without retinopathy (Group 2), with nonproliferative diabetic retinopathy (Group 3), and with proliferative retinopathy (Group 4). To quantitatively determine the amount of BDNF in samples, the RayBio Human BDNF ELISA kit (Norcross, GA), based on an enzyme-labeled immunosorbent assay was used.

RESULTS

The median serum BDNF levels were significantly lower in all the study groups than in the control group (P values: 0.038 Group 2, 0.02 Group 3, and 0.002 Group 4). Serum BDNF was lower in Group 4 than in Group 3 (P = 0.030), and in Group 3 than in Group 2 (P = 0.04). The median aqueous humor BDNF levels were significantly decreased in all groups (P values: 0.047 Group 2, 0.021 Group 3, and 0.007 Group 4). There was no significant difference between Groups 2, 3, and 4 (P = 0.214).

CONCLUSION

The serum and aqueous humor BDNF levels decreased in patients with diabetes mellitus (DM) before the emergence of clinical signs of retinopathy.

An evidence map of clinical practice guideline recommendations and quality on diabetic retinopathy

To present an evidence map for explicating research trends and gaps, we systematically review clinical practice guidelines (CPGs) on diabetic retinopathy (DR) and assess the quality of CPGs and consistency of recommendations. A literature search was performed in PubMed, Embase, Web of Science, CPG databases, and website of diabetes society to include the CPGs. The basic information, methodological quality, and reporting quality of CPGs, recommendations for DR were exacted by the Excel 2013. Methodological and reporting quality of DR CPGs were evaluated by AGREE II instrument and RIGHT checklist. The bubble plot format of evidence map was made by Excel 2013. Nineteen CPGs proved eligible, which included eight DR CPGs and 11 comprehensive diabetic CPGs. The identified CPGs were of mixed quality and they scored poorly in the rigor of development, applicability domains by AGREE II. Field two (background) had the highest reporting rate (86.31%) and field five (review and quality assurance) obtained the lowest reporting rate (31.58%) among the seven domains of RIGHT checklist. According to the recommendations of CPGs, there were three inconsistencies in the screening of DR, and CPGs recommendations for treatment were consistent on the whole. At the same time, recommendations for laser therapy were not accurate. Some recommendations were not specific and clear in some DR CPGs. This evidence map could collect and evaluate the characteristics of published CPGs, add to our knowledge and promote the development of trustworthy CPGs for DR.

Emerging Concepts in the Treatment of Diabetic Retinopathy

PURPOSE OF REVIEW

Diabetic retinopathy (DR) is the leading cause of vision loss in working-age adults in the developed world. This review discusses the current approach to managing the disease, such as glycemic and blood pressure control, as well as laser photocoagulation, as well as emerging concepts and controversies on novel therapies.

RECENT FINDINGS

In recent years, the rise of intraocular anti-angiogenesis treatments is changing the paradigm of classic laser photocoagulation in the management of DR, but its long-term benefits remain an area of controversy. We also discuss new targets including anti-inflammation, neuroprotection, and novel laser technologies. Finally, we discuss new advances in retinal imaging that has vastly improved the diagnosis and management of DR. Diagnosis and management of diabetic retinopathy is a rapidly progressing field. Emerging concepts in ophthalmic imaging, medical treatments, and surgical approaches provide insights into how DR management will evolve in the near future.

Clinical Effectiveness of Intravitreal Fluocinolone Acetonide (FAc) (ILUVIEN™) in Patients with Diabetic Macular Oedema (DMO) Refractory to Prior Therapy: The Manchester Experience

INTRODUCTION

Diabetic macular oedema (DMO) remains a significant cause of sight loss in the UK. Despite macular laser and anti-VEGF agents, a large proportion of patients remain with persistent DMO. We present our results of using 0.19 mg fluocinolone acetonide (FAc) intravitreal implant in this cohort with up to 3 years of follow-up.

METHODS

This is a single-centre retrospective review of patients treated with FAc implant for refractory DMO. The primary efficacy end point was visual acuity and secondary efficacy end point was central retinal thickness (CRT) on OCT. A primary safety end point was a rise in IOP requiring treatment.

RESULTS

Twenty-one eyes were identified with an average follow-up of 27 months (6-36 months). Visual acuity change from baseline was - 0.1 ETDRS letters at year 1 (n = 13), 8.1 letters at year 2 (n = 13) and 10.7 letters at year 3 (n = 10). CRT improved by - 132.1 µm at year 1 (n = 15), - 172.8 µm at year 2 (n = 13) and - 157.8 µm at year 3 (n = 10). Five eyes (24%) required further anti-VEGF during follow-up and two (9.5%) required further focal laser. IOP rise requiring treatment was noted in eight eyes (38%). Seven were steroid induced. One was caused by rubeotic glaucoma. Six (75%) were managed medically and the remaining two also required surgery.

CONCLUSION

This data add to the limited real-world data on FAc in DMO with 3 years of follow-up. Vision and macular architectures both improved at varying rates over 3 years in patients with refractory DMO. IOP rise is a risk but, in the majority, it can be managed medically.

Intravitreal ranibizumab injection at the end of vitrectomy for diabetic vitreous hemorrhage (Observational Study)

To evaluate the outcomes and complications of intravitreal injections of ranibizumab in patients during pars plana vitrectomy for treatment of diabetic vitreous hemorrhage. This retrospective, observational, comparative study included 103 patients (103 eyes) who underwent pars plana vitrectomy for treatment of diabetic vitreous hemorrhage. Sixty-six patients received an intravitreal injection of 0.05 mg (0.05 cc) of ranibizumab at the end of surgery. Main outcome measures were the occurrence of recurrent early vitreous hemorrhage, reoperation, intraocular pressure, best corrected visual acuity. Mean follow-up time was 6 months. The rate of rebleeding in the intravitreal ranibizumab (IVR) group was 6.1% (4 eyes), which is significantly lower than the control group (24.3%, 9 eyes, P < .01). The incidence of postoperative diabetic vitreous hemorrhage (PDVH) was significantly lower in the IVR group than the control group, OR=0.26, 95% CI= (0.06, 0.95). Visual acuity 6 months after operation was better in IVR group (P<.01) There was no difference in mean intraocular pressure between the 2 groups (P=.56). The present clinical study suggests that intravitreal injection of ranibizumab is effective in the prevention of postoperative diabetic vitreous hemorrhage in eyes undergoing pars plana vitrectomy for the treatment of diabetic vitreous hemorrhage.

Intravitreal fluocinolone acetonide implant (ILUVIEN®) for diabetic macular oedema: a literature review

Diabetic macular oedema (DMO) is a common complication of diabetic retinopathy and may lead to severe visual loss. In this review, we describe the pathophysiology of DMO and review current therapeutic options such as macular laser photocoagulation, anti-vascular endothelial growth factor agents, and steroid implants with a focus on the new fluocinolone acetonide implant, ILUVIEN®. The results of the Fluocinolone Acetonide in Diabetic Macular Edema (FAME) studies are also presented together with the results of real-world studies to support the clinical use of ILUVIEN® in achieving efficient resolution of DMO and improving vision and macular anatomy in this challenging group of patients.

Impact of Baseline Central Retinal Thickness on Outcomes in the VIVID-DME and VISTA-DME Studies

Purpose

To report the impact of baseline central retinal thickness (CRT) on outcomes in patients with diabetic macular edema (DME) in VIVID-DME and VISTA-DME.

Methods

Post hoc analyses of two randomized controlled trials in which 862 DME patients were randomized 1 : 1 : 1 to treatment with intravitreal aflibercept 2.0 mg every 4 weeks (2q4), intravitreal aflibercept 2.0 mg every 8 weeks after five initial monthly doses (2q8), or macular laser photocoagulation at baseline and as needed. We compared visual and anatomical outcomes in subgroups of patients with baseline CRT < 400 μm and ≥400 μm.

Results

At weeks 52 and 100, outcomes with intravitreal aflibercept 2q4 and 2q8 were superior to those in laser control-treated patients regardless of baseline CRT. When looked at in a binary fashion, the treatment effect of intravitreal aflibercept versus laser was not significantly better in the ≥400 μm than the <400 μm group; when looked at as a continuous variable, baseline CRT seemed to have an impact on the treatment effect of intravitreal aflibercept versus laser.

Conclusions

Post hoc analyses of VIVID-DME and VISTA-DME demonstrated the benefits of intravitreal aflibercept treatment in DME patients with baseline CRT < 400 μm and ≥400 μm. This trial is registered with NCT01331681 and NCT01363440.