Diabetic retinopathy and diabetic macular oedema pathways and management: UK Consensus Working Group

The Role of Intravitreal Corticosteroids in the Treatment of DME: Predictive OCT Biomarkers

This work aims to summarize predictive biomarkers to guide treatment choice in DME. Intravitreal anti-VEGF is considered the gold standard treatment for centers involving DME, while intravitreal steroid treatment has been established as a second-line treatment in DME. However, more than 1/3 of the patients do not adequately respond to anti-VEGF treatment despite up to 4-weekly injections. Not surprisingly, insufficient response to anti-VEGF therapy has been linked to low-normal VEGF levels in the serum and aqueous humor. These patients may well benefit from an early switch to intravitreal steroid treatment. In these patients, morphological biomarkers visible in OCT may predict treatment response and guide treatment decisions. Namely, the presence of a large amount of retinal and choroidal hyperreflective foci, disruption of the outer retinal layers and other signs of chronicity such as intraretinal cysts extending into the outer retina and a lower choroidal vascular index are all signs suggestive of a favorable treatment response of steroids compared to anti-VEGF. This paper summarizes predictive biomarkers in DME in order to assist individual treatment decisions in DME. These markers will help to identify DME patients who may benefit from primary dexamethasone treatment or an early switch.

Prevalence and severity of diabetic retinopathy in pregnant women with diabetes-time to individualize photo screening frequency

AIMS

To evaluate the prevalence and severity of diabetic retinopathy including macular oedema in pregnant women with diabetes and to identify women in whom the frequency of retinal screening can be reduced to minimize the burden of health care visits.

METHODS

A cohort study of 348 women with pre-existing diabetes were routinely screened with retinal photo in early (12 weeks) and late pregnancy (27 weeks). Diabetic retinopathy was classified in five stages in accordance with National Danish Guidelines based on the eye with the highest retinopathy level. Sight-threatening retinopathy was defined as the presence of proliferative retinopathy and/or clinically significant macular oedema (CSMO).

RESULTS

Retinopathy was present in 52% (116/223) vs. 14% (17/125), with sight-threatening retinopathy in 16% (35/223) vs. 6% (7/125) of women with type 1 and type 2, respectively. Women without retinopathy in early and late pregnancy were characterized by shorter diabetes duration (p < 0.0001 and p = 0.008) and predominance of type 2 diabetes. Amongst the 50% (175/348) of the cohort having no retinopathy in early pregnancy and HbA1c<53 mmol/mol (7.0%), none developed sight-threatening retinopathy and 94% (165/175) remained without any retinopathy during pregnancy. Development of sight-threatening retinopathy was mainly observed in women with retinopathy in early pregnancy. Treatment for sight-threatening retinopathy was given to a minority (2.7 and 2.4%, respectively).

CONCLUSION

Good glycaemic control and no retinopathy was seen in a large proportion of women in early pregnancy and none of these women developed sight-threatening retinopathy. The frequency of retinal screening can probably be safely reduced during pregnancy in these women.

The Impact of Laboratory Findings and Optical Coherence Tomography Biomarkers on Response to Intravitreal Anti-VEGF Treatment in Patients with Diabetic Macular Edema

PURPOSE

To investigate potential laboratory and imaging biomarkers as treatment response predictors to intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents in patients with diabetic macular edema (DME).

METHODS

The study included 36 treatment naïve patients with DME, treated with intravitreal anti-VEGF agents and followed-up for 12 months. At baseline, all participants underwent best-corrected visual acuity (BCVA) measurement, dilated fundoscopy, optical coherence tomography, color fundus photography and fluorescein angiography, while full blood count and biochemical analysis of various parameters was also performed. At month 12, treatment response was examined and classified as "favorable" or "non-response". Potential associations between laboratory/imaging biomarkers and treatment response were assessed.

RESULTS

Univariate analysis showed that favorable response at month 12 after initiation of anti-VEGF treatment was correlated with baseline central subfield thickness (CST)≤405 μm (p < .001), absence of subretinal fluid (p = .034), absence of exudates (p = .041), absence of disorganization of the inner retinal layers (p = .037), intact ellipsoid zone (EZ) and external limiting membrane (ELM) (p < .001 and p = .002, respectively), absence of epiretinal membrane (ERM) (p = .040) and absence of macular ischemia (p = .042), while increased lipoprotein(a) was associated with no treatment response (p = .025). At the multivariate analysis, CST was found to be independent predictor of treatment response, while EZ, ELM and ERM were found to predict treatment response perfectly and they could not be entered in the model.

CONCLUSION

Intact EZ and ELM, absence of ERM and CST≤405 μm at baseline can predict favorable treatment response in patients with treatment naïve DME, while no correlation with baseline laboratory parameters was found.

Toll-Like Receptor Signalling Pathways and the Pathogenesis of Retinal Diseases

There is growing evidence that the pathogenesis of retinal diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD) have a significant chronic inflammatory component. A vital part of the inflammatory cascade is through the activation of pattern recognition receptors (PRR) such as toll-like receptors (TLR). Here, we reviewed the past and current literature to ascertain the cumulative knowledge regarding the effect of TLRs on the development and progression of retinal diseases. There is burgeoning research demonstrating the relationship between TLRs and risk of developing retinal diseases, utilising a range of relevant disease models and a few large clinical investigations. The literature confirms that TLRs are involved in the development and progression of retinal diseases such as DR, AMD, and ischaemic retinopathy. Genetic polymorphisms in TLRs appear to contribute to the risk of developing AMD and DR. However, there are some inconsistencies in the published reports which require further elucidation. The evidence regarding TLR associations in retinal dystrophies including retinitis pigmentosa is limited. Based on the current evidence relating to the role of TLRs, combining anti-VEGF therapies with TLR inhibition may provide a longer-lasting treatment in some retinal vascular diseases.

Diabetic retinopathy for the non-ophthalmologist

Diabetic retinopathy is a microangiopathy resulting from the chronic effects of diabetes mellitus. Healthcare professionals often work in isolation to deliver highly specialised care efficiently and effectively for people living with diabetes. It is not uncommon for people with diabetes to be making frequent visits to community and hospital clinics to see a variety of specialists and healthcare professionals, with seemingly little opportunity for coordination of this complex health management programme between the wider team. In a field that is so diverse and rapidly changing, healthcare professionals of all specialties need to be aware of developments across all aspects of diabetes management. In this article, we discuss the epidemiology and natural history of diabetic retinopathy and describe an approach to its assessment and diagnosis. We provide an overview of the principles of diabetic retinopathy management and outline possible future treatments for diabetic retinopathy.

Intravitreal Conbercept with Grid/Focal Photocoagulation for the Treatment of Diabetic Macular Edema: A Systematic Review and Meta-Analysis

Diabetic macular edema (DME) is the main cause of blindness in individuals with diabetes mellitus (DM). This meta-analysis compared the effectiveness and safety of macular grid/focal photocoagulation with and without conbercept in the treatment of DME. Studies were identified through systematic searches of PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure database, Wanfang Data Knowledge Service Platform, and VIP Information Resource Integration Service Platform from their earliest records to June 2021. Twelve articles involving 2600 patients with DME were included. Results showed that patients receiving conbercept with macular grid/focal photocoagulation had a statistically significant reduction in central macular thickness (CMT) over macular grid/focal photocoagulation alone at 1 month and 3 months post procedure. Compared with the control group, the combination therapy group had a significantly increased level of effectiveness and best-corrected visual acuity (BCVA) compared with the control group. The combination therapy group significantly increased the level of effectiveness and best-corrected visual acuity (BCVA) compared with the control group. Conbercept with macular grid/focal photocoagulation was more effective than macular grid/focal photocoagulation alone in terms of functional outcomes for DME treatment.

LRG1 as a novel therapeutic target in eye disease

Retinal and choroidal diseases are major causes of blindness and visual impairment in the developed world and on the rise due to an ageing population and diabetes epidemic. Standard of care is centred around blockade of vascular endothelial growth factor (VEGF), but despite having halved the number of patients losing sight, a high rate of patient non-response and loss of efficacy over time are key challenges. Dysregulation of vascular homoeostasis, coupled with fibrosis and inflammation, are major culprits driving sight-threatening eye diseases. Improving our knowledge of these pathological processes should inform the development of new drugs to address the current clinical challenges for patients. Leucine-rich α-2 glycoprotein 1 (LRG1) is an emerging key player in vascular dysfunction, inflammation and fibrosis. Under physiological conditions, LRG1 is constitutively expressed by the liver and granulocytes, but little is known about its normal biological function. In pathological scenarios, such as diabetic retinopathy (DR) and neovascular age-related macular degeneration (nvAMD), its expression is ectopically upregulated and it acquires a much better understood pathogenic role. Context-dependent modulation of the transforming growth-factor β (TGFβ) pathway is one of the main activities of LRG1, but additional roles have recently been emerging. This review aims to highlight the clinical and pre-clinical evidence for the pathogenic contribution of LRG1 to vascular retinopathies, as well as extrapolate from other diseases, functions which may be relevant to eye disease. Finally, we will provide a current update on the development of anti-LRG1 therapies for the treatment of nvAMD.

What advances may the future bring to the diagnosis, treatment, and care of male sexual and reproductive health?

Over the past 40 years, since the publication of the original WHO Laboratory Manual for the Examination and Processing of Human Semen, the laboratory methods used to evaluate semen markedly changed and benefited from improved precision and accuracy, as well as the development of new tests and improved, standardized methodologies. Herein, we present the impact of the changes put forth in the sixth edition together with our views of evolving technologies that may change the methods used for the routine semen analysis, up-and-coming areas for the development of new procedures, and diagnostic approaches that will help to extend the often-descriptive interpretations of several commonly performed semen tests that promise to provide etiologies for the abnormal semen parameters observed. As we look toward the publication of the seventh edition of the manual in approximately 10 years, we describe potential advances that could markedly impact the field of andrology in the future.

Molecular investigation of candidate genes for pyroptosis-induced inflammation in diabetic retinopathy

BACKGROUND

Diabetic retinopathy is a diabetic microvascular complication. Pyroptosis, as a way of inflammatory death, plays an important role in the occurrence and development of diabetic retinopathy, but its underlying mechanism has not been fully elucidated. The purpose of this study is to identify the potential pyroptosis-related genes in diabetic retinopathy by bioinformatics analysis and validation in a diabetic retinopathy model and predict the microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) interacting with them. Subsequently, the competing endogenous RNA (ceRNA) regulatory network is structured to explore their potential molecular mechanism.

METHODS

We obtained mRNA expression profile dataset GSE60436 from the Gene Expression Omnibus (GEO) database and collected 51 pyroptosis-related genes from the PubMmed database. The differentially expressed pyroptosis-related genes were obtained by bioinformatics analysis with R software, and then eight key genes of interest were identified by correlation analysis, Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and protein-protein interaction (PPI) network analysis. Then, the expression levels of these key pyroptosis-related genes were validated with quantitative real-time polymerase chain reaction (qRT-PCR) in human retinal endothelial cells with high glucose incubation, which was used as an in vitro model of diabetic retinopathy. Western blot was performed to measure the protein levels of gasdermin D (GSDMD), dasdermin E (GSDME) and cleaved caspase-3 in the cells. Moreover, the aforementioned genes were further confirmed with the validation set. Finally, the ceRNA regulatory network was structured, and the miRNAs and lncRNAs which interacted with CASP3, TLR4, and GBP2 were predicted.

RESULTS

A total of 13 differentially expressed pyroptosis-related genes were screened from six proliferative diabetic retinopathy patients and three RNA samples from human retinas, including one downregulated gene and 12 upregulated genes. A correlation analysis showed that there was a correlation among these genes. Then, KEGG pathway and GO enrichment analyses were performed to explore the functional roles of these genes. The results showed that the mRNA of these genes was mainly related to inflammasome complex, interleukin-1 beta production, and NOD-like receptor signaling pathway. In addition, eight hub genes-CASP3, TLR4, NLRP3, GBP2, CASP1, CASP4, PYCARD, and GBP1-were identified by PPI network analysis using Cytoscape software. High glucose increased the protein level of GSDMD and GSDME, as critical effectors of pyroptosis, in retinal vascular endothelial cells. Verified by qRT-PCR, the expression of all these eight hub genes in the in vitro model of diabetic retinopathy was consistent with the results of the bioinformatics analysis of mRNA chip. Among them, CASP4, GBP1, CASP3, TLR4, and GBP2 were further validated in the GSE179568 dataset. Finally, 20 miRNAs were predicted to target three key genes-CASP3, GBP2, and TLR4, and 22 lncRNAs were predicted to potentially bind to these 20 miRNAs. Then, we constructed a key ceRNA network that is expected to mediate cellular pyroptosis in diabetic retinopathy.

CONCLUSION

Through the data analysis of the GEO database by R software and verification by qRT-PCR and validation set, we successfully identified potential pyroptosis-related genes involved in the occurrence of diabetic retinopathy. The key ceRNA regulatory network associated with these genes was structured. These findings might improve the understanding of molecular mechanisms underlying pyroptosis in diabetic retinopathy.

EFFECT OF BASELINE CENTRAL RETINAL THICKNESS ON THE RESULTS OF TREATMENT OF DIABETIC MACULAR EDEMA WITH AFLIBERCEPT: REAL-LIFE EVIDENCE IN THE CZECH REPUBLIC

AIM

Presentation of the 1-year results of aflibercept treatment in patients suffering from diabetic macular edema (DME) and comparison of the response to treatment of patients with different baseline central retinal thickness (CRT).

METHODS

This was a multicentre, retrospective observational study of a series of cases. Patients with DME were treated in a fixed regimen (5 injections at 1-monthly intervals and then injections at 2-monthly intervals). The period of follow-up was 12 months. The development of best corrected visual acuity (BCVA) and CRT was evaluated. Measurements were performed prior to the commencement of treatment and then after 4, 6, 8, 10, and 12 months.

RESULTS

The therapeutically naive group consisted of 82 eyes of 79 patients. The total cohort of patients was divided into 3 groups according to the baseline values of CRT. The first group was composed of 28 eyes with baseline CRT &lt; 450 &#956;m (34.1%), the second included 25 eyes with CRT in the range of 450-550 &#956;m (30.5%), and the third group consisted of 29 eyes with baseline CRT &gt; 550 &#956;m (35.4%). The average baseline BCVA and SD in the first group was 66 ±7.1 letters ETDRS optotypes, and then 70 ±7 letters, 69.6 ±7.3 letters, and 71.3 ±7 letters at the follow-ups after 4, 8, and 12 months. The average baseline value of CRT and SD in the first group was 379 ±48.6 &#956;m, and then 337.1 ±76.5 &#956;m, 320.2 ±74.1 &#956;m, and 315.1 ±62.2 &#956;m after 4, 8, and 12 months. The average baseline BCVA and SD in the second group was 64.1 ±9.7 ETDRS letters, and then 66.9 ±10 letters, 70 ±9.9 letters, and 70.5 ±11.5 letters after 4, 8, and 12 months. The average baseline value of CRT and SD in the second group was 497.4 ±76.4 &#956;m, and then 376.5 ±106.1 &#956;m, 360.8 ±70 &#956;m, and 351.3 ±91.3 &#956;m after 4, 8, and 12 months. In the third group, the average baseline value of BCVA and SD was 59.7 ±10.4 ETDRS letters, and then 65 ±10.6 letters, 64.8 ±9.6 letters, and 67 ±10 letters after 4, 8, and 12 months. The average baseline value of CRT and SD in the third group was 639.4 ±79.6 &#956;m, and then 396.7 ±147.1 &#956;m, 416.9 ±139.8 &#956;m, and 368.5 ±109.9 &#956;m after 4, 8, and 12 months. All these changes were statistically significant (p &lt; 0.05).

CONCLUSION

Aflibercept treatment in a fixed regimen in patients suffering from DME results in a statistically significant improvement in BCVA and a decrease in CRT in the first year of treatment. Patients with a higher baseline CRT showed the best anatomical and functional results of the 1-year treatment with aflibercept.

The Association Between Leucine and Diabetic Retinopathy in Different Genders: A Cross-Sectional Study in Chinese Patients With Type 2 Diabetes

OBJECTIVE

To explore the association between serum leucine (leu) and diabetic retinopathy (DR) in patients with type 2 diabetes (T2D) and then to analyze the influence of gender on the association.

METHOD

The electronic medical records of 1,149 T2D patients who met inclusion and exclusion criteria were retrieved from the Second Affiliated Hospital of Dalian Medical University and the First Affiliated Hospital of Jinzhou Medical University. Serum leu levels of all subjects were measured by liquid chromatography-mass spectrometry. Logistic regression was used to obtain the odds ratio (OR) and CI of leu-DR risk in multiple models. When using these models, restricted cubic spline (RCS) was used to test the potential non-linear relationship between multiple continuous independent variables, such as leu and DR (classification), and dependent variables. We also used the additive interaction method to evaluate the interaction effect between leu and gender on DR.

RESULTS

Leu was a protective factor of DR [0.78 (0.66, 0.92)]. When gender was divided into male and female, the above relationship was statistically significant only in men [0.73 (0.58, 0.94)]. Three indicators of additive interaction-RERI, AP, and S-suggested that there is no interaction between gender and leu on the risk of DR.

CONCLUSIONS

Male T2D patients with high leu levels may have a lower risk of DR.

Diabetic macular edema treatment guidelines in India: All India Ophthalmological Society Diabetic Retinopathy Task Force and Vitreoretinal Society of India consensus statement

Diabetic macular edema (DME) is a common cause of moderate visual impairment among people with diabetes. Due to the rising number of people with diabetes in India, the absolute numbers of people with DME are significant. There are several treatment options for DME, and the choice of treatment is based on the availability of retinal specialists and infrastructure for the delivery of treatment. A major challenge is the out-of-pocket expenditure incurred by patients as most treatment options are costly. Treatment also varies based on the associated ocular and systemic conditions. The All India Ophthalmology Society (AIOS) and the Vitreo-Retinal Society of India (VRSI) have developed this consensus statement of the AIOS DR task force and VRSI on practice points of DME management in India. The objective is to describe the preferred practice patterns for the management of DME considering the different presentations of DME in different clinical scenarios.

Combined Phacoemulsification and Intravitreal Dexamethasone Is an Effective Option for High-Risk Diabetic Macula Oedema Patients

Objective

Cataract surgery in diabetic patients carries an increased risk of post-operative macula oedema, particularly in those with a history of diabetic macula oedema (DMO) treatment or DMO at the time of surgery. We investigated whether simultaneous phacoemulsification with intravitreal Ozurdex^® reduces the risk of developing new, or deteriorating current, DMO.

Methods

We conducted a retrospective review of 79 consecutive ‘high-risk’ diabetic patients who underwent phacoemulsification with intraocular lens insertion and intravitreal Ozurdex^® implantation immediately subsequently. ‘High risk’ was defined as diabetic patients with prior treatment history for DMO or current DMO. Central macula thickness (CMT), best-corrected visual acuity and intraocular pressure were recorded pre-operatively, at two to four weeks and at three months post-operatively. A significant change in CMT was defined as a change of ≥0.1 LogOCT units.

Results

The mean age was 72.6 years; 52% were males. The mean pre-operative CMT was 365um. Thirty-seven per cent (37%) patients had prior DMO history that had resolved; 63% had confirmed DMO in surgery. Two to four weeks post-operatively, 82% of patients had stable CMT and 18% showed improvement. No patients deteriorated. Three months post-operatively, 48% of patients had stable CMT relative to pre-operative measurements, 38% improved, and 14% deteriorated. Analysis of variance (ANOVA) indicated no significant differences in response with demographical or pathological factors, including diabetic retinopathy grade and treatment history.

Conclusion

Phacoemulsification surgery combined with Ozurdex^® insertion at the end of the procedure is a highly effective strategy for protecting against the formation of new, or the deterioration of current DMO, in the highest risk diabetic patients undergoing cataract surgery.

The Effect of Ranibizumab Loading Treatment on Vision-Related Quality of Life in Diabetic Macular Edema

AIMS

To investigate the changes in vision-related quality of life after a loading dose of three consecutive intravitreal ranibizumab (IVR) injections in patients with unilateral diabetic macular edema (DME).

MATERIALS AND METHODS

Fifty-two eyes of 52 patients who received IVR injections in only one eye with DME were included in our study. The following characteristics of the patients were recorded: gender, education status, marital status, work status, presence of chronic disease. The changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT) were evaluated at baseline (before treatment) and 1 month after the third intravitreal injection (after treatment). Patients were administered the Turkish form of the National Eye Institute 25-Item Visual Functions Questionnaire (NEI VFQ-25 TR). The quality of life scores assessed by the NEI VFQ-25 TR, the BCVA, intraocular pressure (IOP), and CMT measurements were compared at baseline (before treatment) and 1 month after the third intravitreal injection (after treatment).

RESULTS

We enrolled 52 patients (25 females, 27 males) in our study; mean age was 64.35 ± 9.26 years. After treatment, BCVA improved significantly (p = 0.001), and macular thickness decreased significantly (p < 0.001). All NEI VFQ-25 TR subscale scores were significantly higher after treatment (p < 0.05). However, no significant correlation was found between the change in BCVA and CMT and the change in NEI VFQ-25 TR subscale and composite scores. The increase in near activities scores was significantly higher in males (p = 0.020) and in the retired group (p = 0.022). There were no significant differences in the changes in NEI VFQ-25 TR subscale and composite scores in relation to educational status.

DISCUSSION

Significant improvements in BCVA, macular edema, and vision-related quality of life were found in DME patients who received IVR injections with a loading dose, as shown by the NEI VFQ-25 TR. Interestingly, a significant improvement in quality of life was observed even though the patients could see well with the fellow eye. In conclusion, the NEI VFQ-25 TR is a useful scale to evaluate the changes in visual function and psychosocial characteristics of DME patients after treatment.

Retrospective Analysis of Treatment Patterns in Pseudophakic Diabetic Macular Oedema Eyes Treated with Anti-VEGF

Methods

We performed a retrospective review of outcomes in 81 pseudophakic eyes with DMO that received at least 6 anti-VEGF injections. We reviewed baseline and posttreatment optical coherence tomography images, visual acuity, prescribing patterns, time taken to deliver anti-VEGF injections, and structural and functional outcomes.

Results

It took an average of 913 ± 454.1 days to deliver a mean of 11.1 ± 4.7 anti-VEGF injections. Time from baseline to receiving the first 6 anti-VEGF injections was longer than 9 months in 74.7% (n = 59/79) of eyes. There was a mean gain of 1.6 letters (−0.03 logMAR) from baseline to the end point. After 5 anti-VEGF intravitreal injections, the mean CMT was 391.9 μm from 474.4 μm at baseline (p < 0.0001). In 52 of 79 eyes (65.8%), more than one type of anti-VEGF agent was used.

Conclusions

The anti-VEGF treatment used to treat these eyes with DMO was suboptimal, a finding consistent with recently published “real-world” data. There was a strong tendency for patients to be switched within the class to a second anti-VEGF agent.

Intravitreal Anti-Vascular Endothelial Growth Factor Agents for the Treatment of Diabetic Retinopathy: A Review of the Literature

Background: Diabetic retinopathy (DR) is the leading cause of blindness in the working-age population. The purpose of this review is to gather the existing literature regarding the use of the approved anti-vascular endothelial growth (anti-VEGF) agents in the treatment of DR. Methods: A comprehensive literature review in PubMed engine search was performed for articles written in English language up to 1 July 2021, using the keywords “diabetic retinopathy”, “ranibizumab”, “aflibercept”, and “anti-VEGF”. Emphasis was given on pivotal trials and recent robust studies. Results: Intravitreal anti-VEGF agents have been found to significantly improve visual acuity and reduce retinal thickness in patients with diabetic macular edema (DME) in a long-term follow-up ranging from 1 to 5 years and are considered the standard-of-care in such patients. Regarding DR, intravitreal anti-VEGF agents provided ≥2-step improvement in DR severity on color fundus photography in about 30–35% of patients with NPDR at baseline, in the majority of clinical trials originally designed to evaluate the efficacy of intravitreal anti-VEGF agents in patients with DME. Protocol S and CLARITY study have firstly reported that intravitreal anti-VEGF agents are non-inferior to panretinal photocoagulation (PRP) in patients with proliferative DR (PDR). However, the use of new imaging modalities, such as optical coherence tomography-angiography and wide-field fluorescein angiography, reveals conflicting results about the impact of anti-VEGF agents on the regression of retinal non-perfusion in patients with DR. Furthermore, one should consider the high “loss to follow-up” rate and its devastating consequences especially in patients with PDR, when deciding to treat the latter with intravitreal anti-VEGF agents alone compared to PRP. In patients with PDR, combination of treatment of intravitreal anti-VEGF agents and PRP has been also supported. Moreover, in the specific case of vitreous hemorrhage or tractional retinal detachment as complications of PDR, intravitreal anti-VEGF agents have been found to be beneficial as an adjunct to pars plana vitrectomy (PPV), most commonly given 3–7 days before PPV, offering reduction in the recurrence of vitreous hemorrhage. Conclusions: There is no general consensus regarding the use of intravitreal anti-VEGF agents in patients with DR. Although anti-VEGF agents are the gold standard in the treatment of DME and seem to improve DR severity, challenges in their use exist and should be taken into account in the decision of treatment, based on an individualized approach.

Feasibility Study of a Multimodal, Cloud-Based, Diabetic Retinal Screening Program in a Workplace Environment

Purpose

To evaluate the feasibility of capturing and interpreting retinal images in a workplace environment using a multimodal, cloud-based, diabetic retinal screening program combined with electronic self-reported questionnaires. The burden of diabetic retinopathy (DR) and other retinal conditions, healthcare utilization, and visual function were also assessed.

Methods

A cross-sectional feasibility study was conducted at the Genentech, Inc., Campus Health Center. Eyes of participants were imaged using ultra-widefield (UWF) color fundus photography (CFP) and spectral-domain optical coherence tomography (SD-OCT). A cloud-based platform was used for the automated, seamless transfer of images to a remote reading center for evaluation for DR and other retinal pathologies. Electronic surveys collected participants’ self-reported medical histories, healthcare utilization, and visual function data.

Results

Among 100 participants (mean age, 43.9 years; 44% male), 33% of them self-reported diabetes. Eye examinations within the past 12 months were reported by 71% of all participants (n = 71/100) and by 85% (n = 28/33) of those with self-reported diabetes. Among participants with complete screening images from both UWF-CFP and SD-OCT, 20% (n = 6/30) of those with self-reported diabetes and 8.5% (n = 5/59) of participants with no history of diabetes were unaware they had mild/moderate nonproliferative DR. Among all participants, 20% (20/100) had a retinal finding, on either UWF-CFP or SD-OCT, or both, which prompted a referral for further evaluation.

Conclusions

A retinal screening program deployed via a secure, scalable, and interoperable cloud-based platform was feasible and conveniently integrated into the workplace.

Translational Relevance

Cloud-based platforms could be used to promote a secure, scalable, and interoperable system for retinal screening in nontraditional environments.

Management of Cataract in Patients with Age-Related Macular Degeneration

Cataract and age-related macular degeneration (AMD) are two of the most common eye diseases of aging. This review addresses the pre-operative, intra-operative, and post-operative considerations in managing cataract in patients with age-related macular degeneration. Surgery for visually significant cataracts in patients with AMD can substantially improve the quality of life and reduce the risk of falls. Pre-operative optical coherence tomography is now recommended where possible to identify pre-existing macula disease. Careful counselling of patients is required before cataract surgery, especially with respect to the expected visual outcome, intraocular lens choice and potential risks of surgery. Real-world data has suggested 6 months of intravitreal anti-VEGF therapy for neovascular AMD before cataract surgery is compatible with optimum long-term visual outcomes. Patients receiving intravitreal therapy for neovascular AMD should be advised of the slightly higher risk of intraoperative complications and the surgeon should be prepared to manage these during the operation. During cataract surgery, unnecessary light exposure should be avoided to reduce phototoxicity. Careful planning of intravitreal therapy for neovascular AMD just before cataract surgery allows the eye greater recovery time in the post-operative period before further planned intravitreal therapy.

PACAP is Protective Against Cellular Stress in Retinal Pigment Epithelial Cells

The integrity of the innermost, pigment epithelial layer of the retina is crucial for the photoreceptor survival and for maintaining the outer blood–retina barrier. In several ocular degenerations, such as diabetic retinopathy or macular edema, the stress caused by various harmful stimuli (hypoxia, oxidative stress, hyperosmosis) lead to severe molecular biological changes in this layer, promoting neovascularization of the retina. Pituitary adenylate cyclase activating polypeptide (PACAP) occurs throughout the whole body, including the eye. It has numerous functions in the retina, including the previously described anti-apoptotic and anti-angiogenic effects in retinal pigment epithelial cells. The aim of this present study was to investigate the influence of PACAP on different stress factors. In accordance with previous findings, PACAP significantly ameliorated the increased Hif1-α levels in hypoxic conditions. In H2O2-induced oxidative stress PACAP had an anti-apoptotic effect, it could decrease the expression of cytochrome-c and p53, while it upregulated the concentration of three antioxidants, namely SOD2, PON2 and thioredoxin. In conclusion, we provided new information on the molecular biological background of the retinoprotective effect of PACAP.

Ranibizumab for the treatment of diabetic retinopathy

Introduction: Diabetic retinopathy (DR) is the most common microvascular complication of diabetes mellitus and the leading cause of blindness in young adults. Prior to anti-vascular endothelial growth factor (anti-VEGF) agents, the treatment of DR was based on control of systemic factors and laser photocoagulation. Over the past decade, the use of anti-VEGF agents has revolutionized the treatment of DR, including diabetic macular edema (DME).Areas covered: Ranibizumab has been proven to be effective for the treatment of DME in large clinical trials, while patients in these studies have been assessed in terms of DR severity change. In this review, evidence from randomized trials regarding the use of ranibizumab for DR treatment is presented.Expert opinion: A comprehensive presentation of randomized clinical trials evaluating ranibizumab for DR indicates that it is effective and safe, offering improvement of DR severity in both non-proliferative and proliferative forms. However, there is no general consensus regarding the exact treatment regimen in patients with DR, while the effect of ranibizumab on the progression of retinal ischemia remains unclear.

In-depth transcriptomic analysis of human retina reveals molecular mechanisms underlying diabetic retinopathy

Diabetic Retinopathy (DR) is among the major global causes for vision loss. With the rise in diabetes prevalence, an increase in DR incidence is expected. Current understanding of both the molecular etiology and pathways involved in the initiation and progression of DR is limited. Via RNA-Sequencing, we analyzed mRNA and miRNA expression profiles of 80 human post-mortem retinal samples from 43 patients diagnosed with various stages of DR. We found differentially expressed transcripts to be predominantly associated with late stage DR and pathways such as hippo and gap junction signaling. A multivariate regression model identified transcripts with progressive changes throughout disease stages, which in turn displayed significant overlap with sphingolipid and cGMP-PKG signaling. Combined analysis of miRNA and mRNA expression further uncovered disease-relevant miRNA/mRNA associations as potential mechanisms of post-transcriptional regulation. Finally, integrating human retinal single cell RNA-Sequencing data revealed a continuous loss of retinal ganglion cells, and Müller cell mediated changes in histidine and β-alanine signaling. While previously considered primarily a vascular disease, attention in DR has shifted to additional mechanisms and cell-types. Our findings offer an unprecedented and unbiased insight into molecular pathways and cell-specific changes in the development of DR, and provide potential avenues for future therapeutic intervention.

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.

Treatment choices for diabetic macular oedema: a guideline for when to consider an intravitreal corticosteroid, including adaptations for the COVID-19 era

First-line treatment of centrally involved diabetic macular oedema (CI-DMO) is often with an anti-vascular endothelial growth factor (anti-VEGF) agent. Although this can provide efficacy in the majority of eyes, a sizeable proportion do not respond sufficiently and many continue to receive anti-VEGF therapy after it may be optimal. This imposes a treatment burden on both patients and clinicians and, most importantly of all, can be sight threatening. Changing treatment to an intravitreal corticosteroid implant at the appropriate time may help optimise patient outcomes and reduce injection frequency, thereby reducing treatment burden. Eight retina specialists convened to discuss how to ensure eyes with CI-DMO receiving intravitreal anti-VEGF therapy are evaluated for a potential change to intravitreal corticosteroid therapy at the most effective time in their treatment journey. They concluded that clear criteria on when to consider changing treatment would be helpful and so developed a consensus guideline covering key decision points such as when and how to assess response to anti-VEGF therapy, when to consider a change to corticosteroid therapy and when and how to assess the response to corticosteroid therapy. The guideline was developed before the COVID-19 pandemic but, with the additional challenges arising from this including even greater pressure on clinic capacity, it is more important than ever to reconsider current working practices and adopt changes to improve patient care while also easing pressure on clinic capacity, reducing hospital visits and maintaining patient safety. This publication therefore also includes suggestions for adapting the guidelines in the COVID-19 era.

Role of Oral Antioxidant Supplementation in the Current Management of Diabetic Retinopathy

Oxidative stress has been postulated as an underlying pathophysiologic mechanism of diabetic retinopathy (DR), the main cause of avoidable blindness in working-aged people. This review addressed the current daily clinical practice of DR and the role of antioxidants in this practice. A systematic review of the studies on antioxidant supplementation in DR patients was presented. Fifteen studies accomplished the inclusion criteria. The analysis of these studies concluded that antioxidant supplementation has a IIB level of recommendation in adult Type 1 and Type 2 diabetes mellitus subjects without retinopathy or mild-to-moderate nonproliferative DR without diabetic macular oedema as a complementary therapy together with standard medical care.

Quality of the Australian National Health and Medical Research Council's clinical practice guidelines for the management of diabetic retinopathy

Clinical relevance: Understanding the quality of the commonly used clinical practice guidelines can help busy clinicians in selecting appropriate guidelines for evidence-based eye care for people with diabetes.Background: The National Health and Medical Research Council's (NHMRC) clinical practice guideline on diabetic retinopathy management has been widely used locally and internationally for over 10 years. However, the quality of this guideline has never been formally assessed. This study aimed to systematically evaluate the quality of the NHMRC guideline and compare it against other international guidelines.Methods: The 2008 NHMRC and another five established diabetic retinopathy management international guidelines (Scottish Intercollegiate Guidelines Network, 2017; American Academy of Ophthalmology, 2019; American Optometric Association, 2019; Royal College of Ophthalmologists, UK, 2013, and Canadian Ophthalmologic Society, 2012) were examined using the Appraisal of Guidelines, Research and Evaluation (AGREE II) instrument. Scoring by four independent reviewers was aggregated into six domain and overall rating scores. Consistency among the reviewers was assessed using intraclass correlation coefficient (ICC).Results: The AGREE II domain scores for the NHMRC guideline were: scope and purpose 72%, stakeholder involvement 64%, rigour of development 77%, clarity of presentation 96%, applicability 35%, and editorial independence 15%. The NHMRC guideline's overall score (5.3 of 7) was lower than that of most other guidelines. Compared to others, the NHMRC guideline scored well in clarity of presentation and rigour of development, but less well for editorial independence. The NHMRC guideline was the least current and a need to update it was recognised by all reviewers who identified key areas for improvement.Conclusion: The quality of the NHMRC guideline was comparable to most other established international guidelines. Several areas of strengths and weaknesses in this guideline were identified. Future updates should aim to improve transparency in development and applicability in clinical practice.

Development of a zebrafish screening model for diabetic retinopathy induced by hyperglycemia: Reproducibility verification in animal model

This study aimed at creating a zebrafish screening model for diabetic retinopathy, and evaluated the effects of aflibercept, which is being used to treated diabetic retinopathy. A morphological change occurred at 160 mM of glucose. The survival and hatching rate decreased in a dose-dependent manner. In the 130 mM glucose group, the retinal vessel diameter was more than double that in the normal group. The zebrafish embryo morphology changed in 200 μg/mL and 400 μg/mL at aflibercept. The survival and hatching rate decrease at 400 μg/mL. Aflibercept 100 μg/mL was a nontoxic and effective dose for the zebrafish diabetic retinopathy model. The expression of diabetic retinopathy inflammatory markers was increased in hyperglycemia. But the inflammation was improved by aflibercept in the zebrafish eye. In a zebrafish diabetic retinopathy model, the diameters of retinal vessels were reduced after treatment with aflibercept, and molecular biological and histopathological efficacy was confirmed. This model can serve for screening of new drug candidates for treatment of in diabetic retinopathy.

The innate immune system in diabetic retinopathy

The prevalence of diabetes has been rising steadily in the past half-century, along with the burden of its associated complications, including diabetic retinopathy (DR). DR is currently the most common cause of vision loss in working-age adults in the United States. Historically, DR has been diagnosed and classified clinically based on what is visible by fundoscopy; that is vasculature alterations. However, recent technological advances have confirmed pathology of the neuroretina prior to any detectable vascular changes. These, coupled with molecular studies, and the positive impact of anti-inflammatory therapeutics in DR patients have highlighted the central involvement of the innate immune system. Reminiscent of the systemic impact of diabetes, immune dysregulation has become increasingly identified as a key element of the pathophysiology of DR by interfering with normal homeostatic systems. This review uses the growing body of literature across various model systems to demonstrate the clear involvement of all three pillars of the immune system: immune-competent cells, mediators, and the complement system. It also demonstrates how the relative contribution of each of these requires more extensive analysis, including in human tissues over the continuum of disease progression. Finally, although this review demonstrates how the complex interactions of the immune system pose many more questions than answers, the intimately connected nature of the three pillars of the immune system may also point to possible new targets to reverse or even halt reverse retinopathy.

TXNIP positively regulates the autophagy and apoptosis in the rat müller cell of diabetic retinopathy

AIMS

Diabetic retinopathy (DR) can cause vision loss in patients with diabetes. The present study evaluated the expression of thioredoxin interacting protein (TXNIP) and investigated the role of TXNIP in autophagy and apoptosis of DR.

MAIN METHODS

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were used to measure the expression level of the targets. Clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/cas9) method was applied for knockout of TXNIP. TdT-mediated dUTP Nick-End Labeling (TUNEL) assay and flow cytometry were utilized to detect the apoptosis. Cell Counting Kit-8 (CCK-8) assay was used to evaluate the cell viability. EdU assay was carried out to measure the cell proliferation ability. Retinal immunohistochemistry, retinal frozen section immunofluorescence as well as the electroretinogram (ERG) recording were implemented to detect the function of the retina.

KEY FINDINGS

TXNIP was up-regulated under hyperglycemic condition both in vivo and in vitro. Overexpression of TXNIP activated the autophagy and apoptosis in the rat müller cell. Knockout of TXNIP reduced the autophagy and apoptosis in the rat müller cell under high glucose condition. TXNIP positively regulates autophagy via inhibition of the PI3K/AKT/mTOR signaling pathway. Knockdown of TXNIP improved the visual response to light stimulus of DR.

SIGNIFICANCE

Our study unraveled for the first time that TXNIP positively regulates the autophagy in rat müller cell under high glucose condition by inhibiting the PI3K/AKT/mTOR signaling pathway, providing a novel understanding in the pathogenesis of DR and suggesting a potential new therapeutic target of DR.

SERPINH1, Targeted by miR-29b, Modulated Proliferation and Migration of Human Retinal Endothelial Cells Under High Glucose Conditions

AIM

In the present study, we performed bioinformatics studies and in vitro functional assays to explore the underlying role of serpin family H member 1 (SERPINH1) in the diabetic retinopathy.

METHODS

Common differentially expressed genes (DEGs) between diabetic retinal tissues and normal retinal tissues were analyzed using Gene Expression Omnibus (GEO) database. The proliferation and migration of human retinal endothelial cells (HRECs) was evaluated by MTS, EdU and wound healing assays, respectively; the miRNA and mRNAs expression levels of hub genes in HRECs were determined using quantitative real-time PCR (qRT-PCR). Protein levels were determined using a Western blot assay.

RESULTS

A total of 189 common DEGs were screened between two GEO datasets (GSE60436 and GSE94019), and ten potential hub genes that may link to the progression of diabetic retinopathy were detected. The qRT-PCR results showed that collagen, type I, alpha 1 (COL1A1), Collagen, type I, alpha 2 (COL1A2) and serpin family H member 1 (SERPINH1) mRNA expression levels were up-regulated in the HRECs after being exposed to high glucose for 48 h. Silence of SERPINH1 repressed the high glucose-induced increase in proliferation and migration of HRECs. SERPINH1 was a target of miR-29b and was suppressed by miR-29 in HRECs. SERPINH1 overexpression promoted HREC proliferation and migration. Furthermore, miR-29b suppressed HREC proliferation and migration under high-glucose stimulation, which was significantly attenuated by enforced expression of SERPINH1.

CONCLUSION

In conclusion, by performing the integrated bioinformatics analysis, the present study suggested that 3 hub genes (COL1A1, COL1A2 and SERPINH1) may be associated with diabetic retinopathy pathophysiology. Further mechanistic studies indicated that miR-29b/SERPINH1 signaling participated in high glucose-induced enhancement in the proliferation and migration of HRECs.

Digital Ophthalmology in the UK - Diabetic Retinopathy Screening and Virtual Glaucoma Clinics in the National Health Service

The customary doctor and patient interactions are currently undergoing significant changes through technological advances in imaging and data processing and the need for reducing person-to person contacts during the COVID-19 crisis. There is a trend away from face-to-face examinations to virtual assessments and decision making. Ophthalmology is particularly amenable to such changes, as a high proportion of clinical decisions are based on routine tests and imaging results, which can be assessed remotely. The uptake of digital ophthalmology varies significantly between countries. Due to financial constraints within the National Health Service, specialized ophthalmology units in the UK have been early adopters of digital technology. For more than a decade, patients have been managed remotely in the diabetic retinopathy screening service and virtual glaucoma clinics. We describe the day-to-day running of such services and the doctor and patient experiences with digital ophthalmology in daily practice.

Association of plasminogen activator inhibitor-1 4G5G Polymorphism with risk of diabetic nephropathy and retinopathy: a systematic review and meta-analysis

Background

The 4G5G polymorphism of Plasminogen activator inhibitor-1 (PAI-1) gene is reported to be associated with diabetes nephropathy and retinopathy (DNR) risk. However, the findings are conflicting. Herein, we conducted a case-control and meta-analysis study to explore the association of PAI-1 4G5G polymorphism with risk of DNR.

Methods

We retrieved PubMed, EMBASE, Web of Knowledge, and CNKI databases and screened eligible studies up to August 15, 2020. The strength of associations was assessed by odd ratio (OR) and the corresponding 95% confidence interval (95% CI).

Results

A total of 27 case-control studies including 16 studies with 1,825 cases case and 1,731 controls on DN and eleven studies with 1,397 cases and 1,545 controls on DR were selected. Pooled data showed that the PAI-1 4G5G polymorphism was significantly associated with DN (allele model: OR = 0.674, 95% CI 0.524-0.865, p = 0.002; homozygote model: OR = 0.536, 95% CI 0.351-0.817, p = 0.004; heterozygote model: OR = 0.621, 95% CI 0.427-0.903, p = 0.013; dominant model: OR = 0.575, 95% CI 0.399-0.831, p = 0.003; and recessive model: OR = 0.711, 95% CI 0.515-0.981, p = 0.038) and DR (homozygote model: OR = 0.770, 95% CI 0.621-0.955, p = 0.0.017) risk. Stratified analyses by ethnicity indicated that PAI-1 4G5G polymorphism was associated with DN and DR risk in Asians and Caucasians, respectively.

Conclusions

The present meta-analysis revealed that the PAI-1 4G5G polymorphism was associated with increased risk of DN and DR risk. However, well-designed large-scale clinical studies are required to further validate our results.