Panretinal Photocoagulation vs Intravitreous Ranibizumab for Proliferative Diabetic Retinopathy: A Randomized Clinical Trial

12. Retinopathy, Neuropathy, and Foot Care: Standards of Care in Diabetes-2023

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Association of Treatment Type and Loss to Follow-up With Tractional Retinal Detachment in Proliferative Diabetic Retinopathy

Importance

The association of proliferative diabetic retinopathy (PDR) interventions of panretinal photocoagulation (PRP) and intravitreal injections (IVIs) with tractional retinal detachment (TRD) is unclear.

Objectives

To determine whether different treatment types or a 6-month or longer period of loss to follow-up (LTFU) is associated with TRD.

Design, Setting, and Participants

This nested case-control study included data from January 1, 2000, to June 30, 2021, of patients with PDR. Those who progressed to TRD were matched to non-TRD controls up to a 5:1 ratio. Exclusion criteria included 2 or fewer years in the plan, history of nondiabetic retinopathy, vitreous hemorrhage, previous RD, or any other surgically indicated diagnosis. Patient data were obtained from a deidentified commercial and Medicare Advantage medical claims database. Statistical analysis was performed from January to May 2022.

Exposures

Primary exposures of interest were prior treatment (PRP, IVI, both) and any period of 6 months or longer in which the patient received no eye care.

Main Outcomes and Measures

Odds ratios (ORs) of IVI only compared with PRP and 6-month or longer LTFU on development of TRD.

Results

After application of inclusion and exclusion criteria, a total of 214 patients (mean [SD] age, 55.6 [12.4] years; 115 female [53.7%]) with PDR and TRD were matched to 978 controls (mean [SD] age, 65.6 [11.3] years; 507 female [51.8%]) with only PDR. Among patients with TRD, 69 (32.2%) were treated with laser only, 17 (7.9%) were treated with injection only, 39 (18.2%) were treated with both, and 89 (41.6%) had no prior treatment. Among patients in the PDR-only group, 207 (21.2%) received laser only, 83 (8.5%) received injection only, 57 (5.8%) received both, and 631 (64.5%) received no treatment. After adjusted analysis, no difference in odds of TRD for patients who received injection only compared with patients who received laser only was found (adjusted OR [aOR], 0.56; 95% CI, 0.27-1.14). Patients who received both treatments had higher odds of TRD compared with those who received laser only (aOR, 2.33; 95% CI, 1.21-4.48), and patients who had no treatment had lower odds of TRD (aOR, 0.46; 95% CI, 0.29-0.71; P < .001 for treatment category). Similarly, no difference was seen in the odds of TRD between those with LTFU for 6 months or longer and those without LTFU (aOR, 0.72; 95% CI, 0.49-1.07; P = .11).

Conclusions and Relevance

Results of this case-control analysis suggest that there is no increased risk of TRD associated with IVI-only treatment or with 6-month or longer periods of LTFU, which supports the findings of other investigations. Nonetheless, LTFU rates continue to remain high in patients with PDR, which can contribute to substantial vision loss regardless of treatment regimen.

Diabetic Retinopathy – Diagnostics and Treatment Guidelines

Diabetic retinopathy is one of the most common complications of diabetes mellitus and represents a serious health, social and economic problem. With the expected increase in the number of patients with diabetes, it is becoming the leading cause of severe vision loss in the working-age population.  The presented guidelines summarize the current knowledge about this disease in order to standardize and update the procedures for the diagnosis, classification and treatment of diabetic retinopathy.

Resident Vitreoretinal Procedure Volume: Effect of Intravitreal Injections, Region, Program Size, and Vitreoretinal Fellowship and Veterans Affairs Affiliation

Purpose  To analyze resident vitreoretinal procedure volume across Accreditation Council of Graduate Medical Education (ACGME) accredited ophthalmology residency programs. We assessed the effect of the increase in intravitreal injections (IVI), geographic region, program size, and Veterans Affairs (VA) and vitreoretinal fellowship affiliation on vitreoretinal procedures. Methods  A request was sent to all residency programs in 2018 for their graduating residents' ACGME case logs. Vitreoretinal procedures were defined by ACGME case log categories and included vitreoretinal surgery, peripheral retinal lasers, and IVI. Procedures were categorized by Current Procedural Terminology (CPT) code. Programs were studied by geographic region, program size, and by VA and vitreoretinal fellowship affiliation. Results  A total of 38 of 115 (33.0%) programs responded, and 167 residents logged 32,860 vitreoretinal procedures. The median number of retina procedures per resident was 146 (range 36-729). Programs with a vitreoretinal fellowship had a higher average number of vitreoretinal procedures per resident (208.3 vs. 125.0; p  = 0.002), but there was no difference between the average number of non-IVI vitreoretinal procedures (60.0 vs. 64.2; p  = 0.32). For IVI, VA affiliation (146.6 vs. 71.1; p  = 0.02) and vitreoretinal fellowship (149.4 vs. 60.8; p  < 0.001) were associated with a greater number. More IVI strongly correlated with a larger total volume of retinal procedures ( r  = 0.98), and there was no difference across programs for total retinal procedures when IVI was removed. Conclusions  The presence of a vitreoretinal fellowship at a residency program had a positive effect on resident total vitreoretinal case volume, but their residents performed more IVI. Programs without vitreoretinal fellowships completed on average more non-IVI procedures.

Prevalence of diabetic retinopathy in patients with newly diagnosed type 2 diabetes: A systematic review and meta-analysis

AIMS

Type 2 diabetes mellitus (T2DM) can remain undiagnosed for many years, during which micro- and macro-vascular complications may develop. This study aimed to assess the worldwide prevalence of diabetic retinopathy (DR) in patients with newly diagnosed T2DM.

MATERIALS AND METHODS

We systematically searched electronic databases for relevant studies published from inception to 01 January 2022. Selected studies reported the prevalence of DR among patients with newly diagnosed T2DM, specifying the case definition used. Random-effects meta-analysis was used to derive the pooled prevalence. Subgroup and meta-regression analyses were used to investigate variations in the prevalence estimates in terms of available variables.

RESULTS

Data from 77 studies including 99,847 patients with newly diagnosed T2DM were included from 26 countries. The pooled prevalence of DR among patients with newly diagnosed T2DM was 13.1% (95% CI, 11.1%-15.1%; I²  = 97.0%). DR was higher in clinic-based samples compared with community-based samples (15.0%, 95% CI = 12.4%-17.8% vs. 11.5%, 95% CI = 8.9%-14.5%; p = 0.05; I²  = 97.0%) and was higher in countries in the WHO African 19.2% (95% CI, 14.6%-24.3%; I²  = 76.0%), South-East Asia 15.4% (95% CI, 10.0%-21.6%; I²  = 79.1%), and European 15.0% (95% CI, 11.2%-19.2%; I²  = 82.0%) regions. A higher proportion of female patients was significantly associated with a lower prevalence of DR in patients with newly diagnosed T2DM. We observed that the prevalence of DR in patients with newly diagnosed T2DM has remained unchanged over time.

CONCLUSIONS

Globally, DR is a prevalent complication among patients with newly diagnosed T2DM indicating the importance of establishing effective strategies to promote regular screening for the early diagnosis of T2DM alongside routine ophthalmic assessment at the time of T2DM diagnosis to reduce the burden of vision-threatening retinopathy.

Developments in the detection of diabetic retinopathy: a state-of-the-art review of computer-aided diagnosis and machine learning methods

The exponential increase in the number of diabetics around the world has led to an equally large increase in the number of diabetic retinopathy (DR) cases which is one of the major complications caused by diabetes. Left unattended, DR worsens the vision and would lead to partial or complete blindness. As the number of diabetics continue to increase exponentially in the coming years, the number of qualified ophthalmologists need to increase in tandem in order to meet the demand for screening of the growing number of diabetic patients. This makes it pertinent to develop ways to automate the detection process of DR. A computer aided diagnosis system has the potential to significantly reduce the burden currently placed on the ophthalmologists. Hence, this review paper is presented with the aim of summarizing, classifying, and analyzing all the recent development on automated DR detection using fundus images from 2015 up to this date. Such work offers an unprecedentedly thorough review of all the recent works on DR, which will potentially increase the understanding of all the recent studies on automated DR detection, particularly on those that deploys machine learning algorithms. Firstly, in this paper, a comprehensive state-of-the-art review of the methods that have been introduced in the detection of DR is presented, with a focus on machine learning models such as convolutional neural networks (CNN) and artificial neural networks (ANN) and various hybrid models. Each AI will then be classified according to its type (e.g. CNN, ANN, SVM), its specific task(s) in performing DR detection. In particular, the models that deploy CNN will be further analyzed and classified according to some important properties of the respective CNN architectures of each model. A total of 150 research articles related to the aforementioned areas that were published in the recent 5 years have been utilized in this review to provide a comprehensive overview of the latest developments in the detection of DR.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10462-022-10185-6.

Vitrectomy with ILM peeling in diabetic macular edema in one eye vs. intravitreal anti-VEGF injections in the second eye: a comparative study

PURPOSE

The aim of this study was to compare the results of vitrectomy performed in patients' worse eyes with diabetic macular edema to the results of continuous anti-VEGF treatment performed in patients' fellow eyes.

METHODS

A retrospective interventional study of 14 patients with diabetic macular edema in both eyes. The better eye was always qualified for aflibercept injections (group 1), and the worse eye was scheduled for vitrectomy (group 2). The follow-up lasted 12 months. The following parameters were measured: visual acuity (V), central retinal thickness (CRT), maximum retinal thickness (MRT), central choroidal thickness (CCT), superficial fovea avascular zone (sFAZ) and deep fovea avascular zone (dFAZ), and vessel density at the level of superficial (sVD) and deep (dVD) retinal vessels.

RESULTS

None of the analyzed factors differed between groups with statistical significance at any timepoint. The time of recovery of vision was identical in both eyes (F = 0.91, p = 0.449). The final sFAZ was significantly smaller for group 2 (median 196 μm) than for group 1 (median 375 μm; U = 101.0; p = 0.022; r = 0.44).

CONCLUSION

Both techniques resulted in similar improvements in visual acuity and decreases in CRT after 1 year. sFAZ decreased in all eyes, with a higher extent after vitrectomy.

Recent trends in anti-vascular endothelial growth factor intravitreal injections: a large claims database study in Japan

PURPOSE

To clarify recent trends in the use of intravitreal injections of anti-vascular endothelial growth factor (VEGF) in Japan.

STUDY DESIGN

Retrospective cohort study.

METHODS

We used the DeSC database, a large-scale claims database for Japan, for entries between April 2014 and March 2021. We counted the number of anti-VEGF drug injections (aflibercept, ranibizumab, brolucizumab, and pegaptanib) administered every year, calculated the sex- and age-adjusted injection rates, and stratified these rates according to sex, age categories, anti-VEGF drugs, and diagnoses. We also calculated the number of injections administered within one year after the first injection according to the diagnoses.

RESULTS

In total, 164,451 cases of anti-VEGF injections were identified. The sex- and age-adjusted rates of anti-VEGF injections per 1000 person-years increased from 7.9 in 2014 to 16.1 in 2020. Men were approximately twice as likely to receive anti-VEGF injections than women. The 70-79, 80-89, and ≥90 age categories had the highest rates, accounting for approximately 80%. Neovascular age-related macular degeneration had the highest rate, accounting for 60-70% over the study period. Aflibercept was the most commonly used drug, accounting for approximately 80% over the study period. The average number of injections within one year after the first injection was 4.4 for neovascular age-related macular degeneration, 2.7 for branch retinal vein occlusion, 3.1 for central retinal vein occlusion, and 3.5 for diabetic macular edema in 2020.

CONCLUSION

These findings can be used as a benchmark for the clinical practice of anti-VEGF therapy.

Current Treatments and Innovations in Diabetic Retinopathy and Diabetic Macular Edema

Diabetic retinopathy (DR) is one of the leading causes of blindness worldwide. Multiple treatment options have been used over time to attempt to modify the natural progression of the disease in both proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME). These two retinal complications are the result of microvascular occlusions and vascular hyperpermeability and are considered one of the leading causes of irreversible blindness in patients of working age. It is now well demonstrated that PDR and DME are associated with increased levels of inflammatory and pro-angiogenic factors in the ocular compartment. To date, laser photocoagulation, vascular endothelial growth factor (VEGF) inhibitors, and corticosteroids have demonstrated efficacy in their treatment in large randomized controlled trials and in real-life observational studies. This manuscript aims to provide a comprehensive review of current treatments, including the main drugs used in diabetic pathologic manifestations, as well as new therapeutic alternatives, such as extended-release intraocular devices.

HIF1A Knockout by Biallelic and Selection-Free CRISPR Gene Editing in Human Primary Endothelial Cells with Ribonucleoprotein Complexes

Primary endothelial cells (ECs), especially human umbilical vein endothelial cells (HUVECs), are broadly used in vascular biology. Gene editing of primary endothelial cells is known to be challenging, due to the low DNA transfection efficiency and the limited proliferation capacity of ECs. We report the establishment of a highly efficient and selection-free CRISPR gene editing approach for primary endothelial cells (HUVECs) with ribonucleoprotein (RNP) complex. We first optimized an efficient and cost-effective protocol for messenger RNA (mRNA) delivery into primary HUVECs by nucleofection. Nearly 100% transfection efficiency of HUVECs was achieved with EGFP mRNA. Using this optimized DNA-free approach, we tested RNP-mediated CRISPR gene editing of primary HUVECs with three different gRNAs targeting the HIF1A gene. We achieved highly efficient (98%) and biallelic HIF1A knockout in HUVECs without selection. The effects of HIF1A knockout on ECs' angiogenic characteristics and response to hypoxia were validated by functional assays. Our work provides a simple method for highly efficient gene editing of primary endothelial cells (HUVECs) in studies and manipulations of ECs functions.

Vitreous inflammatory and angiogenic factors on patients with proliferative diabetic retinopathy or diabetic macular edema: the role of Lipocalin2

PURPOSE

Quantitative analysis of vitreous inflammatory and angiogenic factors from patients with proliferative diabetic retinopathy (PDR) or diabetic macular edema (DME).

MATERIALS AND METHODS

Collection of undiluted vitreous samples from 20 diabetic patients: 13 with proliferative diabetic retinopathy (PDR) and 7 with diabetic macular edema (DME). DME patients had suboptimal response to anti-VEGF treatment. Samples from 11 control patients, with vitreomacular interface pathology such as idiopathic epiretinal membrane (iERM) (n = 4), vitreomacular traction syndrome (VMT) (n = 3) and full thickness macular hole (FTMH) (n = 3), were also collected. The levels of IL1b, IL6, IL8, IL27, TNFα, ICAM-1, VCAM, MCP-1, VEGFA and LCN2 were measured using cytometry flow analysis. Median values were compared with Mann-Whitney test since the distributions were skewed. Statistical analysis was performed with the Statistical Package for Social Sciences software (IBM Corp. Released 2012. IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp.).

RESULTS

The median concentration of LCN2, IL6, IL8, IL1b, IL27, ICAM, VCAM-1, MCP-1, TNFa and VEGFA was higher in PDR patients than in controls. Similarly, the median concentration of LCN2, IL6, IL8, IL27, ICAM, VCAM-1, TNFa and VEGFA was higher in DME patients than in controls. In particular, median LCN2 concentration in diabetic patients was 5,711 pg/ml (interquartile range [IR] = 2,534), while in controls was 2,586 pg/ml (IR = 2,345). Moreover, median LCN2 was 6,534 pg/ml in the DME group (IR = 6,850) and 4,785 pg/ml in the PDR group (IR = 2,608), (p = 0.025).

CONCLUSION

Various inflammatory and angiogenic factors are involved in the pathophysiology of PDR and DME. Elevated vitreous levels of LCN2 in PDR and especially in DME patients reveal a potential pathogenic association. More extended studies could verify LCN2 as an alternative therapeutic target.

DCZ19931, a novel multi-targeting kinase inhibitor, inhibits ocular neovascularization

Neovascularization is a prominent cause of irreversible blindness in a variety of ocular diseases. Current therapies for pathological neovascularization are concentrated on the suppression of vascular endothelial growth factors (VEGF). Despite the remarkable efficacy of anti-VEGF drugs, several problems still exist, including ocular complications and drug resistance. Thus, it is still required to design novel drugs for anti-angiogenic treatment. This study aimed to investigate the anti-angiogenic effects of a small molecule multi-target tyrosine kinase inhibitor, DCZ19931, on ocular neovascularization. The results showed that administration of DCZ19931 at the tested concentrations did not cause obvious cytotoxicity and tissue toxicity. DCZ19931 could reduce the size of choroidal neovascularization (CNV) lesions in laser-induced CNV model and suppress ocular neovascularization in oxygen-induced retinopathy (OIR) model. DCZ19931 could suppress VEGF-induced proliferation, migration, and tube formation ability of endothelial cells, exhibiting similar anti-angiogenic effects as Ranibizumab. DCZ19931 could reduce the levels of intercellular cell adhesion molecule-1 (ICAM-1) expression in vivo and in vitro. Network pharmacology prediction and western blots revealed that DCZ19931 exerted its anti-angiogenic effects through the inactivation of ERK1/2-MAPK signaling and p38-MAPK signaling. In conclusion, this study indicates that DCZ19931 is a promising drug for anti-angiogenic therapy for ocular diseases.

Vitreous protein networks around ANG2 and VEGF in proliferative diabetic retinopathy and the differential effects of aflibercept versus bevacizumab pre-treatment

Extracellular signalling proteins interact in networks rather than in isolation. In this context we investigated vitreous protein levels, including placental growth factor (PlGF), angiopoietin-2 (ANG2) and vascular endothelial growth factor (VEGF), in patients with proliferative diabetic retinopathy (PDR) with variable disease severities, and after anti-VEGF pre-treatment. Vitreous samples of 112 consecutive patients undergoing vitrectomy for PDR and of 52 non-diabetic patients with macular holes as controls were studied. A subset of the PDR patients were treated with either aflibercept (AFB, n = 25) or bevacizumab (BVZ)/ranibizumab (RZB) (n = 13), before surgery. Antibody-based analysis of 35 proteins (growth factors and cytokines) showed a significant increase in expression levels of 27 proteins in PDR patients as compared to controls. In network analysis of co-regulated proteins, a strong correlation in expression levels between VEGF, PlGF, MCP1 and ANG2 was found, mostly clustered around ANG2. In the AFB treatment group, concentrations of several proteins were decreased, including VEGFR1, whereas interleukin 6 and 8 were increased as compared to untreated PDR patients. The observed differences in vitreous protein levels between the different treatments and untreated PDR patients may underlie differences in clinical outcomes in patients with PDR.

Molecular mechanism of VEGF and its role in pathological angiogenesis

Over the last seven decades, a significant scientific contribution took place in the delineation of the implications of vascular endothelial-derived growth factor (VEGF) in the processes of angiogenesis. Under pathological conditions, mainly in response to hypoxia or ischemia, elevated VEGF levels promote vascular damage and the growth of abnormal blood vessels. Indeed, the development of VEGF biology has revolutionized our understanding of its role in pathological conditions. Hence, targeting VEGF or VEGF-mediated molecular pathways could be an excellent therapeutic strategy for managing cancers and intraocular neovascular disorders. Although anti-VEGF therapies, such as monoclonal antibodies and small-molecule tyrosine kinase inhibitors, have limited clinical efficacy, they can still significantly improve the overall survival rate. This thus demands further investigation through the development of alternative strategies in the management of VEGF-mediated pathological angiogenesis. This review article focuses on the recent developments toward the delineation of the functional biology of VEGF and the role of anti-VEGF strategies in the management of tumor and eye pathologies. Moreover, therapeutic angiogenesis, an exciting frontier for the treatment of ischemic disorders, is highlighted in this review, including wound healing.

Traditional Chinese Medicine Injections for Diabetic Retinopathy: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

Background: The aim of this study was to compare the efficacy of different injected Traditional Chinese Medicines in the treatment of diabetic retinopathy (DR) and to provide a reference for the selection of adjuvant therapy for DR. Content: Related literature in multiple biological databases and websites was searched up to April 15, 2022, without language and publication time restrictions. A Bayesian network meta-analysis was used to analyze the included studies. Summary: Compared with conventional treatment, the combined use of injected Traditional Chinese Medicines, including astragalus, danhong, Ginkgo biloba extract powder, ginkgo leaf extract and dipyridamole (GLED), ligustrazine (LIG), mailuoning, puerarin, safflower, shuxuetong, safflower yellow sodium chloride, and xueshuantong (XST), can significantly improve the clinical effectiveness in patients with DR, while LIG, XST, and GLED can improve vision. The strength of the evidence ranged from high to very low. Outlook: In patients with DR, the combination of multiple injected Traditional Chinese Medicines is more effective than conventional treatment; some of these medicines may also improve visual acuity. This study may provide a good resource and reference for the selection of adjuvant therapy for DR.

VEGF-targeting drugs for the treatment of retinal neovascularization in diabetic retinopathy

Diabetic retinopathy (DR) is the most common microangiopathic complication of diabetes mellitus, representing a major cause of visual impairment in developed countries. Proliferative DR (PDR) represents the last stage of this extremely complex retinal disease, characterized by the development of neovascularization induced by the abnormal production and release of vascular endothelial growth factor (VEGF). The term VEGF includes different isoforms; VEGF-A represents one of the most important pathogenic factors of DR. Anti-VEGF intravitreal therapies radically changed the outcome of DR, due to combined anti-angiogenic and anti-edematous activities. Nowadays, several anti-VEGF molecules exist, characterized by different pharmacological features and duration. With respect to PDR, although anti-VEGF treatments represented a fundamental step forward in the management of this dramatic complication, a big debate is present in the literature regarding the role of anti-VEGF as substitute of panretinal photocoagulation or if these two approaches may be used in combination. In the present review, we provided an update on VEGF isoforms and their role in DR pathogenesis, on current anti-VEGF molecules and emerging new drugs, and on the current management strategies of PDR. There is an overall agreement regarding the relative advantage provided by anti-VEGF, especially looking at the management of PDR patients requiring vitrectomy, with respect to laser. Based on the current data, laser approaches might be avoided when a perfectly planned anti-VEGF therapeutic strategy can be adopted. Conversely, laser treatment may have a role for those patients unable to guarantee enough compliance to anti-VEGF injections.Key messagesVEGF increased production, stimulated by retinal hypoperfusion and ischaemia, is a major pathogenic factor of neovascular complication onset in diabetic retinopathy and of DR stages progression.Nowadays, several anti-VEGF molecules are available in clinical practice and other molecules are currently under investigation. Each anti-VEGF molecule is characterized by different targets and may interact with multiple biochemical pathways within the eye.All the data agreed in considering anti-VEGF molecules as a first line choice for the management of diabetic retinopathy. Laser treatments may have a role in selected advanced cases and for those patients unable to guarantee enough compliance to intravitreal treatments schemes.

Comprehensive assessment of growth factors, inflammatory mediators, and cytokines in vitreous from patients with proliferative diabetic retinopathy

AIM

To assess alterations in growth factors, inflammatory mediators, and cytokines associated with vitreous-retinal diseases in vitreous humor from patients with proliferative diabetic retinopathy (PDR), and to identify potential new treatment targets and strategies.

METHODS

Control vitreous samples were collected from patients with macular hole, epiretinal membranes, or rhegmatogenous retinal detachments, and PDR samples from patients with complications of PDR, who required pars plana vitrectomy. Specimens were stored at -80°C and then investigated by Luminex multi-factor assay. Parametric and nonparametric analyses of demographic characteristics and cytokine expression levels were conducted using SPSS.

RESULTS

There were no significant differences in demographic characteristics between patients with and without PDR. Expression levels of growth factors [platelet-derived growth factor (PDGF)-AA, glial cell line-derived neurotrophic factor (GDNF), and vascular endothelial growth factor A (VEGFA)], inflammatory mediators [interleukin (IL)-8, IL-11, and tumor necrosis factor-α (TNF-α)] and cytokines [chemokine C-X-C ligand (CXCL)10, interferon-γ (IFN-γ), and granulocyte macrophage-colony stimulating factor (GM-CSF)] were significantly elevated in vitreous humor from patients with PDR compared with those in the control group (all P<0.05). Further, VEGFA levels were lower in patients with PDR treated with anti-VEGF injection than those who were not (P<0.05), and there was no difference between the PDR group treated with anti-VEGF and controls (P>0.05).

CONCLUSION

This proof-of-concept study demonstrates the potential for combinational therapeutic strategies to ameliorate diabetic retinopathy progression by targeting growth factors, inflammatory factors, and cytokines, in addition to VEGFA.

Effective treatment of retinal neovascular leakage with fusogenic porous silicon nanoparticles delivering VEGF-siRNA

Aim: To evaluate an intravitreally injected nanoparticle platform designed to deliver VEGF-A siRNA to inhibit retinal neovascular leakage as a new treatment for proliferative diabetic retinopathy and diabetic macular edema. Materials & methods: Fusogenic lipid-coated porous silicon nanoparticles loaded with VEGF-A siRNA, and pendant neovascular integrin-homing iRGD, were evaluated for efficacy by intravitreal injection in a rabbit model of retinal neovascularization. Results: For 12 weeks post-treatment, a reduction in vascular leakage was observed for treated diseased eyes versus control eyes (p = 0.0137), with a corresponding reduction in vitreous VEGF-A. Conclusion: Fusogenic lipid-coated porous silicon nanoparticles siRNA delivery provides persistent knockdown of VEGF-A and reduced leakage in a rabbit model of retinal neovascularization as a potential new intraocular therapeutic.

Spleen Tyrosine Kinase Contributes to Müller Glial Expression of Proangiogenic Cytokines in Diabetes

Purpose

Neuroglial dysfunction occurs early in the progression of diabetic retinopathy. In response to diabetes or hypoxia, Müller glia secrete cytokines and growth factors that contribute to disease progression. This study was designed to examine common signaling pathways activated in Müller glia by both type 1 and pre-/type 2 diabetes.

Methods

RiboTag (Pdgfra-cre;HA-Rpl22) mice were used to compare the impact of streptozotocin (STZ) and a high-fat, high-sucrose (HFHS) diet on ribosome association of mRNAs in Müller glia by RNA sequencing analysis. Human MIO-M1 Müller cells were exposed to either hyperglycemic or hypoxic culture conditions. Genetic manipulation and pharmacologic inhibition were used to interrogate signaling pathways.

Results

Association of mRNAs encoding triggering receptor expressed on myeloid cells 2 (TREM2), DNAX-activating protein 12 kDa (DAP12), and colony stimulating factor 1 receptor (CSF1R) with ribosomes isolated from Müller glia was upregulated in both STZ diabetic mice and mice fed an HFHS diet. The TREM2/DAP12 receptor-adaptor complex signals in coordination with CSF1R to activate spleen tyrosine kinase (SYK). SYK activation was enhanced in the retina of diabetic mice and in human MIO-M1 Müller cell cultures exposed to hyperglycemic or hypoxic culture conditions. DAP12 knockdown reduced SYK autophosphorylation in Müller cells exposed to hyperglycemic or hypoxic conditions. SYK inhibition or DAP12 knockdown suppressed hypoxia-induced expression of the transcription factor hypoxia-inducible factor 1⍺ (HIF1⍺), as well as expression of vascular endothelial growth factor and angiopoietin-like 4.

Conclusions

The findings support TREM2/DAP12 receptor-adaptor complex signaling via SYK to promote HIF1α stabilization and increased angiogenic cytokine production by Müller glia.

Transition from Laser to Intravitreal Injections for Diabetic Retinopathy: Hospital Utilization and Costs from an Extended Healthcare Perspective

PURPOSE

To describe the trends in hospital utilization and economic outcomes associated with the transition from laser to intravitreal injection (IVI) therapy for diabetic retinopathy (DR) at Oslo University Hospital (OUH), which provides the largest retina service in Norway.

METHODS

This descriptive study analyzed hospital administrative data and determined the average utilization and treatment proportions of laser therapy, IVIs and vitrectomy for each patient per year. The Chi-square test was used to compare resource use between treatment groups. From an extended healthcare perspective, the annual cost per patient was calculated using Norwegian tariff data from 2020 and the National Medication Price Registry for patients seen between 2010 and 2018. Bootstrapping was performed to generate 95% confidence intervals for the cost per patient per year.

RESULTS

Among the 1838 (41% female) patients treated for DR between 2005 and 2018, OUH provided on average 1.09 laser treatments per DR patient and 0.54 vitrectomies per DR patient in 2005, whose utilization declined to 0.54 and 0.05 treatments per DR patient, respectively, by 2018. Laser treatments declined from 64% to 10%, while vitrectomies declined from 32% to 1%. In contrast, IVI treatments increased from 4.5% to 89% of the total share, representing an average increase, from 0.08 injections per patient in 2005 to 4.73 injections per patient in 2018. Both the increasing number of DR patients and the shift in the type of treatment increased the economic costs of treating DR from a total of EUR 0.605 million (EUR 2935 per patient) in 2010 to EUR 2.240 million (EUR 3665 per patient) in 2018, with IVIs contributing considerably to these costs.

CONCLUSIONS

Despite the decline in the use of vitrectomies, the transition from laser to IVI therapy for DR increased the healthcare resource utilization and economic costs of its treatment over the observed time. A main cost driver was the need for long-term IVIs, in addition to the drug cost itself. Trade-offs can be achieved through effective alternative IVI delivery or appropriate drug choice that balances patient needs with the economic burden of treating DR.

Efficacy and safety of intravitreal anti-VEGF therapy in diabetic retinopathy: what we have learned and what should we learn further?

INTRODUCTION

Diabetic retinopathy (DR) is one of the most frequent microvascular complications of diabetes that can lead to blindness. Laser treatment has been the gold standard treatment for diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) for many years. Recently, the role of vascular endothelial growth factor (VEGF) has been established in the pathogenesis of DR, and the use of intravitreal anti-VEGF therapy has gained popularity for the management of DR.

AREAS COVERED

This review includes a brief overview of the efficacy and safety of currently available (bevacizumab, ranibizumab, and aflibercept) and potential future (brolucizumab, faricimab, and KSI-301) anti-VEGF agents in patients with DR based mainly on publicly available data from phase 1, 2 and 3 clinical trials.

EXPERT OPINION

Clinical trials investigating the efficacy of intravitreal bevacizumab, ranibizumab, and aflibercept injections demonstrated favorable functional and anatomical outcomes in patients with DME. Moreover, the use of these anti-VEGF agents showed a significant improvement in the severity of DR. Recent clinical research for future anti-VEGF molecules aims to provide higher target-protein binding affinity and prolonged therapeutic effect. Brolucizumab, faricimab, and KSI-301 are three novel anti-VEGF agents that demonstrate promising data for the management of DME and potentially DR.

Systemic and Ocular Adverse Events with Intravitreal Anti-VEGF Therapy Used in the Treatment of Diabetic Retinopathy: a Review

PURPOSE OF REVIEW

Intravitreal anti-vascular endothelial growth factor (VEGF) agents are used routinely in the management of neovascular conditions including proliferative diabetic retinopathy and diabetic macular edema. While the efficacy of anti-VEGF agents has been well-validated, their ocular and systemic adverse events should always be considered and discussed with patients. The aim of this review is to discuss the most recent literature reports regarding the various ocular and systemic adverse events associated with intravitreal anti-VEGF treatment in diabetic retinopathy.

RECENT FINDINGS

The most frequently reported adverse ocular events include subconjunctival hemorrhage, vitreous hemorrhage, increased intraocular pressure, uveitis, endophthalmitis, ocular surface disease, and traumatic cataract. Subconjunctival hemorrhage and vitreous hemorrhage are the most common ocular adverse events reported with intravitreal anti-VEGF treatment. The most serious (though rare) ocular adverse events include endophthalmitis and rhegmatogenous retinal detachment. A consensus regarding the association of systemic adverse events (such as myocardial infarction, stroke, and death) with intravitreal anti-VEGF treatments has not been established. Intravitreal anti-VEGF therapy is used in the treatment of diabetic retinopathy, macular degeneration, and other diseases. These agents are associated with a variety of ocular and systemic adverse events that ophthalmologists should always consider.

Risk factors for the development or progression of diabetic retinopathy in pregnancy: Meta‐analysis and systematic review

BACKGROUND

Diabetic retinopathy (DR) is the leading cause of blindness in the working-age population, and it increases in severity during pregnancy.

METHODS

Systematic review of literature from PubMed, Cochrane Library and Web of Science using keywords 'diabetic retinopathy' and 'pregnancy' and 'progression' from inception to 2021 was completed. Included studies were (1) peer-reviewed observational studies addressing progression/development of DR in pregnancy, (2) provided the number of diabetic patients that developed/progressed in DR during pregnancy, and (3) included differential data on variables between progression and non-progression groups. This was applied by two independent researchers and referred to a third researcher as necessary. Twenty-seven of the original 138 studies met this criterion. Data were pooled and analysed using fixed-effects in meta-analysis.

RESULTS

From 27 studies, 2537 patients were included. Pre-eclampsia [Risk Ratio (RR) 2.62 (95% CI = 1.72, 4.00)] and hypertension treatment during pregnancy [RR 2.74 (95% CI = 1.72, 4.00)] were significantly associated with the development/progression of DR. HbA1c at baseline [MD 0.82 (95% CI = 0.59, 1.06)], duration of diabetes [mean difference (MD) 5.97 (95% CI = 5.38, 6.57)], and diastolic blood pressure at baseline [MD 3.29 (95% CI = 0.46, 6.12)] were all significantly higher in the progression group while only mean birth weight [MD -0.17 (95% CI = -0.31, -0.03)] was significantly higher in the non-progression group.

CONCLUSIONS

This study fills a gap in the literature and provide physicians with more information on the risk factors associated with the progression of DR in pregnancy and how to counsel this vulnerable patient population appropriately.

Long-Term Outcomes of Same Patient Eyes Treated with Pars Plana Vitrectomy in One Eye and Conventional Treatment in the Other for Complications of Proliferative Diabetic Retinopathy

The purpose of this study was to evaluate the long-term, real-world outcomes of pars plana vitrectomy (PPV) for complications of proliferative diabetic retinopathy. A retrospective review involving 64 patients with proliferative diabetic retinopathy that underwent PPV in their worse-seeing eye were followed for a minimum of 8 years. The fellow eye underwent conventional treatment. Patients were divided into two groups by age: patients younger than 50 years of age and patients older than 50. In the younger than 50 group, 89% of vitrectomized eyes had improved visual acuity (VA) while 3.6% had decreased VA. A total of 14% of vitrectomized eyes required additional laser and 11% required reoperations. In the conventional treatment eyes, 25% had improved VA while 68% had decreased VA (p < 0.05). A total of 72% required additional laser and 60% required PPV. In the older than 50 group, 86% of vitrectomized eyes had VA improvement and 3% had decreased VA. A total of 8% required laser and 8% required reoperations. In the conventional treatment eyes, 30% improved VA and 48% had decreased VA (p < 0.05). Additional procedures required included laser in 70% and PPV in 17%. In both age groups, eyes that underwent PPV had better final visual outcomes than eyes that received conventional treatment for PDR.

A Paradigm Shift in the Management Approaches of Proliferative Diabetic Retinopathy: Role of Anti-VEGF Therapy

Diabetic retinopathy (DR) is considered one of the leading causes of vision loss globally. It principally causes upregulation of pro-angiogenic, proinflammatory, and vascular permeability factors such as vascular endothelial growth factor (VEGF), leading to neovascularisation. The advanced stage of DR or proliferative diabetic retinopathy (PDR) is of more concern, as it leads to vitreous haemorrhage and traction retinal detachment. Various risk factors associated with PDR include hyperglycemia, hypertension, neuropathy, dyslipidemia, anaemia, nephropathy, and retinal complications of drugs used for diabetes. Current management approaches for PDR have been stratified and involve pan-retinal photocoagulation, vitrectomy, and anti-VEGF agents. Given the emerging role of anti-VEGF agents as a favourable adjunct or alternative therapy, they have a critical role in the management of PDR. The review emphasises current management approaches for PDR focusing on anti-VEGF therapy. The review also highlights the risk/benefit evaluation of the various approaches employed for PDR management in various clinical scenarios.

Visual acuity outcome of stable proliferative diabetic retinopathy following initial complete panretinal photocoagulation

Background

Recent clinical trials on proliferative diabetic retinopathy (PDR) show that presenting visual acuity can be stabilised with panretinal photocoagulation (PRP) within 2 years despite the need for supplementary PRP or anti-vascular endothelial growth factor therapy for concomitant diabetic macular oedema (DMO). It is unclear whether similar results can be obtained in daily clinical practice. Here, we query the probability of vision loss in patients with treatment-naïve PDR who have attained stability after PRP and its predictors.

Methods

Retrospective cohort study at a tertiary eye centre between 01 January 2015 and 31 December 2019, wherein 2336 eyes met study criteria with first record of stable PRP-treated PDR in at least one eye. Kaplan-Meier and Cox proportional hazards modelling were used to report the probability of vision loss of at least five Early Treatment Diabetic Retinopathy Study (ETDRS) letters.

Results

The probability of losing at least five ETDRS letters was 50% at 3.32 (95% CI, 2.94 to 3.78) years after achieving first stability post PRP in treatment-naïve PDR. The mean decrease at this event was 14.2 (SD 13.0) ETDRS letters irrespective of the presence of DMO. The strongest risk factor for vision loss was a history of DMO at baseline (HR 1.62 (95% CI, 1.34 to 1.95), p<0.001).

Discussion

One in two patients with stable treated PDR lose a line of vision by 3.5 years. This resulted in 15% of patients losing their eligibility to drive. Notably, 13% of the cohort died during the follow-up period.

Management of complicated proliferative diabetic retinopathy in a patient with oculocutaneous albinism

Purpose

To describe the management and outcome of a patient with oculocutaneous albinism and complicated proliferative diabetic retinopathy, as well as to discuss treatment challenges and strategies in this patient population.

Observation

A 52-year-old patient with oculocutaneous albinism and diabetes presented with light perception vision in her right eye and 20/300 vision in her left eye. Examination showed a diabetic tractional retinal detachment in the right eye and high-risk proliferative diabetic retinopathy (PDR) in the left eye. In the right eye, the patient underwent pars plana vitrectomy, membrane delamination, endolaser therapy, and silicone oil tamponade, with follow-up evaluations showing a flat retina under silicone oil with regressed retinopathy in this eye. In her left eye, pan-retinal photocoagulation was attempted without success, with persistent PDR and absence of laser marks in this eye. Subsequently, the patient underwent six intravitreal anti-VEGF injections, after which she developed a tractional retinal detachment necessitating treatment cessation and a planned surgical intervention.

Conclusion and Importance

This case highlights the difficulty of using standard medical and surgical treatment strategies when caring for patients with oculocutaneous albinism and complicated proliferative diabetic retinopathy. If medical treatments fail in these patients, surgical approaches should be planned with extreme care due to the risks and challenges posed by hypopigmented fundi.

Method

Interventional case report.

Diabetic retinopathy screening in the emerging era of artificial intelligence

Diabetic retinopathy is a frequent complication in diabetes and a leading cause of visual impairment. Regular eye screening is imperative to detect sight-threatening stages of diabetic retinopathy such as proliferative diabetic retinopathy and diabetic macular oedema in order to treat these before irreversible visual loss occurs. Screening is cost-effective and has been implemented in various countries in Europe and elsewhere. Along with optimised diabetes care, this has substantially reduced the risk of visual loss. Nevertheless, the growing number of patients with diabetes poses an increasing burden on healthcare systems and automated solutions are needed to alleviate the task of screening and improve diagnostic accuracy. Deep learning by convolutional neural networks is an optimised branch of artificial intelligence that is particularly well suited to automated image analysis. Pivotal studies have demonstrated high sensitivity and specificity for classifying advanced stages of diabetic retinopathy and identifying diabetic macular oedema in optical coherence tomography scans. Based on this, different algorithms have obtained regulatory approval for clinical use and have recently been implemented to some extent in a few countries. Handheld mobile devices are another promising option for self-monitoring, but so far they have not demonstrated comparable image quality to that of fundus photography using non-portable retinal cameras, which is the gold standard for diabetic retinopathy screening. Such technology has the potential to be integrated in telemedicine-based screening programmes, enabling self-captured retinal images to be transferred virtually to reading centres for analysis and planning of further steps. While emerging technologies have shown a lot of promise, clinical implementation has been sparse. Legal obstacles and difficulties in software integration may partly explain this, but it may also indicate that existing algorithms may not necessarily integrate well with national screening initiatives, which often differ substantially between countries.

Deletion of Tgfβ signal in activated microglia prolongs hypoxia-induced retinal neovascularization enhancing Igf1 expression and retinal leukostasis

Retinal neovascularization (NV) is the major cause of severe visual impairment in patients with ischemic eye diseases. While it is known that retinal microglia contribute to both physiological and pathological angiogenesis, the molecular mechanisms by which these glia regulate pathological NV have not been fully elucidated. In this study, we utilized a retinal microglia-specific Transforming Growth Factor-β (Tgfβ) receptor knock out mouse model and human iPSC-derived microglia to examine the role of Tgfβ signaling in activated microglia during retinal NV. Using a tamoxifen-inducible, microglia-specific Tgfβ receptor type 2 (Tgfβr2) knockout mouse [Tgfβr2 KO (ΔMG)] we show that Tgfβ signaling in microglia actively represses leukostasis in retinal vessels. Furthermore, we show that Tgfβ signaling represses expression of the pro-angiogenic factor, Insulin-like growth factor 1 (Igf1), independent of Vegf regulation. Using the mouse model of oxygen-induced retinopathy (OIR) we show that Tgfβ signaling in activated microglia plays a role in hypoxia-induced NV where a loss in Tgfβ signaling microglia exacerbates and prolongs retinal NV in OIR. Using human iPSC-derived microglia cells in an in vitro assay, we validate the role of Transforming Growth Factor-β1 (Tgfβ1) in regulating Igf1 expression in hypoxic conditions. Finally, we show that Tgfβ signaling in microglia is essential for microglial homeostasis and that the disruption of Tgfβ signaling in microglia exacerbates retinal NV in OIR by promoting leukostasis and Igf1 expression.

Effect of prophylactic anti-VEGF injections on the prevention of recurrent vitreous hemorrhage in PDR patients after PRP

We evaluated the effectiveness of intravitreal anti-vascular endothelial growth factor (anti-VEGF) antibody injection (IVAI) for the prevention of recurrent vitreous hemorrhage (VH) due to neovascularization on disc (NVD) in patients with proliferative diabetic retinopathy (PDR) after panretinal photocoagulation (PRP). This retrospective case series reviewed the medical records of 12 PDR patients with recurrent VH after PRP from NVD. The interval between IVAIs was decided on the basis of the interval between VH recurrences after the initial IVAI, and NVD regression/recurrence during follow-up. We recorded the success rate of VH prevention, and the interval between IVAIs. Fundus examination revealed NVD regression at 1 month after the injection. However, NVD progressed gradually and VH recurred after 3–4 months. Thereafter, IVAIs were administered every 3–4 months; VH did not recur and visual acuity remained stable during the treatment period. In one case, NVD did not recur after 4 years of periodic injections. No systemic or ocular complications of IVAI were observed. In conclusion, proactive and periodic IVAIs (at 3–4-month intervals) may prevent recurrent VH in association with NVD in PDR patients after PRP.

Aflibercept Monotherapy or Bevacizumab First for Diabetic Macular Edema

BACKGROUND

In eyes with diabetic macular edema, the relative efficacy of administering aflibercept monotherapy as compared with bevacizumab first with a switch to aflibercept if the eye condition does not improve sufficiently (a form of step therapy) is unclear.

METHODS

At 54 clinical sites, we randomly assigned eyes in adults who had diabetic macular edema involving the macular center and a visual-acuity letter score of 24 to 69 (on a scale from 0 to 100, with higher scores indicating better visual acuity; Snellen equivalent, 20/320 to 20/50) to receive either 2.0 mg of intravitreous aflibercept or 1.25 mg of intravitreous bevacizumab. The drug was administered at randomization and thereafter according to the prespecified retreatment protocol. Beginning at 12 weeks, eyes in the bevacizumab-first group were switched to aflibercept therapy if protocol-specified criteria were met. The primary outcome was the mean change in visual acuity over the 2-year trial period. Retinal central subfield thickness and visual acuity at 2 years and safety were also assessed.

RESULTS

A total of 312 eyes (in 270 adults) underwent randomization; 158 eyes were assigned to receive aflibercept monotherapy and 154 to receive bevacizumab first. Over the 2-year period, 70% of the eyes in the bevacizumab-first group were switched to aflibercept therapy. The mean improvement in visual acuity was 15.0 letters in the aflibercept-monotherapy group and 14.0 letters in the bevacizumab-first group (adjusted difference, 0.8 letters; 95% confidence interval, -0.9 to 2.5; P = 0.37). At 2 years, the mean changes in visual acuity and retinal central subfield thickness were similar in the two groups. Serious adverse events (in 52% of the patients in the aflibercept-monotherapy group and in 36% of those in the bevacizumab-first group) and hospitalizations for adverse events (in 48% and 32%, respectively) were more common in the aflibercept-monotherapy group.

CONCLUSIONS

In this trial of treatment of moderate vision loss due to diabetic macular edema involving the center of the macula, we found no evidence of a significant difference in visual outcomes over a 2-year period between aflibercept monotherapy and treatment with bevacizumab first with a switch to aflibercept in the case of suboptimal response. (Funded by the National Institutes of Health; Protocol AC ClinicalTrials.gov number, NCT03321513.).

Macrophages in close proximity to the vitreoretinal interface are potential biomarkers of inflammation during retinal vascular disease

Background

Diabetic retinopathy and retinal vein occlusion are vision threatening retinal vascular diseases. Current first-line therapy targets the vascular component, but many patients are treatment-resistant due to unchecked inflammation. Non-invasive inflammatory imaging biomarkers are a significant unmet clinical need for patients. Imaging of macrophage-like cells on the surface of the retina using clinical optical coherence tomography (OCT) is an emerging field. These cells are increased in patients with retinal vascular disease, and could be a potential inflammatory biomarker. However, since OCT is limited by an axial resolution of 5–10 microns, the exact location and identity of these retinal cells is currently unknown.

Methods

We performed OCT followed by confocal immunofluorescence in wild-type mice to identify macrophages within 5–10 microns of the vitreoretinal interface. Next, we used Cx3cr1^CreER/+; Rosa26^zsGreen/+ mice to fate map retinal surface macrophages. Using confocal immunofluorescence of retinal sections and flatmounts, we quantified IBA1⁺Tmem119⁺CD169^neg microglia, IBA1⁺Tmem119^negCD169^neg perivascular macrophages, and IBA1⁺Tmem119^negCD169⁺ vitreal hyalocytes. Finally, we modeled neuroinflammation with CCL2 treatment and characterized retinal surface macrophages using flow cytometry, OCT, and confocal immunofluorescence.

Results

We were able to detect IBA1⁺ macrophages within 5–10 microns of the vitreoretinal interface in wild-type mice using OCT followed by confirmatory confocal immunofluorescence. Retinal surface macrophages were 83.5% GFP⁺ at Week 1 and 82.4% GFP⁺ at Week 4 using fate mapping mice. At steady state, these macrophages included 82% IBA1⁺Tmem119⁺CD169^neg microglia, 9% IBA1⁺Tmem119^negCD169⁺ vitreal hyalocytes, and 9% IBA1⁺Tmem119^negCD169^neg perivascular macrophages. After CCL2-driven neuroinflammation, many Ly6C⁺ cells were detectable on the retinal surface using OCT followed by confocal immunofluorescence.

Conclusions

Macrophages within close proximity to the vitreoretinal interface are self-renewing cells, and predominantly microglia with minor populations of perivascular macrophages and vitreal hyalocytes at steady state. In the context of neuroinflammation, monocytes and monocyte-derived macrophages are a significant component of retinal surface macrophages. Human OCT-based imaging of retinal surface macrophages is a potential biomarker for inflammation during retinal vascular disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02562-3.

Interest of Widefield-Optical Coherence Tomography Angiography for Diagnosis and Follow-Up of Retinal Neovascularisation in Proliferative Diabetic Retinopathy

Aim

The primary aim was to evaluate the use of optical coherence tomography angiography (OCTA) versus fluorescein angiography (FA) for detecting and monitoring retinal neovascularization (NV) in patients with proliferative diabetic retinopathy (PDR) receiving treatment with anti-vascular endothelial growth factor (anti-VEGF).

Methods

Treatment-naïve patients with PDR, willing to begin anti-VEGF treatment without laser from 9/2018–2/2020 were included. FA and OCTA scans were obtained at baseline, and a second OCTA scan was performed after 6 months of anti-VEGF therapy. We calculated sensitivity and specificity for two masked graders with respect to identifying NV on OCTA versus FA. Using ImageJ software, we also measured the change in NV size, at baseline and 6-month follow-up.

Results

Ten eyes in eight patients were included, of which three eyes in three patients received a 6-month follow-up examination. Mean age was 51.7 ± 11.2 years, and 75% of patients were male. Overall, 21 NV sites in the 10 eyes were identified both clinically and on FA. Using OCTA scans, the sensitivity and specificity for both graders were extremely high, ranging from 95.2% to 100%. At 6-month follow-up, NV size decreased by 69.8%.

Conclusion

These results suggest that OCTA may provide a suitable alternative to FA for visualizing, measuring, and monitoring changes in retinal NV in patients with PDR who receive anti-VEGF therapy.

Angiogenic footprints in diabetic retinopathy: opportunities for drug development

Diabetic retinopathy is one of the withering disorders that has been making the lives of patients miserable. Arising as a result of chronic high blood sugar levels in diabetes patients, retinopathy has become a major reason causing permanent blindness, retinal detachment, vitreous humor, rage, or glaucoma among patients. Angiogenesis being the major culprit behind the development of this condition is the growth of new blood vessels from the earlier ones existing. The abnormal growth and poor development of blood vessels also lead to aggravation of the conditions, with vascular endothelial growth factor (VEGF) playing a major role in the process. Various anti-angiogenic therapies or anti-VEGF therapies are being explored for the treatment of this condition. 4 widely explored drugs being-Bevacizumab, pegaptanib sodium, ranibizumab, and aflibercept. The review article tries to summarize studies illustrating the efficacy of these drugs in the treatment of diabetic retinopathy along with some of the herbal therapeutic paradigms displaying anti-angiogenic action that is being used to treat this condition.

Final Outcomes from the Randomized RECOVERY Trial of Aflibercept for Retinal Nonperfusion in Proliferative Diabetic Retinopathy

PURPOSE

Retinal nonperfusion (RNP) is an important biomarker for diabetic retinopathy (DR). Data suggest that consistent anti-VEGF pharmacotherapy can slow RNP development. The RECOVERY trial evaluated the impact of aflibercept (Eylea, Regeneron) on RNP among eyes with proliferative DR (PDR).

DESIGN

Prospective, randomized clinical trial with treatment crossover in the second year.

SUBJECTS

Eyes with PDR and RNP.

METHODS

At baseline, the subjects were randomized 1:1 to monthly (arm 1) or quarterly (arm 2) intravitreal 2 mg aflibercept. At the beginning of year 2, the treatment arms were crossed over so that the monthly-dosed subjects subsequently received quarterly dosing and the quarterly-dosed subjects subsequently received monthly dosing.

MAIN OUTCOME MEASURES

Change in total RNP area (mm²) through year 2. Secondary outcomes included Diabetic Retinopathy Severity Scale (DRSS) scores; best-corrected visual acuity; central subfield thickness; additional measures of RNP, including ischemic index (ISI); and adverse event incidence. Means and 95% confidence intervals were calculated.

RESULTS

Among all subjects, from baseline to year 2, the mean RNP increased from 235 mm² to 402 mm² (P < 0.0001), and the ISI increased from 25.8% to 50.4% (P < 0.0001). Increases in the mean RNP (P < 0.0001) and ISI (P < 0.0001) were also observed from year 1 to year 2. The mean total RNP increased from 264 mm² at baseline to 386 mm² (P < 0.0001) at year 2 in arm 1 and from 207 mm² at baseline to 421 mm² (P < 0.0001) at year 2 in arm 2 (P = 0.023, arm 1 vs. arm 2). Increases in the mean RNP for both treatment arms (P < 0.0001) were also specifically observed within year 2 (P = 0.32, arm 1 vs. arm 2). Compared with baseline, the DRSS scores at the end of year 2 improved in 82% (n = 27) of subjects and remained stable in 18% (n = 6), with no subjects experiencing worsening; at 2 years, the DRSS scores had improved by 2 or more steps in 65% (n = 11) and 81% (n = 13) of subjects in arms 1 and 2, respectively.

CONCLUSIONS

Through year 2 of the RECOVERY trial, both treatment arms experienced significant increases in RNP. Despite the expansion of the RNP area in nearly all subjects, 82% of subjects demonstrated an improvement in DRSS levels from baseline, with no subjects experiencing worsening in DRSS scores.

Experiment-Based Interventions to Diabetic Retinopathy: Present and Advances

Diabetic retinopathy is the major blinding disease among working-age populations, which is becoming more significant due to the growth of diabetes. The metabolic-induced oxidative and inflammatory stress leads to the insult of neovascular unit, resulting in the core pathophysiology of diabetic retinopathy. Existing therapies focus on the inflammation, oxidation, and angiogenesis phenomena of diabetic retinopathy, without effect to radically cure the disease. This review also summarizes novel therapeutic attempts for diabetic retinopathy along with their advantages and disadvantages, mainly focusing on those using cellular and genetic techniques to achieve remission on a fundamental level of disease.

Changes in aqueous and vitreous inflammatory cytokine levels in proliferative diabetic retinopathy: a systematic review and meta-analysis

BACKGROUND

Diabetic retinopathy is a major complication of diabetes mellitus, where in its most advanced form ischemic changes lead to the development of retinal neovascularization, termed proliferative diabetic retinopathy (PDR). While the development of PDR is often associated with angiogenic and inflammatory cytokines, studies differ on which cytokines are implicated in disease pathogenesis and on the strength of these associations. We therefore conducted a systematic review and meta-analysis to quantitatively assess the existing body of data on intraocular cytokines as biomarkers in PDR.

METHODS

A comprehensive search of the literature without year limitation was conducted to January 18, 2021, which identified 341 studies assessing vitreous or aqueous cytokine levels in PDR, accounting for 10379 eyes with PDR and 6269 eyes from healthy controls. Effect sizes were calculated as standardized mean differences (SMD) of cytokine concentrations between PDR and control patients.

RESULTS

Concentrations (SMD, 95% confidence interval, and p-value) of aqueous IL-1β, IL-6, IL-8, MCP-1, TNF-α, and VEGF, and vitreous IL-2, IL-4, IL-6, IL-8, angiopoietin-2, eotaxin, erythropoietin, GM-CSF, GRO, HMGB-1, IFN-γ, IGF, IP-10, MCP-1, MIP-1, MMP-9, PDGF-AA, PlGF, sCD40L, SDF-1, sICAM-1, sVEGFR, TIMP, TNF-α, and VEGF were significantly higher in patients with PDR when compared to healthy nondiabetic controls. For all other cytokines no differences, failed sensitivity analyses or insufficient data were found.

CONCLUSIONS

This extensive list of cytokines speaks to the complexity of PDR pathogenesis, and informs future investigations into disease pathogenesis, prognosis, and management.

12-month outcomes of ranibizumab versus aflibercept for macular oedema in central retinal vein occlusion: data from the FRB! registry

PURPOSE

To compare 12-month treatment outcomes of eyes receiving aflibercept or ranibizumab for macular oedema secondary to central retinal vein occlusion (CRVO) in routine clinical practice.

METHODS

296 treatment-naïve eyes receiving either aflibercept (171 eyes, 2 mg) or ranibizumab (125 eyes, 0.5 mg) for macular oedema secondary to CRVO were recruited retrospectively from centres using the prospectively designed FRB! registry. The primary outcome measure was the mean change in LogMAR letter scores of visual acuity (VA). Secondary outcomes included change in central subfield thickness (CST), injections and visits, time to first grading of inactivity, switching and non-completion from baseline to 12 months.

RESULTS

Baseline VA (SD) was somewhat better in aflibercept- versus ranibizumab-treated eyes (42.5 ± 25.5 letters versus 36.9 ± 26 letters; p = 0.07) with similar CST (614 (240) μm versus 616 (234) μm: p = 0.95). The 12-month adjusted mean (95%CI) VA change was +16.6 (12.9, 20.4) letters for aflibercept versus +9.8 (5.5, 14.1) letters for ranibizumab (p = 0.001). The mean (95%CI) adjusted change in CST was significantly greater in aflibercept- versus ranibizumab-treated eyes: -304 (-276, -333) µm versus -252 (-220, -282) µm (p < 0.001). Both groups had a median (Q1, Q3) of 7 (5, 9) injections and 10 (8,13) visits. Aflibercept-treated eyes became inactive sooner than ranibizumab (p = 0.02). Switching occurred more commonly from ranibizumab (26 eyes, 21%) than from aflibercept (9 eyes, 5%) (p < 0.001).

CONCLUSION

Both aflibercept and ranibizumab improved VA and reduced CST in eyes with CRVO in routine clinical practice, with aflibercept showing significantly greater improvements in this comparative analysis.

Optical Coherence Tomography Combined with Fluorescein Fundus Angiography under Intelligent Algorithm to Evaluate the Clinical Efficacy of Ranibizumab Combined with Panretinal Photocoagulation in the Treatment of Macular Edema of Diabetic Retinopathy Patients

This study aimed at investigating the clinical effect of ranibizumab combined with panretinal photocoagulation in the treatment of macular edema in diabetic retinopathy (DR) patients. A parametric deformation model was constructed, and based on this, it was evaluated using optical coherence tomography (OCT) combined with fluorescein fundus angiography (FFA). 56 DR patients (80 eyes) who needed surgery were selected for OCT and FFA scanning, and 0.5 mg ranibizumab was administered intravitreal injection before surgery. It should observe the OCT and FFA image characteristics of patients. In addition, the vision correction status before the surgery, 1 month, 3 months, and 6 months after the surgery, the thickness of the macular retina, operation time, the number of intraoperative electrocoagulation, and complications of patients were recorded. It was found that 82.85% of patients had improved visual acuity after surgery. Compared with preoperative, the average logarithm of the minimum angle of resolution (logMAR) of patients at 6 months after surgery increased significantly ( $P<0.01$ ). With the increase of the grade of fibrosis and the grade of hemorrhage, the logMAR visual acuity recovery at 6 months after the surgery became worse; the macular retinal thickness at 6 months after the surgery decreased significantly ( $P<0.01$ ). With the increase of the grade of fibrous proliferation and the grade of bleeding, the operation time, the number of electrocoagulation, and the possibility of iatrogenic holes of patient would increase. It can be known that ranibizumab combined with panretinal photocoagulation surgery could not only reduce the macular edema but also effectively reduce the intraoperative bleeding, simplify the removal of proliferative membranes, decrease the number of electrocoagulation, and shorten the operation time, enhancing the visual function of patients.

Brolucizumab for the treatment of diabetic macular edema

PURPOSE OF REVIEW

To review the available data supporting the use of brolucizumab in the treatment of diabetic macular edema (DME).

RECENT FINDINGS

Brolucizumab is a humanized single- chain variable antibody fragment (scFv), the smallest functional subunit of an antibody approved for intravitreal use. Three phase III studies demonstrate that at 52 weeks, brolucizumab has statistically superior anatomical outcomes of reducing retinal thickness (54.0-57.5% of brolucizumab treated eyes achieved central subfield thickness <280 μm compared to 40.1 - 41.4% of aflibercept treated eyes) and retinal fluid (present in 54.2-60.3% of brolucizumab treated eyes compared to 72.9-78.2% of aflibercept treated eyes). Brolucizumab also demonstrated a prolonged durability up to 16 weeks, thus reducing treatment burden. The visual outcomes appear noninferior to current anti-VEGF agents with an increased risk for intraocular inflammatory events (0.3-4.7% compared to 0.6-1.7%).

SUMMARY

Results from recent phase III trials showing the efficacy and safety of brolucizumab presents an additional therapeutic option in the DME treatment landscape. It can reduce treatment burden in DME with increased inter-treatment intervals while conferring efficacy in both functional and anatomical outcomes. Caution should be taken regarding the risks of intraocular inflammation, retinal vasculitis, and retinal vascular occlusion.

Initial observation or treatment for diabetic macular oedema with good visual acuity: two-year outcomes comparison in routine clinical practice: data from the Fight Retinal Blindness! Registry

Purpose

To compare visual acuity (VA) change at 24 months in eyes with clinically significant DME (CSDME) and good VA initially treated versus initially observed in routine clinical practice.

Methods

Retrospective analysis of treatment‐naïve eyes with CSDME and good VA (baseline VA ≥ 79 letters), with at least 24 months of follow‐up and initially managed with treatment (intravitreal treatment and/or macular laser) or observation with possible treatment after 4 months that were tracked in a prospectively designed observational registry.

Results

We identified 150 eligible eyes (98 initially observed, 52 initially treated) of 130 patients. The proportion of eyes with at least a 5‐letter VA loss at 24 months was not significantly different between the groups: 65% with initial observation and 42% with initial treatment (p = 0.39). However, initially observed eyes were more likely to have a 10‐letter VA loss at 24 months (OR = 4.6, p = 0.022). Most of eyes in the initial observation group received at least one treatment (an intravitreal injection in 66% and macular laser in 20%) during the 24‐month period.

Conclusions

The risk of 5 letters loss was similar between both management groups. However, initially observed eyes were more at risk of developing moderate visual loss and more than 80% of them required treatment over 24 months.

Predictive factors associated with anatomical and functional outcomes following panretinal photocoagulation in people with proliferative diabetic retinopathy

PURPOSE

To determine effects of baseline characteristics and laser type performed on outcomes in people with proliferative diabetic retinopathy (PDR) undergoing panretinal photocoagulation (PRP).

METHODS

Medical records of all consecutive patients with PDR naïve to PRP, identified using an electronic database, evaluated at the Macula Clinic, Belfast Health and Social Care Trust, receiving their first PRP between 1st January 2016 and 30th June 2017, and followed for a minimum of 6 months following stabilization of PDR, were retrospectively reviewed. Outcomes included time to stabilization following PRP, progression of PDR, and mean change in best-corrected visual acuity from baseline to last follow-up. Cox regression was used to estimate hazard ratios (HRs) for the effect of baseline characteristics and type of laser on outcomes following treatment.

RESULTS

One hundred and fourteen patients (135 eyes) with a mean age of 57.6 (SD: 13.1) years were included, 67% males. People receiving pattern or mixed laser had a statistically significantly delayed stabilization (HR: 0.54, p=0.004; and HR: 0.41, p=0.001, respectively) and increased risk of progression (HR: 1.83, p=0.028; and HR: 2.04, p=0.018, respectively) when compared to those receiving standard laser. Among other potential predictors in multivariable regression analysis, only vitreous hemorrhage and fibrosis or traction at baseline increased risk of progression (HR: 1.70, p=0.017; and HR: 4.14, p<0.001 respectively). Baseline characteristics and type of laser had no statistically significant effect on vision.

CONCLUSION

These findings should be considered when selecting laser treatment, planning surveillance, and counselling patients with PDR undergoing PRP.

Course of Diabetic Retinopathy in Untreated Fellow Eyes in RIDE and RISE: A Post Hoc Analysis

BACKGROUND AND OBJECTIVE

To characterize diabetic retinopathy (DR) progression without therapy.

PATIENTS AND METHODS

This post hoc analysis of the phase 3 RIDE and RISE trials examined the association between baseline DR severity on rates of ≥ 2-step DR progression and improvement in untreated fellow eyes (n = 530) and ranibizumab-treated study eyes (n = 369). Kaplan-Meier analyses estimated progression to proliferative DR (PDR) over 2 years in eyes with nonproliferative DR (NPDR) at baseline.

RESULTS

At month 24, 28.8% of untreated fellow eyes with moderately severe to severe NPDR at baseline experienced ≥ 2-step DR progression, versus 10.3% of eyes with absent to moderate NPDR and 0 eyes with mild- to high-risk proliferative DR. Of the untreated fellow eyes with moderately severe to severe NPDR, 18.9% achieved ≥ 2-step DR improvement, compared with 88.4% of ranibizumab-treated eyes.

CONCLUSION

Without treatment, patients with moderately severe to severe NPDR are at risk of rapid disease progression and vision loss. [Ophthalmic Surg Lasers Imaging Retina. 2022;53(4):202-207.].

Trends in Prevalence and Treatment of Diabetic Macular Edema and Vision-Threatening Diabetic Retinopathy Among Medicare Part B Fee-for-Service Beneficiaries

IMPORTANCE

While diabetes prevalence among US adults has increased in recent decades, few studies document trends in diabetes-related eye disease.

OBJECTIVE

To examine 10-year trends (2009-2018) in annual prevalence of Medicare beneficiaries with diabetes with a diagnosis of diabetic macular edema (DME) or vision-threatening diabetic retinopathy (VTDR) and trends in treatment.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional study using Centers for Medicare & Medicaid Services research identifiable files, data for patients 65 years and older were analyzed from claims. Beneficiaries were continuously enrolled in Medicare Part B fee-for-service (FFS) insurance for the calendar year and had a diagnosis of diabetes on 1 or more inpatient claims or 2 or more outpatient claims during the calendar year or a 1-year look-back period.

MAIN OUTCOMES AND MEASURES

Using diagnosis and procedure codes, annual prevalence was determined for beneficiaries with 1 or more claims for (1) any DME, (2) either DME or VTDR, and (3) anti-vascular endothelial growth factor (VEGF) injections, laser photocoagulation, or vitrectomy, stratified by any DME, VTDR with DME, and VTDR without DME. Racial and ethnic disparities in diagnosis and treatment are presented for 2018.

RESULTS

In 2018, 6 960 823 beneficiaries (27.4%) had diabetes; half were aged 65 to 74 years (49.7%), half (52.7%) were women, and 75.7% were non-Hispanic White. From 2009 to 2018, there was an increase in the annual prevalence of beneficiaries with diabetes who had 1 or more claims for any DME (1.0% to 3.3%) and DME/VTDR (2.8% to 4.3%). Annual prevalence of anti-VEGF increased, particularly among patients with any DME (15.7% to 35.2%) or VTDR with DME (20.2% to 47.6%). Annual prevalence of laser photocoagulation decreased among those with any DME (45.5% to 12.5%), VTDR with DME (54.0% to 20.3%), and VTDR without DME (22.5% to 5.8%). Among all 3 groups, prevalence of vitrectomy in 2018 was less than half that in 2009. Prevalence of any DME and DME/VTDR was highest among Hispanic beneficiaries (5.0% and 7.0%, respectively) and Black beneficiaries (4.5% and 6.2%, respectively) and lowest among non-Hispanic White beneficiaries (3.0% and 3.8%, respectively). Among those with DME/VTDR, anti-VEGF was most prevalent among non-Hispanic White beneficiaries (30.3%).

CONCLUSIONS AND RELEVANCE

From 2009 to 2018, prevalence of DME or VTDR increased among Medicare Part B FFS beneficiaries alongside an increase in anti-VEGF treatment and a decline in laser photocoagulation and vitrectomy.

Novel Role of Prereplication Complex Component Cell Division Cycle 6 in Retinal Neovascularization

BACKGROUND

The major aim of this study is to investigate whether CDC6 (cell division cycle 6), a replication origin recognition complex component, plays a role in retinal neovascularization, and if so, to explore the underlying mechanisms.

METHODS

In this study, we used a variety of approaches including cellular and moleculer biological methodologies as well as global and tissue-specific knockout mice in combination with an oxygen-induced retinopathy model to study the role of CDC6 in retinal neovascularization.

RESULTS

VEGFA (vascular endothelial growth factor A)-induced CDC6 expression in a time-dependent manner in human retinal microvascular endothelial cells. In addition, VEGFA-induced CDC6 expression was dependent on PLCβ3 (phospholipase Cβ3)-mediated NFATc1 (nuclear factor of activated T cells c1) activation. Furthermore, while siRNA-mediated depletion of PLCβ3, NFATc1, or CDC6 levels blunted VEGFA-induced human retinal microvascular endothelial cell angiogenic events such as proliferation, migration, sprouting, and tube formation, CDC6 overexpression rescued these effects in NFATc1-deficient mouse retinal microvascular endothelial cells. In accordance with these observations, global knockdown of PLCβ3 or endothelial cell-specific deletion of NFATc1 or siRNA-mediated depletion of CDC6 levels substantially inhibited oxygen-induced retinopathy-induced retinal sprouting and neovascularization. In addition, retroviral-mediated overexpression of CDC6 rescued oxygen-induced retinopathy-induced retinal neovascularization from inhibition in PLCβ3 knockout mice and in endothelial cell-specific NFATc1-deficient mice.

CONCLUSIONS

The above observations clearly reveal that PLCβ3-mediated NFATc1 activation-dependent CDC6 expression plays a crucial role in VEGFA/oxygen-induced retinopathy-induced retinal neovascularization.

Progression to Vision-Threatening Retinopathy Complications Following Panretinal Laser for Proliferative Diabetic Retinopathy

BACKGROUND AND OBJECTIVE

To report the time in which patients with panretinal photocoagulation (PDR) progress to vision-threatening retinopathy (VTR) complications after receiving PRP, and risk factors in routine clinical practice.

PATIENTS AND METHODS

Records of patients with complete PRP for PDR were retrospectively reviewed for up to 3.5 years after PRP. Two hundred twenty eyes were selected.

RESULTS

Time from PRP to VTR was 1.25 ± 0.82 years. Age, Black race, neovascularization of the disc on examination, diabetic foot disease (DFD), and high-risk PDR characteristics on fluorescein angiography were identified as significant risk factors. Half of patients with DFD on examination developed a VTR within 1.5 years after PRP (P < .001).

CONCLUSION

In clinical practice, providers may consider DFD and Black race as predictors of time to VTR event within 4 years after PRP in patients with PDR. [Ophthalmic Surg Lasers Imaging Retina. 2022;53(4):186-193.].