Switching Anti-VEGF Drugs in the Treatment of Diabetic Macular Edema

Anti-vascular endothelial growth factor drugs combined with laser photocoagulation maintain retinal ganglion cell integrity in patients with diabetic macular edema: study protocol for a prospective, non-randomized, controlled clinical trial

The integrity of retinal ganglion cells is tightly associated with diabetic macular degeneration that leads to damage and death of retinal ganglion cells, affecting vision. The major clinical treatments for diabetic macular edema are anti-vascular endothelial growth factor drugs and laser photocoagulation. However, although the macular thickness can be normalized with each of these two therapies used alone, the vision does not improve in many patients. This might result from the incomplete recovery of retinal ganglion cell injury. Therefore, a prospective, non-randomized, controlled clinical trial was designed to investigate the effect of anti-vascular endothelial growth factor drugs combined with laser photocoagulation on the integrity of retinal ganglion cells in patients with diabetic macular edema and its relationship with vision recovery. In this trial, 150 patients with diabetic macular edema will be equally divided into three groups according to therapeutic methods, followed by treatment with anti-vascular endothelial growth factor drugs, laser photocoagulation therapy, and their combination. All patients will be followed up for 12 months. The primary outcome measure is retinal ganglion cell-inner plexiform layer thickness at 12 months after treatment. The secondary outcome measures include retinal ganglion cell-inner plexiform layer thickness before and 1, 3, 6, and 9 months after treatment, retinal nerve fiber layer thickness, best-corrected visual acuity, macular area thickness, and choroidal thickness before and 1, 3, 6, 9, and 12 months after treatment. Safety measure is the incidence of adverse events at 1, 3, 6, 9, and 12 months after treatment. The study protocol hopes to validate the better efficacy and safety of the combined treatment in patients with diabetic macula compared with the other two monotherapies alone during the 12-month follow-up period. The trial is designed to focus on clarifying the time-effect relationship between imaging measures related to the integrity of retinal ganglion cells and best-corrected visual acuity. The trial protocol was approved by the Medical Ethics Committee of the Affiliated Hospital of Beihua University with approval No. (2023)(26) on April 25, 2023, and was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR2300072478, June 14, 2023, protocol version: 2.0).

Management of treatment-naïve diabetic macular edema patients: Review of real-world clinical data

The high prevalence of Diabetic macular edema (DME) is a real global health problem. Its complex pathophysiology involves different pathways. Over the last decade, the introduction of intravitreal treatments has dramatically changed the management and prognosis of DME. Among the different treatment options, inhibitors of vascular endothelial growth factor (anti-VEGF) and intravitreal steroids implants represent the first-line therapy of DME. We conducted a review of electronic databases to compile the available evidence about the clinical management of DME in a clinical setting, with a special focus on treatment-naïve patients. Anti-VEGF therapies represent a valuable option for treating DME patients. However, many patients do not respond properly to this treatment and, due to its administration regimen, many patients receive suboptimal treatment in real life. Current evidence demonstrated that in patients with DME, DEX-i improved significantly both anatomic and visual outcomes. Besides eyes with insufficient anti-VEGF respond or recalcitrant DME cases, DEX-i can be effectively and safely used in treatment-naïve DME patients as first line therapy. DEX-i may be considered first line therapy in different clinical scenarios, such as DME eyes with a greater inflammatory component, patients with cardiovascular events, vitrectomized eyes, or those requiring cataract surgery. In conclusion, there are still many points for improvement pending in the clinical management of the patient with DME. Since DME treatment must follow a patient-tailored approach, selecting the best therapeutic approach for each patient requires a good understanding of the pathophysiology of DME.

Identifying Genetic Biomarkers Predicting Response to Anti-Vascular Endothelial Growth Factor Injections in Diabetic Macular Edema

Intraocular anti-vascular endothelial growth factor (VEGF) therapies are the front-line treatment for diabetic macular edema (DME); however, treatment response varies widely. This study aimed to identify genetic determinants associated with anti-VEGF treatment response in DME. We performed a genome-wide association study on 220 Australian patients with DME treated with anti-VEGF therapy, genotyped on the Illumina Global Screening Array, and imputed to the Haplotype Reference Consortium panel. The primary outcome measures were changes in central macular thickness (CMT in microns) and best-corrected visual acuity (BCVA in ETDRS letters) after 12 months. Association between single nucleotide polymorphism (SNP) genotypes and DME outcomes were evaluated by linear regression, adjusting for the first three principal components, age, baseline CMT/BCVA, duration of diabetic retinopathy, and HbA1c. Two loci reached genome-wide significance (p < 5 × 10−8) for association with increased CMT: a single SNP on chromosome 6 near CASC15 (rs78466540, p = 1.16 × 10−9) and a locus on chromosome 12 near RP11-116D17.1 (top SNP rs11614480, p = 2.69 × 10−8). Four loci were significantly associated with reduction in BCVA: two loci on chromosome 11, downstream of NTM (top SNP rs148980760, p = 5.30 × 10−9) and intronic in RP11-744N12.3 (top SNP rs57801753, p = 1.71 × 10−8); one near PGAM1P1 on chromosome 5 (rs187876551, p = 1.52 × 10−8); and one near TBC1D32 on chromosome 6 (rs118074968, p = 4.94 × 10−8). In silico investigations of each locus identified multiple expression quantitative trait loci and potentially relevant candidate genes warranting further analysis. Thus, we identified multiple genetic loci predicting treatment outcomes for anti-VEGF therapies in DME. This work may potentially lead to managing DME using personalized treatment approaches.

The Fundus Structural and Functional Predictions of DME Patients After Anti-VEGF Treatments

Diabetic retinopathy (DR) is an important complication with a high incidence of 34.6% in the diabetic populations. DR could finally lead to vision impairment without effective interventions, during which, diabetic macular edema (DME) is a key phase causing visual loss. Up to date, antivascular endothelial growth factor (anti-VEGF) therapy is the first-line treatment for DME which has achieved relatively better clinical outcomes than traditional treatments. However, there are several kinds of anti-VEGF medicines, and patients are sensitive to different anti-VEGF treatments. In addition, its effectiveness is unstable. Considering the patients' need to accept continual anti-VEGF treatments and its price is comparatively high, it is clinically important to predict the prognosis after different anti-VEGF treatments. In our research, we used the demographic and clinical data of 254 DME patients and 2,763 optical coherence tomography (OCT) images from three countries to predict the fundus structural and functional parameters and treatment plan in 6 months after different anti-VEGF treatments. Eight baseline features combined with 11 models were applied to conduct seven prediction tasks. Accuracy (ACC), the area under curve (AUC), mean absolute error (MAE), and mean square error (MSE) were respectively used to evaluate the classification and regression tasks. The ACC and AUC of structural predictions of retinal pigment epithelial detachment were close to 1.000. The MAE and MSE of visual acuity predictions were nearly 0.3 to 0.4 logMAR. The ACC of treatment plan regarding continuous injection was approaching 70%. Our research has achieved great performance in the predictions of fundus structural and functional parameters as well as treatment plan, which can help ophthalmologists improve the treatment compliance of DME patients.

Pathologic sequelae of vascular cognitive impairment and dementia sheds light on potential targets for intervention

Vascular contributions to cognitive impairment and dementia (VCID) is one of the leading causes of dementia along with Alzheimer's disease (AD) and, importantly, VCID often manifests as a comorbidity of AD(Vemuri and Knopman 2016; Schneider and Bennett 2010)(Vemuri and Knopman 2016; Schneider and Bennett 2010). Despite its common clinical manifestation, the mechanisms underlying VCID disease progression remains elusive. In this review, existing knowledge is used to propose a novel hypothesis linking well-established risk factors of VCID with the distinct neurodegenerative cascades of neuroinflammation and chronic hypoperfusion. It is hypothesized that these two synergistic signaling cascades coalesce to initiate aberrant angiogenesis and induce blood brain barrier breakdown trough a mechanism mediated by vascular growth factors and matrix metalloproteinases respectively. Finally, this review concludes by highlighting several potential therapeutic interventions along this neurodegenerative sequalae providing diverse opportunities for future translational study.

Place of intravitreal dexamethasone implant in the treatment armamentarium of diabetic macular edema

Diabetic macular edema (DME) is a very important and well-known cause of visual loss in diabetics. Blood–retina barrier disruption and consequent intraretinal fluid accumulation may lead to retinal thickening at the posterior pole namely DME. Even though it is not clearly understood, current evidence suggests that chronic low-grade inflammation characterized with various cytokines has a major role in the occurrence of DME. Clinical trials are continuously shaping our treatment approaches for the eyes with DME. Today, vascular endothelial growth factor (VEGF) inhibitor and steroid administrations are the main alternatives in DME treatment. Dexamethasone (DEX) implant (Ozurdex^®; Allergan, Inc., Irvine, CA, United States) was approved by the United States Food & Drug Administration in 2014 for DME treatment. The implant is made up of a biodegradable solid copolymer that is broken down by releasing its active ingredient into the vitreous cavity over time. Biphasic release feature of this sustained-release drug delivery system ensures its efficacy for up to 6 mo with an acceptable and manageable safety profile. DEX implant provides a favorable anatomical and functional outcome in DME as shown in several randomized-controlled studies but has a relatively higher ocular side-effect profile such as increased risk of cataract formation and raised intraocular pressure when compared to the gold standard anti-VEGF agents. Thus, DEX implant becomes the second-line treatment option demonstrating inadequate clinical response to anti-VEGF therapy. However, it can be preferred as the first-line treatment in vitrectomized and pseudophakic eyes. Even in some selected conditions DEX implant is favored over anti-VEGF agents where the use of VEGF-inhibitors is either inappropriate or contraindicated such as the patients with a recent history of a major cardiovascular or cerebrovascular event, pregnancy and noncompliant to frequent visits. This mini-review briefly overviews the efficacy, safety profile and complications of DEX implant and summarizes the outcome of DEX implant administration in major clinical studies on DME 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.

Diabetic Macular Edema Treated With Intravitreal Aflibercept Injection After Treatment With Other Anti-VEGF Agents (SWAP-TWO Study)—12-Month Analysis

Purpose:

This article reports 12-month outcomes of patients with diabetic macular edema previously treated with other antivascular endothelial growth factor agents and transitioned to fixed dosing of intravitreal aflibercept (IAI).

Methods:

This prospective, single-arm study enrolled patients to receive IAI 2 mg (0.05 mL) every 4 weeks until optical coherence tomography demonstrated no fluid. Patients then received fixed dosing of IAI 2 mg once every 8 weeks through 12 months. Primary outcome was mean absolute change from baseline central subfield thickness (CST) at 12 months measured by optical coherence tomography.

Results:

Twenty eyes were enrolled. At baseline, best-corrected visual acuity was 70.0 letters, mean CST was 419.7 µm ± 92.0, superficial capillary perfusion density (CPD) was 46.0 ± 4.2%, and deep CPD was 50.8 ± 4.3%. At 12 months, the mean CST improved to 287.2 µm ± 80.2 ( P < .001), superficial CPD decreased to 43.6 ± 4.8% ( P = .04), and deep CPD decreased to 47.6 ± 4.8% ( P = .05).

Conclusions:

Patients who switched to fixed dosing of IAI demonstrated significant anatomic improvements in CST at 12 months. CPD values decreased significantly both in superficial and deep layers without significant changes in vision.

Efficacy of switching therapy to aflibercept for patients with persistent diabetic macular edema: a systematic review and meta-analysis

BACKGROUND

To evaluate functional and anatomical consequences of switching anti-vascular endothelial growth factor (anti-VEGF) therapy from bevacizumab and/or ranibizumab to aflibercept intravitreal injection for the treatment of persistent diabetic macular edema (DME).

METHODS

Analysis of switching treatment in patients with persistent DME was performed using a literature search across multiple databases (PubMed, Medline, EMBASE, Cochrane Library and Web of Science) prior to May 2019. Therapeutic effect parameters, including mean change of best-corrected visual acuity (BCVA) and central macular thickness (CMT), were extracted from baseline to different follow-up times post initial injections. The quality of studies was assessed with the Downs and Black checklist. Data pertaining to ocular and systemic safety adverse events (SAEs) were collected as well as subgroup analysis stratified by pre-switch anti-VEGF reagents. All results were analyzed and pooled using random-effects models with 95% confidence intervals (CI).

RESULTS

Fourteen studies involving 489 eyes met the inclusion criteria. The mean differences in BCVA were significantly improved at 1, 2 and 3 months with -0.11 logMAR (P=0.016), -0.22 logMAR (P<0.001) and -0.24 logMAR (P<0.01), respectively. Vision gain was also assessed following the aflibercept injection with a mean change of -0.10 logMAR (P<0.001) at 6 months and -0.08 logMAR (P=0.01) at 12 months. CMT reduction was significant from baseline with a mean decrease of 80.52 µm (P<0.001) at 1 month, 89.6 µm (P<0.013) at 2 months, 113.88 µm (P<0.001) at 3 months and 125.12 µm (P<0.001) at 6 months. Mean CMT continued to decline by 75.70 µm (P<0.001) at 12 months as well.

CONCLUSIONS

This meta-analysis indicated the comparable efficacy and safety of a conversion treatment to aflibercept in cases of unsatisfactory responses to other anti-VEGF drugs. Switching treatment produces significant advantage for vision acuity recovery and macular edema improvement among persistent DME patients.

Role of Smad4 from ocular surface ectoderm in retinal vasculature development

AIM

To investigate how signals from lens regulate retinal vascular development and neovascularization.

METHODS

Le-Cre transgenic mouse line was employed to inactivate Smad4 in the surface ectoderm selectively. Standard histological and whole-mount retina staining were employed to reveal morphological changes of retinal vasculature in Smad4 defective eye. cDNA microarray and subsequent analyses were conducted to investigate the molecular mechanism underlying the vascular phenotype. Quantitative polymerase chain reaction (qPCR) was carried out to verify the microarrays results.

RESULTS

We found that inactivation of Smad4 specifically on surface ectoderm leads to a variety of retinal vasculature anomalies. Microarray analyses and qPCR revealed that Sema3c, Sema3e, Nrp1, Tie1, Sox7, Sox17, and Sox18 are significantly affected in the knockout retinas at different developmental stages, suggesting that ocular surface ectoderm-derived Smad4 can signal to the retina and regulates various angiogenic signaling in the retina.

CONCLUSION

Our data suggest that the cross-talk between ocular surface ectoderm and retina is important for retinal vasculature development, and Smad4 regulates various signaling associated with sprouting angiogenesis, vascular remodeling and maturation in the retina of mice.

Emerging Concepts in the Treatment of Diabetic Retinopathy

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Pattern of adverse events induced by aflibercept and ranibizumab: A nationwide spontaneous adverse event reporting database, 2007-2016

Data regarding the safety of anti-vascular endothelial growth factor (anti-VEGF) treatment is limited.To compare the adverse events (AEs) induced by aflibercept and ranibizumab using a spontaneous reporting system and determine the signals.We used data from the Korea Institute of Drug Safety & Risk Management-Korea Adverse Event Reporting System Database (KIDS-KD), collected between 2007 and 2016. Differences in patient demographics, report type, reporter, causality, and serious-AEs between aflibercept and ranibizumab were compared. Metrics including proportional reporting ratio (PRR), reporting odds ratio (ROR), and information component (IC), were used to compare signals with the AEs on the drug labels in the United States of America and Korea. Logistic regression analysis was performed to identify AEs that are more likely to occur with drug use.A total of 32 aflibercept and 103 ranibizumab cases of AEs were identified. The proportion of AEs that were reported voluntarily was higher with aflibercept (50.5%) use than ranibizumab (4.9%), whereas the AEs reported by post-marketing surveillance were higher with ranibizumab (46.6%) use than aflibercept (31.3%). The percentage of AEs in patients >60 years old, reports by consumers, and the ratio of SAEs to AEs associated with aflibercept (84. %, 9.4%, and 75.0%, respectively) were higher than those of ranibizumab (77.7%, 1.9%, and 19.4%, respectively). The number of newly detected AEs after aflibercept and ranibizumab treatment was 3 and 8, respectively. Among these, conjunctivitis and medicine ineffective were not included on the aflibercept and ranibizumab labels, respectively. Endophthalmitis (OR 6.96, 95% CI 2.74-17.73) was more likely to be reported in patients with aflibercept than in patients without aflibercept, whereas medicine ineffective (OR 18.49, 95% CI 2.39-143.29) and retinal disorder (OR 7.03, 95% CI 1.60-30.96) were more likely to be reported in patients with ranibizumab than in patients without ranibizumab.New signals have been identified for aflibercept and ranibizumab. Further research is necessary to evaluate the causality of AEs that were detected as signals in this study.

Diabetic macular edema treated with intravitreal aflibercept injection after treatment with other anti-VEGF agents (SWAP-TWO study): 6-month interim analysis

Background

Diabetic macular edema (DME) is an important cause of vision loss and despite the anatomical and functional improvement achieved with treatment, there are reports of persistent DME regardless of continuous anti-VEGF therapy. The purpose of this study is to examine the effect of patients with DME previously treated with other anti-VEGF agents who are transitioned to intravitreal aflibercept (IAI) on a fixed dosing regimen.

Methods

This prospective study included 20 patients presenting with DME with a history of previous anti-VEGF treatment with ranibizumab or bevacizumab. Patients received a 2 mg (0.05 mL) IAI every 4 weeks until no evidence of fluid by optical coherence tomography (OCT) followed by a fixed dosing schedule of 2 mg IAI once every 8 weeks through 24 months. There was a pre-planned interim analysis of the mean absolute change from baseline central foveal thickness at month 6 as measured by OCT. Secondary outcomes included mean change from baseline in ETDRS visual acuity and anatomic parameters. Optical Coherence tomography angiography (OCTA) capillary perfusion density (CPD) after transitioning to IAI therapy were also reported.

Results

Average central subfield thickness on OCT at baseline was 419.7 ± 92.0 and improved to 303.8 ± 73.1 at 6-months (p < 0.001). At 6 months after IAI treatment, BCVA increased + 1.5 letters from baseline (p = 0.38). OCTA CPD analysis revealed significant increase from baseline in the foveal avascular zone in non-proliferative diabetic retinopathy group (p = 0.02).

Conclusions

Patients with prior anti-VEGF therapy who were transitioned to IAI therapy revealed significant anatomic improvements through 6 months.

Trial registration Treatment of Diabetic Macular Edema With Aflibercept in Subjects Previously Treated With Ranibizumab or Bevacizumab (SwapTwo), Trial registration number: NCT02559180. Date of registration: September 24, 2015.https://clinicaltrials.gov/ct2/show/NCT02559180

Inflammatory mediators in the vitreal reflux of patients with diabetic macular edema

PURPOSE

To quantify inflammatory, growth/angiogenic, and tissue remodeling mediators in vitreal reflux (VR) in patients with diabetic macular edema (DME), as collected at first and third intravitreal anti-vascular endothelial growth factor (anti-VEGF, ranibizumab) injection.

METHODS

Thirty (30) consecutive patients (type-2 diabetes mellitus) with visual impairments due to DME and undergoing the first (untreated DME) or the third (treated DME) intravitreal injection of anti-VEGF were included in the study. At the time of surgery, patients were subjected to clinical assessment and spectral domain-optical coherence tomography (SD-OCT), including central retinal thickness (CRT), macular volume, and outer nuclear layer/retinal pigment epithelial (ONL/RPE) measurements. VR sampling was performed at the time of needle removal and subjected to customized protein-array, Western blotting (WB), Ella™ microfluidic, and/or enzyme-linked immunosorbent assay (ELISA) analysis. Biostrumental and biochemical data were collected just prior to the surgery and are representative of disease state. Clinical, biostrumental, and numerous biomarkers and cytokines were statistically compared.

RESULTS

Decreased CRT values were detected in treated DME retinas, as compared to untreated ones (p ≤ 0.05). Differences in VEGF and other mediator expressions between treated and untreated DME were detected in VR samples. Particularly, osteopontin (p ≤ 0.05), interleukin 6 (IL6) (p ≤ 0.05), and VEGF (p ≤ 0.1) values were decreased after treatment. Significant changes were validated by WB, ELISA, and Ella™ analysis.

CONCLUSION

Overall, the biostrumental and biochemical data suggest the presence of a specific pattern of inflammation in VR after treatment. The data would suggest the presence of other mechanisms and mediators, in addition to VEGF, accountable for DME progression.