Intravitreal Dexamethasone Implant versus Intravitreal Ranibizumab Injection for Treatment of Non-Proliferative Diabetic Macular Edema: A Prospective, Randomized and Blinded Trial

Comparing the efficacy of dexamethasone implant and anti-VEGF for the treatment of macular edema: A systematic review and meta-analysis

OBJECTIVES

To evaluate the clinical efficacy of dexamethasone (DEX) implant, for the treatment of macular edema (ME) caused by retinal vein occlusion (RVO) and diabetic retinopathy (DR) through a systematic review and meta-analysis.

METHODS

The PubMed, Embase and Cochrane Library databases were comprehensively searched from inception to November 21, 2022, for studies evaluating the clinical efficacy of DEX implant for patients with retinal vein occlusion macular edema (RVO-ME) or diabetic macular edema (DME). Randomized controlled trials (RCTs) published in English were considered eligible. The Cochrane Collaboration tool was applied to assess the risk of bias in each study. Effect estimates with 95% confidence intervals (CIs) were pooled using the random effects model. We also conducted subgroup analyses to explore the sources of heterogeneity and the stability of the results.

RESULTS

This meta-analysis included 8 RCTs (RVO-ME [n = 2] and DME [n = 6]) assessing a total of 336 eyes. Compared with anti-VEGF therapy, DEX implant treatment achieved superior outcomes in terms of best corrected visual acuity (BCVA) (mean difference [MD] = -3.68 ([95% CI, -6.11 to -1.25], P = 0.003), and no heterogeneity was observed (P = 0.43, I2 = 0%). DEX implant treatment also significantly reduced central macular thickness (CMT) compared with anti-VEGF treatment (MD = -31.32 [95% CI, -57.92 to -4.72], P = 0.02), and there was a high level of heterogeneity between trials (P = 0.04, I2 = 54%). In terms of severe adverse events, DEX implant treatment had a higher risk of elevated intraocular pressure than anti-VEGF therapy (RR = 6.98; 95% CI: 2.16 to 22.50; P = 0.001), and there was no significant difference in cataract progression between the two groups (RR = 1.83; 95% CI: 0.63 to 5.27, P = 0.31).

CONCLUSIONS

Compared with anti-VEGF therapy, DEX implant treatment is more effective in improving BCVA and reducing ME. Additionally, DEX implant treatment has a higher risk of elevated intraocular pressure. Due to the small number of studies and the short follow-up period, the results should be interpreted with caution. The long-term effects of the two treatments need to be further determined.

TRIAL REGISTRATION

Prospero Registration Number CRD42021243185.

Comparative Efficacy of Anti-vascular Endothelial Growth Factor (Anti-VEGF) Agents and Corticosteroids in Managing Diabetic Retinopathy-Associated Diabetic Macular Edema: A Meta-Analysis and Comprehensive Systematic Review

Diabetic macular edema (DME) is a significant condition linked to diabetes that can result in visual loss. In recent times, there has been a notable change in the desire for treatment, with a shift toward anti-vascular endothelial growth factor (anti-VEGF) therapy and intravitreal steroids while moving away from conventional laser therapies. This comprehensive meta-analysis explicitly compares the efficacy of two therapies for DME: anti-VEGF therapy and corticosteroid. We conducted a thorough search using PubMed and Google Scholar to identify publications that compare the effects of anti-VEGF therapy and corticosteroid implants on DME. Using Review Manager 5.0 (RevMan), we incorporated data from nine research studies, which involved a total of 877 people. The group was split into two factions: 453 patients were administered corticosteroids, while 466 patients underwent treatment with anti-VEGF therapy. Our investigation demonstrated that both corticosteroid and anti-VEGF therapy positively improved the best-corrected visual acuity (BCVA) and reduced the central macular thickness (CMT). Nevertheless, comparing the mean BCVA on the logarithm of the minimum angle of resolution (logMAR) scale revealed no statistically significant changes between the two treatments. This indicates considerable inconsistency, as evidenced by the weighted mean difference (WMD) of -0.13 (-0.41, 0.16) with a P-value of 0.39 and an I2 value of 99%. In addition, both treatments improved BCVA compared to the initial measurement. However, there was no statistically significant benefit for corticosteroid over anti-VEGF therapy, as indicated by the WMD of 0.03 (-0.07, 0.13) with a P-value of 0.55 and an I2 value of 80%. The examination of the average CMT also yielded findings that lacked statistical significance, displaying a significant amount of variation (WMD -36.37, 95% confidence interval [-127.52, 54.78], P = 0.43, I2 = 98%). Remarkably, there were no significant alterations among the anti-VEGF therapy group despite a rise in CMT from the initial measurement. The main conclusion drawn from our research is that corticosteroid demonstrates encouraging immediate enhancements in BCVA and CMT. However, anti-VEGF therapy seems to provide more significant long-term advantages. Nevertheless, it is crucial to acknowledge that the corticosteroid group had a greater susceptibility to acquiring elevated intraocular pressure (IOP) and the possibility of glaucoma.

Safety and efficacy profile of intravitreal ranibizumab vs dexamethasone in treatment of naïve diabetic macular edema

PURPOSE

To compare the safety and efficacy parameters of intravitreal ranibizumab vs intravitreal dexamethasone (IVD) in the treatment of patients with naïve diabetic macular edema (DME) in terms of best-corrected visual acuity (BCVA), central macular thickness (CMT), and possible complications like intraocular pressure (IOP) rise and cataract progression.

METHODS

A hospital-based prospective and comparative study of naïve DME patients was conducted between November 2020 and October 2021 with a minimum follow-up (F/U) period of 6 months. Thirty phakic patients received one dose of IVD implant (Group A) and the other 30 (Group B) received three consecutive monthly doses of ranibizumab. The main exclusion criteria were steroid responders and the presence of ocular inflammation.

RESULTS

The mean pre-injection CMT in Group A was 405µ and reduced to 297.07µ at 3 months and 278.35µ at 6 months. Mean increase in logMAR BCVA was 0.55. The mean pre-injection IOP was 16.28 and 17.64 mm of Hg at 6 months. In Group B, the mean pre-injection CMT was 401.07µ and reduced to 276.1µ at 3 months and 292.9µ at 6 months. Mean BCVA increased to 0.37. The mean pre-injection IOP was 17.28 mm Hg and 16.42 mm Hg at 6 months. There was no significant progression of cataract in both groups.

CONCLUSION

The mean decrease in CMT was comparable in both the groups at 6 months F/U with an improvement of BCVA with no significant IOP fluctuation or cataract progression. Hence, IVD appears to be noninferior to ranibizumab in the treatment of naïve DME.

The ideal treatment timing for diabetic retinopathy: the molecular pathological mechanisms underlying early-stage diabetic retinopathy are a matter of concern

Diabetic retinopathy (DR) is a prevalent complication of diabetes, significantly impacting patients' quality of life due to vision loss. No pharmacological therapies are currently approved for DR, excepted the drugs to treat diabetic macular edema such as the anti-VEGF agents or steroids administered by intraocular route. Advancements in research have highlighted the crucial role of early intervention in DR for halting or delaying disease progression. This holds immense significance in enhancing patients' quality of life and alleviating the societal burden associated with medical care costs. The non-proliferative stage represents the early phase of DR. In comparison to the proliferative stage, pathological changes primarily manifest as microangiomas and hemorrhages, while at the cellular level, there is a loss of pericytes, neuronal cell death, and disruption of components and functionality within the retinal neuronal vascular unit encompassing pericytes and neurons. Both neurodegenerative and microvascular abnormalities manifest in the early stages of DR. Therefore, our focus lies on the non-proliferative stage of DR and we have initially summarized the mechanisms involved in its development, including pathways such as polyols, that revolve around the pathological changes occurring during this early stage. We also integrate cutting-edge mechanisms, including leukocyte adhesion, neutrophil extracellular traps, multiple RNA regulation, microorganisms, cell death (ferroptosis and pyroptosis), and other related mechanisms. The current status of drug therapy for early-stage DR is also discussed to provide insights for the development of pharmaceutical interventions targeting the early treatment of DR.

Efficacy and safety profile of intravitreal dexamethasone implant versus antivascular endothelial growth factor treatment in diabetic macular edema: a systematic review and meta-analysis

To better understand the efficacy of intravitreal dexamethasone implant (Ozurdex) versus antivascular endothelial growth factor (anti-VEGF) treatment in patients with diabetic macular edema (DME). A systematic review and meta-analysis. The study included randomized control trials (RCTs) and non-randomized control trials (Non-RCTs) before December 2021 that compare the efficacy of Ozurdex-related therapyand anti-VEGF therapy. We searched PubMed, Cochrane Library, and EMBASE. The quality of the included studies was assessed carefully. 30 studies were included. Regarding BCVA change, the overall result revealed no significant differences between Ozurdex and anti-VEGF therapies in patients with nonresistant DME, but Ozurdex group had significantly more VA improvement than anti-VEGF therapies in patients with resistant DME (MD 0.12, 95% CI 0.02-0.21). In terms of central retinal thickness (CRT) decrease, there was a significant difference between Ozurdex therapy and anti-VEGF therapy in patients with nonresistant DME (MD 48.10, 95% CI 19.06-77.13) and resistant DME (MD 65.37, 95% CI 3.62-127.13). Overall, Ozurdex therapy resulted in significantly greater VA improvement and CRT decrease than anti-VEGF therapy in resistant DME patients. Ozurdex therapy was not inferior to anti-VEGF therapy in patients with nonresistant DME.

Intravitreal steroids compared to anti-vascular endothelial growth factor treatment for diabetic macular edema: a meta-analysis

TOPIC

Diabetic macular edema (DME) can be treated with either intravitreal anti-VEGF injections or intravitreal corticosteroid injections.

CLINICAL RELEVANCE

We provide an updated meta-analysis of the comparative efficacy and safety of intravitreal steroids and anti-VEGF agents for DME.

METHODS

A systematic search was performed on Ovid MEDLINE, Embase, and Cochrane Controlled Register of Trials from January 2005 to November 2021. Inclusion criteria included published randomized clinical trial data comparing the efficacy and safety of intravitreal steroids versus anti-VEGF agents for DME. Nonrandomized, noncomparative, and non-English studies were excluded.

RESULTS

Fourteen randomized clinical trials reporting on 827 eyes were included. Between these 2 treatments, our analysis revealed no significant difference in best-corrected visual acuity (BCVA) outcomes at 3 months (P = 0.11), 6 months (P = 0.21), 12 months (P = 0.24), and final follow-up (P = 0.91). Retinal thickness was significantly lower with steroid treatment at 3 months (P = 0.04), 6 months (P < 0.00001), and final follow-up (weighted mean difference = 39.99 μm; 95% confidence interval [CI] = 14.58,65.41; P = 0.002); however, there was no significant difference at 12 months (P = 0.18). Intravitreal anti-VEGF agents were associated with a lower incidence of intraocular pressure-related adverse events (risk ratio = 0.13; 95% CI = 0.05, 0.34; P < 0.00001). There was no significant difference between comparators for other adverse events, including cataract-related adverse events (P = 0.22).

CONCLUSIONS

Overall, intravitreal steroid treatment for DME was associated with no significant differences in BCVA, a significantly lower retinal thickness, and a higher risk of intraocular pressure-related events. The certainty of evidence ranged from low to moderate and the analysis was limited by heterogeneity. Our results reinforce the importance of a continual reevaluation of the role of intravitreal steroids in DME management.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Monoclonal antibodies in diabetic retinopathy

INTRODUCTION

Diabetic retinopathy (DR), as one of the main complications of diabetes, is among the leading causes of blindness and visual impairment worldwide.

AREAS COVERED

Current clinical therapies include photocoagulation, vitrectomy, and anti-vascular endothelial growth factor (VEGF) therapies. Bevacizumab and ranibizumab are two monoclonal antibodies (mAbs) inhibiting angiogenesis. Intravitreal ranibizumab and bevacizumab can decrease the rate of blindness and retinal thickness, and improve visual acuity whether as monotherapy or combined with other treatments. They can increase the efficacy of other treatments and decrease their adverse events. Although administered intravitreally, they also might enter the circulation and cause systemic effects. This study is aimed to review our current knowledge about mAbs, bevacizumab and ranibizumab, in DR including superiorities, challenges, and limitations. Meanwhile, we tried to shed light on new ideas to overcome these limitations. Our latest search was done in April 2021 mainly through PubMed and Google Scholar. Relevant clinical studies were imported.

EXPERT OPINION

Future direction includes detection of more therapeutic targets considering other components of DR pathophysiology and shared pathogenesis of DR and neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, the treat-and-extend regimen, and new ways of drug delivery and other routes of ocular drug administration.