Dexamethasone intravitreal implant in diabetic macular oedema refractory to anti-vascular endothelial growth factors: the AUSSIEDEX study

Role of inflammation in diabetic macular edema and neovascular age-related macular degeneration

Diabetic macular edema (DME) and neovascular age-related macular degeneration (nAMD) are multifactorial disorders that affect the macula and cause significant vision loss. Although inflammation and neoangiogenesis are hallmarks of DME and nAMD, respectively, they share some biochemical mediators. While inflammation is a trigger for the processes that lead to the development of DME, in nAMD inflammation seems to be the consequence of retinal pigment epithelium and Bruch membrane alterations. These pathophysiologic differences may be the key issue that justifies the difference in treatment strategies. Vascular endothelial growth factor inhibitors have changed the treatment of both diseases, however, many patients with DME fail to achieve the established therapeutic goals. From a clinical perspective, targeting inflammatory pathways with intravitreal corticosteroids has been proven to be effective in patients with DME. On the contrary, the clinical relevance of addressing inflammation in patients with nAMD has not been proven yet. We explore the role and implication of inflammation in the development of nAMD and DME and its therapeutical relevance.

Clinical and optical coherence tomography biomarkers as prognostic factors in dexamethasone intravitreal implant for diabetic macular edema

PURPOSE

Aim of the study was to evaluate the efficacy of dexamethasone (DEX) 0.7 mg intravitreal implant in patients with diabetic macular edema (DME) and serous retinal detachment (SRD), and to study the prognostic factors on a follow up of 12 months.

METHODS

Forty eyes of twenty- six patients with centre involving DME and SRD, who underwent DEX implant, were enrolled. Best-corrected visual acuity (BCVA), Swept source OCT imaging and intraocular pressure were evaluated. Central macular thickness (CMT), vitreomacular adhesion (VMA), disorganization of retinal inner layers (DRILs), hyperreflective dots (HRD), SRD and ellipsoid zone (EZ) disruption were included in the analysis at baseline and 12 months after implant.

RESULTS

According to our parametric analysis, at 12 months, BVCA improvement from 48.6 ± 23.4 letters to 53.3 ± 24.5 letters was statistically significant (p = 0.04), CMT decreased from 460 ± 99.52 μm to 322.9 ± 117 μm. The presence at baseline of VMA (p = 0.01), EZ disruption (p = 0.03) and DRILs (p = 0.04), were associated with poor BCVA improvement at the end of follow-up.

CONCLUSION

In conclusion, OCT biomarkers can be considered significant prognostic factors for treatment outcome in patients with DME undergoing DEX intravitreal implant.

Dexamethasone implant in naive versus refractory patients with diabetic macular edema: a Meta-analysis

AIM

To evaluate the efficacy and safety of the intravitreal dexamethasone implant in naive and refractory patients with diabetic macular edema (DME).

METHODS

PubMed, Embase, Web of Science, and Medline databases were searched. The main outcomes were best-corrected visual acuity (BCVA) and central retinal thickness (CRT). The secondary outcomes included mean number of injections, intraoperative or postoperative complications including intraocular pressure (IOP) elevation and cataract.

RESULTS

Ten comparative studies involving a total of 1000 DME eyes including 402 naive eyes and 598 refractory eyes were selected. The postoperative BCVA in the naive group was significantly better than in the refractory group [mean difference (MD) -0.11, 95% confidence interval (CI) -0.17 to -0.05, P=0.0003; MD 8.69, 95%CI 5.08 to 12.30, P<0.00001)]. Additionally, the naive group got greater improvement of BCVA change as well as more gains of BCVA letters than the refractory group [MD 7.71, 95%CI 2.02 to 13.40, P=0.008; odds ratio (OR) 2.99, 95%CI 2.05 to 4.37, P<0.00001]. The subgroup analysis revealed that the naive group had significantly higher BCVA gains of ≥5, ≥10, and ≥15 letters compared to the refractory group (P=0.002, 0.0001, 0.003, respectively). No significant difference was detected between the two groups in either postoperative CRT (MD -22.36, 95%CI -46.39 to 1.66, P=0.07) or the overall mean number of injections (MD -0.08, 95%CI -0.38 to 0.22, P=0.61). Intraoperative and postoperative complications including the elevation of IOP (OR 0.47, 95%CI 0.20 to 1.13, P=0.09) and cataract (OR 1.78, 95%CI 0.97 to 3.24, P=0.06) showed no significant differences between the two groups during the follow-up time.

CONCLUSION

Intravitreal dexamethasone implants for DME can improve anatomical and functional outcomes in both naive and refractory eyes and have a well-acceptable safety profile. Moreover, naive eyes maintain better visual outcomes than refractory eyes. It provides further evidence of better visual response when used for naive eyes as first-line therapy.

Dexamethasone implant for refractory macular edema secondary to diabetic retinopathy and retinal vein occlusion

AIM

To evaluate the efficacy, timing of retreatment and safety of dexamethasone (DEX) implant on macular edema (ME) secondary to diabetic retinopathy (DME) and retinal vein occlusion (RVO-ME) patients who were refractory to anti-vascular endothelial growth factor (VEGF) treatment.

METHODS

This retrospective study included 37 eyes received at least one DEX implant treatment for DME or RVO-ME between January 1, 2019, and January 1, 2023. These refractory DME and RVO-ME cases received at least 5 anti-VEGF injections and failure to gain more than 5 letters or a significant reduction in central retinal thickness (CRT). The best corrected visual acuity (BCVA) and CRT were measured at baseline, and at 1, 3, 4 and 6mo post-DEX implant injection. Adverse events such as elevated intraocular pressure (IOP) and cataract were recorded.

RESULTS

For RVO cases (n=22), there was a significant increase in BCVA from 0.27±0.19 to 0.35±0.20 at 6mo post-DEX injection (P<0.05) and CRT decreased from 472.1±90.6 to 240.5±39.0 µm at 6mo (P<0.0001). DME cases (n=15) experienced an improvement in BCVA from 0.26±0.15 to 0.43±0.20 at 6mo post-DEX implant injection (P=0.0098), with CRT reducing from 445.7±55.7 to 271.7±34.1 µm at 6mo (P<0.0001). Elevated IOP occurred in 45.9% of patients but was well-controlled with topical medications. No cases of cataract or other adverse events were reported.

CONCLUSION

DEX implants effectively improve BCVA and reduce CRT in refractory DME and RVO-ME. Further research with larger cohorts and longer follow-up periods is needed to confirm these findings and assess long-term outcomes.

Switching to an Intravitreal Dexamethasone Implant after Intravitreal Anti-VEGF Therapy for Diabetic Macular Edema: A Review

Among working-age people, diabetic retinopathy and diabetic macular edema are currently considered the main causes of blindness. Nowadays, intravitreal injections are widely acknowledged as a significant milestone in ophthalmology, especially for the treatment of several retinal diseases, including diabetic macular edema. In particular, anti-vascular endothelial growth factor (VEGF) agents are typically the first line of treatment; however, monthly injections are required, at least, during the loading dosage. Notably, an intravitreal 0.7 mg dexamethasone (DEX) implant (Ozurdex®, AbbVie Inc., North Chicago, IL, USA) is considered a legitimate substitute treatment for diabetic eyes that have not responded to anti-VEGF treatment. In fact, clinical trials and real-life studies have demonstrated the effectiveness and safety of an intravitreal DEX implant in treating such conditions over a period of three to six months. For this reason, wisely selecting diabetic patients might be crucial to decreasing the load of injections in clinics and hospitals. The purpose of this review is to analyze the available scientific literature to highlight the benefits, efficacy, and clinical criteria for choosing whether to switch from intravitreal anti-VEGF therapy to an intravitreal DEX implant in diabetic macular edema.

Perspectives on the currently available pharmacotherapy for wet macular degeneration

INTRODUCTION

Wet age-related macular degeneration (w-AMD) is a leading cause of visual impairment globally, with its prevalence expected to rise alongside increasing life expectancy. The current standard treatment involves frequent intravitreal injections of anti-VEGF agents, which although revolutionary, pose significant burdens on both patients and healthcare services.

AREAS COVERED

This review explores current and emerging pharmaceutical treatments for w-AMD, focusing on their pharmacokinetics, pharmacodynamics, efficacy, and safety. Promising developments include extending treatment intervals with newer anti-VEGF agents like brolucizumab and faricimab, biosimilars offering cost-effective options, and exploring innovative drug delivery methods such as subretinal gene therapy. Combination therapies, gene therapies, and novel agents like KSI-301 and OPT-302 show potential for improving treatment outcomes and reducing treatment burden.

EXPERT OPINION

While current treatments for w-AMD have significantly advanced with the advent of anti-VEGF therapies, their limitations in terms of treatment burden and incomplete responses have spurred research into diverse alternative approaches. These innovative strategies offer hope for improving patient outcomes and reducing healthcare burdens, suggesting a promising future for w-AMD management.