Morphological and functional changes in recalcitrant diabetic macular oedema after intravitreal dexamethasone implant

Multimodal imaging to distinguish microvascular and morphological changes in retinal vein occlusion after intravitreal ranibizumab with or without triamcinolone acetonide injection

BACKGROUND

The study was designed to investigate microvascular and morphological changes in retinal vein occlusion (RVO) using multimodal imaging after intravitreal ranibizumab (IVR) with or without triamcinolone acetonide (IVTA) injections.

METHODS

This was a retrospective and observational study. Fifty patients (52 eyes) diagnosed with RVO were enrolled. Best corrected visual acuity (BCVA), ophthalmoscopy, fundus fluorescein angiography (FFA), spectral domain optical coherence tomography (SDOCT), and optical coherence tomography angiography (OCTA) were employed sequentially both before treatment and at the last visit after treatment.

RESULTS

The mean logMAR VAs in BRVO eyes decreased significantly after treatment (P = 0.029). OCTA showed there was a significant difference in foveal avascular zone (FAZ) in BRVO eyes (P = 0.024), superificial foveal vessel density in both CRVO (P = 0.0004) and BRVO eyes (P = 0.02155). OCT showed the foveal thickness had significant differences after treatment in both CRVO (P < 0.0001) and BRVO eyes (P = 0.0001). BCVA was associated most commonly with ellipsoid zone integrity (P = 0.022). The BCVA in eyes treated with IVR and IVTA was significantly decreased compared with IVR only in BRVO group (P = 0.021). However, the combination of IVR + IVTA significantly improved intraocular pressure (IOP) compared with IVR only in BRVO group (P = 0.037).

CONCLUSION

Both IVR and IVR + IVTA can significantly improve the central vision, macular structure, and functions in BRVO group. Simultaneous IVR with IVTA can significantly increase BCVA compared with IVR only in BRVO group.

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.

Intravitreal DEX Implant for the Treatment of Diabetic Macular Edema: A Review of National Consensus

Diabetic macular edema (DME)'s therapeutic approach can frequently be challenging. The purpose of the review is to propose evidence-based recommendations on the employment of intravitreal dexamethasone implants (DEX) when approaching patients suffering from DME. Seven national consensuses redacted by different groups of retina specialists from Europe and Asia were examined and confronted. Each consensus was redacted utilizing a Delphi approach, in person meetings, or by reviewing the literature. DEX can be studied as a first-line strategy in individuals suffering from DME with inflammatory OCT biomarkers, in vitrectomized eyes, in patients with recent cardiovascular events, in pregnant women, in patients scheduled to undergo cataract surgery or with poor compliance. The other parameters considered were the indications to the DME treatment, when to switch to DEX, the definition of non-responder to anti-VEGFs agents and to the DEX implant, whether to combine DEX with laser photocoagulation, the association between glaucoma and DEX, and the management of DEX and the cataract. Although several years have passed since the introduction of DEX implants in the DME treatment, there is still not a unified agreement among retina specialists. This paper compares the approach in the DME treatment between countries from different continents and provides a broader and worldwide perspective of the topic.

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

AIM

To evaluate effectiveness of dexamethasone intravitreal implant 0.7 mg (DEX) monotherapy in the AUSSIEDEX study non-responder subgroup, defined by diabetic macular oedema (DME) refractory to anti-vascular endothelial growth factor (anti-VEGF) agents.

METHODS

This prospective, open-label, observational, real-world study included pseudophakic and phakic (scheduled for cataract surgery) eyes that did not achieve a ≥5-letter best corrected visual acuity (BCVA) gain and/or clinically significant central subfield retinal thickness (CRT) improvement after 3-6 anti-VEGF injections for DME (N=143 eyes), regardless of baseline BCVA and CRT. After an initial DEX injection (baseline visit), reinjection was permitted at ≥16-week intervals.

PRIMARY ENDPOINTS

changes in mean BCVA and CRT from baseline to week 52. Safety assessments included adverse events.

RESULTS

Of 143 eyes, 53 (37.1%) and 89 (62.2%) switched to DEX after 3-6 (early) and >6 (late) anti-VEGF injections, respectively; 1 (0.7%) had missing information. With 2.3 injections (mean) over 52 weeks, the change in mean BCVA from a baseline of 57.8 letters was not significant at week 52. Mean CRT improved significantly from a baseline of 417.8 μm at week 52 (mean change -60.9 μm; p<0.001). Outcomes were similar in eyes switched to DEX early and late. No unexpected adverse events were reported; no filtration surgeries were required.

CONCLUSION

To date, AUSSIEDEX is the largest prospective, real-world study of DEX monotherapy for treatment-naïve or anti-VEGF-refractory DME. Following early or late switch from anti-VEGF agents, DEX significantly improved anatomic outcomes at 52 weeks without new safety concerns, supporting use in anti-VEGF-refractory DME.

TRIAL REGISTRATION NUMBER

NCT02731911.

Expert recommendations for the management of diabetic macular edema with intravitreal dexamethasone implant: A Turkish Delphi study

PURPOSE

To provide consensus on the clinical use of intravitreal dexamethasone (DEX) implant for the treatment of diabetic macular edema (DME) in Turkey.

METHODS

A panel of 22 retina experts prepared 77 statements of recommendation, and 80 retinal specialists practicing in Turkey were chosen to vote either in support or against each one. A Delphi-based method was used through which the ophthalmologists were able to view all of the results anonymously after two rounds and modify their subsequent answers. The survey was conducted via a mini website, and statements without consensus were resent to the specialists with the latest vote results a week later.

RESULTS

A total of 72 ophthalmologists answered the first and second round questions. After the first stage, consensus was achieved on 55 of the statements, leaving 22 without agreement. After the second stage, consensus was reached on 11 of the remaining statements. Strong consensus was achieved on statements regarding the etiopathogenesis of DME and the first-line indications and safety of the DEX implant procedure. The panel recommended the use of DEX implant for patients with an arterial thromboembolic event in the last three months and also agreed that pro re nata DEX implant treatment not only provides better outcomes for DME patients but also reduces the treatment burden for those who could not receive an adequate number of anti-vascular endothelial growth factor (VEGF) injections.

CONCLUSION

This study provides clinical consensus and recommendations about the use of DEX implant in the clinical practice of DME management in Turkey.

Early-switch versus late-switch in patients with diabetic macular edema: a cost-effectiveness study

Background

To evaluate the cost-effectiveness of early- versus late-switch to the intravitreal-dexamethasone implant (DEX-i) in patients with diabetic macular edema (DME) who did not adequately respond to vascular endothelial growth factor inhibitors (anti-VEGF).

Methods

Retrospective analysis of a multicenter Clinical Data Registry. The registry included DME eyes who received 3 intravitreal anti-VEGF injections (early-switch) or > 3 intravitreal anti-VEGF injections (late-switch) before switching to DEX-i injections. The primary outcome was to estimate the incremental cost needed to obtain a best-corrected visual acuity (BCVA) improvement ≥ 0.1 or a central-retinal thickness CRT ≤ 250 μm.

Results

The analysis included 108 eyes, 32 (29.6%) and 76 (70.4%) in the early- and late-switch groups, respectively. Early-switch strategy was associated with a cost saving of €3,057.8; 95% CI: €2,406.4–3,928.4, p < 0.0001). Regarding incremental-cost-effectiveness ratio, late-switch group was associated with an incremental cost of €25,735.2 and €13,533.2 for achieving a BCVA improvement ≥ 0.1 at month 12 and at any of the time-point measured, respectively. At month 12, 38 (35.2%) eyes achieved a BCVA improvement ≥ 0.1. At month 12, 52 (48.1) eyes had achieved a CRT ≤ 250 micron. As compared to baseline, the mean (95% CI) CRT reduction was − 163.1 (− 212.5 to − 113.7) µm and − 161.6 (− 183.8 to − 139.3) µm in the early-switch and late-switch groups, respectively, p = 0.9463.

Conclusions

In DME eyes, who did not adequately respond to anti-VEGF, switching to DEX-i at early stages (after the first 3-monthly injections) was found to be more cost-effective than extending the treatment to 6-monthly injections of anti-VEGF.

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

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

Relationship Between Final Visual Acuity and Optical Coherence Tomography Findings in Patients with Diabetic Macular Edema Undergoing Anti-VEGF Therapy

Objectives:

To identify the prevalence of findings in optical coherence tomography (OCT) sections before intravitreal anti-VEGF treatment in patients with diabetic macular edema (DME), and to evaluate the relationship between these findings and final visual acuity and number of injections.

Materials and Methods:

This retrospective study included 296 eyes of 191 patients (104 male, 87 female) who started intravitreal ranibizumab treatment after being diagnosed with DME in the retina unit between January 2013 and April 2017 were included the study. Spectral domain OCT findings at the time of presentation such as presence of serous macular detachment (SD), vitreomacular traction (VMT), and epiretinal membrane (ERM) were recorded. In addition, the regularity of the ellipsoid zone (EZ) and inner retinal layers was also studied.

Results:

The mean central retinal thickness measured in SD-OCT was 449±81 μm before treatment and 350±96 μm after treatment (p<0.001). SD was detected in 155 eyes (52.4%), ERM in 67 eyes (22.6%), and VMT in 9 eyes (3%). Thirty eyes (10.1%) had disorganization of the retinal inner layers (DRIL) and 54 eyes (18.2%) had EZ deterioration. The presence of ERM, EZ irregularity, and DRIL were associated with significantly lower final visual acuity (p<0.0001), while there was no relationship between pre-treatment SD and final visual acuity (p=0.11). Injection number was higher in eyes with SD and ERM compared to those without, but this difference was statistically significant only in the presence of SD (p=0.01 and p=0.59, respectively). There was no difference in injection number according to EZ irregularity or presence of DRIL.

Conclusion:

The coexistence of SD with DME was associated with increased need for treatment but not with final visual acuity. EZ irregularities, DRIL, and ERM are findings that negatively affect visual acuity.

Challenges in Diabetic Macular Edema Management: An Expert Consensus Report

Purpose

This paper aimed to present daily-practice recommendations for the management of diabetic macular edema (DME) patients based on available scientific evidence and the clinical experience of the consensus panel.

Methods

A group of Spanish retina experts agreed to discuss different aspects related with the clinical management of DME patients.

Results

Panel was mainly focused on therapeutic objectives in DME management; definition terms; and role of biomarkers as prognostic and predictive factors to intravitreal treatment response. The panel recommends to start DME treatment as soon as possible in those eyes with a visual acuity less than 20/25 (always according to the retina unit capacity). Naïve patient was defined, in a strict manner, as a patient who, up to that moment, had never received any treatment. A refractory DME patient may be defined as the one who did not achieve a complete resolution of the disease, regardless of the treatment administered. Different optical coherence tomography biomarkers, such as disorganization of the retinal inner layers, hyperreflective dots, and cysts, have been identified as prognostic factors.

Conclusion

This document has sought to lay down a set of recommendations and to identify key issues that may be useful for the daily management of DME patients.

Anti-VEGF-Resistant Retinal Diseases: A Review of the Latest Treatment Options

Anti-vascular endothelial growth factor (anti-VEGF) therapy currently plays a central role in the treatment of numerous retinal diseases, most notably exudative age-related macular degeneration (eAMD), diabetic retinopathy and retinal vein occlusions. While offering significant functional and anatomic benefits in most patients, there exists a subset of 15–40% of eyes that fail to respond or only partially respond. For these cases, various treatment options have been explored with a range of outcomes. These options include steroid injections, laser treatment (both thermal therapy for retinal vascular diseases and photodynamic therapy for eAMD), abbreviated anti-VEGF treatment intervals, switching anti-VEGF agents and topical medications. In this article, we review the effectiveness of these treatment options along with a discussion of the current research into future directions for anti-VEGF-resistant eyes.

Effect of Dexamethasone Intravitreal Implant on Visual Acuity and Foveal Photoreceptor Integrity in Macular Edema Secondary to Retinal Vascular Disease

PURPOSE

The aim of this study was to evaluate the effect of the dexamethasone intravitreal (DEX) implant on the external limiting membrane (ELM) and ellipsoid zone (EZ) integrity in treatment-naïve patients with macular edema (ME) secondary to retinal vascular disease (RVD).

METHODS

This is a retrospective study conducted on patients with ME secondary to RVD, who underwent a DEX implant.

RESULTS

One-hundred eyes were included. Mean age was 70.3 ± 11.1 years. Mean ELM integrity significantly improved from 1,575.9 ± 285.9 μm at baseline to 1,711.7 ± 244.0 μm at month 3 (p < 0.0001). Similarly, there was a significant improvement in EZ integrity from baseline to month 3 (1,531.5 ± 317.1 vs. 1,694.3 ± 252.8 μm, respectively, p < 0.0001). At month 3, mean visual acuity (VA) gain was 9.9 ± 14.1 letters (p < 0.0001). Mean central retinal thickness (CRT) significantly decreased by -193.2 ± 185.7 μm from baseline to month 3 (p < 0.0001). Mean changes in VA and CRT were significantly correlated with baseline ELM integrity (p = 0.0065 and p = 0.0046, respectively) and EZ integrity (p = 0.0300 and p = 0.0035, respectively). At month 3, the proportion of eyes which had an intact ELM (mean difference 16.0%, 95% CI 5.4-26.4%, p = 0.0033) and EZ (mean difference 12.0%, 95% CI 1.8-22.1%, p = 0.0210) was significantly higher than at baseline.

CONCLUSIONS

DEX implant was able to significantly improve ELM and EZ integrity in naïve patients with ME.

Rebound Phenomenon after Intravitreal Injection of Triamcinolone Acetonide for Macular Edema

INTRODUCTION

The aim of this article was to report on a rebound phenomenon after intravitreal triamcinolone acetonide (IVTA) injection for macular edema secondary to diabetic retinopathy (DR) and central or branch retinal vein occlusion (CRVO/BRVO).

METHODS

The data were analyzed retrospectively. Complete ophthalmic examinations, including spectral domain optical coherence tomography, were performed before and 2 months after IVTA injection. The incidence of a rebound phenomenon was defined as an increase in central retinal thickness of >10% from baseline at 2 months after IVTA injection.

RESULTS

This retrospective study included 211 consecutive patients (268 eyes). One hundred ninety (71.2%), 39 (14.6%), and 39 (14.6%) eyes had macular edema (ME) due to DR, CRVO, and BRVO. In total, 9.7% of the eyes showed a rebound phenomenon (DR: 9.5%, CRVO: 5.2%, BRVO: 15.4%). The mean number of prior injections of vascular endothelial growth factor inhibitor or corticosteroid agent was statistically significantly higher in the rebound group (6.8 vs. 5.3) than in the nonrebound group (p = 0.01).

CONCLUSION

Our study shows that 9.7% of the eyes with ME secondary to DR and RVO developed a rebound phenomenon following IVTA injection, limiting its therapeutic effect. We found an increased number of prior intravitreal pharmacotherapy to be a risk factor for a rebound phenomenon.

DEXAMETHASONE IMPLANT FOR DIABETIC MACULAR EDEMA IN NAIVE COMPARED WITH REFRACTORY EYES: The International Retina Group Real-Life 24-Month Multicenter Study. The IRGREL-DEX Study

PURPOSE

To investigate efficacy and safety of repeated dexamethasone (DEX) implants over 24 months, in diabetic macular edema (DME) eyes that were treatment naive compared with eyes refractory to anti-vascular endothelial growth factor treatment, in a real-life environment.

METHODS

This multicenter international retrospective study assessed best-corrected visual acuity and central subfield thickness (CST) of naive and refractory eyes to anti-vascular endothelial growth factor injections treated with dexamethasone implants. Safety data (intraocular pressure rise and cataract surgery) were recorded.

RESULTS

A total of 130 eyes from 125 patients were included. Baseline best-corrected visual acuity and CST were similar for naive (n = 71) and refractory eyes (n = 59). Both groups improved significantly in vision after 24 months (P < 0.001). However, naive eyes gained statistically significantly more vision than refractory eyes (+11.3 ± 10.0 vs. 7.3 ± 2.7 letters, P = 0.01) and were more likely to gain ≥10 letters (OR 3.31, 95% CI 1.19-9.24, P = 0.02). At 6, 12, and 24 months, CST was significantly decreased compared with baseline in both naive and refractory eyes; however, CST was higher in refractory eyes than in naive eyes (CST 279 ± 61 vs. 313 ± 125 μm, P = 0.10).

CONCLUSION

Over a follow-up of 24 months, vision improved in diabetic macular edema eyes after treatment with dexamethasone implants, both in eyes that were treatment naive and eyes refractory to anti-vascular endothelial growth factor treatment; however, improvement was greater in naive eyes.

Glucocorticoid and progesterone mechanisms in photoreceptor survival

Death of retinal photoreceptors is the basis of prevalent blinding diseases. Since steroids might have a therapeutic role in retinal degenerations, we compared the protective effects of dexamethasone and progesterone on photoreceptor death induced by mifepristone and light exposure. Therefore, we studied the effective protection doses for each steroid in the two models. In addition, we analyzed changes in the levels of pro- and antiapoptotic molecules, glucocorticoid receptors α and β (GRα and GRβ), and rhodopsin under conditions of successful protection and photoreceptor survival. Mifepristone and light exposure selectively damaged photoreceptors. In light exposed retinas, photoreceptors mainly disappeared in the dorsotemporal region, while mifepristone produced a uniform damage. Dexamethasone and progesterone, at the same dose of 4 mg/kg/day for 2 days, preserved over 88% photoreceptor nuclei in both models. Assessment of cell death regulators showed that, in control retinas, both steroids activated BCL-X_L, a prosurvival molecule, and decreased BID, a proapoptotic regulator. After steroid treatment of damaged retinas, BCL-X_L, BCL2 and BAX showed characteristic patterns depending on the use of dexamethasone or progesterone on mifepristone or light exposed retinas. By contrast, BID decreased with any injury-steroid combination. Changes in GRα or GRβ levels did not correlate with survival but were consistent with a mechanism of ligand induced downregulation of receptor expression. GRβ might be upregulated by progesterone. Both dexamethasone and progesterone increased retinal rhodopsin stores, suggesting a link between photoreceptor protection and transduction pathways. Results show that dexamethasone and progesterone induced comparable but not identical protection responses in each model.

Retinal angiographic alteration in diabetic macular edema after dexamethasone implantation: a case report

Here we reported a rare case of the implantation of a dexamethasone intravitreal implant (DEX) in which decreased retinal vessel density (VD) was found by optical coherence tomography angiography (OCTA). A 74-year-old male with diabetes mellitus presented with bilateral macular edema. The best-corrected visual acuity (BCVA) was 0.6 in the right eye. Diabetic macular edema (DME) was diagnosed. A DEX for the right eye was planned, and the preoperative evaluation showed a superficial VD of 48.74 percent, a deep VD of 53.12 percent, and a foveal avascular zone (FAZ) 0.165 mm² in size by OCTA. The BCVA in the right eye recovered to 0.8, and a notably lower superficial VD of 45.97 percent and a deep VD of 45.40 percent were observed with an enlarged FAZ of 0.294 mm² one month postoperatively. Moreover, BCVA in the right eye was maintained at 0.8, while further reductions in both superficial (40.07 percent) and deep (40.91 percent) VD were noted with a FAZ measured at 0.305 mm² two months postoperatively. In conclusion, retinal superficial and deep VD decreased, while the FAZ increased, after the implantation of the DEX in a patient with DME.

Management of diabetic macular edema with intravitreal dexamethasone implants: Expert recommendations using a Delphi-based approach

OBJECTIVES:

Despite being approved and effective, steroids, and especially dexamethasone intravitreal implants, still have a poorly-defined role in management of diabetic macular edema. In order to overcome some of the limitations in current recommendations, a group of experts met to define consensus on some of the most controversial issues on the use of dexamethasone intravitreal implants in daily management of diabetic macular edema.

METHODS:

A Delphi-based approach was utilized to develop clinically relevant statements applicable to routine treatment settings. A Steering Committee composed of four experts formulated 30 relevant statements, which were voted upon by a panel of 40 ophthalmologists/retinal specialists from across Italy.

RESULTS:

Dexamethasone intravitreal implants were considered to be a valid first-line alternative to treatment with an anti-vascular endothelial growth factor agent and should be the first choice in pseudophakic and vitrectomized patients. A Pro Re Nata regimen was felt to be appropriate for retreatment with dexamethasone intravitreal implants while a 6-month waiting period was not considered suitable. Among steroid treatments, dexamethasone intravitreal implants were considered to have the best ocular tolerability. In patients with persistent macular edema after the loading-phase treatment with an anti-vascular endothelial growth factor, consensus was reached that clinicians should consider switching therapy to dexamethasone intravitreal implants. Moreover, dexamethasone intravitreal implants can reduce the treatment burden for individuals who are not able to cope with the more intensive treatment regimen required by anti-vascular endothelial growth factor therapy.

CONCLUSIONS:

While further studies are needed, this survey provides some key recommendations for clinicians treating diabetic macular edema that may be useful when choosing dexamethasone intravitreal implants in daily practice.

Clinical Decision-Making when Treating Diabetic Macular Edema Patients with Dexamethasone Intravitreal Implants

Diabetes mellitus (DM) is a metabolic disease frequently associated with comorbidities that include diabetic macular edema (DME). The current medical approach to treating DME involves intravitreal injections with either anti-vascular endothelial growth factors or steroids. However, the burden associated with intravitreal injections and DM-derived complications is high, underlining the need to find optimal treatment regimens. In this article we describe the considerations we apply when treating DME patients with dexamethasone intravitreal implants (Ozurdex®), particularly those that influence the clinical decision-making process during the follow-up period. These considerations are based both on the available medical literature and on our clinical experience following the use of these implants in this type of patient, the goal being to optimize the number of injections and the clinical outcome of this therapy. We also provide a general overview of the pathophysiology of DME, highlighting the inflammatory component as a rationale to use steroids in these patients.