Dexamethasone Intravitreal Implant for Diabetic Macular Edema: Indications for a PRN Regimen of Treatment

Global research trends and future directions in diabetic macular edema research: A bibliometric and visualized analysis

BACKGROUND

Diabetic Macular Edema (DME) significantly impairs vision in diabetics, with varied patient responses to current treatments like anti-vascular endothelial growth factor (VEGF) therapy underscoring the necessity for continued research into more effective strategies. This study aims to evaluate global research trends and identify emerging frontiers in DME to guide future research and clinical management.

METHODS

A qualitative and quantitative analysis of publications related to diabetic macular edema retrieved from the Web of Science Core Collection (WoSCC) between its inception and September 4, 2023, was conducted. Microsoft Excel, CiteSpace, VOSviewer, Bibliometrix Package, and Tableau were used for the bibliometric analysis and visualization. This encompasses an examination of the overall distribution of annual output, major countries, regions, institutions, authors, core journals, co-cited references, and keyword analyses.

RESULTS

Overall, 5624 publications were analyzed, indicating an increasing trend in DME research. The United States was identified as the leading country in DME research, with the highest h-index of 135 and 91,841 citations. Francesco Bandello emerged as the most prolific author with 97 publications. Neil M. Bressler has the highest h-index and highest total citation count of 46 and 9692, respectively. The journals "Retina - the Journal of Retinal and Vitreous Diseases" and "Ophthalmology" were highlighted as the most prominent in this field. "Retina" leads with 354 publications, a citation count of 11,872, and an h-index of 59. Meanwhile, "Ophthalmology" stands out with the highest overall citation count of 31,558 and the highest h-index of 90. The primary research focal points in diabetic macular edema included "prevalence and risk factors," "pathological mechanisms," "imaging modalities," "treatment strategies," and "clinical trials." Emerging research areas encompassed "deep learning and artificial intelligence," "novel treatment modalities," and "biomarkers."

CONCLUSION

Our bibliometric analysis delineates the leading role of the United States in DME research. We identified current research hotspots, including epidemiological studies, pathophysiological mechanisms, imaging advancements, and treatment innovations. Emerging trends, such as the integration of artificial intelligence and novel therapeutic approaches, highlight future directions. These insights underscore the importance of collaborative and interdisciplinary approaches in advancing DME research and clinical management.

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.

Effect of intravitreal dexamethasone implant in treatment-naive and previously-treated patients with diabetic macular edema

PURPOSE

To document the effects of intravitreal dexamethasone implant on retinal microvasculature in patients with diabetic retinopathy complicated by center-involving macular edema.

METHODS

35 eyes of 35 patients affected by retinopathy due to type 2 diabetes (15 treatment-naïve and 20 previously treated) were included in this retrospective study with a follow-up of 4 months. Foveal avascular zone (FAZ) area and superficial capillary plexus (SCP) and deep capillary plexus (DCP) densities in the foveal and parafoveal areas were measured by optical coherence tomography angiography (OCTA) at baseline and 2 and 4 months post-injection. Intraocular pressure, morphological and functional parameters were evaluated.

RESULTS

a significant difference was found in both groups at 2 months after injection in terms of functional (BCVA, p < 0.05) and morphological (CMT, p < 0.05) parameters. During follow-up, FAZ area, SCP, and DCP in the foveal and parafoveal areas did not change significantly.

CONCLUSIONS

intravitreal dexamethasone implant is effective in the treatment of diabetic center-involving macular edema and was associated with significant improvements in BCVA and CMT at 2 months after injection. After a single dexamethasone implant injection, FAZ area and retinal vascular density does not show significant variations in both naive and non-naive DME patients subgroups.

The effect of pars plana vitrectomy with internal limiting membrane peeling on the durability of the intravitreal dexamethasone implant in the treatment of diabetic macular edema

Purpose

To evaluate the influence of pars plana vitrectomy with internal limiting membrane peeling on recurrence time of diabetic macular edema in eyes under treatment with dexamethasone intravitreal implant injections.

Material and methods

Twelve pseudophakic eyes of 12 patients with non-proliferative diabetic retinopathy and non-tractional diabetic macular edema were included. All eyes had already been treated with two or more dexamethasone intravitreal implant injections evidencing a recurrence time of three months or less (early recurrence). At baseline, they underwent pars plana vitrectomy with internal limiting membrane peeling, ending with dexamethasone intravitreal implant injection. Patients were then followed-up monthly, treated with a second injection at the first recurrence, and followed up to the second recurrence. Measurements of best corrected visual acuity, intraocular pressure, and central foveal thickness by spectral-domain optical coherence tomography were performed at each follow-up examination.

Results

Vitrectomized eyes showed a significant extension of recurrence time of diabetic macular edema, and specifically from 3.4 (3.2–3.7) to 6.5 (5.7–8.2) months after the first injection, and to 7.0 (5.7–8.2) months (p < 0.01) after the second injection (p < 0.01).

Conclusions and importance

Pars plana vitrectomy with internal limiting membrane peeling seems not to influence functional and anatomical results in eyes under treatment with dexamethasone intravitreal implant injections for diabetic macular edema, but appears to significantly extend the benefit of the drug.

Recommendations for the management of diabetic macular oedema with intravitreal dexamethasone implant: A national Delphi consensus study

PURPOSE

The intravitreal dexamethasone implant (DEX-I) is an alternative to anti-VEGF for the first-line treatment of diabetic macular oedema (DME). However, several questions remain regarding its routine use and its place in certain situations not always specified in current recommendations. A national consensus approach was, therefore, initiated by French retinal experts.

METHODS

An iterative Delphi consensus approach was used. A steering committee (SC) of seven experts analysed data from the literature to formulate statements divided into five key areas of treatment. These statements were submitted to the independent and anonymous electronic vote of 87 French retina experts among whom 39 expressed their opinion and therefore constituted the voting panel.

RESULTS

After two rounds of voting, 22 and 7 of 38 statements received a strong consensus and a good consensus, respectively. The consensus level was higher for statements regarding first-line indications and safety of DEX-I compared to those regarding efficacy assessment, reprocessing time or pathophysiological biomarkers. The panellists recommended the preferential use of DEX-I for patients with limited availability for multiple injections, those who needed to undergo cataract surgery or who had a recent cardiovascular history, and as a therapeutic alternative to anti-VEGF in patients with a history of vitrectomy, retinal serous detachment, hyper-reflective points or dry exudates in optical coherence tomography (OCT). However, some statements proposed by SC experts were not validated.

CONCLUSION

This study provides some key recommendations to clinicians treating diabetic macular oedema, which may be useful when using intravitreal dexamethasone implants in daily practice.

A Real-World Study of Dexamethasone Implant in Treatment-Naïve Patients with Diabetic Macular Edema: Efficacy and Correlation Between Inflammatory Biomarkers and Treatment Outcome

Purpose

There has been an increasing clinical interest in specific retinal parameters as non-invasive biomarkers of retinal inflammation in diabetic macular edema (DME) that have been shown to have prognostic value, such as hyperreflective retinal fields (HRFs) and subfoveal neuroretinal detachment (SND).

Methods

We conducted a prospective, non-comparative study of treatment-naïve patients with DME to evaluate the efficacy of a Pro Re Nata (PRN) regimen of intravitreal dexamethasone implant 0.7 mg (DexI, Ozurdex™). After administration, patients underwent subsequent injections according to PRN criteria in case of edema relapse, but not earlier than 4 months after the previous treatment. Patients were evaluated at baseline, within 15 days of injection, and every month thereafter. During all visits, best-corrected visual acuity (BCVA) was recorded; central retinal thickness (CRT), type of edema, presence of SND, and presence and number of HRFs were evaluated using swept-source optical coherence tomography (SS-OCT) 3D. Treatment outcome was defined as changes in BCVA, CRT, SND and HRFs at 12 (T12) and 24 (T24) months compared with baseline (T0).

Results

The study enrolled 24 eyes of 18 patients. The mean duration of follow-up was 18±6.6 months; for all eyes, T12 data were available, while follow-up reached T24 for 12 eyes. BCVA improved significantly and CRT decreased significantly during treatment; the edema was no longer detectable in 13/24 eyes at T12 and 8/12 eyes at T24. No patient presented SND at T12 and T24, and the mean number of HRFs decreased significantly during treatment. Results with CRT and HRFs correlated with BCVA at 12 and 24 months. No significant adverse events were observed.

Conclusion

In patients with DME, the intravitreal dexamethasone implant was effective and safe in improving both functional and tomographic parameters. This result is consistent with improvement in biomarkers of inflammation.

Efficacy and safety of intravitreal dexamethasone implant in treatment naïve eyes with diabetic macular edema: Real world experience

PURPOSE

To evaluate the efficacy and safety of intravitreal dexamethasone implant in treatment naïve eyes with diabetic macular edema (DME).

METHODS

A retrospective analysis of treatment naïve eyes with DME which received intravitreal dexamethasone implant between January 2016 and March 2018 was done. Demographic details of the patients, ocular examination findings at baseline and on follow up visits were noted. Morphological features of DME and central macular thickness were noted on optical coherence tomography at each visit. The details regarding additional treatment for macular edema on follow up were noted.

RESULTS

Sixty five eyes were included in the study. The mean age was 59.14 ± 9.59 years. The follow up ranged from 6 to 48 months. Psuedophakic eyes showed visual improvement whereas the phakic eyes showed stable vision. The central foveal thickness showed significant reduction (p = 0.05) in all the eyes. The best corrected visual acuity at final follow up (+0.65 logMAR) was slightly less as compared to baseline (+0.62 logMAR). Retreatment was needed in 37% eyes and antiglaucoma medications in 8% eyes. Cataract progression was noted in 24 eyes (37%); 17 eyes (26.1%) underwent surgery. Notably, 27 eyes (41.5%) had some degree of macular ischemia at baseline. And five eyes (7.7%) showed progression of retinopathy leading to vitreous hemorrhage.

CONCLUSION

Dexamethasone implant is helpful in reducing the macular thickness and stabilizing the vision in treatment naïve DME; requiring less number of treatment sessions. However, it does not prevent progression of diabetic retinopathy. The visual improvement may be affected by cataract and macular ischemia.

Incidence and treatment outcomes of secondary epiretinal membrane following intravitreal injection for diabetic macular edema

The purpose of this study was to investigate the incidence of secondary epiretinal membrane (ERM) after intravitreal injection and the effect of ERM on visual acuity and central macular thickness (CMT) in patients with diabetic macular edema (DME). We included 147 eyes of 95 patients over 18 years old who were diagnosed with DME from 2012 to 2016, treated with intravitreal injection, and followed-up more than 24 months. Mean CMT in the ERM group was significantly thicker than in the non-ERM group after 9, 12, 18, and 24 months. Secondary ERM developed in 9.5% of patients during follow-up. Compared to other agents, the incidence of secondary ERM was significantly higher after intravitreal injection of dexamethasone implant. Among patients in the ERM group, the mean decrease of CMT between pre-injection and 2 weeks post-injection was significantly less after secondary ERM formation than before ERM formation. Secondary ERM formation was significantly associated with the number of intravitreal injections and the use of dexamethasone implant. Therefore, secondary ERM develops more frequently as the number of intravitreal injections increases and after intravitreal dexamethasone implant injection. The therapeutic effects of intravitreal injections for DME patients decrease after secondary ERM formation.

Association between Hyperreflective Foci on Spectral-Domain Optical Coherence Tomography and Early Recurrence of Diabetic Macular Edema after Intravitreal Dexamethasone Implantation

PURPOSE

To investigate the associations between hyperreflective foci (HRF) on spectral-domain optical coherence tomography (SD-OCT) and early recurrence of macular edema after intravitreal dexamethasone (DEX) implantation in eyes with refractory diabetic macular edema (DME) to bevacizumab.

METHODS

Medical records of patients with refractory DME to bevacizumab, who underwent intravitreal DEX implantation and 12-month follow-up, were reviewed. Eyes in which central subfield thickness (CST) increased over 50 μm at 3 months compared with the first month after intravitreal DEX implantation were categorized into the early recurrence group, and the others were categorized into the late recurrence group. Best-corrected visual acuity (BCVA), CST, and number of HRF on SD-OCT were analyzed.

RESULTS

Twenty-nine eyes of 26 patients (16 eyes in the early recurrence group and 13 eyes in the late recurrence group) were included in this study. The numbers of HRF in entire retina, inner retina, and outer retina at baseline in the early recurrence group (11.38 ± 3.07 in entire retina, 5.44 ± 1.50 in inner retina, 5.94 ± 2.74 in outer retina) were significantly greater than those in the late recurrence group (7.54 ± 3.60 in entire retina, p=0.006; 4.08 ± 1.70 in inner retina, p=0.034; 3.46 ± 2.30 in outer retina, p=0.013). Multivariate logistic regression analysis showed that a higher number of HRF increased the risk of early recurrence after intravitreal DEX implantation (odds ratio in entire retina: 1.518, p=0.012; odds ratio in inner retina: 2.058, p=0.027; odds ratio in outer retina: 1.610, p=0.029).

CONCLUSIONS

Higher baseline numbers of HRF on SD-OCT may be a predictive indicator of early recurrence of macular edema after intravitreal DEX implantation for DME.

Pro Re Nata Dexamethasone Implant for Treatment-Naive Phakic Eyes with Diabetic Macular Edema: A Prospective Study

PURPOSE

To determine the utility and safety of the intravitreal dexamethasone implant as primary therapy (pro re nata [PRN]) in phakic eyes with early treatment-naive diabetic macular edema (DME).

DESIGN

Prospective, case series.

PARTICIPANTS

Patients with diabetes mellitus whose eyes were phakic and had early treatment-naive clinically significant macular edema.

METHODS

Patients whose eyes were phakic with DME (<3 months) were included if the central subfield thickness (CST) was >300 μm and corrected distance visual acuity (CDVA) between 0.3 and 1.0 logarithm of minimum angle of resolution. A comprehensive ocular and systemic examination was performed and the implant injected PRN using a standardized technique. Patients had follow-up at least monthly for 2 years. Descriptive statistics were used to analyze categorical variables in terms of size and proportions. The repeated-measures analysis of variance test was used to determine the change in CDVA, CST, intraocular pressure, and hard exudate area over time.

MAIN OUTCOME MEASURES

The primary outcome measure was the determination of the change in CDVA at month 24 from baseline. Secondary outcome measures included determining the change in CST, median number of injections, proportion gaining 15 letters, and complications, if any.

RESULTS

A total of 153 patients (85 males) were included. At 2 years, mean CDVA improved from 0.62 to 0.4 logarithm of minimum angle of resolution, and median CST improved from 397 to 236 μm. The median number of injections was 1.6. Cataract developed in 3 patients with a clear lens, and 31 patients required topical antiglaucoma therapy. Proliferative disease developed in 4 patients, which was managed with panretinal photocoagulation. None of the study patients required rescue therapy.

CONCLUSIONS

In patients with treatment-naive phakic eyes who had DME, primary therapy with the intravitreal dexamethasone implant PRN (for 2 years) resulted in significantly improved mean CDVA. A fifth of the patients required control of intraocular pressure, and new-onset cataract developed in 3 of 153 patients.

Anatomical and functional changes after dexamethasone implant and ranibizumab in diabetic macular edema: a retrospective cohort study

AIM

To investigate the efficacy and safety of ranibizumab (RZB group) and dexamethasone implant (DEX group) intravitreal treatments in patients with treatment-naïve center involved diabetic macular edema (DME) by means of functional and morphological assessments.

METHODS

This retrospective cohort study included 50 eyes of 50 patients with DME treated either with RBZ or DEX. Best-corrected visual acuity (BCVA) and microperimetry were evaluated at baseline and during a 6-month follow-up. In addition, central macular thickness (CMT) by means of structural optical coherence tomography (OCT) and retinal capillary plexus density and choriocapillary density by means of OCT angiography were assessed in all cases.

RESULTS

Functional and morphological parameters significantly improved during the study period in both groups. BCVA improved significantly in both groups with a greater increase in the DEX group compared to the RBZ group (P=0.030). Microperimetry significantly differed during follow-up between the two treatments (P=0.031). In both groups CMT significantly decreased (P<0.001) without statistically significant differences between the two groups. A statistically significant increase of deep capillary plexus density was detected in both groups at 30d after therapy. The retreatment rate was 0.70±0.10 and 0.65±0.10 in the RBZ group and 0.65±0.10 and 0.50±0.11 in DEX group at 120 and 180d respectively. Two out of 25 patients in DEX group showed intraocular pressure increase requiring hypotonic eye drops.

CONCLUSION

Both treatments are very effective for DME treatment during 6mo of follow-up with a lower retreatment rate in DEX group.

Dexamethasone implant in the management of diabetic macular edema from clinician's perspective

The aim of this article is to provide an overview of characteristics and principles of use of dexamethasone implant in patients with diabetic macular edema (DME). The condensed information about patient selection, dosing, and postinjection management is provided to make the clinician’s decisions easier in real-life practice. DME is a common complication of diabetes and the leading cause of visual loss in the working-age population. Inflammation plays an important role in the pathogenesis of DME. The breakdown of the blood–retinal barrier involves the expression of inflammatory cytokines and growth factors, including vascular endothelial growth factor (VEGF). Steroids have proved to be effective in the treatment of DME by blocking the production of VEGF and other inflammatory cytokines, by inhibiting leukostasis, and by enhancing the barrier function of vascular endothelial cell tight junctions. Dexamethasone intravitreal implant has demonstrated efficacy in the treatment of DME resistant to anti-VEGF therapy and in vitrectomized eyes. Data from clinical trials suggest that dexamethasone implant can be considered as first-line treatment in pseudophakic eyes. Dexamethasone implant is also the first-line therapy in patients not suited for anti-VEGF therapy, pregnant women, and patients unable to return for frequent monitoring. It has been shown that the maximum effect of dexamethasone implant on visual gain and retinal thickness occurs approximately 2 months after injection. Various treatment regimens are used in real-life situations, and reported reinjection intervals were usually <6 months. The number of retreatments needed decreased over time. Treatment algorithms should be personalized. Postinjection management and follow-up should consider potential adverse events such as intraocular pressure elevation and cataract.

Long-term efficacy and safety profile of multiple injections of intravitreal dexamethasone implant to manage diabetic macular edema: A systematic review of real-world studies

INTRODUCTION

Systematic review of real-world studies about repeated dexamethasone intravitreal implant (DEXi) 0.7 mg in diabetic macular edema management, in order to identify the effective window of time occurring between injections, the critical evaluation of efficacy of the treatment, and the relative long-term safety in the real life setting.

METHODS

Literature databases such as PubMed, SCOPUS, and EMBASE were used to identify reports including DEX implant injections.

RESULTS

Twenty-one peer-reviewed publications were identified. DEX implants retreatment was considered on a pro re nata (PRN) basis at any time or starting from month three or four. About 1/3 of the eyes were retreated before six months from first injection (range 0-86.7%). Mean retreatment average time was 5.3 ± 0.9 months, with an estimated average of 1.3 injections each six months. There was no statistical correlation between average retreatment time and incidence of adverse events or other variables investigated. Limited safety issues related to implants number have been found, suggesting an overall good tolerance of long-term DEXi.

CONCLUSIONS

Comprehensive evaluation of real-world data suggests an average DEXi duration close to five months, following a PRN treatment strategy, including about 1/3 of patients. Repeated DEXi administration revealed an acceptable long-term efficacy/safety ratio.

INTRAVITREAL DEXAMETHASONE IMPLANTATION IN PATIENTS WITH DIFFERENT MORPHOLOGICAL DIABETIC MACULAR EDEMA HAVING INSUFFICIENT RESPONSE TO RANIBIZUMAB

PURPOSE

To evaluate the effectiveness of a single intravitreal injection of dexamethasone implant in resistant diabetic macular edema that have different morphological types.

METHODS

In this retrospective study, 31 patients (35 eyes) with persistent diabetic macular edema, who underwent a single injection of dexamethasone implant, were evaluated. Diabetic macular edema was classified into three types: diffuse retinal thickening (n = 10), cystoid macular edema (n = 13), and serous retinal detachment (n = 12). Primary outcome measures were best corrected visual acuity, and central macular thickness.

RESULTS

The three subgroups were similar in terms of age and gender (P > 0.05). Total duration of diabetes was significantly less in the serous retinal detachment subgroup (P = 0.01). There were no differences in the best corrected visual acuity between the three subgroups until the sixth month. However, the best corrected visual acuity was significantly better in the diffuse retinal thickness subgroup at the sixth month (P = 0.008). Regarding the central macular thickness values, it was statistically better in serous retinal detachment than in diffuse retinal thickening and cystoid macular edema subgroups till the sixth month (P = 0.001). However, at the sixth month, there was not any statistical difference between subgroups regarding central macular thickness values. Antiglaucomatous agents were required in 4 (11.4%) patients throughout the study.

CONCLUSION

Treatment algorithms should differ according to the morphology of diabetic macular edema; however, more data is needed to give specific recommendations.

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.

Qualitative and Quantitative Assessment of Vascular Changes in Diabetic Macular Edema after Dexamethasone Implant Using Optical Coherence Tomography Angiography

The aim of this study was to investigate retinal and choriocapillaris vessel changes in diabetic macular edema (DME) after the intravitreal dexamethasone implant (IDI) using optical coherence tomography angiography (OCTA). Moreover, a comparison between morphological and functional parameters of DME and healthy patients was performed. Twenty-five eyes of 25 type 2 diabetic retinopathy patients complicated by macular edema (DME group) and 25 healthy subjects (control group) were enrolled. Superficial capillary plexus density (SCPD) and deep capillary plexus density (DCPD) in the foveal and parafoveal areas, choricapillary density (CCD) and optic disc vessel density (ODVD) were detected using OCTA at baseline and after 7, 30, 60, 90 and 120 days post injection. Best corrected visual acuity (BCVA), retinal sensitivity, and central retinal thickness (CMT) were also evaluated in both groups of patients. A statistically significant difference between the two groups (DME and controls) was found in terms of functional (MP, p < 0.001 and BCVA, p < 0.001) and morphological (CMT, p < 0.001; SCPD in the parafoveal area, p < 0.001; DCPD in the foveal area, p < 0.05 and parafoveal area, p < 0.001; CCD, p < 0.001) parameters. After the treatment, SCPD and DCPD in the foveal and parafoveal areas did not modify significantly during the follow up.

Diabetic macular oedema

Diabetic macular oedema, characterised by exudative fluid accumulation in the macula, is the most common form of sight-threatening retinopathy in people with diabetes. It affects one in 15 people with diabetes resulting in more than 20 million cases worldwide. Few epidemiological studies have been done to specifically investigate risk factors for diabetic macular oedema, although poor glycaemic and blood pressure control are associated with the presence and development of the disorder. The pathophysiological processes begin with chronic hyperglycaemia, and interplay between vascular endothelial growth factor (VEGF) and inflammatory mediators. Non-invasive imaging using optical coherence tomography has allowed clinicians to detect mild levels of diabetic macular oedema in order to monitor progress and guide treatment. Although focal or grid laser photocoagulation was the traditional mode of treatment, intraocular pharmacotherapy with anti-VEGF agents is now the standard of care. However, these therapies are expensive and resource intensive. Emerging therapeutic strategies include improving efficacy and duration of VEGF suppression, targeting alternative pathways such as inflammation, the kallikrein-kinin system, the angiopoietin-Tie2 system, and neurodegeneration, and using subthreshold and targeted laser therapy. Ongoing research should lead to improvements in screening, diagnosis, and management of diabetic macular oedema.

Dexamethasone Intravitreal Implant at the Time of Cataract Surgery in Eyes with Diabetic Macular Edema

Purpose

To determine the potential role of intraoperative dexamethasone intravitreal implant (DEX-I) in reducing diabetic macular edema (DME) worsening after phacoemulsification.

Methods

This was a prospective study on 19 eyes of 19 patients with type 2 diabetes mellitus with DME and cataract. Mean preoperative Early Treatment Diabetic Retinopathy Study visual acuity (VA) was 16.7 letters. Mean foveal thickness (FT) was 451 μm. The DME was naive in 11 eyes and refractory in 8 eyes. All eyes underwent a standard phacoemulsification and intraocular lens implantation; DEX-I was injected at the end of surgery. Follow-up was performed at 1 week and then monthly until DME recurrence (up to 8 months).

Results

At 1 week, mean VA improved by 15 letters (range 0-29 letters) and mean FT decreased by 147 μm (range 69-236 μm). Improvement consolidated at month 1, with a mean VA improvement of 18 letters (range 3-32 letters) and a mean improvement in FT of 193 μm (range 76-304 μm), remaining stable at month 2 after surgery in all eyes. The DME recurred in 1 eye at month 3, in 14 eyes (73.8%) between months 4 and 5, and after month 6 in 4 eyes (21%). Refractory DMEs demonstrated the same benefit but recurred earlier than naive ones (4 months versus 5.8 months, p<0.01).

Conclusions

Intraoperative DEX-I prevents DME worsening after phacoemulsification. Its positive effects last for at least 3 months.

An eighteen-month follow-up study on the effects of Intravitreal Dexamethasone Implant in diabetic macular edema refractory to anti-VEGF therapy

AIM

To evaluate the long-term efficacy and safety of dexamethasone implants in subjects affected by diabetic macular edema (DME) resistant to anti-vascular endothelial growth factor (VEGF) therapy.

METHODS

Thirty-two DME patients were enrolled. A 700 microgram slow release Intravitreal Dexamethasone Implant (Ozurdex^®) was placed in the vitreous cavity. All patients were followed for 18mo. Best-corrected visual acuity (BCVA) measured with Early Treatment Diabetic Retinopathy Study (ETDRS) and central macular thickness (CMT) exams were carried out at baseline (T0) and after 1 (T1), 3 (T3), 4 (T4), 6 (T6), 9 (T9), 12 (T12), 15 (T15), and 18mo (T18) post injection.

RESULTS

Repeated measures ANOVA showed an effect of treatment on ETDRS (P<0.0001). Post hoc analyses revealed that ETDRS values were significantly increased at T1, T3, T4, T9, and T15 (P<0.001) as compared to baseline value (T0). At T6, T12, and T18, ETDRS values were still statistically higher than baseline (P<0.001 vs T0). However, at these time points, we observed a trend to return to baseline conditions. ANOVA also showed an effect of treatment (P<0.0001). CMT decreased significantly at T1, T3, T4, T9, and T15 (P<0.001). At T6 (P<0.01), T12 and T18 (P<0.001) CMT was also significantly lower than T0 although a trend to return to the baseline conditions was also observed.

CONCLUSION

Our findings demonstrate that Intravitreal Dexamethasone Implant is a good option to improve BCVA and CMT in DME patients resistant to anti-VEGF therapy. Our data also show that the use of drugs administered directly into the vitreous allows achieving appropriate and long-lasting concentration at the site of disease without systemic side effects.

Management of anterior chamber dislocation of a dexamethasone intravitreal implant: a case report

Background

Ozurdex is a 700 mcg dexamethasone intravitreal implant, approved for the management of macular edema secondary to retinal vein occlusion, and other related pathoglogiesAnterior chamber dislocation of Ozurdex represents an uncommon complication of the intravitreal injection, which can be managed by repositioning the implant into the vitreous cavity. We describe the case of a successful repositioning of an Ozurdex implant by mobilization and subsequent balanced saline solution injection in the anterior chamber.

Case presentation

An 83-year-old white woman presented to our Emergency Unit complaining of pain and vision loss in herright eye lasting a week. Her anamnesis revealed a history of persistent cystoid macular edema after phacoemulsification with scleral-fixated posterior chamber intraocular lens implantation, recently treated with an intravitreal Ozurdex implant. She also took a long-distance flight 2 days after the injection.

An anterior segment examination showed corneal edema and the rod implant adherent to corneal endothelium. To avoid corneal decompensation, we opted for a implant repositioning. Under topical anesthesia, a 30-gauge needle was introduced through a limbar incisionto mobilize the dislocated rod. Balanced saline solution was injected, with a successful repositioning of the implant into the vitreous cavity. Topical 5 % hypertonic saline solution and 0.2 % betamethasone associated with 0.5 % chloramphenicol drops were administered four times a day. To prevent redislocation of the Ozurdex implant, she was instructed to avoid prone position, any kind of physical effort, and not to undertake long-distance flights during the first postoperative week. One week after surgery, an anterior segment examination showed an improvement of corneal edema. Funduscopy showed that the Ozurdex implant was settled into the vitreous cavity.

Conclusions

Anterior chamber dislocation of Ozurdex from the vitreous cavity is rare. In our patient, in addition to the posterior capsule tearing, the long-distance flight could have contributed to implant dislocation. Repositioning of the implant is necessary to avoid endothelial decompensation. It can be carried out by using saline balanced solution with the same efficacy as other surgical procedures reported in the literature. A possible disadvantage of this procedure could be implant migration.

A multicenter, 12-month randomized study comparing dexamethasone intravitreal implant with ranibizumab in patients with diabetic macular edema

PURPOSE

To evaluate whether treatment with dexamethasone intravitreal implant (DEX implant) 0.7 mg every 5 months provides a similar average change in best-corrected visual acuity (BCVA) from baseline as ranibizumab 0.5 mg administered as per its European Summary of Product Characteristics in patients with diabetic macular edema (DME).

METHODS

This was a multicenter, open-label, 12-month, randomized, parallel-group, noninferiority study in patients with DME (one eye/patient). The primary efficacy measure was BCVA using the Early Treatment Diabetic Retinopathy Study (ETDRS) method. Secondary efficacy measures included area of leakage on fluorescein angiography and central retinal thickness (CRT) on optical coherence tomography.

RESULTS

Baseline patient characteristics were similar in the two treatment groups (DEX implant, n = 181; ranibizumab, n = 182); mean DME duration was ∼33 months. The mean average BCVA change from baseline over 12 months was 4.34 letters with DEX implant and 7.60 letters with ranibizumab. The lower limit of the 95 % confidence interval of the between-group difference was -4.74 letters, and therefore, DEX was demonstrated to be noninferior to ranibizumab based on the prespecified noninferiority margin of 5 letters. At monthly follow-up visits, the percentage of patients with ≥15-letter BCVA gain from baseline ranged from 7.2 to 17.7 % with DEX implant and 4.4 to 26.9 % with ranibizumab. Both DEX implant and ranibizumab effectively reduced CRT and reduced the area of fluorescein leakage. Between-group differences in change from baseline CRT favored DEX implant at 1, 2, 6, and 7 months (p ≤ 0.007) and ranibizumab at 4, 5, 9, and 10 months (p < 0.001); the decrease in fluorescein leakage area was greater with DEX implant than ranibizumab at month 12 (p < 0.001). Ocular adverse events in the study eye were more frequent in the DEX implant group because of the occurrence of intraocular pressure (IOP) increases and cataract. IOP increases were transient and generally managed with topical medication.

CONCLUSIONS

Both DEX implant and ranibizumab were well tolerated and improved BCVA and anatomic outcomes in patients with DME. DEX implant met the a priori criterion for noninferiority to ranibizumab in average change from baseline BCVA over 12 months. Noninferiority was achieved with an average of 2.85 DEX implant injections and 8.70 ranibizumab injections per patient.

Intravitreal Injection of Ozurdex(®) Implant in Patients with Persistent Diabetic Macular Edema, with Six-Month Follow-Up

AIM

To evaluate the efficacy of intravitreal dexamethasone injections in diabetic macular edema (DME).

METHODS

A 700 μg slow-release intravitreal dexamethasone implant (Ozurdex®) was placed in the vitreal cavity of 17 patients (19 eyes) affected with persistent DME. Best corrected visual acuity (BCVA) was assessed through Early Treatment Diabetic Retinopathy Study (ETDRS). Central macular thickness (CMT) was measured by spectral-domain optical coherence tomography. BCVA and CMT examinations were carried out at baseline (T0) and repeated after three days, one month (T1), three months (T3), four months (T4), and six months (T6) post injection.

RESULTS

Dexamethasone implant induced an improvement in ETDRS at T1, T3, T4, and T6 post injection. CMT was reduced at T1, T3, and T4, while at T6, CMT values were not statistically different from baseline. No complications were observed during the follow-up.

CONCLUSION

Our data suggest that dexamethasone implant is effective in reducing DME symptoms within a six-month frame.

Role of implants in the treatment of diabetic macular edema: focus on the dexamethasone intravitreal implant

Diabetic macular edema (DME) is the leading cause of sight-threatening complication in diabetic patients, and several treatment modalities have been developed and evaluated to treat this pathology. Intravitreal agents, such as anti-vascular endothelial growth factors (anti-VEGF) or corticosteroids, have become more popular in recent years and are widely used for treating DME. Sustained release drugs appear to be mentioned more often nowadays for extending the period of intravitreal activity, and corticosteroids play a key role in inhibiting the inflammatory process in DME. A potent corticosteroid, dexamethasone (Ozurdex(®)), in the form of an intravitreal implant, has been approved for various ocular etiologies among which DME is also one. This review evaluates the role of implants in the treatment of DME, mainly focusing on the dexamethasone intravitreal implant.