Perspective on the role of Ozurdex (dexamethasone intravitreal implant) in the management of diabetic macular oedema

Intravitreal OZURDEX vs. Intravitreal Bevacizumab for Diabetic Macular Edema: A Comprehensive Review

This comprehensive review examines the efficacy, safety, and implications of intravitreal OZURDEX and intravitreal bevacizumab in treating diabetic macular edema (DME). DME is a common complication of diabetes mellitus and a leading cause of vision loss. OZURDEX, through sustained release of dexamethasone, targets inflammation and vascular permeability, while bevacizumab inhibits vascular endothelial growth factor (VEGF), reducing angiogenesis. However, differences in safety profiles exist, with OZURDEX associated with an increased risk of intraocular pressure elevation and cataract formation and bevacizumab potentially carrying systemic risks. The choice between these treatments should be individualized, considering patient preferences, ocular and systemic comorbidities, and cost-effectiveness. Collaboration among healthcare providers is essential for the comprehensive management of DME. Future research should focus on long-term comparative studies, predictors of treatment response, and exploration of novel therapeutic targets to optimize treatment outcomes for patients with DME.

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.

Mid-term safety and effectiveness of macular peeling one month after intravitreal dexamethasone implant for tractional diabetic macular edema

Macular peeling combined or followed by intravitreal dexamethasone implant (DEX-i) was recommended as an efficacy approach for tractional diabetic macular edema (tDME). Knowing the synergistic effect of cataract surgery and DEX-i one month earlier in eyes with DME, we compared Epiretinal Membrane/Inner Limiting Membrane (ERM/ILM) peeling preceded by DEX-i one month before versus ERM/ILM peeling alone for the treatment of tDME. A retrospective study on patients affected by tDME who underwent ERM/ILM peeling one month after DEX-i (n = 11; Group A) or ERM/ILM peeling alone (n = 10; Group B) was performed. Longitudinal comparison of best-correct visual acuity (BCVA), central retinal thickness (CRT), and intraocular pressure (IOP) between the time of surgery (T₀) and each time point (months 1,3,5,6) within and among the groups were assessed. To evaluate the repeated measurements of BCVA, CRT, and IOP, a linear mixed-effects model was used. In Group A, DEX-i significantly improved mean BCVA and CRT (P < 0.001) just after 1 month (T₀). After ERM/ILM peeling, mean BCVA and CRT significantly improved from month 1 in Group A and month 3 in Group B. Mixed model revealed a significant difference in BCVA (P ≤ 0.0001) and CRT (P ≤ 0.02) at different time-points among the groups with better results in Group A. Neither complications nor uncontrolled IOP increase was detected. ERM/ILM peeling confirmed its effectiveness in treating tDME. DEX-i performed one month before surgery seemed to be a safe approach and ensured a greater and faster recovery considering functional and tomographic parameters.

Diabetic Macular Oedema Guidelines: An Australian Perspective

The number of people living with diabetes is expected to rise to 578 million by 2030 and to 700 million by 2045, exacting a severe socioeconomic burden on healthcare systems around the globe. This is also reflected in the increasing numbers of people with ocular complications of diabetes (namely, diabetic macular oedema (DMO) and diabetic retinopathy (DR)). In one study examining the global prevalence of DR, 35% of people with diabetes had some form of DR, 7% had PDR, 7% had DMO, and 10% were affected by these vision-threatening stages. In many regions of the world (Australia included), DR is one of the top three leading causes of vision loss amongst working age adults (20-74 years). In the management of DMO, the landmark ETDRS study demonstrated that moderate visual loss, defined as doubling of the visual angle, can be reduced by 50% or more by focal/grid laser photocoagulation. However, over the last 20 years, antivascular endothelial growth factor (VEGF) and corticosteroid therapies have emerged as alternative options for the management of DMO and provided patients with choices that have higher chances of improving vision than laser alone. In Australia, since the 2008 NHMRC guidelines, there have been significant developments in both the treatment options and treatment schedules for DMO. This working group was therefore assembled to review and address the current management options available in Australia.

Management of Diabetic Macular Edema: Guidelines from the Emirates Society of Ophthalmology

In the United Arab Emirates, retinopathy has been shown to be present in 19% of the diabetic population, with diabetes identified in up to 40% of individuals aged over 55 years. Despite the prevalence of diabetic retinal diseases, there are no unified national guidelines on the management of diabetic macular edema (DME). These published guidelines are based on evidence taken from the literature and published trials of therapies, and consensus opinion of a representative expert panel with an interest in this condition, convened by the Emirates Society of Ophthalmology. The aim is to provide evidence-based, clinical guidance for the best management of different aspects of DME, with a special focus on vision-threatening diabetic retinopathy. Treatment should be initiated in patients with best-corrected visual acuity 20/30 or worse, and/or features of DME as seen on optical coherence tomography (OCT) with central retinal thickness (CRT) of at least 300 μm or in symptomatic patients with vision better than 20/25, and/or CRT less than 300 μm where there are OCT features consistent with center-involving macular edema. The treatment of DME is effective irrespective of glycated hemoglobin (HbA1c) level, and treatment must not be denied or delayed in order to optimize systemic parameters. All ophthalmic treatment options should be discussed with the patient for better compliance and expectations. Non-center-involving DME can be initially observed until progression toward the center is documented. Macular laser no longer has a primary role in center-involving DME, and anti-vascular endothelial growth factor (anti-VEGF) therapy should be considered as first-line treatment for all patients, unless contraindicated. If anti-VEGF is contraindicated, a steroid dexamethasone implant can be considered for first-line treatment. Recommendations for the treatment of DME in special circumstances and in relapsing and refractory DME are also discussed.

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.

Local Dexamethasone Administration Delays Allogeneic Islet Graft Rejection in the Anterior Chamber of the Eye of Non-Human Primates

Pancreatic islet transplantation into the anterior chamber of the eye (ACE) has been shown to improve glycemic control and metabolic parameters of diabetes in both murine and primate models. This novel transplantation site also allows the delivery of therapeutic agents, such as immunosuppressive drugs, locally to prevent islet graft rejection and circumvent unwanted systemic side effects. Local intravitreal administration of micronized dexamethasone implant was performed prior to allogeneic islet transplantation into the ACEs of non-human primates. Two study groups were observed namely allogeneic graft without immunosuppression (n = 4 eyes) and allogeneic graft with local immunosuppression (n = 8 eyes). Survival of islet grafts and dexamethasone concentration in the ACE were assessed in parallel for 24 weeks. Allogeneic islet grafts with local dexamethasone treatment showed significantly better survival than those with no immunosuppression (median survival time- 15 weeks vs 3 weeks, log-rank test p<0.0001). Around 73% of the grafts still survived at week 10 with a single local dexamethasone implant, where the control group showed no graft survival. Dexamethasone treated islet grafts revealed a good functional response to high glucose stimulation despite there was a transient suppression of insulin secretion from week 8 to 12. Our findings show a significant improvement of allografts survival in the ACE with local dexamethasone treatment. These results highlight the feasibility of local administration of pharmacological compounds in the ACE to improve islet graft survival and function. By eliminating the need for systemic immunosuppression, these findings may impact clinical islet transplantation in the treatment of diabetes, and the ACE may serve as a novel therapeutic islet transplantation site with high potential for local pharmacological intervention.

Synthesis and Characterization of Novel Succinyl Chitosan-Dexamethasone Conjugates for Potential Intravitreal Dexamethasone Delivery

The development of intravitreal glucocorticoid delivery systems is a current global challenge for the treatment of inflammatory diseases of the posterior segment of the eye. The main advantages of these systems are that they can overcome anatomical and physiological ophthalmic barriers and increase local bioavailability while prolonging and controlling drug release over several months to improve the safety and effectiveness of glucocorticoid therapy. One approach to the development of optimal delivery systems for intravitreal injections is the conjugation of low-molecular-weight drugs with natural polymers to prevent their rapid elimination and provide targeted and controlled release. This study focuses on the development of a procedure for a two-step synthesis of dexamethasone (DEX) conjugates based on the natural polysaccharide chitosan (CS). We first used carbodiimide chemistry to conjugate DEX to CS via a succinyl linker, and we then modified the obtained systems with succinic anhydride to impart a negative ζ-potential to the polymer particle surface. The resulting polysaccharide carriers had a degree of substitution with DEX moieties of 2–4%, a DEX content of 50–85 μg/mg, and a degree of succinylation of 64–68%. The size of the obtained particles was 400–1100 nm, and the ζ-potential was −30 to −33 mV. In vitro release studies at pH 7.4 showed slow hydrolysis of the amide and ester bonds in the synthesized systems, with a total release of 8–10% for both DEX and succinyl dexamethasone (SucDEX) after 1 month. The developed conjugates showed a significant anti-inflammatory effect in TNFα-induced and LPS-induced inflammation models, suppressing CD54 expression in THP-1 cells by 2- and 4-fold, respectively. Thus, these novel succinyl chitosan-dexamethasone (SucCS-DEX) conjugates are promising ophthalmic carriers for intravitreal delivery.

DIABETIC MACULAR EDEMA AND CATARACT SURGERY: Phacoemulsification Combined With Dexamethasone Intravitreal Implant Compared With Standard Phacoemulsification

PURPOSE

To compare functional and anatomical results of combined phacoemulsification and dexamethasone intravitreal implant (Ozurdex; DEX-I) with standard phacoemulsification in diabetic patients with cataract.

METHODS

Retrospective, comparative, cohort study. Patients with nonproliferative diabetic retinopathy, macular edema, and cataract, treated routinely at the Eye Clinic, Azienda Ospedaliero Universitaria Policlinico, Bari, Italy with phacoemulsification associated with DEX-I (n = 23; Phaco-Dex) or standard phacoemulsification (n = 23; Phaco-alone). Best-correct visual acuity, central subfield thickness, and intraocular pressure were assessed at baseline and monthly for 3 months after surgery, and t-test was used to assess change from baseline. A multilevel regression model with an unstructured correlation-type matrix to account for repeated data measures was used for statistical analysis in and between groups.

RESULTS

With Phaco-Dex, best-correct visual acuity increased significantly from the first month (P = 0.0005 vs. baseline) and remained stable at the following visits; central subfield thickness decreased significantly from Month 2 (P = 0.049 and P = 0.04 vs. baseline, respectively); at each timepoint, central subfield thickness was significantly lower in the Phaco-Dex group versus Phaco-alone. Intraocular pressure increased significantly during follow-up (P = 0.001 at Month 3 vs. baseline) but remained within the normal range. In the Phaco-alone group, best-correct visual acuity, and intraocular pressure did not show any significant changes after surgery, whereas central subfield thickness increased from Month 2 (P = 0.05 vs. baseline).

CONCLUSION

In diabetic patients with macular edema and visually significant cataract, combined treatment with phacoemulsification and DEX-I seemed to be effective, safe, and superior to standard phacoemulsification considering both functional and tomographic parameters.

Short-Term Outcomes of Refractory Diabetic Macular Edema Switch From Ranibizumab to Dexamethasone Implant and the Influential Factors: A Retrospective Real World Experience

Introduction: To evaluate the effectiveness and safety of intravitreal dexamethasone (DEX) implants in refractory diabetic macular edema (DME) treated by intravitreal ranibizumab.

Materials and Methods: We retrospectively analyzed DME patients who received DEX implant treatment after being refractory to at least 3 monthly intravitreal ranibizumab injections. The main outcomes were best-corrected visual acuity (BCVA), central retinal thickness (CRT), and intraocular pressure (IOP).

Results: Twenty-nine eyes of 26 patients who had previously received an average of 8.1 ± 4.4 ranibizumab injections were included. Patients received between one and three DEX implants during 12.4 ± 7.4 months of follow-up. The mean final CRT significantly decreased from 384.4 ± 114.4 μm at baseline to 323.9 ± 77.7 μm (p = 0.0249). The mean final BCVA was 51.4 ± 21.3 letters, which was not significant compared to baseline (44.9 ± 30.2 letters, p = 0.1149). Mean IOP did not increase significantly. All patients tolerated the treatment well without serious adverse events. Higher baseline CRT and worse BCVA correlated with better therapeutic responses.

Conclusion: Switching to DEX implant is feasible and safe for treating patients of DME refractory to intravitreal ranibizumab in real world. Further larger-scale or multicenter studies would be conducted to explore different DEX treatment strategies for DME, such as first-line or early switch therapy, for better BCVA improvement.

Dexamethasone Conjugates: Synthetic Approaches and Medical Prospects

Dexamethasone (DEX) is the most commonly prescribed glucocorticoid (GC) and has a wide spectrum of pharmacological activity. However, steroid drugs like DEX can have severe side effects on non-target organs. One strategy to reduce these side effects is to develop targeted systems with the controlled release by conjugation to polymeric carriers. This review describes the methods available for the synthesis of DEX conjugates (carbodiimide chemistry, solid-phase synthesis, reversible addition fragmentation-chain transfer [RAFT] polymerization, click reactions, and 2-iminothiolane chemistry) and perspectives for their medical application as GC drug or gene delivery systems for anti-tumor therapy. Additionally, the review focuses on the development of DEX conjugates with different physical-chemical properties as successful delivery systems in the target organs such as eye, joint, kidney, and others. Finally, polymer conjugates with improved transfection activity in which DEX is used as a vector for gene delivery in the cell nucleus have been described.

COMBINED VITRECTOMY WITH INTRAVITREAL DEXAMETHASONE IMPLANT FOR REFRACTORY MACULAR EDEMA SECONDARY TO DIABETIC RETINOPATHY, RETINAL VEIN OCCLUSION, AND NONINFECTIOUS POSTERIOR UVEITIS

PURPOSE

To compare the efficacy of intraoperative intravitreal dexamethasone implant for macular edema secondary to diabetic retinopathy (DME), retinal vein occlusion (RVO), and noninfectious posterior uveitis.

METHODS

A retrospective review of 62 patients (29 men and 33 women; mean age 51.19 ± 14.41 years; 65 eyes) was performed. Best-corrected visual acuity (in logarithm of the minimal angle of resolution), central foveal thickness, intraocular pressure, and postoperative edema-free period were postoperatively assessed up to 1 year. The preoperative and postoperative numbers of other intravitreal injections needed were compared.

RESULTS

Best-corrected visual acuity gradually improved in the DME group (from 0.87 to 0.51) but failed to improve from Month 3 onward in the RVO and uveitis groups. Central foveal thickness decreased in all groups, especially in the DME group (from 550.93 to 338.10 μm). Edema-free period was longest in the DME group (19.34 ± 15.12 months), followed by the uveitis (12.91 ± 7.85 months) and RVO (8.50 ± 8.76 months) groups. Subjects in the uveitis group used more intraocular pressure-lowering agents (1.00 ± 1.27) than those in the DME (0.13 ± 0.49) and RVO (0.36 ± 0.79) groups. Increased intraocular pressure events were most frequent in postoperative Week 1, especially in the uveitis group.

CONCLUSION

Vitrectomy combined with intravitreal dexamethasone implant for DME, RVO, and noninfectious posterior uveitis had a favorable clinical outcome.

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

INTRODUCTION

In the working age population, Diabetic Macular Edema (DME) is the most common cause of visual loss.

PURPOSE

The present study is aimed to assess the safety and efficacy of intravitreal injection of Ranibizumab (IVR) versus intravitreal Dexamethasone implant (IVD) in patients with DME in a tertiary care centre upto 4 months.

METHODS

This is a comparative, prospective, randomized study that was done on 140 patients with macular edema confirmed on optical coherence tomography (OCT). IVD group received Ozurdex® (Allergan, Inc, Ireland) while the IVR group received Lucentis® (Novartis, Basel, Switzerland); the groups were followed up at day-1 and weeks 4, 8, 12, 16. Patients were divided into Group A, in which patients were given 3 doses (monthly) of IVR 0.3 mg in 0.05 ml (n=70). Group B patients were given a single dose of IVD implant 0.7 mg (n=70).

RESULTS

The mean number of injections given was 1 Ozurdex® per patient vs. 3 Lucentis® per patient. The maximum reduction in central macular thickness (CMT) with IVD was 167.8 μm and 138.8μm in the 2nd and 3rd months, respectively, with IVR. The mean best-corrected visual acuity (BCVA) in the 4th month was 0.34 logMAR and 0.33 logMAR, in IVD and IVR groups, respectively, with consistent improvement. Patients with 0-5 letters, 6-10 letters and 10-15 letters, and >15 letters visibility in IVD group were 9.5, 20.6, 4.8, 6.4%, and 20.4, 18.8, 20.3 20.3% in IVR groups, respectively. The maximum intraocular pressure (IOP) rise with IVD was found to be 16 mmHg in 2 patients (3.17%). IOP rise >10 mmHg was observed in 14/63 patients (22.22%); the majority of patients indicated a high rise at 2nd month with all returning to baseline by 4th month. No reports of infectious endophthalmitis or new cataracts were detected in either of the treated groups.

CONCLUSION

Both intravitreal Ranibizumab injection and Dexamethasone implants were found to be safe and effective in lowering CMT and improving BCVA at the 4-month follow up in patients with DME. Since there was no recurrence of CMT in the Dexamethasone implant group, we suggest that early administration before the 4th month may indicate superior efficacy over the ranibizumab injection. Further randomized trials in a large sample size with a longer period follow- up would be performed to justify the obtained results in the present study.

Real Life Experience of Dexamethasone Implant in Refractory Diabetic Macular Oedema

Purpose

The purpose of this retrospective study was to examine the efficacy of dexamethasone implant in refractory diabetic macular oedema (DMO) in real life settings.

Methods

In all, 24 eyes of 22 patients that required treatment with single or multiple intravitreal dexamethasone implants for refractory DMO were included in the study. Patients having macular oedema for another retinal disease were excluded from the study. The patient data were collected and analyzed retrospectively. As a demographic data age, gender, the type of diabetes and the duration of DMO were collected. Changes in central foveal thickness and the number of hyper reflective spots (HRS) were analyzed with Heidelberg SD-OCT. Furthermore, the best-corrected visual acuity (BCVA) and changes in the intraocular pressure (IOP) were measured.

Results

In all, 50.0% of the eyes with baseline BCVA 0.45 (±2.4) lines in ETDRS LogMAR scale received only one implant during the follow-up of 332 (±79) days. At the end of the follow-up, BCVA was 0.26 (±2.0) lines. The other 50.0% of the eyes with baseline BCVA 0.64 (±3.0) lines received the second implant in 156 (±38) days. Central retinal thickness (CRT) at baseline was 333 (±44) μm in the eyes with only one implant and 497 (±125) μm in the eyes with 2 or more implants. IOP lowering medication was needed for 8.3% of the eyes. The decrease in the number of HRS was significant (8±17, p=0.048) in response to dexamethasone implantation.

Conclusion

The dexamethasone implant is a useful treatment in refractory DMO and HRS seen in the OCT might indicate inflammation in the retina.

Recent advances in slow and sustained drug release for retina drug delivery

INTRODUCTION

Striking recent advance has occurred in the field of medical retina, greatly because intraocular drugs have been developed, enhancing their clinical efficacy while avoiding systemic side-effects. However, the burden of repeated intraocular administration makes limits the optimal efficacy of treatments, prompting the development of new drugs with prolonged half-life or of sustained drug delivery systems.

AREAS COVERED

In this review, we describe the various drugs and drug delivery systems that have reached the clinical stage and those that are in clinical development and we discuss the limitations to clinical translation.

EXPERT OPINION

Substantial fundamental work is still required to build guidelines on optimal animal models for ocular pharmacokinetics and safety studies depending on the target disease site and the on the type of therapeutic compounds. The effects of a drug administered as a bolus at high concentration in the vitreous might differ from those resulting from the sustained release of a lower concentration, and no delivery platform can be simply adapted to any drug. For the treatment of retinal diseases, development of therapeutic compounds should integrate from its early conception, the combination of an active drug with a specific drug delivery system, administered by a specific route.

Principles of pharmacology in the eye

The eye is a highly specialized organ that is subject to a huge range of pathology. Both local and systemic disease may affect different anatomical regions of the eye. The least invasive routes for ocular drug administration are topical (e.g. eye drops) and systemic (e.g. tablets) formulations. Barriers that subserve as protection against pathogen entry also restrict drug permeation. Topically administered drugs often display limited bioavailability due to many physical and biochemical barriers including the pre-corneal tear film, the structure and biophysiological properties of the cornea, the limited volume that can be accommodated by the cul-de-sac, the lacrimal drainage system and reflex tearing. The tissue layers of the cornea and conjunctiva are further key factors that act to restrict drug delivery. Using carriers that enhance viscosity or bind to the ocular surface increases bioavailability. Matching the pH and polarity of drug molecules to the tissue layers allows greater penetration. Drug delivery to the posterior segment is a greater challenge and, currently, the standard route is via intravitreal injection, notwithstanding the risks of endophthalmitis and retinal detachment with frequent injections. Intraocular implants that allow sustained drug release are at different stages of development. Novel exciting therapeutic approaches include methods for promoting transscleral delivery, sustained release devices, nanotechnology and gene therapy.

SAFETY OF CONSECUTIVE SAME-DAY BILATERAL INTRAVITREAL DEXAMETHASONE IMPLANT (OZURDEX)

PURPOSE

The objective of this study was to evaluate patient safety and tolerance of consecutive bilateral intravitreal dexamethasone (Ozurdex) injections during a single visit for the treatment of cystoid macular edema secondary to retinal vein occlusion, diabetic macular edema, or noninfectious posterior uveitis.

METHODS

This was a retrospective single-center institutional review board-approved study from March 1, 2013, through August 1, 2016. All patients had a complete ophthalmologic examination and optical coherence tomography imaging. Bilateral intravitreal dexamethasone (Ozurdex) injection was performed according to standard sterile procedure. Twelve patients (24 eyes) were included in the study.

RESULTS

A total of 48 injections were administered to 24 eyes of 12 patients that qualified for the study. Patients received intravitreal dexamethasone (Ozurdex) injections for treatment of diabetic macular edema (10 patients), retinal vein occlusion (1 patient), or noninfectious posterior uveitis (1 patient). There were no complications.

CONCLUSION

Consecutive same-day bilateral intravitreal dexamethasone (Ozurdex) is safe and well tolerated. There were no significant complications, and patients preferred continuing bilateral implantation after their initial trial. Same-day treatment may optimize efficiency and decrease patient visits and ultimate treatment burden without compromising patient safety or clinical efficacy.

Simultaneous Therapy with Intravitreal Dexamethasone Implant and Bevacizumab for the Treatment of Macular Edema

To investigate the safety profile and benefits of a short-term simultaneous treatment regimen combining two drugs-an intravitreal implant of dexamethasone with an intravitreal injection of bevacizumab-in patients with macular edema. This was a retrospective, non-randomized, open-label case series study. Patients were treated between April 2014 and July 2015 and were diagnosed with recurrent macular edema secondary to diabetic retinopathy and retinal vein occlusion. They underwent simultaneous treatment with an intravitreal injection of bevacizumab (1.25 mg) and an intravitreal implant of dexamethasone (0.7 mg). Patients were evaluated at baseline and at each subsequent visit with a complete ophthalmological examination and spectral-domain optical coherence tomography (OCT) scans. They were examined 24 hours after the treatment, and then followed up after 30 days and 60 days. Twenty patients (representing 20 eyes) were included in the study. At the time of injection (i.e., baseline), the best-corrected visual acuity (BCVA) was 0.758 ± 0.42 logarithm of the minimum angle of resolution (logMAR). It improved significantly to 0.51 ± 0.33 logMAR at 1 month and to 0.5 ± 0.34 logMAR at 2 months (P ≤ 0.03). The median baseline central macular thickness (CMT) was 542 µm (interquartile range, 466 - 751 µm). The median CMT decreased significantly to 321 µm (interquartile range, 288-381 µm) at 1 month and 310 µm (interquartile range, 286 - 354 µm) at 2 months (P ≤ 0.0002). The mean intraocular pressure (IOP) increased from 14.9 ± 2.29 mmHg (at baseline) to 16.5 ± 2.99 mmHg (P = 0.04) after 2 months. Two (10%) eyes showed cataract progression. There were no other ocular or systemic complications for the duration of this study. Simultaneous therapy combining a dexamethasone implant plus bevacizumab for macular edema may be an attractive treatment regimen with an acceptable safety profile.

Efficacy of dexamethasone versus bevacizumab on regression of hard exudates in diabetic maculopathy: data from the BEVORDEX randomised clinical trial

OBJECTIVE

To report the effect of bevacizumab versus dexamethasone on hard exudates (HEX) in diabetic macular oedema (DME).

DESIGN

Post hoc analysis of 24-month data from the Randomised clinical trial of BEVacizumab OR DEXamethasone for diabetic macular oedema (BEVORDEX) phase 2 multicentre randomised clinical trial. Eyes with centre-involving DME resistant to or unlikely to benefit from macular laser therapy were included. Eyes were randomly assigned to bevacizumab every 4 weeks or Ozurdex dexamethasone implant (DEX) every 16 weeks, both as required. The 68 eyes from 48 patients that completed 24-month follow-up were analysed. Two masked graders assessed extent and location of HEX on baseline, 12-month and 24-month foveal-centred colour fundus photographs using validated grading software.

RESULTS

Macular HEX was present in 60% of study eyes. Of these, 21 eyes were treated with DEX and 20 eyes with bevacizumab. Both treatments led to reduction in area of macular HEX at 12 months and 24 months. There was greater regression of HEX from the foveal centre in DEX-treated eyes (median change +890 µm, IQR=1040 µm) than bevacizumab-treated eyes (median change +7.0 µm, IQR=590 µm) at 12 months (p=0.04) but the difference was no longer statistically significant (p=0.10) by 24 months (DEX +1400 µm, IQR=1590 µm; bevacizumab +20 µm, IQR=2680 µm). Reassuringly, no study eye developed HEX at the foveal centre, a visually devastating consequence of diabetic maculopathy.

CONCLUSIONS

Bevacizumab and DEX were effective in reducing area of HEX in eyes with DME. DEX provided more rapid regression of HEX from the foveal centre although bevacizumab-treated eyes started to catch up by 24 months. Distance from the foveal centre as well as total area of macular HEX should be assessed when evaluating treatments for foveal-threatening HEX.

TRIAL REGISTRATION NUMBER

NCT01298076; Post-results.