Three-Year, Randomized, Sham-Controlled Trial of Dexamethasone Intravitreal Implant in Patients with Diabetic Macular Edema

Efficacy and safety of different doses of a slow-release corticosteroid implant for macular edema: meta-analysis of randomized controlled trials

Background

The purpose of this meta-analysis was to assess the efficacy and safety of intravitreal corticosteroid implants for macular edema.

Methods

A total of 3,586 patients from previously reported randomized controlled trials were included. The meta-analysis was performed using RevMan 5.2. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated, employing random-effects or fixed-effects models according to between-study heterogeneity. The main outcome measures were the ORs for effects and safety of intravitreal corticosteroid implants.

Results

Four eligible studies were included. Compared with the sham group, the ORs for ≥15 letter improvement of visual acuity in the high-dose and low-dose groups were 1.89 (95% CI 1.33–2.69, P=0.0004) and 1.62 (95% CI 1.10–2.41, P=0.02), respectively. The weight mean differences in central retinal thickness increases were −75.46 (95% CI −90.29, −60.63, P<0.0001) and −46.47 (95% CI −92.08, −0.86, P=0.05), respectively. However, the ORs for increased intraocular pressure in both intervention groups were higher than in the sham group, and were 11.50 (95% CI 7.24–18.28, P<0.00001) and 10.30 (95% CI 6.49–16.36, P<0.00001), respectively. The incidence of cataract was 7.25 (95% CI 5.68–9.25, P<0.00001) and 3.56 (95% CI 1.28–9.96, P=0.02) in the two intervention groups, respectively. There was no significant difference between the intervention groups except for the incidence of cataract in which the OR was 1.59 (95% CI 1.28–1.97, P<0.001).

Conclusion

Intravitreal corticosteroid implants are effective in treating macular edema. However, the efficacy is not related to corticosteroid dose.

Sustained-release fluocinolone acetonide intravitreal insert for macular edema: clinical pharmacology and safety evaluation

INTRODUCTION

Inflammation plays a key role in the pathological processes leading to macular edema. Sustained release, low-dose intraocular corticosteroid delivery devices provide long-term anti-inflammatory therapy. Recently, a novel fluocinolone acetonide intravitreal insert (FAi, Iluvien), has been introduced with promising long-term results in the treatment of macular edema.

AREAS COVERED

An extensive review of the literature in the English language was performed to provide comprehensive information on the pharmacological properties of FAi and its safety and efficacy data from various multi-center randomized clinical trials.

EXPERT OPINION

The FAc, Retisert is a sustained-release device that is surgically implanted in the vitreous and has been approved by the US FDA for the treatment of non-infectious intermediate, posterior or panuveitis. FAi was developed after FAc and is an intravitreal corticosteroid delivery system that allows controlled release of therapeutic levels of fluocinolone acetonide (FA). Initial efficacy and safety data suggest that this delivery system maintains clinical effectiveness for up to 3 years after a single delivery of the device. This second-generation fluocinolone delivery device has shown superior safety results in clinical trials compared to the previous version of the higher dose FAc (0.59 mg). Sustained delivery preparations may help to reduce the treatment burden and its associated risks by decreasing the frequency of intravitreal injections. However, much needs to be learnt from additional clinical trials, post-marketing surveillance and results of extension studies. Concerns of intravitreal corticosteroids, such as cataract and increase in intraocular pressure, remain major challenges for this therapeutic strategy.

Recent Innovations in Medical and Surgical Retina

PURPOSE

To summarize major innovations in retinal disease management during fiscal year 2014.

DESIGN

Literature review.

METHODS

A subset of papers published in the peer-reviewed literature were selected.

RESULTS

Major innovations in retina include: (1) advances in the treatment of diabetic macular edema, including the use of aflibercept and sustained delivery dexamethasone intravitreal implants as well as subthreshold micropulse diode laser therapy; (2) reduced progression of age-related macular degeneration (AMD) using zinc, vitamin C, vitamin E, lutein, and zeaxanthin supplements as reported in the Age-Related Eye Disease Study-2; (3) use of enhanced-depth imaging optical coherence tomography for choroidal imaging; (4) use of gene therapy to treat choroideremia; (5) use of combination pharmacotherapy (i.e., squalamine + ranibizumab) and gene therapy to treat the neovascular complications of AMD; and (6) use of stem cell-derived retinal pigment epithelium transplants to treat atrophic AMD and Stargardt macular dystrophy. In addition, we review the ocular and systemic risks associated with sustained intraocular steroid delivery and inhibition of vascular endothelial growth factor signaling pathways. We also review potential applications of gene- versus cell-based therapy for the treatment of retinal degenerative diseases.

CONCLUSIONS

Several treatment approaches are effective in the treatment of diabetic macular edema. Prophylaxis against AMD progression with Age-Related Eye Disease Study-2 supplements seems to reduce the risk of developing neovascular but not atrophic complications of AMD. Enhanced-depth imaging optical coherence tomography data provide new information on the role of the choroid in a variety of conditions. Advances in gene- and cell-based therapy will revolutionize the development of regenerative medicine in ophthalmology.

Efficacy and Safety of Intravitreal Dexamethasone Implant in Patients with Diabetic Macular Edema

Purpose: To evaluate the efficacy and safety of intravitreal implant of dexamethasone (Ozurdex®) in diabetic macular edema (DME). Methods: This was a retrospective multicenter noncomparative study. Seventy-eight patients with DME followed for at least 6 months were included (P1.5 Network). Best-corrected visual acuity (BCVA), central retinal thickness (CRT), intraocular pressure (IOP) and cataract progression were studied at baseline and then at 1, 2, 4 and 6 months. Results: The mean CRT decrease from baseline was 145.2 µm at 6 months. The mean BCVA improvement from baseline was 6.7 at 6 months. An increase in IOP was observed for 11.7% of patients, and all patients were managed by topical treatment. No glaucoma or cataract surgery was necessary, and no endophthalmitis was reported. Conclusions: One injection of Ozurdex has an anatomical and functional effectiveness for the treatment of DME. Side effects were rare and manageable in our practice.

Diabetic retinopathy - ocular complications of diabetes mellitus

In industrialized nations diabetic retinopathy is the most frequent microvascular complication of diabetes mellitus and the most common cause of blindness in the working-age population. In the next 15 years, the number of patients suffering from diabetes mellitus is expected to increase significantly. By the year 2030, about 440 million people in the age-group 20-79 years are estimated to be suffering from diabetes mellitus worldwide (prevalence 7.7%), while in 2010 there were 285 million people with diabetes mellitus (prevalence 6.4%). This accounts for an increase in patients with diabetes in industrialized nations by 20% and in developing countries by 69% until the year 2030. Due to the expected rise in diabetic patients, the need for ophthalmic care of patients (i.e., exams and treatments) will also increase and represents a challenge for eye-care providers. Development of optimized screening programs, which respect available resources of the ophthalmic infrastructure, will become even more important. Main reasons for loss of vision in patients with diabetes mellitus are diabetic macular edema and proliferative diabetic retinopathy. Incidence or progression of these potentially blinding complications can be greatly reduced by adequate control of blood glucose and blood pressure levels. Additionally, regular ophthalmic exams are mandatory for detecting ocular complications and initiating treatments such as laser photocoagulation in case of clinical significant diabetic macular edema or early proliferative diabetic retinopathy. In this way, the risk of blindness can considerably be reduced. In advanced stages of diabetic retinopathy, pars-plana vitrectomy is performed to treat vitreous hemorrhage and tractional retinal detachment. In recent years, the advent of intravitreal medication has improved therapeutic options for patients with advanced diabetic macular edema.

Novel pharmacotherapies in diabetic retinopathy

This is a summary of current and emerging pharmacologic therapies utilized in the treatment of diabetic retinopathy (DR). Current therapies, such as ranibizumab, bevacizumab, triamcinolone acetonide, and fluocinolone acetonide, inhibit angiogenesis and inflammation and may be used alone or in combination with laser treatment. Emerging therapies aim to reduce oxidative stress or inhibit other signal transduction pathways, including the protein kinase C cascade and aldose reductase pathway. Future therapies may target other molecules crucial to the pathogenesis of DR, including hepatocyte growth factors and matrix metalloproteinase 9. Finally, the emergence of novel mechanisms of medication delivery may also be on the horizon.

Long-term resolution of immunological graft rejection after a dexamethasone intravitreal implant

PURPOSE

To present the results of the injection of an intravitreal implant of dexamethasone 0.7 mg (DEX 0.7 mg) in 4 patients with an immunologic graft rejection after penetrating keratoplasty.

METHODS

Two of the patients received DEX 0.7 mg because inflammation and corneal edema not related to endothelial cell loss persisted despite the administration of topical prednisolone acetate, subconjunctival betamethasone, and systemic methylprednisolone. The other 2 cases received DEX 0.7 mg at the time rejection was diagnosed.

RESULTS

At 1 and 6 months after implantation, all rejection episodes resolved with improvement in uncorrected and best-corrected visual acuity, restoration of graft transparency, reduction of central corneal thickness, and no significant increase in intraocular pressure.

CONCLUSIONS

In 4 eyes with an immunologic graft rejection after penetrating keratoplasty, the dexamethasone 0.7 mg intravitreal implant was an effective treatment option, even in cases refractory to standard topical and systemic therapy.

Dexamethasone Implants in Patients with Naïve or Refractory Diffuse Diabetic Macular Edema

PURPOSE

To assess the effect of dexamethasone (DEX) 0.7 mg (Ozurdex™) on refractory and treatment-naïve diffuse diabetic macular edema.

METHODS

A prospective study was conducted in 76 patients (40 refractory and 36 naïve) with visual acuities (VA) of 15-72 ETDRS letters, central macular thickness (CMT) >300 µm and intraocular pressure (IOP) <25 mm Hg. After the DEX implant (±photocoagulation), VA, CMT and total macular volume (TMV) were assessed monthly for 6 months.

RESULTS

At every visit, VA improved significantly from baseline (p < 0.001) in both groups, but values were significantly better in the naïve group, while CMT and TMV decreased significantly (p < 0.001) and similarly in both groups. The naïve group received more photocoagulations (p = 0.001). There were 7.9% transient IOP increases >10 mm Hg.

CONCLUSIONS

Substantial improvements in VA and CMT were achieved in both groups, and a gain of 1 ETDRS line was observed in the treatment-naïve group as compared to the refractory group, with a good safety profile in both.

[Efficacy of intravitreal dexamethasone implants in macular edema excluding venous occlusions: results for a cohort of 80 patients]

INTRODUCTION

The intravitreal dexamethasone implant has shown efficacy in the treatment of macular edema (ME) arising after retinal venous occlusions (central or branch), and in the treatment of non-infectious uveitis. The purpose of this study was to evaluate the efficacy of this implant in the treatment of other diffuse macular edemas with an inflammatory mechanism.

MATERIALS AND METHODS

We carried out a retrospective cohort study over 2 years: from January 2012 to December 2013, including all patients who received at least one injection of intravitreal dexamethasone implant, excluding venous occlusions and non-infectious uveitis. The primary study parameter was the progression of visual acuity. The study protocol had the approval of the institutional review board of the respective clinical ethics committees, and was conducted in accordance to the tenets of the Declaration of Helsinki.

RESULTS

Eighty patients were included. Eighty-eight percent of patients were pseudophakic. The indications for treatment were: diabetic ME when anti-VEGF were ineffective (53%), ME after retinal detachment (RD) (22%), ME of Irvine-Gass syndrome (16%), ME after endophthalmitis (4%), macular telangiectasia (4%), ME secondary to retinitis pigmentosa (1%). The mean ETDRS visual acuity was 53.7 letters prior to injection, improving to 62.3 letters after injection (P<0.001). The average gain in visual acuity was 6.7 letters [4.53;8.84] (P<0.001) in patients treated for diabetic ME, 9.6 letters [6.1;13.1] (P<0.001) in patients with ME after RD, and 15.2 letters [10.25;20.28] (P<0.001) for Irvine-Gass syndrome. The mean duration of efficiency was 4.6 months, with a median of 3.8 months.

CONCLUSION

The intravitreal dexamethasone implant appears to be an effective second-line treatment even in patients with diabetic ME after failure or in the case of contraindication of anti-VEGF. It is also effective and well tolerated in patients with ME after RD, as well as in patients with Irvine-Gass syndrome.

Kinematic study of ozurdex injection in balanced salt solution: modeling the behavior of an injectable drug delivery device in vitrectomized eyes

PURPOSE

To analyze the kinematics of a dexamethasone intravitreal implant, Ozurdex, after its injection in a balanced salt solution (BSS) at different release angles to simulate its movement in BSS/aqueous-filled eyes.

METHODS

Eighteen Ozurdex implants were injected into a BSS-filled box at different release angles (15°, 30°, 45°), using 6 implants/group. The movement of injected implants was recorded by a high-speed video camera. Each implant's trajectory was graphically demonstrated by plotting over time. By using a distance-time function graph, the implant's velocity and normalized energy were calculated.

RESULTS

The high-speed video revealed that implants injected at 15° followed a more horizontal trajectory compared to those injected from 30° and 45°, respectively. The implant injected at 15° also achieved the highest mean initial velocity and mean initial normalized energy. The implant velocity from each injection angle decreased exponentially over time and reached nearly zero at 0.1 s. An injection of the implant at a flatter angle was also associated with higher mean retinal impact normalized energy.

CONCLUSIONS

An implant injected at a flatter angle tends to travel farther in the horizontal plane and has more initial velocity, which theoretically generates higher initial normalized energy and retinal impact normalized energy. The accidental injection at a flatter angle, which results in shortening of the effective travel distance, may carry the potential risk of direct retinal injury from the injected implant. The amount of energy necessary to cause direct retinal injury, and whether this would be clinically significant, requires further study.

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.

Diabetic retinopathy: variations in patient therapeutic outcomes and pharmacogenomics

Diabetes and its microvascular complications in patients poses a significant challenge and constitutes a major health problem. When it comes to manifestations in the eye, each case of diabetic retinopathy (DR) is unique, in terms of the phenotype, genotype, and, more importantly, the therapeutic response. It is therefore important to identify factors that distinguish one patient from another. Personalized therapy in DR is a new trend aimed at achieving maximum therapeutic response in patients by identifying genotypic and phenotypic factors that may result in less than optimal response to conventional therapy, and consequently, lead to poorer outcome. With advances in the identification of these genetic markers, such as gene polymorphisms and human leucocyte antigen associations, as well as development of drugs that can target their effects, the future of personalized medicine in DR is promising. In this comprehensive review, data from various studies have been analyzed to present what has been achieved in the field of pharmacogenomics thus far. An insight into future research is also provided.