Iluvien™ (Fluocinolone Acetonide 0.19 mg Intravitreal Implant) in the Treatment of Diabetic Macular Edema: A Review

Injectable biodegradable microchamber array films for long-term delivery of glucocorticoids

Glucocorticoids (GCs) are widely recognized for their potent anti-inflammatory and analgesic effects. Although they can cause an array of side effects when delivered systemically these are generally avoided when delivered locally at disease sites such as the eyes, lungs and joints. Glucocorticoid formulations for local use range from crystals and particles through to non-biodegradable implants. In many formulations burst release means that their effectiveness does not persist for more than a few weeks. Novel delivery methods that achieve prolonged delivery of GCs along with sequential degradation of the polymer vehicle has the potential to enhance the effectiveness of these drugs and achieve better control of disease. In this study we use a soft lithography method to produce polymer microchamber array films (MCAs) containing crystals of GCs. We demonstrate that the rate of glucocorticoid release can be adjusted through the choice of polymer used in the manufacture of films with rapid release observed with PLGA 50/50 over the course of 9 weeks and the longest duration of release observed with PLA films which continued beyond a year. Importantly, these release studies do not show evidence of burst release and all films displayed a significant duration of zero order release kinetics. Observations of film degradation were made through changes in their size, microscopic appearance and liberation of lactic acid from the films during the course of experiments demonstrated the association with GC release kinetics. These flexible films can be rolled into fibers with little change in release kinetics and the rolled MCAs can also be injected in vivo through a syringe needle to a delivery site. We envisage that this study could lead to an innovative approach to achieve prolonged release of GCs from biodegradable formulations at disease sites.

Revolutionizing drug delivery strategies with probucol to combat oxidative stress in retinal degeneration: A comprehensive review

Localized oxidative stress plays a key role in the development of retinal degenerative diseases, with diabetic retinopathy (DR) being one of them, contributing significantly to this vision-threatening complication of diabetes. Increased oxidative burden leads to dysfunction across various retinal cell types, including vascular endothelial cells, neurons, glial cells and pericytes. Importantly, even after achieving normalized glycemia, the detrimental effects of oxidative stress persist. Nonetheless, growing data highlights the therapeutic potential of antioxidants in safeguarding vision. However, extensive clinical trials using traditional antioxidants have produced mixed results. Therefore, probucol, known for its ability to limit vascular oxidative stress, decrease superoxide generation, and improve endogenous antioxidant activity, is a promising candidate explored in this review. In addition to describing probucol, this review will explore novel therapeutic formulation strategies by incorporating bile acid into probucol-loaded nanoparticles to enhance drug delivery to the posterior segment of the eye for more effective management of DR. The integration of bio-nanotechnology with probucol and bile acids represents a promising avenue for developing effective therapies for DR, addressing the limitations of traditional antioxidant treatments.

Advanced drug delivery strategies for diabetic retinopathy: current therapeutic advancement, and delivery methods overcoming barriers, and experimental modalities

INTRODUCTION

Diabetic retinopathy, a significant trigger for blindness among working age individuals with diabetes, poses a substantial global health challenge. Understanding its underlying mechanisms is pivotal for developing effective treatments. Current treatment options, such as anti-VEGF agents, corticosteroids, laser photocoagulation, and vitreous surgery, have their limitations, prompting the exploration of innovative approaches like nanocapsules based drug-delivery systems. Nanoparticles provide promising solutions to improve drug delivery in ocular medicine, overcoming the complexities of ocular anatomy and existing treatment constraints.

AREAS COVERED

This review explored advanced therapeutic strategies for diabetic retinopathy, focusing on current medications with their limitations, drug delivery methods, device innovations, and overcoming associated barriers. Through comprehensive review, it aimed to contribute to the discovery of more efficient management strategies for diabetic retinopathy in the future.

EXPERT OPINION

In the next five to ten years, we expect a revolutionary shift in how diabetic retinopathy is treated. As we deepen our understanding of oxidative stress and metabolic dysfunction, antioxidants with specialised delivery matrices are poised to take center stage in prevention and treatment strategies. Our vision is to create a more integrated approach to diabetic retinopathy management that not only improves patient outcomes but also reduces the risks associated to traditional therapies.

Role of EYP-1901 in neovascular age-related macular degeneration and diabetic eye diseases: review of Phase I/II trials

EYP-1901 (Duravyu) has demonstrated promising outcomes in Phases I and II clinical trials for the treatment of neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME)/diabetic retinopathy. This innovative treatment capitalizes on the potent anti-angiogenic properties of vorolanib, an inhibitor that targets all isoforms of VEGF, effectively mitigating the pathological neovascularization and vascular permeability that underpin these retinal conditions. EYP-1901 is integrated with the Durasert drug delivery system to administer a sustained release of vorolanib directly to the posterior segment of the eye. This delivery system ensures a consistent therapeutic effect over an extended period and significantly reduces the frequency of clinical interventions required, offering a more convenient treatment regimen while maintaining patient safety.

The Treatment of Diabetic Retinal Edema with Intravitreal Steroids: How and When

Diabetic macular edema (DME) is a common complication of diabetes mellitus and a leading cause of visual impairment worldwide. It is defined as the diabetes-related accumulation of fluid, proteins, and lipids, with retinal thickening, within the macular area. DME affects a significant proportion of individuals with diabetes, with the prevalence increasing with disease duration and severity. It is estimated that approximately 25-30% of diabetic patients will develop DME during their lifetime. Poor glycemic control, hypertension, hyperlipidemia, diabetes duration, and genetic predisposition are recognized as risk factors for the development and progression of DME. Although the exact pathophysiology is still not completely understood, it has been demonstrated that chronic hyperglycemia triggers a cascade of biochemical processes, including increased oxidative stress, inflammation, activation of vascular endothelial growth factor (VEGF), cellular dysfunction, and apoptosis, with breakdown of the blood-retinal barriers and fluid accumulation within the macular area. Early diagnosis and appropriate management of DME are crucial for improving visual outcomes. Although the control of systemic risk factors still remains the most important strategy in DME treatment, intravitreal pharmacotherapy with anti-VEGF molecules or steroids is currently considered the first-line approach in DME patients, whereas macular laser photocoagulation and pars plana vitrectomy may be useful in selected cases. Available intravitreal steroids, including triamcinolone acetonide injections and dexamethasone and fluocinolone acetonide implants, exert their therapeutic effect by reducing inflammation, inhibiting VEGF expression, stabilizing the blood-retinal barrier and thus reducing vascular permeability. They have been demonstrated to be effective in reducing macular edema and improving visual outcomes in DME patients but are associated with a high risk of intraocular pressure elevation and cataract development, so their use requires an accurate patient selection. This manuscript aims to provide a comprehensive overview of the pathology, epidemiology, risk factors, physiopathology, clinical features, treatment mechanisms of actions, treatment options, prognosis, and ongoing clinical studies related to the treatment of DME, with particular consideration of intravitreal steroids therapy.

Current Insights into Targeting Strategies for the Effective Therapy of Diseases of the Posterior Eye Segment

The eye is one a unique sophisticated human sense organ with a complex anatomical structure. It is encased by variety of protective barriers as responsible for vision. There has been a paradigm shift in the prevalence of several major vision threatening ocular conditions with enhanced reliance on computer-based technologies in our workaday life and work-from-home modalities although aging, pollution, injury, harmful chemicals, lifestyle changes will always remain the root cause. Treating posterior eye diseases is a challenge faced by clinicians worldwide. The clinical use of conventional drug delivery systems for posterior eye targeting is restricted by the ocular barriers. Indeed, for overcoming various ocular barriers for efficient delivery of the therapeutic moiety and prolonged therapeutic effect requires prudent and target-specific approaches. Therefore, for efficient drug delivery to the posterior ocular segment, advancements in the development of sustained release and nanotechnology-based ocular drug delivery systems have gained immense importance. Therapeutic efficacy and patient compliance are of paramount importance in clinical translation of these investigative drug delivery systems. This review provides an insight into the various strategies employed for improving the treatment efficacies of the posterior eye diseases. Various drug delivery systems such as systemic and intraocular injections, implants have demonstrated promising outcomes, along with that they have also exhibited side-effects, limitations and strategies employed to overcome them are discussed in this review. The application of artificial intelligence-based technologies along with an appreciation of disease, delivery systems, and patient-specific outcomes will likely enable more effective therapy for targeting the posterior eye segment.

Effectiveness and safety of fluocinolone acetonide intravitreal implant in diabetic macular edema patients considered insufficiently responsive to available therapies (REACT): a prospective, non-randomized, and multicenter study

OBJECTIVE

To assess the effectiveness and safety of the intravitreal fluocinolone-acetonide implant (FAc-i) in patients with chronic diabetic macular edema who did not sufficiently respond to other available therapies.

METHODS

This was a multicenter, prospective, non-randomized, and phase-IV observational study conducted on patients with recurrent-DME who were insufficient responders to currently available therapies (REACT-Study). The primary end-point was the mean change in best-corrected-visual-acuity from baseline to month-24 values.

RESULTS

Thirty-one eyes from 31 patients were included in the study. Mean age was 68.0 ± 7.7 years, and 10 (32.3%) were women. Study patients had received 5.3 ± 7.3 previous DME treatments before starting the study. In the overall study sample, BCVA improved from 56.1 ± 12.3 letters at baseline to 62.4 ± 17.0 letters at month-24 (p = 0.0510). The eyes with a baseline BCVA < 70 ETDRS letters had a significant improvement in BCVA from 53.2 ± 10.2 letters at baseline to 61.5 ± 17.9 letters at month-24 (p = 0.0165). In the overall study population, central-subfoveal-thickness (CST) was significantly reduced from 474.0 ± 135.1 µm at baseline to 333.4 ± 135.6 at month-24 (p < 0.0001). Similarly, macular-volume (MV) was significantly reduced from 10.7 ± 2.7 mm3 at baseline to 9.6 ± 2.9 mm3 (p = 0.0027) at month-24. Among the 31 study eyes, 19 (61.3%) required an additional treatment for DME. Throughout the study, 9 (29.0%) eyes required ocular hypotensive medication for controlling their intraocular-pressure and 5 (16.1%) eyes underwent cataract surgery.

CONCLUSIONS

In DME eyes who did not sufficiently respond to previous therapies, the FAc-i was associated with an improvement in visual and anatomic outcomes. There were no unexpected adverse-events.

TRIAL REGISTRATION NUMBER

EudraCT identifier: 2016-001680-37.

Challenges and strategies for ocular posterior diseases therapy via non-invasive advanced drug delivery

Posterior segment diseases, such as age-related macular degeneration (AMD) and diabetic retinopathy (DR) are vital factor that seriously threatens human vision health and quality of life, the treatment of which poses a great challenge to ophthalmologists and ophthalmic scientists. In particular, ocular posterior drug delivery in a non-invasive manner is highly desired but still faces many difficulties such as rapid drug clearance, limited permeability and low drug accumulation at the target site. At present, many novel non-invasive topical ocular drug delivery systems are under development aiming to improve drug delivery efficiency and biocompatibility for better therapy of posterior segment oculopathy. The purpose of this review is to present the challenges in the noninvasive treatment of posterior segment diseases, and to propose strategies to tackle these bottlenecks. First of all, barriers to ocular administration were introduced based on ocular physiological structure and behavior, including analysis and discussion on the influence of ocular structures on noninvasive posterior segment delivery. Thereafter, various routes of posterior drug delivery, both invasive and noninvasive, were illustrated, along with the respective anatomical obstacles that need to be overcome. The widespread and risky application of invasive drug delivery, and the need to develop non-invasive local drug delivery with alternative to injectable therapy were described. Absorption routes through topical administration and strategies to enhance ocular posterior drug delivery were then discussed. As a follow-up, an up-to-date research advances in non-invasive delivery systems for the therapy of ocular fundus lesions were presented, including different nanocarriers, contact lenses, and several other carriers. In conclusion, it seems feasible and promising to treat posterior oculopathy via non-invasive local preparations or in combination with appropriate devices.

Trends in Ophthalmological Patents, 2005-2020

Purpose: Technological development drives the optimization of therapeutics in ophthalmology, but quantifiable and systematic review of such innovation is lacking. To fill this gap, we characterize trends in ophthalmology-related patents in the United States from 2005 to 2020. Methods: Publicly available patent data from the US Patent and Trademark Office was analyzed with the R programming language. Ophthalmology-related patents were identified with a keyword search of their titles and claims text. Temporal trends were assessed with the Mann-Kendall trend test (α = 0.05, two-sided). Results: Of 4.5 million collected patents, some 21,000 (0.5%) were ophthalmology related. The number of annually granted ophthalmology patents increased over time (Mann-Kendall test: z = 4.91; P < 0.001), from 619 patents released in 2005 to 2,019 patents in 2020. Patent counts also increased over time for all ophthalmic subspecialties except oculoplastics, with steepest rises in retina (z = 4.91; P < 0.001) and cornea (z = 4.64; P < 0.001). The most cited patents were in biocompatible intraocular implants and implantable controlled-release drug delivery systems, which underscores particular advancement in therapeutic efficacy and safety in devices used in the treatment and management of common yet debilitating eye conditions. Conclusion: This exploratory analysis reveals hotspots for ophthalmology-related innovation in the United States that may predict current and future growth trends in device development and pharmacologic advancement in ophthalmology, paving the way for more diverse and effective treatment options for preserving vision.

Visual function and retinal morphological changes after single suprachoroidal delivery of fluocinolone acetonide (Iluvien®) implant in eyes with chronic diabetic macular edema

BACKGROUND

To assess the efficacy and safety of supra-choroidal (SC) Iluvien in the management of chronic diabetic macular edema (DME).

METHODS

A retrospective interventional non-comparative consecutive case series including patients with chronic DME who received an SC Iluvien implant. All patients had persistent central macular thickness (CMT) ≥ 300µ after previous treatment with anti-vascular endothelial growth factor (VEGF) agents or laser photocoagulation. The main outcome measures were improvement of best-corrected visual acuity (BCVA), reduction of CMT, and detection of ocular hypertension/glaucoma or cataract formation. Friedman's two-way ANOVA was used to analyze BCVA, intraocular pressure (IOP), and DME across different time points. P-value = 0.05.

RESULTS

The study included 12 eyes of 12 patients. Six patients (50%) were males. The median age was 58 years (range 52-76 years). The median duration of DM was 13 years (range 8-20 years). Ten patients (83.3%) were phakic and 2 patients (17%) were pseudophakic. The median pre-operative BCVA was 0.07 (range 0.05-0.8). The median pre-operative CMT was 544µ (range 354-745µ). The median pre-operative IOP was 17 mmHg (range 14-21mmHg). The median follow-up period was 12 months, range (12-42). Post-operatively, the median final BCVA was 0.15 (range 0.03-1), p 0.02, the median CMT was 404µ (range 213-747), p 0.4 and the median IOP was 19.5 mmHg (range 15-22), p 1. Two out of 10 phakic patients (20%) developed nuclear sclerosis grade I by 12 months. Six patients (50%) developed a transient rise in IOP < 10 mmHg from the baseline that resolved within 3 weeks with antiglaucoma drops.

CONCLUSION

SC Iluvien is potentially effective in improving visual function, reducing macular edema, and reducing the incidence of steroid-induced cataracts and glaucoma.

Topical treatment of diabetic macular edema using dexamethasone ophthalmic suspension: A randomized, double-masked, vehicle-controlled study

PURPOSE

To evaluate topical dexamethasone ophthalmic suspension OCS-01 (Oculis SA, Lausanne, Switzerland) in diabetic macular edema (DME).

METHODS

This was a multicenter, double-masked, parallel-group, randomized, Phase 2 study. Patients aged 18-85 years with DME of <3 years duration, ETDRS central subfield thickness ≥ 310 μm by SD-OCT, and ETDRS letter score ≤ 73 and ≥ 24 in the study eye were randomized 2:1 to OCS-01 or matching vehicle, 1 drop 3 times/day for 12 weeks. Efficacy was evaluated as change from baseline to Week 12 of ETDRS letter score and central macular thickness (CMT). The primary analysis used a linear model with baseline ETDRS letters as a covariate, and missing data imputed using multiple imputation pattern mixture model techniques. Active treatment was considered superior to vehicle if the one-sided p-value was <0.15 and the difference in mean change from baseline in ETDRS letters was >0.

RESULTS

Mean CMT showed a greater decrease from baseline with OCS-01 (N = 99) than vehicle (N = 45) at Week 12 (-53.6 vs -16.8 μm, p = 0.0115), with significant differences favouring OCS-01 from Weeks 2 to 12. OCS-01 was well-tolerated, and increased intraocular pressure was the most common adverse event. Mean change in ETDRS letter score from baseline to Week 12 met the p was +2.6 letters with topical OCS-01 and 1 letter with vehicle (p = 0.125). In a post-hoc analysis, there was a greater difference in patients with baseline BCVA ≤65 letters, the OCS-01 group improved 3.8 letters compared with 0.9 letters with vehicle.

CONCLUSION

Topical OCS-01 was significantly more effective than vehicle in improving central macular thickness in patients with DME. Visual improvement was better in eyes with lower baseline vision.

Recent achievements in nano-based technologies for ocular disease diagnosis and treatment, review and update

Ocular drug delivery is one of the most challenging endeavors among the various available drug delivery systems. Despite having suitable drugs for the treatment of ophthalmic disease, we have not yet succeeded in achieving a proper drug delivery approach with the least adverse effects. Nanotechnology offers great opportunities to overwhelm the restrictions of common ocular delivery systems, including low therapeutic effects and adverse effects because of invasive surgery or systemic exposure. The present review is dedicated to highlighting and updating the recent achievements of nano-based technologies for ocular disease diagnosis and treatment. While further effort remains, the progress illustrated here might pave the way to new and very useful ocular nanomedicines.

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.

Aqueous Humor Analyses in Patients with Diabetic Retinopathy Who Had Undergone Panretinal Photocoagulation

PURPOSE

To determine the associations between aqueous humor cytokine levels and the severity of diabetic retinopathy and the prior panretinal photocoagulation (PRP) status of patients with diabetic macular edema (DME).

METHODS

We divided 98 DME patients into those with nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), and PRP patients. We compared the concentrations of interleukin- (IL-) 1β, IL-6, IL-8, IL-10, and IL-17; placental growth factor (PlGF); and vascular endothelial growth factor (VEGF) in the aqueous humors. We subclassified PRP patients by the interval between PRP and aqueous sampling and analyzed the associations between aqueous cytokine levels and this interval.

RESULTS

The aqueous humor levels of IL-6, IL-8, VEGF, and PlGF were significantly higher in the PDR group than in the NPDR group. The PlGF and VEGF levels in the PDR group were significantly higher than those in the PRP group. On PRP subgroup analyses, patients who had undergone PRP within 6 months prior exhibited higher levels of VEGF, PlGF, and TNF-α than did those who had undergone PRP more than 12 months prior. The TNF-α level of the PRP subgroup treated within 6 months prior was significantly higher than that of the PDR group. Regression analyses showed that the levels of VEGF, PlGF, and TNF-α decreased significantly as the interval between PRP and aqueous sampling became longer.

CONCLUSIONS

PDR patients exhibited higher concentrations of VEGF and certain inflammatory cytokines than did NPDR and PRP patients. In the latter patients, the intraocular VEGF and inflammatory cytokine levels fell gradually over time.

In vitro dissolution testing models of ocular implants for posterior segment drug delivery

The delivery of drugs to the posterior segment of the eye remains a tremendously difficult task. Prolonged treatment in conventional intravitreal therapy requires injections that are administered frequently due to the rapid clearance of the drug molecules. As an alternative, intraocular implants can offer drug release for long-term therapy. However, one of the several challenges in developing intraocular implants is selecting an appropriate in vitro dissolution testing model. In order to determine the efficacy of ocular implants in drug release, multiple in vitro test models were emerging. While these in vitro models may be used to analyse drug release profiles, the findings may not predict in vivo retinal drug exposure as this is influenced by metabolic and physiological factors. This review considers various types of in vitro test methods used to test drug release of ocular implants. Importantly, it discusses the challenges and factors that must be considered in the development and testing of the implants in an in vitro setup.

Real-World Outcomes in Diabetic Macular Edema for the 0.2 µg/Day Fluocinolone Acetonide Implant: Case Series from the Midlands, UK

Aim

To investigate real-world effectiveness and safety of fluocinolone acetonide (FAc) implant over three years of treatment in eyes with diabetic macular edema (DME) in a population with large ethnic diversity.

Methods

This audit of three large treatment centres in the UK involved retrospective collection of outcome data (best recorded visual acuity [BRVA] by Early Treatment Diabetic Retinopathy Study [ETDRS] letters, central retinal thickness [CRT], intraocular pressure [IOP] and use of supplementary treatments) from patients with DME treated with 0.2 µg/day FAc intravitreal implant with three-year follow-up expected.

Results

A total of 96 eyes were included. Ninety (93.8%) eyes had received prior intravitreal treatment. Increases in mean BRVA were significant at one, two and three years (p<0.05). Overall, 78.1% of eyes gained or maintained BRVA; just over 50% gained ≥5 letters, representing a functional response. Eleven (11.6%) patients lost ≥10 letters by year three. Decreases in central retinal thickness (CRT) nearing 200 µm in the first year were sustained to three years (p < 0.0001). Patients with baseline VA ≥60 letters maintained their BRVA throughout follow-up, while significant improvements at month 12 (p<0.0001) in those with baseline BRVA <60 letters were maintained through month 36 (p < 0.005). Fifty-three (55.2%) eyes required no supplementary therapy during follow-up. Increases in IOP to ≥30 mmHg and ≥25 mmHg were seen in 12 (12.5%) and 23 (24.0%) eyes, respectively.

Conclusion

This study confirms the effectiveness and tolerability of FAc implant up to 36 months in a real-world setting, highlighting the importance of early treatment for sustaining functional vision for patients.

Polymer-free corticosteroid dimer implants for controlled and sustained drug delivery

Polymeric drug carriers are widely used for providing temporal and/or spatial control of drug delivery, with corticosteroids being one class of drugs that have benefitted from their use for the treatment of inflammatory-mediated conditions. However, these polymer-based systems often have limited drug-loading capacity, suboptimal release kinetics, and/or promote adverse inflammatory responses. This manuscript investigates and describes a strategy for achieving controlled delivery of corticosteroids, based on a discovery that low molecular weight corticosteroid dimers can be processed into drug delivery implant materials using a broad range of established fabrication methods, without the use of polymers or excipients. These implants undergo surface erosion, achieving tightly controlled and reproducible drug release kinetics in vitro. As an example, when used as ocular implants in rats, a dexamethasone dimer implant is shown to effectively inhibit inflammation induced by lipopolysaccharide. In a rabbit model, dexamethasone dimer intravitreal implants demonstrate predictable pharmacokinetics and significantly extend drug release duration and efficacy (>6 months) compared to a leading commercial polymeric dexamethasone-releasing implant.

Intravitreal Therapy for Diabetic Macular Edema: An Update

Diabetic macular edema (DME) represents a prevalent and disabling eye condition. Despite that DME represents a sight-threatening condition, it is also among the most accessible to treatment. Many different treatment options including photocoagulation, intravitreal medical treatment (either vascular endothelial growth factor inhibitors or corticosteroids therapies), and surgical removal are currently available. Although laser has been considered as the gold standard for many years, over the past several years vascular endothelial growth factor inhibitors (anti-VEGFs) have become first-line therapy. However, many patients do not adequately respond to them. With the development of sustained-release corticosteroid devices, steroids have gained a presence in the management of the DME. We review and update the role of anti-VEGF and intravitreal sustained-release corticosteroid management of DME. According to the currently available scientific evidence, the choice of one anti-VEGF over another critically depends on the baseline best-corrected visual acuity (BCVA). While aflibercept may be the drug of choice in low baseline BCVA, the three anti-VEGFs (bevacizumab, ranibizumab, and aflibercept) provided similar functional outcomes when the baseline BCVA was higher. DEX implants are a valuable option for treating DME, although they are usually seen as a second choice, particularly in those eyes that have an insufficient response to anti-VEGF. The new evidence suggested that, in eyes that did not adequately respond to anti-VEGF, switching to a DEX implant at the time to 3 monthly anti-VEGF injections provided better functional outcomes.

Real-World Efficacy and Safety of Fluocinolone Acetonide Implant for Diabetic Macular Edema: A Systematic Review

To assess real-world outcomes of fluocinolone acetonide (FAc) implant in treating diabetic macular edema (DME), a systematic literature review was conducted on PubMed in order to identify publications assessing the efficacy and safety of the FAc implant in DME in daily practice. Case reports and randomized controlled trials were excluded. Twenty-two observational real-world studies analyzing a total of 1880 eyes were included. Mean peak visual gain was +8.7 letters (11.3 months post-FAc injection) and was greater for lower baseline best corrected visual acuity (BCVA) and for more recent DME. Mean central retinal thickness (CRT) decreased 34.3% from baseline. 77.0% of the analyzed studies reported both BCVA improvement of at least five letters and a CRT decrease by 20% or more. Rescue therapy was needed more frequently when FAc was administered for chronic DME. FAc-induced ocular hypertension was reported in 20.1% of patients but only 0.6% needed surgery. Cataract extraction was performed in 43.2% of phakic patients. Adequate patient selection is essential for optimal FAc response and better safety profile. Currently positioned as second- or third-line treatment in the management algorithm, FAc implant decreases treatment burden and provides better letter gain when administered for more recent DME.

Anterior migration of intravitreal fluocinolone acetonide (Iluvien®) implant in a pseudophakic eye with intact posterior capsule

Purpose

To describe a case of spontaneous anterior migration of intravitreal fluocinolone acetonide (Iluvien®) implant in a pseudophakic eye with intact posterior capsule.

Observation

A 60-year old woman with proliferative diabetic retinopathy underwent uneventful pars plana vitrectomy and phacoemulsification with posterior chamber intraocular lens (PCIOL) implants in both eyes. She developed diabetic macular edema (DME) in her right eye which failed to respond to repeated intravitreal injections of Aflibercept 2mg/0.05ml (Eylea®). The patient received an intravitreal Iluvien® implant to treat the recalcitrant DME after she showed a favorable temporary response to dexamethasone intravitreal implant (Ozurdex™).Six months later she presented with pain in the right eye due to elevated intraocular pressure (IOP). The Iluvien® implant was found to be dislodged into the anterior chamber (AC) in the presence of an intact posterior capsule and stable PCIOL implant. The migrated Iluvien implant was removed and IOP was controlled with a glaucoma drainage valve as it failed to respond to maximum anti-glaucoma medication.

Conclusions and Importance

Intravitreal Iluvien® implant could migrate into the AC in a previously vitrectomized eyes in the presence of an intact posterior capsule.

Outcomes in diabetic macular edema switched directly or after a dexamethasone implant to a fluocinolone acetonide intravitreal implant following anti-VEGF treatment

AIMS

Fluocinolone acetonide (FAc) is an intravitreal corticosteroid implant approved for the second-line treatment of diabetic macular edema (DME). This study compared outcomes of patients with DME switched directly to an FAc implant, versus indirectly via dexamethasone, after anti-VEGF therapy failure.

METHODS

This is a retrospective, single-center chart review. Patients were assigned to Group A (switched to FAc after anti-VEGF) or Group B (switched to dexamethasone and then to FAc after > 4 months). Charts were reviewed for best-corrected visual acuity (BCVA), central macular thickness (CMT), intraocular pressure (IOP) and cataract development.

RESULTS

Forty-nine eyes were included. BCVA increased and CMT decreased with anti-VEGF (both groups), and dexamethasone (Group B only), but regressed after stopping treatment. With FAc, BCVA increased rapidly and significantly: increases were maintained up to 36 months (P < 0.001), except at 18 and 9 months in Groups A and B, respectively. Significant CMT reductions (P < 0.001) were evident after 3 months and maintained up to 36 months in both groups. IOP increase > 21 mmHg occurred in 14 patients (nine in Group A, five in Group B): all were sufficiently treated with IOP-lowering drops. Nineteen phakic eyes (73.1%) developed cataract: seven underwent phaco-emulsification (two in Group A, five in Group B).

CONCLUSIONS

Similar functional and anatomical improvements occurred in FAc-treated eyes, regardless of whether they first received dexamethasone or switched directly to FAc after anti-VEGF. Safety signals were consistent with corticosteroid class effects. Early switch to FAc could benefit patients who respond insufficiently to anti-VEGF.

Factors associated with the duration of action of dexamethasone intravitreal implants in diabetic macular edema patients

We designed this study to determine the association between the duration of action of intravitreal dexamethasone implants and aqueous humor biomarkers or optical coherence tomography (OCT) findings of diabetic macular edema (DME) patients. We measured the concentrations of interleukin (IL)-1β, -8, -10, -17; placental growth factor; and vascular endothelial growth factor in the aqueous humor, and identified the number of hyperreflective foci (HF), grades of ellipsoid zone disruptions, and baseline central subfield thicknesses (CSTs) using OCT of patients with DME. The average duration of action of dexamethasone implants was 4.32 ± 1.18 months. In multivariate linear regression analyses, the duration of action was associated with aqueous IL-8 levels and the number of HF (β = -0.016, p = 0.037 and β = -0.073, p = 0.035, respectively). Multivariate logistic regression showed that the number of HF (>10) was significantly associated with a shorter duration (<4 months) of action (odds ratio: 17.17, p = 0.010). The duration of action of intravitreal dexamethasone implants in DME patients was associated with the level of aqueous IL-8 and the number of HF using OCT. Specifically, higher number of HF in the OCT was associated with a shorter duration of action.

The Outcomes of Switching from Short- to Long-Term Intravitreal Corticosteroid Implant Therapy in Patients with Diabetic Macular Edema

BACKGROUND

First-line treatment for diabetic macular edema (DME) is usually with antivascular endothelial growth factor agents, followed by intravitreal corticosteroids as a second-line treatment option. Long-term corticosteroids may offer quality of life and effectiveness benefits over short-term implants.

OBJECTIVES

To evaluate outcomes of patients with persistent or recurrent DME who switched from a short-term (dexamethasone) to a long-term (fluocinolone acetonide, FAc) corticosteroid intravitreal implant in a real-world setting.

METHODS

This is a retrospective study in 9 Portuguese centers. An FAc intravitreal implant was administered according to product labeling. Effectiveness outcomes were mean change in visual acuity (VA; ETDRS letters), central retinal thickness (CRT; µm), and macular volume (MV; mm3). The safety outcome was mean change in intraocular pressure (IOP; mm Hg). All were analyzed at months 1 and 3, and then quarterly until month 24 after implantation.

RESULTS

Forty-four eyes from 36 patients were analyzed. Mean duration of DME was 3.3 ± 1.9 years, and mean follow-up was 8 months. From baseline following FAc implantation, VA increased significantly at months 1 and 6 (mean +6.82 and +13.02 letters, respectively; p = 0.005), and last observation carried forward (LOCF; mean +8.3 letters; p = 0.002). CRT improved significantly at months 1 and 6 (mean -71.81 and -170.77 µm, respectively; p = 0.001), and LOCF (mean -121.46 µm; p = 0.001). MV was consistently, but not significantly, decreased from baseline to LOCF (mean -0.69 mm3; p = 0.062). The mean change in IOP was -0.25 and +0.88 mm Hg at months 1 and 6, respectively (p = 0.268), and +1.86 mm Hg at LOCF (p = 0.036). Increases were controlled with topical medication in most cases.

CONCLUSIONS

The FAc intravitreal implant is effective in patients previously treated with short-term corticosteroid implants. Thus, after a suboptimal response to antiangiogenics or a short-term corticosteroid, a single FAc implant may be considered an effective and tolerable treatment that can improve long-term outcomes for patients with sight-threatening DME.

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.