Improving corneal permeability of dexamethasone using penetration enhancing agents: First step towards achieving topical drug delivery to the retina

With an ever-increasing burden of vision loss caused by diseases of the posterior ocular segment, there is an unmet clinical need for non-invasive treatment strategies. Topical drug application using eye drops suffers from low to negligible bioavailability to the posterior segment as a result of static and dynamic defensive ocular barriers to penetration, while invasive delivery systems are expensive to administer and suffer potentially severe complications. As the cornea is the main anatomical barrier to uptake of topically applied drugs from the ocular surface, we present an approach to increase corneal permeability of a corticosteroid, dexamethasone sodium-phosphate (DSP), using a novel penetration enhancing agent (PEA). We synthesised a novel polyacetylene (pAc) polymer and compared its activity to two previously described cell penetrating peptide (CPP) based PEAs, TAT and penetratin, with respect to increasing transcorneal permeability of DSP in a rapid ex-vivo porcine corneal assay over 60 min. The transcorneal apparent permeability coefficients (Papp) for diffusion of pAc, and fluorescein isothiocyanate (FITC) conjugated TAT and penetratin were up to 5 times higher (p < 0.001), when compared to controls. When pAc was used in formulation with DSP, an almost 5-fold significant increase was observed in Papp of DSP across the cornea (p = 0.0130), a significant 6-fold increase with TAT (p = 0.0377), and almost 7-fold mean increase with penetratin (p = 0.9540). Furthermore, we investigated whether the PEAs caused any irreversible damage to the barrier integrity of the corneal epithelium by measuring transepithelial electrical resistance (TEER) and immunostaining of tight junction proteins using zonula occludens-1 (ZO-1) and occludin antibodies. There was no damage or structural toxicity, and the barrier integrity was preserved after PEA application. Finally, an in-vitro cytotoxicity assessment of all PEAs in human retinal pigment epithelium cells (ARPE-19) demonstrated that all PEAs were very well-tolerated, with IC50 values of 64.79 mM for pAc and 1335.45 µM and 87.26 µM for TAT and penetratin, respectively. Our results suggest that this drug delivery technology could potentially be used to achieve a significantly higher intraocular therapeutic bioavailability after topical eye drop administration, than currently afforded.

Optical coherence tomography biomarkers as outcome predictors to guide dexamethasone implant use in patients with iERM: a randomized controlled trial

BACKGROUND

We aimed to investigate the anatomical features of optical coherence tomography (OCT) and vitreous cytokine levels as predictors of outcomes of combined phacovitrectomy with intravitreal dexamethasone (DEX) implants for idiopathic epiretinal membrane (iERM) treatment.

METHODS

A prospective, single-masked, randomized, controlled clinical trial included 48 eyes. They were randomly assigned in a 1:1 ratio to undergo the DEX group (combined phacovitrectomy with ERM peeling and Ozurdex implantation) and control group (phacovitrectomy only). Best-corrected visual acuity (BCVA) and central macular thickness (CMT) were assessed at 1 d, 1 week, 1 month, and 3 months. The structural features of OCT before surgery were analysed for stratified analysis. Baseline soluble CD14 (sCD14) and sCD163 levels in the vitreous fluid were measured using ELISA.

RESULTS

BCVA and CMT were not significantly different in the DEX and control groups. Eyes with hyperreflective foci (HRF) at baseline achieved better BCVA (Ptime*group=0.746; Pgroup=0.043, Wald χ²=7.869) and lower CMT (Ptime*group = 0.079; Pgroup = 0.001, Wald χ²=6.774) responses to DEX during follow-up. In all patients, the mean vitreous level of sCD163 in eyes with HRF was significantly higher than that in eyes without HRF (P = 0.036, Z=-2.093) at baseline. In the DEX group, higher sCD163 predicted greater reduction in CMT from baseline to 1 month (r = 0.470, P = 0.049).

CONCLUSIONS

We found that intraoperative DEX implantation did not have beneficial effects on BCVA and CMT over a 3-month period in all patients with iERM, implying that the use of DEX for all iERM is not recommended. In contrast, for those with HRF on OCT responded better to DEX implants at the 3-month follow-up and thier vitreous fluid expressed higher levels of sCD163 at baseline. These data support the hypothesis that DEX implants may be particularly effective in treating cases where ERM is secondary to inflammation.

TRIAL REGISTRATION

The trail has been registered at Chinese Clinical Trail Registry( https://www.chictr.org.cn ) on 2021/03/12 (ChiCTR2100044228). And all patients in the article were enrolled after registration.

Anterior migration of Ozurdex implant: a review on risk factors, complications, and management

PURPOSE

To describe the common risk factors, complications, and management options for anterior migration of Ozurdex implant.

METHODS

A comprehensive review of the literature was performed.

RESULTS

Amongst the most common risk factors predisposing to implant anterior migration we found a history of pseudophakia or aphakia or previous vitrectomy. The most common complication is that of corneal edema.

CONCLUSIONS

A variety of management options to treat migration of the dexamethasone implant are utilized by different specialists around the world. These depend on the doctor's preference, presence of corneal damage and history of previous migrations after repositioning the implant. The most common approaches are operative or non-operative implant repositioning and surgical implant removal.

Advances in development of exosomes for ophthalmic therapeutics

Exosomes contain multiple bioactive molecules and maintain the connection between cells. Recent advances in exosome-based therapeutics have witnessed unprecedented opportunities in treating ophthalmic diseases, including traumatic diseases, autoimmune diseases, chorioretinal diseases and others. Utilization of exosomes as delivery vectors to encapsulate both drugs and therapeutic genes could yield higher efficacy and avoid the unnecessary immune responses. However, exosome-based therapies also come with some potential ocular risks. In this review, we first present a general introduction to exosomes. Then we provide an overview of available applications and discuss their potential risks. Moreover, we review recently reported exosomes as delivery vectors for ophthalmic diseases. Finally, we put forward future perspectives to grapple with its translation and underlying issues.

The Challenge of Treating the Severest Forms of Chronic Noninfectious Posterior and Panuveitis

BACKGROUND

Noninfectious posterior and panuveitis may exhibit a chronic relapsing clinical course and are challenging to treat. Most affected patients are continuously treated with systemic immunosuppressive therapy, which is potentially associated with significant adverse side effects.

METHODS

A cohort of 18 patients presenting with severe noninfectious posterior or panuveitis were evaluated with respect to the clinical course of the disease, with particular focus on best-corrected visual acuity (BCVA), treatment duration, remission rates, reported negative side effects, and the necessity for switching medication.

RESULTS

The mean follow-up was 27.8 months. Although BCVA improved significantly, complete or partial remission was observed in only 66.7% of patients. Of the patients, 72.2% underwent a change in medical treatment due to either adverse events or inefficacy of medication.

CONCLUSION

Despite new immunosuppressive therapies, effective treatment of severe noninfectious posterior and panuveitis remains a major challenge. We discuss the urgent need for novel treatment strategies in order to prevent systemic adverse effects, and to improve visual outcome and quality of life.

Intravitreal Fluocinolone Acetonide Implant (ILUVIEN®) for the Treatment of Retinal Conditions. A Review of Clinical Studies

Fluocinolone acetonide (FAc) intravitreal implant (Iluvien®) is a corticosteroid implant indicated for the treatment of diabetic macular oedema (DMO) in patients who have previously received conventional treatment without good response, non-infectious posterior uveitis, and as an off-label treatment of the macular oedema secondary to retinal vein occlusion. FAc is a non-biodegradable 0.19 mg intravitreal implant which is designed to release FAc over 3 years at a rate of approximately 0.2 mcg per day. The aim of this review is to describe the special pharmacological properties of Iluvien and display the outcomes of the most important clinical trials and real-world studies regarding its efficacy and safety for the management of the above retinal disorders.

Intravitreal injection versus systematic treatment in patients with uveitis undergoing cataract surgery: a systematic review and meta-analysis

PURPOSE

Cataract surgery in patients with uveitis is challenging, and postoperative inflammation control is crucial for successful outcomes. No consensus exists regarding the optimal method of controlling postoperative inflammation. In this systematic review and meta-analysis, we compared the outcome of intravitreal injection (IVI), including steroid (triamcinolone acetonide) or steroid implant (dexamethasone), with systemic anti-inflammatory therapy (ST), such as systemic steroids with or without immunomodulatory therapy, in patients with uveitis undergoing cataract surgery.

METHODS

We searched PubMed, EMBASE, and Cochrane Library databases for randomized controlled trials (RCTs), comparative cohort studies, and case-control studies published through May 2021 that compared intraoperative IVI of triamcinolone acetonide or steroid implant with ST with or without immunomodulatory therapy. The following outcomes were evaluated: preoperative best-corrected visual acuity, intraocular pressure, laser flare photometry, central macular thickness and cystoid macular edema rate.

RESULTS

Five studies were selected. Our analysis indicated that compared with ST, IVI treatment may be associated with less anterior chamber inflammation and a lower cystoid macular edema rate, but the difference in best-corrected visual acuity, intraocular pressure, or central macular thickness was not significant.

CONCLUSIONS

IVI of steroid or steroid implants might be beneficial in controlling postoperative inflammation for uveitis cataract, especially in patients who cannot tolerate ST. To the best of our knowledge, this is the first meta-analysis to compare the efficacy of intraoperative IVI of steroids with standard-of-care treatment as a prophylaxis for uveitis cataract. However, large-scale RCTs are warranted to compare the IVI of steroid implants and steroids.

Vitreous Humor: Composition, Characteristics and Implication on Intravitreal Drug Delivery

Purpose: Intravitreal administration of drug molecules is one of the most common routes for treating posterior segment eye diseases. However, the properties of vitreous humour changes with the time. A number of ocular complications such as liquefaction of the vitreous humour, solidification of the vitreous humour in the central vitreous cavity and detachment of the limiting membrane due to the shrinking of vitreous humour are some of the factors that can drastically affect the efficacy of therapeutics delivered via intravitreal route. Although significant research has been conducted for studying the properties of vitreous humour and its changes during the ageing process, there have been limited work to understand the effect of these changes on therapeutic efficacy of intravitreal drug delivery systems. Therefore, in this review we discussed both the coomposition and characteristics of the vitreous humour, and their subsequent influence on intravitreal drug delivery.Methods: Articles were searched on Scopus, PubMed and Web of Science up to March 2022.Results: In this review, we discussed the biological composition and biomechanical properties of vitreous humour, methods to study the properties of vitreous humour and the changes in these properties and their relevance in ocular drug delivery field, with the aim to provide a useful insight into these aspects which can aid the process of development of novel intravitreal drug delivery systems.Conclusions: The composition and characteristics of the vitreous humour, and how these change during natural aging processes, directly influence intravitreal drug delivery. This review therefore highlights the importance of understanding the properties of the vitreous and identifies the need to achieve greater understanding of how changing properties of the vitreous affect the therapeutic efficacy of drugs administered for the treatment of posterior eye diseases.

Inhibition of proliferative vitreoretinopathy by a newly developed methotrexate loaded drug carrier in vitro

PURPOSE

Repeated intravitreal injections of methotrexate for proliferative vitreoretinopathy, a rare ocular condition that can cause vision loss, have shown beneficial effects in recent clinical studies. The purpose of this study was to develop a slow-release, long-term drug carrier composed of the polymer polylactide-co-glycolide and methotrexate that can be injected intravitreally.

METHODS

The required composition of the drug carrier was modeled using pharmacokinetic parameters based on current literature. Release kinetics were determined using an ocular pharmacokinetic model. Epiretinal PVR-membranes were harvested during pars plana vitrectomy and subsequently transferred to cell culture. The effect of the drug carrier on cell migration was investigated using time-lapse microscopy and a scratch-induced migration assay. The colorimetric WST-1-assay and a live-dead-assay were performed to determine viability, and the BrdU-assay was applied for proliferation.

RESULTS

The release profile showed an initial and a final burst of methotrexate with an intervening steady state that lasted 9-11 weeks. It showed inhibitory effects on pathobiological processes in human PVR-cells in vitro. Cell velocity in the time-lapse assay, migration in the scratch assay (p = 0.001), and proliferation in the BrdU assay (p = 0.027) were reduced after addition of the drug carrier. These effects occurred without causing a reduction in viability in the WST-1 assay (p > 0.99) and the live-dead assay.

CONCLUSION

The methotrexate-loaded drug carrier can maintain a stable concentration for 9-11 weeks and influence the pathobiological process of PVR cells in vitro. Therefore, it represents a potential therapeutic orphan drug for PVR.

Dropless penetrating keratoplasty using a subconjunctival dexamethasone implant: safety pilot study

BACKGROUND/AIM

Rejection is the main cause of graft failure after penetrating keratoplasty (PK). Its prevention by repeated instillation of steroid eye-drops has not evolved in decades. Poor adherence and discontinuous nature of eye-drop treatment may explain some PK failures. In a rabbit model, we previously demonstrated that a subconjunctival dexamethasone implant was well tolerated and prevented rejection efficiently in the first 5-6 weeks. This clinical trial investigates its tolerance and safety after PK.

METHODS

Single-centre, phase II non-randomised tolerance and safety pilot study (NCT02834260). Designed to analyse the risk of elevated intraocular pressure (IOP), discomfort and resorption time. Fourteen patients with a low rejection risk indication of PK were enrolled between January 2017 and August 2018. The implant was injected in the 12 o'clock position, 5 mm from the limbus, at the end of PK. A steroid eye-drop treatment was planned when implant resorption was complete. Patients were monitored regularly for 12 months: IOP (main outcome measure at 1 month), discomfort and redness scores, implant status, rejection episode and central corneal thickness by optical coherence tomography. An independent data safety monitoring committee verified safety aspects.

RESULTS

No increase in IOP or other adverse event related to the implant was observed. Average resorption time was 6 weeks. The switch to steroid eye-drops was uneventful. One patient, included despite preoperative corneal neovascularisation (unintended protocol deviation) experienced a rejection.

CONCLUSIONS

This is the first proof of concept that dropless immunosuppression is possible after low rejection risk PK.

TRIAL REGISTRATION NUMBER

NCT02834260.

Progress in the pharmacotherapy of uveitis: the art of personalized care

INTRODUCTION

Uveitis is a heterogeneous group of inflammatory intraocular disorders which can lead to blindness, but prompt diagnosis and management can improve visual outcomes and reduce treatment burden.

AREAS COVERED

In this review, the authors provide an overview of commonly used treatments of the management of non-infectious uveitis.

EXPERT OPINION

Initially, the treatment of non-infectious uveitis was limited to corticosteroids which have a broad range of adverse ocular and systemic effects. Now new options, such as biological response modulators, are a novel yet exciting addition to this armory and have the potential to change the course of treatment as well as prognostic outcomes for uveitis patients. Additionally, further research is needed to evaluate the efficacy of this novel class of immunomodulators in uveitis therapy.

Dexamethasone: Insights into Pharmacological Aspects, Therapeutic Mechanisms, and Delivery Systems

Dexamethasone (DEX) has been widely used to treat a variety of diseases, including autoimmune diseases, allergies, ocular disorders, cancer, and, more recently, COVID-19. However, DEX usage is often restricted in the clinic due to its poor water solubility. When administered through a systemic route, it can elicit severe side effects, such as hypertension, peptic ulcers, hyperglycemia, and hydro-electrolytic disorders. There is currently much interest in developing efficient DEX-loaded nanoformulations that ameliorate adverse disease effects inhibiting advancements in scientific research. Various nanoparticles have been developed to selectively deliver drugs without destroying healthy cells or organs in recent years. In the present review, we have summarized some of the most attractive applications of DEX-loaded delivery systems, including liposomes, polymers, hydrogels, nanofibers, silica, calcium phosphate, and hydroxyapatite. This review provides our readers with a broad spectrum of nanomedicine approaches to deliver DEX safely.

Recent Fabrication Methods to Produce Polymer-Based Drug Delivery Matrices (Experimental and In Silico Approaches)

The study of novel drug delivery systems represents one of the frontiers of the biomedical research area. Multi-disciplinary scientific approaches combining traditional or engineered technologies are used to provide major advances in improving drug bioavailability, rate of release, cell/tissue specificity and therapeutic index. Biodegradable and bio-absorbable polymers are usually the building blocks of these systems, and their copolymers are employed to create delivery components. For example, poly (lactic acid) or poly (glycolic acid) are often used as bricks for the production drug-based delivery systems as polymeric microparticles (MPs) or micron-scale needles. To avoid time-consuming empirical approaches for the optimization of these formulations, in silico-supported models have been developed. These methods can predict and tune the release of different drugs starting from designed combinations. Starting from these considerations, this review has the aim of investigating recent approaches to the production of polymeric carriers and the combination of in silico and experimental methods as promising platforms in the biomedical field.

Pediatric uveitis: Role of the pediatrician

The challenges of childhood uveitis lie in the varied spectrum of its clinical presentation, the often asymptomatic nature of disease, and the evolving nature of the phenotype alongside normal physiological development. These issues can lead to delayed diagnosis which can cause significant morbidity and severe visual impairment. The most common ocular complications include cataracts, band keratopathy, glaucoma, and macular oedema, and the various associated systemic disorders can also result in extra-ophthalmic morbidity. Pediatricians have an important role to play. Their awareness of the various presentations and etiologies of uveitis in children afford the opportunity of prompt diagnosis before complications arise. Juvenile Idiopathic Arthritis (JIA) is one of the most common associated disorders seen in childhood uveitis, but there is a need to recognize other causes. In this review, different causes of uveitis are explored, including infections, autoimmune and autoinflammatory disease. As treatment is often informed by etiology, pediatricians can ensure early ophthalmological referral for children with inflammatory disease at risk of uveitis and can support management decisions for children with uveitis and possible underling multi-system inflammatory disease, thus reducing the risk of the development of irreversible sequelae.

Topical drug delivery to the retina: obstacles and routes to success

INTRODUCTION

Retinal diseases are one of the main reasons for vision loss where all available drug treatments are based on invasive drug administration such as intravitreal injections. Despite huge efforts and some promising results in animal models, almost all delivery technologies tested have failed in human trials. There are however examples of clinically effective topical delivery systems such as fast dissolving aqueous eye drop suspensions.

AREAS COVERED

Six obstacles to topical drug delivery to the eye have been identified and discussed in some details. These obstacles consist of static membrane barriers to drug permeation into the eye, dynamic barriers such as the lacrimal drainage and physiochemical barriers such as low thermodynamic activity. It is explained how and why these obstacles hamper drug permeation and how different technologies, both those that are applied in marketed drug products and those that are under investigation, have addressed these obstacles.

EXPERT OPINION

The reason that most topical drug delivery systems have failed to deliver therapeutic drug concentrations to the retina is that they do not address physiochemical barriers such as the thermodynamic activity of the permeating drug molecules. Topical drug delivery to the retina has only been successful when the static, dynamic, and physiochemical barriers are addressed simultaneously.

Anti-Tumor Necrosis Factor α versus Tocilizumab in the Treatment of Refractory Uveitic Macular Edema: A Multicenter Study from the French Uveitis Network

PURPOSE

To analyze the factors associated with response (control of ocular inflammation and corticosteroid-sparing effect) to biologics (anti-tumor necrosis factor [TNF]-α agents and tocilizumab) in patients with refractory uveitic macular edema (ME).

DESIGN

Multicenter, retrospective, observational study.

PARTICIPANTS

Adult patients with uveitic ME refractory to systemic corticosteroids, disease-modifying antirheumatic drugs, or both.

METHODS

Patients received anti-TNF-α agents (infliximab 5 mg/kg at week 0, 2, 6, and every 4-6 weeks [n = 69] and adalimumab 40 mg/2 weeks [n = 80]) and tocilizumab (8 mg/kg every 4 weeks intravenously [n = 39] and 162 mg/week subcutaneously [n = 16]).

MAIN OUTCOME MEASURES

Analysis of complete and partial response rates, relapse rate, low vision (visual acuity in at least 1 eye of ≥ 1 logarithm of the minimum angle of resolution), corticosteroid-sparing effect, and adverse events at 6 months.

RESULTS

Two hundred four patients (median age, 40 years [interquartile range, 28-58 years]; 42.2% men) were included. Main causes of uveitis included Behçet's disease (17.2%), birdshot chorioretinopathy (11.3%), and sarcoidosis (7.4%). The overall response rate at 6 months was 46.2% (21.8% of complete response) with anti-TNF-α agents and 58.5% (35.8% of complete response) with tocilizumab. In multivariate analysis, treatment with tocilizumab (odds ratio, 2.10; 95% confidence interval [CI], 1.06-4.06; P = 0.03) was associated independently with complete response of uveitic ME compared with anti-TNF-α agents. Anti-TNF-α agents and tocilizumab did not differ significantly in terms of relapse rate (hazard ratio, 1.00; 95% CI, 0.31-3.18; P = 0.99) or occurrence of low vision (odds ratio, 1.02; 95% CI, 0.51-2.07; P = 0.95) or corticosteroid-sparing effect (P = 0.29). Adverse events were reported in 20.6% of patients, including serious adverse events reported in 10.8% of patients.

CONCLUSIONS

Tocilizumab seems to improve complete response of uveitic ME compared with anti-TNF-α agents.

Intravitreal Dexamethasone Implants for Refractory Macular Edema in Eyes with Noninfectious Uveitis

Macular edema (ME) is a common cause of visual loss among eyes with uveitis, and its management can be challenging. Steroids are an effective treatment for ME, and intravitreal dexamethasone (DEX) implants provide sustained steroid release. The purpose of this study is to evaluate intravitreal DEX implant on refractory ME in eyes with noninfectious uveitis. A retrospective study including 52 eyes of 37 patients with refractory uveitic ME was conducted from January 2011 through August 2017 at Linkou Chang Gung Memorial Hospital in Taiwan. Patients’ demographic characteristics were collected. In addition, clinical information, including corrected visual acuity (VA), intraocular pressure (IOP), and central retinal thickness (CRT) on optical coherence tomography, was recorded and analyzed. During the study period, affected eyes received a total of 110 intravitreal DEX implants (range, one to six in each eye). After the first DEX implant injection in all eyes, VA significantly improved at one and two months. CRT significantly decreased one month after a single DEX implant, and the effect lasted for six months and waned over time. Patients receiving multiple DEX implants still showed significant decreases in CRT one month after the first implant. Increases in IOP were noted one month after the DEX implant, but the IOP could be medically controlled. Intravitreal DEX implants can effectively treat refractory uveitic ME, improving both VA and CRT with an acceptable safety profile. Further studies are necessary to evaluate the effect of multiple implants and long-term outcomes.

Blocking the inflammasome: A novel approach to treat uveitis

Uveitis is a complex ocular inflammatory disease often accompanied by bacterial or viral infections (infectious uveitis) or underlying autoimmune diseases (non-infectious uveitis). Treatment of the underlying infection along with corticosteroid-mediated suppression of acute inflammation usually resolves infectious uveitis. However, to develop more effective therapies for non-infectious uveitis and to better address acute inflammation in infectious disease, an improved understanding of the underlying inflammatory pathways is needed. In this review, we discuss the disease aetiology, preclinical in vitro and in vivo uveitis models, the role of inflammatory pathways, as well as current and future therapies. In particular, we highlight the involvement of the inflammasome in the development of non-infectious uveitis and how it could be a future target for effective treatment of the disease.

Systemic contribution of inflammatory mediators to the severity of diabetic and uveitic macular edema

PURPOSE

To assess whether serum cytokine and growth factor levels are associated with diabetic macular edema (DME) and uveitic macular edema (UME) objective severity.

METHODS

Cross-sectional observational study of 81 patients (1 eye/patient) with DME (n=48) and UME (n=33). Macular edema (ME) was defined upon central macular thickness (CMT) ≥ 300 μm on spectral domain optical coherence tomography (OCT). Serum samples were obtained from peripheral blood and IL-1β, IL-6, IL-8, IL-10, MCP-1, TNF-α, and VEGF levels were determined by Luminex analysis. Main outcome measure was the correlation between mediators' levels and CMT and macular volume (MV) on OCT for ME cases.

RESULTS

In DME, IL-6 levels were found to significantly correlate with MV (r=0.324; p=0.028) whereas in UME, IL-8 was significantly associated with both CMT (r=0.401; p=0.021) and MV (r=0.391; p=0.024). IL-8 independently correlated with CMT (ß=177.2; p=0.033) and MV (ß=3.17; p=0.008) in UME multivariate model.

CONCLUSION

Peripheral blood IL-6 and IL-8 levels could play a role in the severity of DME and UME, respectively. IL-8 even seems to be independently associated with CMT and MV in UME cases. Such systemic implications could enforce DME and UME personalized diagnostic and therapeutic approaches.

[Anti-TNF-α in the treatment of non-infectious uveitis]

Non-infectious uveitis is a heterogenous group of potentially blinding ocular autoimmune diseases that may represent a manifestation of a systemic condition or may affect the eyes only. A systemically administered anti-TNF has recently been approved for the treatment of non-infectious uveitis, broadening the therapeutic arsenal available to control intraocular inflammation and reduce uveitis complications that can lead to vision loss. When uveitis affects only the eyes, a local anti-TNF-α administration strategy could optimize the ocular therapeutic effect and reduce undesirable systemic side-effects. A new ocular method of non-viral gene therapy, currently in development, may broaden the indications for ocular anti-TNF-α agents, not only for uveitis but also for other diseases in which TNF-α-mediated neuro-inflammation has been demonstrated.

Evaluation of intraoperative slow-release dexamethasone implant combined with idiopathic epiretinal membrane removal

PURPOSE

To evaluate the efficacy of intraoperative slow-release dexamethasone implant (DEX) combined with removal of idiopathic epiretinal membrane (ERM).

METHODS

In this observational retrospective study, data of 40 patients with phakic eyes affected by idiopathic ERM were analysed. All patients underwent cataract phacoemulsification, 25-gauge (G) pars plana vitrectomy (PPV), ERM removal with DEX implant ("DEX YES" group, #20) or without DEX implant ("DEX NO" group, #20). We collected data on best-corrected visual acuity (BCVA) < 20/40 Snellen charts, central macular thickness (CMT) ≤ 400 μm (measured by SD-OCT) and integrity of sub-foveal ellipsoid/myoid zone. BCVA, CMT and intraocular pressure (IOP) were evaluated at baseline as well as 15, 30 and 90 days after surgery.

RESULTS

In the "DEX YES" group, statistically significant BCVA improvement was observed at 15, 30 and 90 days (p < 0.001), while in the "DEX NO" group, improvements were observed only at 30 and 90 days (p < 0.001). In both groups, CMT significantly decreased at each follow-up visit (p < 0.001), and no statistically significant increase of IOP was detected at each follow-up visit.

CONCLUSIONS

In this study, DEX accelerated the improvement of BCVA at 15 days after surgery. However, no evidence of further anatomical (CMT) and functional (BCVA) DEX effectiveness combined with removal of idiopathic ERM by 25-G PPV at 30 and 90 days follow-up was observed.

Macular edema associated with non-infectious uveitis: pathophysiology, etiology, prevalence, impact and management challenges

Macular edema (ME) is the most common sight-threatening complication in uveitis. The diagnostic and therapeutic management of the uveitic macular edema (UME) might be challenging due to the complex diagnostic workup and the difficulties physicians face to find the underlying cause, and due to its usually recurrent nature and the fact that it can be refractory to conventional treatment. Some of the mild cases can be treated with topical steroids, which can be combined with non-steroid anti-inflammatory drugs. However, immunomodulators such as methotrexate, tacrolimus, azathioprine, cyclosporine and mycophenolate mofetil together with anti-tumor necrosis factor-α (anti-TNF alpha) monoclonal antibodies such as adalimumab and infliximab, may be required to control the inflammation and the associated ME in refractory cases, or when an underlying disease is present. This review of the literature will focus mostly on the non-infectious UME.