Intravitreal Dexamethasone Implant for the Treatment of Macular Edema in Chronic Non-infectious Uveitis

Clinical and imaging biomarkers of response to intravitreal dexamethasone implant in eyes with non-infectious uveitic macular oedema

OBJECTIVE

To investigate clinical and spectral-domain optical coherence tomography (SD-OCT) biomarkers correlating with pre-injection visual acuity (VA), post-injection VA, and the likelihood of macular oedema (MO) regression following dexamethasone (DEX) implant injection in non-infectious uveitic (NIU) patients.

METHODS

Patient data from Uveitis Services in Milan, Paris, and Berlin were analysed. Eligible participants were NIU patients aged >18 years with MO as the primary indication for DEX treatment. SD-OCT scans and clinical data were collected at the time of DEX injection (pre-injection visit) and after 3 months (post-injection visit). Multivariable regression models, adjusted for pre-injection VA and lens status, were employed to explore associations. MO regression was defined as the absence of intraretinal/subretinal fluid at the post-injection visit.

RESULTS

Our analysis comprised data from 173 DEX treatments, encompassing 103 eyes from 80 patients, with 38 eyes (37%) receiving repeated DEX injections. The absence of the ellipsoid zone (EZ) layer and disorganisation of the inner retinal layers (DRIL) were associated with worse pre- (+0.19 LogMAR, 95% CI 0.01-0.38, p = 0.06, and +0.10 LogMAR, 95% CI 0.02-0.21, p = 0.01) and post-injection VA (+0.33 LogMAR, 95% CI 0.08-0.57, p = 0.01, and +0.17 LogMAR, 95% CI 0.01-0.32, p = 0.04). EZ disruption and DRIL increased significantly (p = 0.01 and p = 0.04), and the chance of gaining ≥5 letters declined in eyes undergoing repeated DEX (p = 0.002). The rate of MO regression after each DEX was 67%. Prolonged MO duration (OR = 0.75/each year, p = 0.02) was associated with reduced likelihood of MO regression. Subretinal fluid was associated with higher rate of MO regression (OR = 6.09, p = 0.01).

CONCLUSION

Integrity of the inner and outer retina is associated with better visual response to DEX. Long-standing or recurrent MO is associated with less chance of both visual and anatomic response. Timely treatment is necessary to maximise the outcomes of MO in NIU patients.

Efficacy of intravitreal dexamethasone implant used as monotherapy for the treatment of macular edema in non-infectious uveitis: a retrospective analysis

BACKGROUND

Uveitic macular edema is a complication of acute or chronic uveitis. Current treatment regiments frequently have numerous side effects, often requiring supplemental treatment. This study investigates the efficacy of dexamethasone (DEX) intravitreal implants as monotherapy for treatment of macular edema in non-infectious intermediate, posterior or panuveitis.

METHODS AND RESULTS

Retrospective chart review of thirty patients with intermediate, posterior and panuveitis treated with DEX. Outcomes measured were central retinal thickness (CRT) and best corrected visual acuity (BCVA). Baseline measurements of CRT and BCVA were measured within 1 month prior to intravitreal DEX implant and follow up measurements were collected until 1 year post implant. 48 implants on 39 eyes of 30 patients were included in this study; 64.1% of patients had an improvement in BCVA and 65.4% had a reduction in CRT. BCVA improved from 0.285 logMAR (SD: 0.312) at baseline to 0.175 logMAR (SD: 0.194) at 1 month and was sustained thereafter. Preliminary CRT data showed a decrease from 392 [Formula: see text] (SD: [Formula: see text]) at baseline to 303 [Formula: see text] (SD: [Formula: see text] at 1 month and 313 [Formula: see text] (SD: [Formula: see text] at 12 months.

CONCLUSIONS

The DEX implant as monotherapy for macular edema in non-infectious uveitis was associated with a reduction in CRT and improvement in BCVA. The DEX implant, used as a monotherapy in eyes with intermediate, posterior and panuveitis, has the potential to treat uveitis without oral corticosteroid or other immunomodulatory therapy.

Intravitreal immunotherapy in non-infectious uveitis: an update

INTRODUCTION

In the past several years, there have been numerous advances in pharmacotherapeutics for the management of uveitis and other ocular inflammatory diseases, including newer therapeutic agents and ocular drug delivery systems. One of the most attractive modes of drug delivery is the intravitreal route since it has proven to be safe and efficacious and prevents unwanted systemic adverse events related to the agent.

AREAS COVERED

In this review, intravitreal delivery of various pharmacotherapeutic agents for noninfectious uveitis has been described. An extensive review of the literature was performed using specific keywords on the PubMed database to identify clinical studies employing various pharmacotherapeutic agents with intravitreal drug delivery for noninfectious uveitis. The mode of action, safety, efficacy, and tolerability of these drugs have also been elucidated.

EXPERT OPINION

Several agents, including biologic response modifier agents, have been found to be safe and efficacious for various indications of uveitis, such as cystoid macular edema, active uveitis, and other conditions such as retinal vasculitis and vitreous haze. The use of intravitreal biological therapies, especially infliximab, has been fraught with potential safety signals such as photoreceptor toxicity. However, pharmacotherapeutic agents such as corticosteroids and anti-vascular endothelial growth factor agents are now widely used in the clinical management of uveitis and its complications.

Dexamethasone intravitreal implant for macular edema and some other rare indications in uveitis

In the present study, 110 eyes of 81 patients with uveitis who underwent intravitreal dexamethasone implant (IDI) injection and had a follow-up of at least 6 months between January, 2012 and September, 2022, were retrospectively analyzed. A total of 298 IDI injections were administered (mean, 2.71±2.37; range, 1-12). The mean age of the patients was 49.44±16.67 years (range, 15-86 years). The mean follow-up time after the first IDI was 34.31±26.53 months (range, 6-115 months). In total, 77 (95.1%) patients had non-infectious uveitis, while 4 patients (4.9%) received IDI for uveitic macular edema in association with infectious uveitis (1 patient with acute retinal necrosis and 3 patients with systemic tuberculosis). IDI was injected under the umbrella of intravitreal ganciclovir injection in the patient with healed acute retinal necrosis for the associated pseudophakic cystoid macular edema. A total of 6 patients (7.4%) received IDI prior to phacoemulsification surgery to control the possible post-operative macular edema. In addition, 3 patients (3.7%) with Vogt-Koyanagi-Harada disease received bilateral IDI as the systemic therapy could not be administered due to side-effects of the systemic treatment. In total, 1 patient (1.2%) with idiopathic retinal vasculitis, aneurysms and neuroretinitis was treated with IDI injections in both eyes in addition to systemic therapy to reduce the ongoing inflammation. Of note, two eyes (1.8%) received simultaneous single IDI and anti-vascular endothelial growth factor administration for the treatment of unilateral extrafoveal macular neovascularization (one with active serpiginous choroiditis and one with sympathetic ophthalmia). IDI was administered for the treatment of uveitic macular edema in 68 patients (83.9%). Best-corrected visual acuity improved from 0.69±0.64 to 0.60±0.76 logMAR at the final visit (P=0.008). Baseline mean central macular thickness (CMT) was 499.74±229.60 µm (range, 187-1,187 µm) and the mean final CMT was 296.60±152.02 µm (range, 126-848 µm). Intraocular pressure elevation requiring topical antiglaucomatous eye drops occurred in 28 eyes (25.5%). During the follow-up period, bilateral glaucoma surgery was required in 1 patient (1.2%) and 25 of 65 phakic eyes (38.4%) underwent phacoemulsification. Retinal detachment occurred in one eye (0.9%), endophthalmitis in one eye (0.9%), and transient intravitreal hemorrhage occurred in three eyes (2.7%) after the IDI injections. On the whole, the present study demonstrates that although IDI is mostly employed in non-infectious uveitic eyes with macular edema, it can also be administered in cases with systemic therapy intolerance, pseudophakic macular edema prophylaxis, and with great caution, in selected cases involving infectious uveitis and macular edema.

Efficacy and safety of single-dose intravitreal dexamethasone implant in non-infectious uveitic macular edema: A systematic review and meta-analysis

Purpose

We conducted a systematic review and meta-analysis to investigate the efficacy and safety of single-dose intravitreal dexamethasone (DEX) implant for treating non-infectious uveitic macular edema (UME).

Methods

Studies including clinical outcomes of the DEX implant in UME were comprehensively searched in PubMed, Embase, and Cochrane databases for potential studies from inception to July 2022. The primary outcomes were best corrected visual acuity (BCVA) and central macular thickness (CMT) during the follow-up period. Stata 12.0 was used to perform the statistical analyses.

Results

Six retrospective studies and one prospective investigation involving 201 eyes were ultimately included. Significantly improved BCVA was observed from baseline to 1 month (WMD = -0.15, 95%CI = -0.24, -0.06), 3 months (WMD = -0.22, 95%CI = -0.29, -0.15), and 6 months (WMD = -0.24, 95%CI = -0.35, -0.13), after single-dose DEX implant. When considering CMT, macular thickness of 1 month (WMD = -179.77, 95%CI = -223.45, -136.09), 3 months (WMD = -179.13, 95%CI = -232.63, -125.63), and 6 months (WMD = -140.25, 95%CI = -227.61, -52.88) decreased in comparison with baseline, with statistical significance.

Conclusion

Based on the current results, this meta-analysis confirmed favorable visual prognosis and anatomical improvement in patients with UME, after receiving the single-dose DEX implant. The most common adverse event is increased intraocular pressure, which could be controlled with topical medications.Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022325969.

Microvascular changes in the recurrent cystoid macular edema secondary to posterior noninfectious uveitis on optical coherence tomography angiography

Background

Posterior uveitis represents the second most frequent type of uveitis (15–30% of all uveitis). Noninfectious posterior uveitis complicated with secondary cystoid macular edema (CME) affects the visual prognosis negatively. The objective of the current study is to detect possible microvascular changes causing relapsing uveitis-related CME using optical coherence tomography angiography (OCTA).

Methods

This is an interventional, observational, retrospective study with 1 year follow-up. Patients with noninfectious, posterior uveitis-related CME undergoing dexamethasone (DEX) implant were evaluated. Following the DEX-implant were carried out control visits after 1 month, 2-months, 4-months, 6-months, and for up 1-year. A total of 76 eyes of 38 consecutive patients with noninfectious posterior uveitis were enrolled (consecutive sample). Complicated noninfectious posterior uveitis with secondary CME was diagnosed in 56 eyes of uveitis patients (73.7%) and reviewed.

Results

Our investigation showed (1) a reduction in superficial vessel plexus (SVP) measurements within 2-month (84%), reaching 96.4% for up 1-year, (2) an irregular profile of SVP in 69.6% of cases, persisting for up 1-year; relapsing uveitis-related CME eyes with irregular superficial foveal avascular zone (FAZ) profile were in 51%, while the SVP measurements reestablished in 100% of cases. Conversely, (3) the deep vascular plexus (DVP) parameters restored in a lower number of eyes within the 2-month (39.3%), remaining abnormal in 46.4% of cases for up 1-year; despite DVP restored in 53.6% of cases for up 1 year, (4) a capillary rarefaction ring around the FAZ appeared in 80.4% of cases; the relapsing uveitis-related CME eyes with abnormal DVP parameters were present in 41% of cases, of which 92.1% showed a rarefaction ring had abnormal DVP.

Conclusions

The use of OCTA enabled the evaluation in detail of retinal microvascular changes. We suggested that the possibility of the recurrence of the uveitis-related CME depends on the persistence of modifications of the superficial and deep layers. In this regard, we propose to implement the current imaging armamentarium with OCTA for the follow-up of patients with noninfectious uveitis-related CME.

Dexamethasone Intravitreal Implant for the Treatment of Macular Edema and Uveitis: A Comprehensive Narrative Review

Purpose

The purpose of this review article is to provide a comprehensive review of the current applications of intravitreal DEX implant (Ozurdex^®, Allergan Inc, Irvine, CA) for a variety of ophthalmic conditions – ranging from FDA approved indications to off-label uses. We have attempted to provide relevant evidence from the literature to help a reader develop an understanding of the biological and pharmacokinetic properties of DEX implant, its uses, and potential side effects.

Methods

PubMed searches were performed using the terms “Ozurdex”, or “intravitreal DEX implant”, AND “retinal vein occlusion”, or “diabetic macular edema”, or “uveitis”. The search was performed in July of 2021, with an additional search in October 2021. All original English language articles were considered for this review.

Results

DEX implant has evidence of efficacy in a variety of clinical situations including macular edema associated with retinal vein occlusion, diabetes, uveitis, and others. Safety concerns include cataract formation and progression, intraocular pressure elevation, complications related to intravitreal injection, and opportunistic infections secondary to steroid-induced immune suppression.

Conclusion

DEX implant is a useful tool in the management of several retinal disorders. Further studies are needed for head-to-head comparison with other treatment modalities and to determine its precise place in clinical practice.

Intraocular therapy in noninfectious uveitis

Systemic corticosteroids and immunosuppressant agents are the mainstay of therapy for non-infectious uveitis (NIU). However, the risks associated with systemic administration and the need of delivering an effective and safe anti-inflammatory treatment targeted to the site of inflammation have prompt the use of local therapy in the management of NIU. This review will analyse the different local treatment options available, including corticosteroids, anti-vascular endothelial growth factor (VEGF), methotrexate and the recent biologics.

UVEITIS TREATED WITH DEXAMETHASONE IMPLANT

PURPOSE

To evaluate the real-life efficacy and safety of the intravitreal dexamethasone implant in uveitis.

METHODS

This retrospective observational multicentric study included 152 eyes treated exclusively by 358 dexamethasone implant injections. The main outcome measures included change in the best-corrected visual acuity, central macular thickness, and vitreous haze score.

RESULTS

Patients were treated with dexamethasone implant for macular edema (51.3%), vitritis with macular edema (40.1%), vitritis (5.3%), and other causes (3.3%). The mean duration of follow-up was 19.0 months. The mean gain in best-corrected visual acuity during follow-up was +12.1 letters. An improvement in best-corrected visual acuity ≥5, 10, and 15 letters was found in 64.5, 50.7, and 35.5% of cases, respectively. 59.7% of eyes with macular edema at baseline were found to be anatomical responders. Vitritis resolution (vitreous haze = 0+) was obtained in 81.4% of cases. Ocular hypertension (intraocular pressure ≥25 mmHg and/or gain ≥10 mmHg from baseline) occurred in 28.3% of patients. No filtering surgery/laser therapy was required. A total of 40.2% of phakic subjects underwent cataract surgery on average 11.2 months after the first injection.

CONCLUSION

This study confirms the efficacy and safety of the dexamethasone implant in noninfectious uveitis. Cataract and ocular hypertension were not uncommon but easily manageable.

Uveitis Therapy: The Corticosteroid Options

Uveitis is characterized by intraocular inflammation involving the uveal tract; its etiologies generally fall into two broad categories: autoimmune/inflammatory or infectious. Corticosteroids  are a powerful and important class of medications ubiquitous in the treatment of uveitis. They may be given systemically or locally, in the form of topical drops, periocular injection, intravitreal suspension, or intravitreal implant. This review describes each of the currently available corticosteroid treatment options for uveitis, including favorable and unfavorable characteristics of each as well as applicable clinical trials. The main advantage of corticosteroids as a whole is their ability to quickly and effectively control inflammation early on in the course of uveitis. However, they can have serious side effects, whether localized to the eye (such as cataract and elevated intraocular pressure) or systemic (such as osteonecrosis and adrenal insufficiency) and in the majority of cases of uveitis are not an appropriate option for long-term therapy.

Intravitreal Dexamethasone Implant in the Treatment of Non-infectious Uveitis

Objectives:

To evaluate the long-term results of intravitreal dexamethasone implant (DEX) for noninfectious uveitis.

Materials and Methods:

The study included 62 eyes of 44 patients treated with DEX implant due to noninfectious uveitis and followed up for at least a year. Best-corrected visual acuity (BCVA), central foveal thickness, intraocular pressure (IOP), vitreous haze score, indications, immunomodulatory therapy and steroid usage before/after injection, number of injections, and adverse events were analyzed retrospectively.

Results:

Average follow-up was 20 months (range 12-64 months). The female/male ratio was 29/15. Mean age was 50 years (range 22-75 years). The most frequent uveitis etiologies were idiopathic (25 patients, 40.3%) and Behçet’s uveitis. (17 patients, 27.4%) The signedmost common indication for DEX injection was cystoid macular edema together with resistant vitreous haze (26 eyes, 41.9%). Twenty-two eyes (30%) received more than one DEX injection. Mean BCVA was improved from 0.55 logMAR at baseline to 0.38, 0.32, and 0.35 after 1, 3, and 6 months, respectively (p<0.001 for each). Mean CFT was decreased from 386 μm at baseline to 288, 311, and 302 μm after 1, 3, and 6 months, respectively (p<0.001 for each). Mean IOP did not change significantly during follow-up. Five eyes (8%) received topical anti-glaucoma medication (IOP ≥25 mmHg). Eighteen (46%) of 39 phakic eyes underwent cataract surgery during follow-up. Similar efficacy of the DEX implant was observed in eyes that received multiple injections. Systemic immunomodulatory therapy did not change significantly during follow-up.

Conclusion:

Intravitreal DEX injection does not alter systemic immunomodulatory therapy, but may facilitate the management of noninfectious uveitis by suppressing local intraocular inflammation. Multiple injections yielded comparable visual and anatomical outcomes to single injections. Follow-up for ocular hypertension and cataract formation are important, especially in eyes receiving multiple injections.

Emerging therapies in the management of macular edema: a review

Macular edema (ME) is a major complication of several vascular and inflammatory retinal diseases. Multiple mechanisms are implicated in its development and lead to visual impairment that could be reversible (the acute stages) or not reversible (long-standing ME). For this reason, an effective approach to the treatment of ME is of paramount importance in order to prevent irreversible damage of visual function. In this review, we discuss the management of ME and, in particular, current data of studies and clinical trials about drugs that have already been evaluated or are under investigation in the management of ME. Although several diseases could lead to the development of ME, we focus on the three main causes: diabetic retinopathy (DR), retinal vein occlusion (RVO), and uveitis. The introduction into clinical practice of anti-vascular endothelial growth factor injections (ranibizumab and aflibercept) and dexamethasone implants has revolutionized the treatment of ME secondary to DR and RVO. However, new drugs are needed in the treatment of resistant forms of ME secondary to DR and RVO. A fluocinolone acetonide implant has been approved by the US Food and Drug Administration for the treatment of diabetic ME but not for RVO. Furthermore, brolucizumab and abicipar pegol have been shown to be effective in preliminary studies and have the chance to be approved soon for diabetic ME treatment. In ME secondary to uveitis, a crucial role is played by corticosteroids and non-biologic immunomodulatory drugs. However, several new biologic agents are under investigation in different clinical trials and could be important new therapeutic options in cases with a low response to first-line therapy. However, only a few of these drugs will enter the market after proving their safety and efficacy. Only after that will we be able to offer a new therapeutic option to patients affected by uveitic ME.

Dexamethasone intravitreal implant (OZURDEX®) for macular edema secondary to noninfectious uveitis: a review of the literature

Macular edema (ME) is the leading cause of visual loss in uveitis and may persist long after ocular inflammation has been resolved. Local steroids are the first line treatment for uveitis and uveitic ME. Dexamethasone intravitreal implant (OZURDEX®; Allergan, Inc., CA, USA) has been used to treat diabetic ME and ME secondary to retinal vein occlusion. Recent studies have also demonstrated that Ozurdex may be effective treatment for patients with persistent uveitic ME. In this review, we present the results of the real word studies concerning the efficacy and safety of Ozurdex for the treatment of uveitic ME.

Long-Term Intravitreal Dexamethasone Implant Outcomes in Uveitis

Purpose: To describe the long-term clinical outcomes in a cohort of uveitic eyes treated with the intravitreal dexamethasone implant (Ozurdex; Allergan, Inc).Methods: Seventy-nine (63 patients) receiving 134 implant injections over 82 months were included. Indication, visual acuity (VA), intraocular pressure (IOP), vitreous haze score (VHS), central retinal thickness (CRT), time to reinjection, systemic treatments, and complications data were recorded.Results: The cumulative probability of VA improvement was 80% at 1 month and 90% at 12 months, and it was maintained until 60 months. Eyes with baseline vitritis (VHS >0.5; 68%) had a probability of VHS improvement of 33% at 1 month, 75% at 12 months, and 85% at 60 months. The probability of CRT improvement was 33% at 1 month, 75% at 12 months, and 85% at 60 months. The most frequent adverse event was moderate IOP elevation (≥25 mmHg) in 30.3%, no cases of retinal detachment or endophthalmitis were observed.Conclusions: The dexamethasone implant provides favorable VA, CRT, and VHS long-term outcomes in uveitis with a reduced rate of severe adverse events.

Update in treatment of uveitic macular edema

Macular edema (ME) represents the most common cause for visual loss among uveitis patients. The management of uveitic macular edema (UME) may be challenging, due to its often recalcitrant nature. Corticosteroids remain the mainstay of treatment, through their capability of effectively controlling inflammation and the associated ME. Topical steroids may be effective in milder cases of UME, particularly in edema associated with anterior uveitis. Posterior sub-Tenon and orbital floor steroids, as well as intravitreal steroids often induce rapid regression of UME, although this may be followed by recurrence of the pathology. Intra-vitreal corticosteroid implants provide sustained release of steroids facilitating regression of ME with less frequent injections. Topical nonsteroidal anti-inflammatory drugs may provide a safe alternative or adjuvant therapy to topical steroids in mild UME, predominantly in cases with underlying anterior uveitis. Immunomodulators including methotrexate, mycophenolate mofetil, tacrolimus, azathioprine, and cyclosporine, as well as biologic agents, notably the anti-tumor necrosis factor-α monoclonal antibodies adalimumab and infliximab, may accomplish the control of inflammation and associated ME in refractory cases, or enable the tapering of steroids. Newer biotherapies have demonstrated promising outcomes and may be considered in persisting cases of UME.

Intravitreal therapeutic agents in noninfectious uveitic macular edema

The management of uveitis is challenging for most treating ophthalmologists. The treatment of uveitis often requires the use of high dose of systemic corticosteroid and immunosuppressive agents, which are almost always associated with potential side effects. Intravitreal medications have become a popular mode of drug administration in uveitis patients as they provide high volume of drug to the target tissues, eliminating the risk of systemic toxicity. There has been tremendous development in the intravitreal therapeutics over the last few years. With the advent of sustained-release technique, increasing patient compliance, biodegradable nature of the implant, and introduction of newer agents with better safety profile, the intravitreal medications have become more popular in recent years. This review presents evidence in the scientific literature supporting the use of intravitreal medications for the management of uveitis and its complications.

[Steroid implant in treatment of sympathetic ophthalmia : Intravitreal implant of dexamethasone in cystoid macular edema in the context of sympathetic ophthalmia]

We present the case of a 39-year-old female patient with cystoid macular edema of the left eye in the context of sympathetic ophthalmia. The right eye underwent several surgical interventions of both cornea and retina after ocular trauma and was enucleated after first clinical signs compatible with sympathetic ophthalmia and after exclusion of other infectious/non-infectious etiologies. The patient was treated with parabulbar triamcinolone injections and intravitreal injections of a dexamethasone slow-release implant with a good clinical course with respect to the macular edema. A steroid response did not occur over the treatment period of more than 12 months.

Dexamethasone implants in paediatric patients with noninfectious intermediate or posterior uveitis: first prospective exploratory case series

BACKGROUND

To evaluate the efficacy and safety of dexamethasone (DEX) implants in paediatric patients with noninfectious intermediate or posterior uveitis.

METHODS

Prospective single center exploratory case series. Children and adolescents, 6 to 17 years old, with a vitreous haze score of ≥1.5+ or cystoid macular edema (CME) of >300 μm were enrolled. Vitreous haze score at month 2 was chosen as primary endpoint. Best corrected visual acuity (BCVA), central retinal thickness (CRT) and concomitant medication at month 6 were defined as secondary endpoints. Intraocular pressure (IOP) and cataract formation were determined as safety endpoints.

RESULTS

Three out of 6 eligible patients participated in the case series. At month 2, vitreous haze was reduced from a score of 1.5+ to 0.5+ and 0 and BCVA improved by ≥3 lines, ≥4 lines and ≥2 lines of Early Treatment of Diabetic Retinopathy (ETDRS)-letters, respectively. Visual acuity gain was accompanied by a CRT reduction of -186 μm and -83 μm in the first and third patient, in whom CME was the indication for DEX implantation. A reduction of concomitant medication was achieved in 1 patient. IOP increase was seen in all 3 patients, but could be treated sufficiently with primarily IOP lowering medications and without need for glaucoma surgery. Cataract progression did not occur.

CONCLUSIONS

DEX implants led to an improvement in all endpoints, especially BCVA. This study confirms that IOP rises may also occur in the paediatric population and should be monitored and treated appropriately.

TRIAL REGISTRATION

European Union Drug Regulating Authorities Clinical Trials (EudraCT)- nr: 2013-000541-39.

Controllable continuous sub-tenon drug delivery of dexamethasone disodium phosphate to ocular posterior segment in rabbit

Corticosteroids have been used for treatment of posterior segment eye diseases, but the delivery of drug to the posterior segments is still a problem to resolve. In our study, we explore the feasibility of Sub-tenon's Controllable Continuous Drug Delivery to ocular posterior segment. Controllable continuous sub-tenon drug delivery (CCSDD) system, intravenous injections (IV) and sub-conjunctival injections (SC) were used to deliver dexamethasone disodium phosphate (DEXP) in rabbits, the dexamethasone concentration was measured in the ocular posterior segment tissue by Shimadzu LC-MS 2010 system at different time points in 24 h after first dose injection. Levels of dexamethasone were significantly higher at 12, 24 h in CCSDD than two other approaches, and at 3, 6 h in CCSDD than IV in vitreous body (p < 0.01); at 6, 12, 24 h in CCSDD than two other approaches, and at 1, 3 h in CCSDD than IV in retinal/choroidal compound (p < 0.01); at 3, 6, 12, 24 h in CCSDD than two other approaches, and at 1 h in CCSDD than IV in sclera (p < 0.05). The AUC0-24 in CCSDD group is higher than two other groups in all ocular posterior segment tissue. Our results demonstrated that dexamethasone concentration could be sustained moderately higher in the posterior segment by CCSDD than SC and IV, indicating that CCSDD might be a therapeutic alternative to treat a variety of intractable posterior segment diseases.

Pentablock copolymer dexamethasone nanoformulations elevate MYOC: in vitro liberation, activity and safety in human trabecular meshwork cells

AIM

The aim of this study is to examine the elevation of MYOC in long-term treatment of human trabecular meshwork (HTM) cells using dexamethasone (DEX) encapsulated pentablock (PB) copolymer-based nanoparticles (NPs) (DEX-PB-NPs).

MATERIALS & METHODS

PB copolymers and DEX-PB-NPs were synthesized and characterized using nuclear magnetic resonance, gel permeation chromatography, and X-ray diffraction analyses. MYOC levels secreted from HTM cells were measured by western blot (WB) analysis.

RESULTS

DEX-PB-NPs were formulated in the size range of 109 ± 3.77 nm (n = 3). A long term DEX release from the NPs was observed over three months. Cell viability and cytotoxicity were not affected up to 12 weeks of treatment with PB-copolymer or DEX-PB-NPs. WB data from five HTM cell strains showed that MYOC levels increased by 5.2 ± 1.3, 7.4 ± 4.3, and 2.8 ± 1.1-fold in the presence of DEX-PB-NPs compared with 9.2 ± 3.8, 2.2 ± 0.5, and 1.5 ± 0.3-fold at 4, 8 and 12 weeks in control-DEX treatment group, respectively (n = 5). Based on the decline in MYOC levels after withdrawal of DEX from control wells, DEX-PB-NPs released the DEX for at least 10 weeks.

CONCLUSION

The treatment of HTM cells using DEX-PB-NPs were analyzed in this study. The in vitro cell-based system developed here is a valuable tool for determining the safety and effects of steroids released from polymeric NPs.