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Comparison of the Effect of Intravitreal Dexamethasone Implant in Vitrectomized and Nonvitrectomized Eyes for the Treatment of Diabetic Macular Edema. J Ophthalmol 2018; 2018:1757494. [PMID: 29850199 PMCID: PMC5937369 DOI: 10.1155/2018/1757494] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 03/22/2018] [Accepted: 04/03/2018] [Indexed: 12/25/2022] Open
Abstract
Purpose To compare the effectiveness of sustained-release dexamethasone (DEX) intravitreal implant in nonvitrectomized eyes and vitrectomized eyes with diabetic macular edema (DME). Methods A retrospective review of the medical records of 40 eyes of 30 consecutive patients with diabetic macular edema who underwent intravitreal DEX implant injection. Patients were divided into 2 subgroups: 31 eyes that were nonvitrectomized (group 1) and 9 eyes that had previously undergone standard pars plana vitrectomy (group 2). The main outcome measures were BCVA and foveal thickness (FT). Results A significant improvement was seen in BCVA in both group 1 and group 2 at the 1st, 2nd, and 6th months after treatment with DEX implant (p < 0.05). In group 1, a significant reduction in FT was observed at the 1st, 2nd, and 6th months (p < 0.05). In group 2, a significant reduction in FT was seen at the 1st and 2nd months (p < 0.05), but the reduction rate at the 6th month after the injection was not statistically significant (p = 0.06). Conclusion DEX implant is effective for the treatment of diabetic macular edema, and the effectiveness of the drug is similar in vitrectomized and nonvitrectomized eyes.
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Jiang K, Weaver JD, Li Y, Chen X, Liang J, Stabler CL. Local release of dexamethasone from macroporous scaffolds accelerates islet transplant engraftment by promotion of anti-inflammatory M2 macrophages. Biomaterials 2017; 114:71-81. [DOI: 10.1016/j.biomaterials.2016.11.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/03/2016] [Accepted: 11/04/2016] [Indexed: 02/05/2023]
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Salama AH, Mahmoud AA, Kamel R. A Novel Method for Preparing Surface-Modified Fluocinolone Acetonide Loaded PLGA Nanoparticles for Ocular Use: In Vitro and In Vivo Evaluations. AAPS PharmSciTech 2016; 17:1159-72. [PMID: 26589410 DOI: 10.1208/s12249-015-0448-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 11/06/2015] [Indexed: 11/30/2022] Open
Abstract
Our objective was to prepare nanoparticulate system using a simple yet attractive innovated method as an ophthalmic delivery system for fluocinolone acetonide to improve its ocular bioavailability. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were prepared by adopting thin film hydration method using PLGA/poloxamer 407 in weight ratios of 1:5 and 1:10. PLGA was used in 75/25 and 50/50 copolymer molar ratio of DL-lactide/glycolide. Results revealed that using PLGA with lower glycolic acid monomer ratio exhibited high particle size (PS), zeta potential (ZP) and drug encapsulation efficiency (EE) values with slow drug release pattern. Also, doubling the drug concentration during nanoparticles preparation ameliorated its EE to reach almost 100%. Furthermore, studies for separating the un-entrapped drug in nanoparticles using centrifugation method at 20,000 rpm for 30 min showed that the separated clear supernatant contained nanoparticles encapsulating an important drug amount. Therefore, separation of un-entrapped drug was carried out by filtrating the preparation using 20-25 μm pore size filter paper to avoid drug loss. Aiming to increase the PLGA nanoparticles mucoadhesion ability, surface modification of selected formulation was done using different amount of stearylamine and chitosan HCl. Nanoparticles coated with 0.1% w/v chitosan HCl attained most suitable results of PS, ZP and EE values as well as high drug release properties. Transmission electron microphotographs illustrated the deposition of chitosan molecules on the nanoparticles surfaces. Pharmacokinetic studies on Albino rabbit's eyes using HPLC indicated that the prepared novel chitosan-coated PLGA nanoparticles subjected to separation by filtration showed rapid and extended drug delivery to the eye.
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Cebeci Z, Kir N. Role of implants in the treatment of diabetic macular edema: focus on the dexamethasone intravitreal implant. Diabetes Metab Syndr Obes 2015; 8:555-66. [PMID: 26604809 PMCID: PMC4655951 DOI: 10.2147/dmso.s73540] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Diabetic macular edema (DME) is the leading cause of sight-threatening complication in diabetic patients, and several treatment modalities have been developed and evaluated to treat this pathology. Intravitreal agents, such as anti-vascular endothelial growth factors (anti-VEGF) or corticosteroids, have become more popular in recent years and are widely used for treating DME. Sustained release drugs appear to be mentioned more often nowadays for extending the period of intravitreal activity, and corticosteroids play a key role in inhibiting the inflammatory process in DME. A potent corticosteroid, dexamethasone (Ozurdex(®)), in the form of an intravitreal implant, has been approved for various ocular etiologies among which DME is also one. This review evaluates the role of implants in the treatment of DME, mainly focusing on the dexamethasone intravitreal implant.
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Affiliation(s)
- Zafer Cebeci
- Department of Ophthalmology, Istanbul Faculty of Medicine, Istanbul University, Capa, Istanbul, Turkey
- Correspondence: Zafer Cebeci, Department of Ophthalmology, Istanbul Faculty of Medicine, Istanbul University, Capa 34390, Istanbul, Turkey, Tel +90 212 414 2000, Fax +90 212 414 2026, Email
| | - Nur Kir
- Department of Ophthalmology, Istanbul Faculty of Medicine, Istanbul University, Capa, Istanbul, Turkey
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Kiernan DF, Mieler WF. Intraocular corticosteroids for posterior segment disease: 2012 update. Expert Opin Pharmacother 2012; 13:1679-94. [PMID: 22783878 DOI: 10.1517/14656566.2012.690736] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Diabetic macular edema (DME), cystoid macular edema (CME), age-related macular degeneration (AMD), retinal vascular occlusion (RVO) and uveitis are responsible for severe visual impairment worldwide. In some patients with these conditions, treatment with intraocular corticosteroids may be beneficial. Although off-label use of these agents has occurred for many years, novel agents including preservative-free and sustained-release intravitreal implants are currently being studied in clinical trials (CTs). AREAS COVERED This paper reviews the use of CTs for vitreoretinal (VR) diseases including choroidal neovascularization, CME, DME, RVO and posterior uveitis. It also discusses the use of corticosteroids for treating VR disease, including dexamethasone, fluocinolone acetonide, intravitreal implants and triamcinolone acetonide. EXPERT OPINION Used alone, intravitreal corticosteroids may benefit disorders such as DME, RVO and uveitis compared with standard therapy. Cases of exudative AMD non-responsive to standard treatment may benefit from combination therapy, including usage of intravitreal corticosteroid injections. Intraoperative use of these agents may aid visualization of retinal structures. Sustained-release intraocular implants have been approved for posterior uveitis and RVO associated with macular edema. In spite of this, most intraocular corticosteroids have a limited duration of action along with significant side effects, including cataract and glaucoma. Currently, intravitreal corticosteroid usage for DME is considered off-label.
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Affiliation(s)
- Daniel F Kiernan
- Ophthalmic Consultants of Long Island, Rockville Centre, NY, USA
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Abstract
BACKGROUND Diabetic macular edema (DME), cystoid macular edema (CME), age-related macular degeneration (AMD), retinal vascular occlusion (RVO) and uveitis are responsible for severe visual impairment worldwide. In some patients with these conditions, treatment with intraocular corticosteroids may be beneficial. Although off-label use of these agents has occurred for many years, novel agents including preservative-free and sustained-release intravitreal implants are currently being studied in clinical trials (CTs). OBJECTIVE To review the use of intraocular corticosteroids. METHODS Literature review. RESULTS Used alone, intravitreal corticosteroids may benefit disorders such as DME, RVO and uveitis compared with standard therapy or observation. Patients with AMD may benefit more from combination treatment with photodynamic therapy, intravitreal corticosteroid and intravitreal anti-VEGF injections. Intraoperative use of these agents may assist in visualization and manipulation of fine retinal structures. Sustained-release intraocular implants have been approved for severe posterior uveitis, and have shown benefits in ongoing CTs. CONCLUSION Although intraocular corticosteroid injections have a limited duration of action requiring frequent re-treatment, and significant side effects including cataract and glaucoma development, intraocular injections may be of benefit in certain ocular disorders. Corticosteroid implants are emerging as potential treatments for macular edema due to uveitis, DME or RVO.
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Affiliation(s)
- Daniel F Kiernan
- Department of Ophthalmology & Visual Sciences, University of Illinois at Chicago, Illinois 60612, USA
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Fialho SL, Rêgo MB, Siqueira RC, Jorge R, Haddad A, Rodrigues AL, Maia-Filho A, Silva-Cunha A. Safety and Pharmacokinetics of an Intravitreal Biodegradable Implant of Dexamethasone Acetate in Rabbit Eyes. Curr Eye Res 2009; 31:525-34. [PMID: 16769612 DOI: 10.1080/02713680600719036] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The treatment of vitreoretinal diseases is limited and, nowadays, new drug delivery approaches have been reported in order to increase drug bioavailability. The objective of the current study was to determine the pharmacokinetic profile of a biodegradable dexamethasone acetate implant inserted into the vitreous of rabbits and to evaluate its potential signs of toxicity to the rabbits' eyes. The results showed that the intravitreous drug concentration remained within the therapeutic range along the 8-week period of evaluation. The system under study was not toxic to the normal rabbit retina, and no significant increase in intraocular pressure was observed.
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Affiliation(s)
- S L Fialho
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Barcia E, Herrero-Vanrell R, Díez A, Alvarez-Santiago C, López I, Calonge M. Downregulation of endotoxin-induced uveitis by intravitreal injection of polylactic-glycolic acid (PLGA) microspheres loaded with dexamethasone. Exp Eye Res 2009; 89:238-45. [PMID: 19341729 DOI: 10.1016/j.exer.2009.03.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Revised: 03/03/2009] [Accepted: 03/20/2009] [Indexed: 11/25/2022]
Abstract
We tested the short- and long-term ability of polylactic-glycolic acid (PLGA) microspheres loaded with dexamethasone to reduce ocular inflammation in rabbits elicited by intravitreal lipopolysaccharide (LPS) injection. PLGA microspheres loaded with dexamethasone were prepared by the solvent evaporation technique from an oil/water emulsion and sterilized by gamma irradiation (25 kGy). The microsphere fraction selected was 2:10 (dexamethasone:PLGA) and contained 141 +/- 0.38 microg dexamethasone/mg PLGA. Microsphere diameters were 20-53 microm, and the mean encapsulation efficiency was 92.97 +/- 0.75%. Seven days prior to the induction of panuveitis, 10 mg of dexamethasone-free or dexamethasone-loaded microspheres were injected into the vitreous. Control animals received no injection. Panuveitis was induced in male New Zealand rabbits (2.5-3.0 kg) by intravitreal injection of Escherichia coli LPS. Clinical evaluation, electroretinography and histopathologic studies were performed in short-term studies of 15 days and in long-term studies of 33 days. Efficacy in reducing inflammation was also studied in vitrectomized eyes. In short-term studies eyes injected with dexamethasone-loaded microspheres had less inflammation than control eyes and eyes injected with blank microspheres. Inflammation reverted in all groups by 15 days after LPS injection. A second LPS dose given on Day 30 provoked a high peak of inflammation in control eyes and in those injected with blank microspheres. In contrast, only slight inflammation occurred in eyes injected with dexamethasone-loaded microspheres. Histopathology and electroretinography supported these results. Dexamethasone-loaded microspheres effectively reduced intraocular inflammation caused by LPS in both short- and long-term studies.
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Affiliation(s)
- Emilia Barcia
- Departamento de Farmacia y Tecnología Farmacéutica, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
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Abstract
We review the epidemiology, pathophysiology, and etiology of cystoid macular edema (CME). Inflammatory, diabetic, post-cataract, and macular edema due to age-related macular degeneration is described. The role of chronic inflammation and hypoxia and direct macular traction is evaluated in each case according to different views from the literature. The different diagnostic methods for evaluating the edema are described. Special attention is given to fluoroangiography and the most modern methods of macula examination, such as ocular coherence tomography and multifocal electroretinography. Finally, we discuss the treatment of cystoid macular edema in relation to its etiology. In this chapter we briefly refer to the therapeutic value of laser treatment especially in diabetic maculopathy or vitrectomy in some selected cases. Our paper is focused mainly on recent therapeutic treatment with intravitreal injection of triamcinolone acetonide and anti-VEGF factors like bevacizumab (Avastin), ranibizumab (Lucentis), pegaptamid (Macugen), and others. The goal of this paper is to review the current status of this treatment for macular edema due to diabetic maculopathy, central retinal vein occlusion and post-cataract surgery. For this reason the results of recent multicenter clinical trials are quoted, as also our experience on the use of intravitreal injections of anti-VEGF factors and we discuss its value in clinical practice.
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Affiliation(s)
- Tryfon G Rotsos
- Medical Retina Service, Moorfields Eye Hospital, London, UK.
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Gómez-Gaete C, Fattal E, Silva L, Besnard M, Tsapis N. Dexamethasone acetate encapsulation into Trojan particles. J Control Release 2008; 128:41-9. [DOI: 10.1016/j.jconrel.2008.02.008] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 02/13/2008] [Accepted: 02/15/2008] [Indexed: 11/28/2022]
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Bourges JL, Touchard E, Kowalczuk L, Berdugo M, Thomas-Doyle A, Bochot A, Gomez A, Azan F, Gurny R, Behar-Cohen F. Dispositifs de délivrance de principes actifs pour des applications ophtalmologiques. J Fr Ophtalmol 2007; 30:1070-88. [DOI: 10.1016/s0181-5512(07)79290-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Mohammad DA, Sweet BV, Elner SG. Retisert: is the new advance in treatment of uveitis a good one? Ann Pharmacother 2007; 41:449-54. [PMID: 17341531 DOI: 10.1345/aph.1h540] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE To review the use of corticosteroids for the treatment of uveitis, with a focus on the pharmacology, efficacy, and safety of a newer delivery device, Retisert. DATA SOURCES A PubMed/MEDLINE search from 1950 through February 2007 was conducted, and manufacturer-provided data were reviewed. STUDY SELECTION AND DATA EXTRACTION Animal studies and Phase II and III clinical trials evaluating the safety and efficacy of Retisert for the treatment of uveitis were considered. The data were extracted from PubMed/MEDLINE using the search terms fluocinolone acetonide, corticosteroids, intravitreal implant, uveitis, ocular steroids, and Retisert. DATA SYNTHESIS The findings of the clinical studies showed, with use of Retisert, a reduction in the recurrence of uveitis, improvement in visual acuity, and a decreased need for adjunctive therapy with corticosteroids and immunosuppressant agents. There are currently no studies directly comparing Retisert with other treatment options. The most commonly reported adverse events (ADEs) in clinical trials included cataracts, increased intraocular pressure, post-procedural complications associated with implant insertion, and ocular pain. Other ocular ADEs included decreased visual acuity, glaucoma, blurred vision, an abnormal sensation in the eye, eye irritation, and a change in tearing. These ADEs are similar to those seen with chronic corticosteroid therapy delivered by other ocular routes. CONCLUSIONS Retisert implants have been shown to deliver sufficient drug for a longer period of time compared with the traditional steroid delivery methods. Promising efficacy results show a significant reduction in recurrence rate and improvement in visual acuity for approximately 3 years after implant. However, the drug carries the risks associated with the implant procedure and with chronic exposure of the eye to steroids. Until more data on the long-term safety are known, Retisert should be reserved for patients who are no longer tolerant of or responsive to more traditional treatment modalities.
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Affiliation(s)
- Dina A Mohammad
- University of Michigan Health System and College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
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Sivaprasad S, McCluskey P, Lightman S. Intravitreal steroids in the management of macular oedema. ACTA ACUST UNITED AC 2007; 84:722-33. [PMID: 17083528 DOI: 10.1111/j.1600-0420.2006.00698.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The use of intravitreal corticosteroids in the management of macular oedema has recently gained widespread acceptance. New long-acting steroid preparations and methods of delivery have facilitated the use of these new modalities. This review describes the various types of macular oedema for which this therapeutic option is used and the results.
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Affiliation(s)
- Sobha Sivaprasad
- Department of Clinical Ophthalmology, Institute of Ophthalmology, Moorfields Eye Hospital, London, UK
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Bourges JL, Bloquel C, Thomas A, Froussart F, Bochot A, Azan F, Gurny R, BenEzra D, Behar-Cohen F. Intraocular implants for extended drug delivery: therapeutic applications. Adv Drug Deliv Rev 2006; 58:1182-202. [PMID: 17107737 DOI: 10.1016/j.addr.2006.07.026] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Accepted: 07/31/2006] [Indexed: 12/16/2022]
Abstract
An overview of ocular implants with therapeutic application potentials is provided. Various types of implants can be used as slow release devices delivering locally the needed drug for an extended period of time. Thus, multiple periocular or intraocular injections of the drug can be circumvented and secondary complications minimized. The various compositions of polymers fulfilling specific delivery goals are described. Several of these implants are undergoing clinical trials while a few are already commercialized. Despite the paramount progress in design, safety and efficacy, the place of these implants in our clinical therapeutic arsenal remains limited. Miniaturization of the implants allowing for their direct injection without the need for a complicated surgery is a necessary development avenue. Particulate systems which can be engineered to target specifically certain cells or tissues are another promising alternative. For ocular diseases affecting the choroid and outer retina, transscleral or intrasscleral implants are gaining momentum.
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Affiliation(s)
- J L Bourges
- INSERM, U598, Physiopathology of Ocular Diseases, Therapeutic Innovations, 15 Rue de l'Ecole de Médecine 75006 Paris, France
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Felt-Baeyens O, Eperon S, Mora P, Limal D, Sagodira S, Breton P, Simonazzi B, Bossy-Nobs L, Guex-Crosier Y, Gurny R. Biodegradable scleral implants as new triamcinolone acetonide delivery systems. Int J Pharm 2006; 322:6-12. [PMID: 16824708 DOI: 10.1016/j.ijpharm.2006.05.053] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2005] [Revised: 04/20/2006] [Accepted: 05/03/2006] [Indexed: 10/24/2022]
Abstract
The goal of this study was to develop ocular scleral implants able to release triamcinolone acetonide (TA) overall several months. Scleral discs were manufactured by a compression-molding method using a new synthetic polymer, poly(methylidene malonate) (PMM2.1.2), as matrix. Implants with good mechanical properties adapted for in vivo implantation have been obtained when using high M(w) PMM2.1.2 (100,000 - 150,000 Da) associated with ethoxylated derivatives of stearic acid (Simulsol) or oligomers of methylidene malonate as plasticizer. After implantation in rabbit eyes, scleral implants showed a good ocular biocompatibility. Indeed, the clinical follow-up and ocular inflammation parameters, such as inflammatory cell number and protein content in aqueous humor, demonstrated that implants were well tolerated and did not provoke abnormal inflammation. Implants were able to release significant concentrations of TA in the vitreous and the sclera throughout 5 weeks.
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Affiliation(s)
- O Felt-Baeyens
- Department of Pharmaceutics and Biopharmaceutics, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 30 Quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland
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Steroids in Macular Disease. Retina 2006. [DOI: 10.1016/b978-0-323-02598-0.50061-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Driot JY, Novack GD, Rittenhouse KD, Milazzo C, Pearson PA. Ocular pharmacokinetics of fluocinolone acetonide after Retisert intravitreal implantation in rabbits over a 1-year period. J Ocul Pharmacol Ther 2004; 20:269-75. [PMID: 15279731 DOI: 10.1089/1080768041223611] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE The present study was designed to examine the pharmacokinetics of a fluocinolone acetonide (FA) intravitreal implant in pigmented rabbits. METHODS Pigmented rabbits were randomly assigned to receive either a 0.5 mg or 2.0 mg FA intravitreal implant (Retisert). Four animals were sacrificed per time point (2 hours; 2 weeks; and 3, 6, 9, and 12 months after implantation) for FA intraocular levels determination. RESULTS In the vitreous, concentration of FA was relatively constant from the first time point, 2 hours, through 1 year, and dose-related, approximately seven- to eight-fold greater in the 2-mg implant. Concentrations of FA were generally higher in the vitreous (11-18 and 75-146 ng/g) and retina (42-87 and 224-489 ng/g) than in the aqueous humor (0.21-1.1 and 2.6-13.0 ng/g) for the 0.5- and 2-mg implants, respectively. Urine and plasma values were below the lower limit of quantitation (200 pg/mL) for all observations, indicating no evidence of systemic absorption. CONCLUSIONS In this rabbit study, the Retisert provides relatively constant levels of FA in the posterior pole, which is consistent with previous reports of its clinical utility.
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Cavallaro G, Maniscalco L, Giammona G, Civiale C, Mazzone M, Enea V. Chemical conjugation of dexamethasone to a polyaspartamide and in vitro evaluation studies. J Drug Deliv Sci Technol 2004. [DOI: 10.1016/s1773-2247(04)50066-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jaffe GJ, Ben-Nun J, Guo H, Dunn JP, Ashton P. Fluocinolone acetonide sustained drug delivery device to treat severe uveitis. Ophthalmology 2000; 107:2024-33. [PMID: 11054326 DOI: 10.1016/s0161-6420(00)00466-8] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
PURPOSE Uveitis is often a chronic disease requiring long-term medical therapy. In this report, we describe a pilot safety and efficacy trial of a novel sustained drug delivery system containing fluocinolone acetonide to treat patients with severe uveitis. DESIGN Prospective, noncomparative, interventional case series PARTICIPANTS Patients with severe uveitis. METHODS Sustained drug delivery devices designed to release fluocinolone acetonide for at least 2.5 years were implanted through the pars plana into the vitreous cavity of seven eyes of five patients. All patients had severe uveitis not well controlled with, or intolerant to, repeated periocular corticosteroid injections, systemic corticosteroids, nonsteroidal immunosuppressive agents, or a combination thereof at the time of device implantation. Before device implantation, patients underwent complete evaluation including history, ophthalmologic examination, fluorescein angiography, visual field testing, and electroretinography. After surgery, patients were reexamined at 1 week, 2 weeks, 4 weeks, and at 1- to 3-month intervals. Visual fields, electroretinograms, and fluorescein angiography were repeated at 3- to 6-month intervals. MAIN OUTCOME MEASURES Preoperative and postoperative visual acuity, ocular inflammation, anti-inflammatory medication use, and intraocular pressure. RESULTS Patients had a diagnosis of Behçet's syndrome (two eyes), or idiopathic panuveitis (five eyes, including two with necrotizing retinitis, two with progressive chorioretinitis, and one with iridocyclitis and intermediate uveitis). Patients were observed an average of 10 months (range, 5-19 months). All eyes had stabilized or improved visual acuity after device implantation, and four of seven eyes had an improvement of three lines or more. The mean initial visual acuity, measured by Snellen chart, was 20/207, and the mean final visual acuity was 20/57 (P = 0.02). After surgery, at the final visit, no eye had clinically detectable inflammation, and all seven eyes had a marked reduction in systemic, topical, and periocular anti-inflammatory medication use. Four eyes had increased intraocular pressure 6 weeks to 6 months after device implantation. Intraocular pressure has been controlled on topical medications. No patient experienced intraoperative complications. CONCLUSIONS A fluocinolone acetonide sustained drug delivery device is a promising new therapy for the treatment of severe uveitis. Intraocular pressure must be carefully monitored long after device implantation. Based on these data, a randomized study of a larger group of patients is warranted.
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Affiliation(s)
- G J Jaffe
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, USA.
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Einmahl S, Zignani M, Varesio E, Heller J, Veuthey JL, Tabatabay C, Gurny R. Concomitant and controlled release of dexamethasone and 5-fluorouracil from poly(ortho ester). Int J Pharm 1999; 185:189-98. [PMID: 10460914 DOI: 10.1016/s0378-5173(99)00149-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A viscous bioerodible and hydrophobic poly(ortho ester) has been developed as a biocompatible, sustained drug release system for an ophthalmic application in intraocular proliferative disorders. The combination of wound healing modulators such as 5-fluorouracil and dexamethasone is a major advantage since these drugs act at different stages of these diseases. Since 5-fluorouracil is an acidic, water-soluble compound and dexamethasone exists in three chemical forms, i.e. the water-insoluble base, the highly hydrophobic acetate ester or the basic phosphate salt, it was of interest to investigate whether the physicochemical properties of the drugs have an influence on their release rates, and whether a concomitant and sustained release of both 5-fluorouracil and dexamethasone could be achieved. It has been found that lipophilicity and acidobasicity play a major role in controlling drug release rates and polymer degradation. The combination of 5-fluorouracil and dexamethasone phosphate allows a sustained and concomitant release of both drugs, due to the basic characteristics of the corticosteroid which stabilize the polymer. This system appears to be promising for concomitant and controlled drug delivery aimed at the pharmacological treatment of intraocular proliferative disorders.
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Affiliation(s)
- S Einmahl
- Department of Pharmaceutical Technology and Biopharmaceutics, School of Pharmacy, University of Geneva, CH-1211, Geneva, Switzerland
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Jaffe GJ, Yang CS, Wang XC, Cousins SW, Gallemore RP, Ashton P. Intravitreal sustained-release cyclosporine in the treatment of experimental uveitis. Ophthalmology 1998; 105:46-56. [PMID: 9442778 DOI: 10.1016/s0161-6420(98)91176-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE Uveitis often is a chronic disease requiring long-term medical therapy. Despite treatment, the disease may be difficult to control and may produce serious, vision-threatening ocular complications. In this study, the authors determined whether an intravitreal cyclosporine-sustained delivery device was effective in the treatment of ocular inflammation in a rabbit model of uveitis. METHODS New Zealand White rabbits were immunized subcutaneously with Mycobacterium tuberculosis H37Ra antigen. Fourteen days later, sustained-release cyclosporine devices were implanted into the vitreous cavity of the right eye of experimental rabbits. Control animals received sham devices. Seven days after device implantation, rabbits were challenged with an intravitreal injection of tuberculin antigen. To simulate chronic inflammation with exacerbations, some animals were rechallenged with intravitreal antigen on day 21 after device implantation. Inflammation was assessed clinically by a masked observer who graded anterior chamber cells, flare, corneal neovascularization, iris congestion, and vitreous opacity daily until day 7 and on day 13 after the initial intravitreous challenge, and on days 1 and 2 after the rechallenge. Retinal function was evaluated by electroretinography. Animals were killed 3, 6, 8, and 14 days after the initial intravitreal challenge and on the second day after rechallenge for aqueous leukocyte count, protein measurement, and histologic examination. The number of aqueous and peripheral blood proliferating lymphocytes and the subset of CD4+ T cells were determined by flow cytometry. High-performance liquid chromatography was used to measure cyclosporine A levels in vitreous and peripheral blood. Light microscopy was used to evaluate the eyes histopathologically. RESULTS By clinical criteria, treated eyes had significantly less inflammation than untreated eyes. The number of aqueous cells and protein concentration determined quantitatively paralleled the clinical assessment of anterior chamber cells and flare. The electroretinography B-wave was depressed significantly in untreated eyes compared with that of treated eyes (P < 0.02). Histopathologic examination results showed marked inflammation and tissue disorganization in untreated eyes, whereas cyclosporine-treated eyes had preserved architecture and greatly reduced inflammatory cells. Intravitreal cyclosporine remained at therapeutic levels for at least 6 months after intravitreal device implantation, whereas blood levels were low to nondetectable. CONCLUSIONS The intravitreal cyclosporine A device effectively suppresses ocular inflammation in a rabbit model of uveitis. This device may be useful in the treatment of patients with severe chronic uveitis who are intolerant to currently available therapies.
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Affiliation(s)
- G J Jaffe
- Department of Ophthalmology, Duke University Medical Center, Durham 27710, USA
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