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Morén S, Kallberg M, Strom L. Equine uveitis: Outcome and adverse effects after one or two intravitreal low-dose gentamicin injections. Equine Vet J 2024. [PMID: 38329024 DOI: 10.1111/evj.14056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 12/06/2023] [Indexed: 02/09/2024]
Abstract
BACKGROUND Uveitis is common in horses, potentially turning chronic (persistent or recurrent) resulting in impaired vision or blindness. All mainstay therapeutics aims at controlling inflammation, but long-term or lifelong treatment is often needed with possibly severe side effects. Therefore, intravitreal injections with low-dose gentamicin (IVGI) have been used in attempt to give a long-lasting result with potentially less side effects. OBJECTIVES To retrospectively assess outcome and long-term complications following one or two low-dose IVGI in Swedish horses with chronic uveitis. STUDY DESIGN Retrospective case series. METHODS Medical records of horses diagnosed with uveitis examined at the Equine Clinic of the University Animal Hospital of Sweden between 2016 and 2021 were reviewed. Inclusion criteria were horses with a diagnosis of chronic uveitis that were treated with 4 mg IVGI. After injection, tapering doses of anti-inflammatory medications were administered. Due to persistence or recurrence of uveitis despite IVGI, some horses received a second injection. A positive outcome was defined as controlled uveitis, despite no or minimal anti-inflammatory medication. RESULTS 32 eyes (29 horses) were included. Based on clinical evaluation, uveitis was classified as anterior (91%) or panuveitis (9%). 10 eyes were treated with IVGI twice. A positive outcome was observed in 13/32 eyes (41%). Inflammation in 9/32 eyes was controlled after the first, and in 4/10 eyes after the second IVGI treatment. Long-term complications included retinal degeneration in seven eyes, and mature cataracts in five eyes. Enucleations were performed in 14/32 eyes, due to lack of favourable response of IVGI, or due to complications, that is, glaucoma, corneal ulceration, and/or corneal mineralisation. One horse was euthanised due to painful bouts of inflammation in both eyes despite treatment. MAIN LIMITATIONS Small sample size, retrospective design with no control group, no histopathology performed, infrequent sampling for Leptospira and no standardised treatment protocol after the IVGI. CONCLUSIONS In this group of Swedish horses, predominantly diagnosed clinically with anterior uveitis, a positive outcome was observed in 41% of eyes following one or two low-dose IVGI. Retinal degeneration in the visual streak was observed in 22% of eyes, which is a higher proportion of this complication than previously described.
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Affiliation(s)
- S Morén
- Equine Clinic, University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - M Kallberg
- Equine Clinic, University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - L Strom
- Equine Clinic, University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Padjasek M, Qasem B, Cisło-Pakuluk A, Marycz K. Cyclosporine A Delivery Platform for Veterinary Ophthalmology—A New Concept for Advanced Ophthalmology. Biomolecules 2022; 12:biom12101525. [PMID: 36291734 PMCID: PMC9599649 DOI: 10.3390/biom12101525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/11/2022] [Accepted: 10/14/2022] [Indexed: 11/16/2022] Open
Abstract
Cyclosporine A (CsA) is a selective and reversible immunosuppressant agent that is widely used as a medication for a wide spectrum of diseases in humans such as graft versus host disease, non-infectious uveitis, rheumatoid arthritis, psoriasis, and atopic dermatitis. Furthermore, the CsA is used to treat keratoconjunctivitis sicca, chronic superficial keratitis, immune-mediated keratitis and equine recurrent uveitis in animals. The selective activity of Cyclosporine A (CsA) was demonstrated to be an immunomodulation characteristic of T-lymphocyte proliferation and inhibits cytokine gene expression. Moreover, the lipophilic characteristics with poor bioavailability and low solubility in water, besides the side effects, force the need to develop new formulations and devices that will provide adequate penetration into the anterior and posterior segments of the eye. This review aims to summarize the effectiveness and safety of cyclosporine A delivery platforms in veterinary ophthalmology.
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Hasan N, Chawla R, Shaikh N, Kandasamy S, Azad SV, Sundar MD. A comprehensive review of intravitreal immunosuppressants and biologicals used in ophthalmology. Ther Adv Ophthalmol 2022; 14:25158414221097418. [PMID: 35602659 PMCID: PMC9121505 DOI: 10.1177/25158414221097418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 04/11/2022] [Indexed: 12/18/2022] Open
Abstract
Systemic immunosuppressants and biologicals have been a valuable tool in the
treatment of inflammatory diseases and malignancies. The safety profile of these
drugs has been debatable, especially in localized systems, such as the eye. This
has led to the search for fairly local approaches, such as intravitreal,
subconjunctival, and topical route of administration. Immunosuppressants have
been used as a second-line drug in patients intolerable to corticosteroids or
those who develop multiple recurrences on weaning corticosteroids. Similarly,
biologicals have also been used as the next line of therapy, when adequate
control of inflammation could not be attained or immunosuppressants were
contraindicated to patients. Intravitreal immunosuppressants, such as
methotrexate and sirolimus, have been extensively studied in noninfectious
posterior uveitis, whereas limited studies have established the efficacy of
intravitreal biologicals, such as infliximab and adalimumab. Most of these drugs
have shown good safety profile and tolerability in animal studies alone and have
not been studied further in human subjects. However, most of the studies in
literature are single-case reports or case series which limits the level of
evidence. In this comprehensive review, we discuss the mechanism of action,
pharmacodynamics, pharmacokinetics, indications, efficacy, and side effects of
different intravitreal immunosuppressants and biologicals that have been studied
in literature.
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Affiliation(s)
- Nasiq Hasan
- All India Institute of Medical Sciences, New Delhi, New Delhi, India
| | - Rohan Chawla
- Associate Professor, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, New Delhi 110029, India
| | - Nawazish Shaikh
- All India Institute of Medical Sciences, New Delhi, New Delhi, India
| | | | | | - M. Dheepak Sundar
- All India Institute of Medical Sciences, New Delhi, New Delhi, India
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Voelter K, Vial Z, Pot SA, Spiess BM. Leptospiral antibody prevalence and surgical treatment outcome in horses with Equine Recurrent Uveitis (ERU) in Switzerland. Vet Ophthalmol 2020; 23:648-658. [PMID: 32352624 DOI: 10.1111/vop.12767] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 03/30/2020] [Accepted: 03/30/2020] [Indexed: 01/06/2023]
Abstract
OBJECTIVE To evaluate leptospiral antibody prevalence in 65 horses with ERU and compare outcome in 36 surgically treated eyes (2010-2015). PROCEDURES Retrospective data analysis of horses with ERU (n = 65). C-value calculation with microagglutination assay titer (MAT) results for Leptospira spp. Evaluation of follow-up data after pars plana vitrectomy (PPV, n = 21 eyes) and suprachoroidal cyclosporine device implantation (SCDI, n = 15 eyes). Differences between groups were statistically analyzed using Fishers exact test, significance set at P < .05. RESULTS Positive leptospiral titers were found in 28/65 blood, 31/65 aqueous humor (AH), and 19/20 vitreal (post-PPV) samples. The most common intraocular serovars were Leptospira interrogans grippotyphosa, pomona, and bratislava. Intraocular antibody production was suspected in samples of 22 horses (c-values > 1). Mean follow-up of surgical cases was 3.8 years (PPV) and 3.4 years (SCDI). PPV was performed in 21 eyes with positive, SCDI in 15 eyes with negative leptospiral test results. Uveitis recurred less often after PPV (2/21) compared to SCDI (6/15, P = .04). Retinal detachment occurred after PPV only (5/21, SCDI 0/15, P = .06), whereas only SCDI-treated eyes were enucleated (PPV 0/21, SCDI 3/15, P = .06). Blindness or visual impairment was equally likely to occur in both treatment groups after surgery (PPV 7/21, SCDI 7/15, P = .5). CONCLUSIONS Leptospiral antibody prevalence is high in horses with ERU in Switzerland. Recurrence of uveitis is uncommon following PPV in the present study; an increased risk of retinal detachment exists. Enucleation is more often warranted in horses after SCDI in this study due to a higher uveitis recurrence.
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Affiliation(s)
- Katrin Voelter
- Veterinary Ophthalmology, Equine Clinic, Vetsuisse Faculty Zurich, Zurich, Switzerland
| | - Zoe Vial
- Veterinary Ophthalmology, Equine Clinic, Vetsuisse Faculty Zurich, Zurich, Switzerland
| | - Simon A Pot
- Veterinary Ophthalmology, Equine Clinic, Vetsuisse Faculty Zurich, Zurich, Switzerland
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Gilger BC. Immune Relevant Models for Ocular Inflammatory Diseases. ILAR J 2018; 59:352-362. [DOI: 10.1093/ilar/ily002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/18/2018] [Accepted: 01/27/2018] [Indexed: 02/03/2023] Open
Abstract
Abstract
Ocular inflammatory diseases, such as dry eye and uveitis, are common, painful, difficult to treat, and may result in vision loss or blindness. Ocular side effects from the use of antiinflammatory drugs (such as corticosteroids or nonsteroidal antiinflammatories) to treat ocular inflammation have prompted development of more specific and safer medications to treat inflammatory and immune-mediated diseases of the eye. To assess the efficacy and safety of these new therapeutics, appropriate immune-relevant animal models of ocular inflammation are needed. Both induced and naturally-occurring models have been described, but the most valuable for translating treatments to the human eye are the animal models of spontaneous, immunologic ocular disease, such as those with dry eye or uveitis. The purpose of this review is to describe common immune-relevant models of dry eye and uveitis with an overview of the immuno-pathogenesis of each disease and reported evaluation of models from small to large animals. We will also review a selected group of naturally-occurring large animal models, equine uveitis and canine dry eye, that have promise to translate into a better understanding and treatment of clinical immune-relevant ocular disease in man.
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Affiliation(s)
- Brian C Gilger
- Professor of Ophthalmology, Comparative Medicine Institute, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, USA
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McMullen RJ, Fischer BM. Medical and Surgical Management of Equine Recurrent Uveitis. Vet Clin North Am Equine Pract 2017; 33:465-481. [PMID: 28985983 DOI: 10.1016/j.cveq.2017.07.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Equine recurrent uveitis (ERU) is characterized by recurrent bouts of inflammation interrupted by periods of quiescence that vary in duration. There is little consensus on the clinical manifestations, the underlying causes, or the management. The 3 commonly recognized syndromes of ERU (classic, insidious, and posterior) do not accurately separate the clinical manifestations of disease into distinct categories. An accurate diagnosis and early intervention are essential to minimizing the effects of disease and preserving vision. There are multiple medical and surgical options for controlling ERU as long as the disease is recognized early and targeted treatment is initiated immediately.
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Affiliation(s)
- Richard Joseph McMullen
- Department of Clinical Sciences, Auburn University, Auburn University College of Veterinary Medicine, JT Vaughan Large Animal Teaching Hospital, 1500 Wire Road, Auburn, AL 36849-5540, USA.
| | - Britta Maria Fischer
- Large Animal Internal Medicine, Auburn University, Auburn University College of Veterinary Medicine, JT Vaughan Large Animal Teaching Hospital, 1500 Wire Road, Auburn, AL 36849-5540, USA
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Immunological and pathological investigations in equine experimental uveitis. Vet Res Commun 2016; 40:107-115. [DOI: 10.1007/s11259-016-9659-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 06/20/2016] [Indexed: 12/14/2022]
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de Almeida FPP, Saliba JB, Ribeiro JAS, Siqueira RC, Fialho SL, Silva-Cunha A, Jorge R, Messias A. In vivo release and retinal toxicity of cyclosporine-loaded intravitreal device. Doc Ophthalmol 2015; 131:207-14. [PMID: 26576763 DOI: 10.1007/s10633-015-9520-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/02/2015] [Indexed: 10/22/2022]
Abstract
PURPOSE To determine the in vivo release profile and retinal safety of cyclosporine A (CsA) delivered from a biodegradable poly-lactide-co-glycolide (PLGA) device in the vitreous cavity of rabbits' eyes. METHODS A total of 60 animals (60 eyes) divided into two groups were used. For the in vivo release study, 32 eyes received PLGA implants containing 350 µg of CsA, and 16 eyes received the implants without drug (control). Four animals of CsA group and two of the control group were killed weekly until 8 weeks; the vitreous was removed, and CsA concentration was evaluated. Ophthalmological examination was performed in the animals prior to implant placement and weekly during the study period. Electroretinography (ERG) was performed in other six animals for each group, treated and control, at the beginning and at the end of the study (8 weeks) when they were killed and had their eyes processed for histology. RESULTS No sign of inflammation was noticed on slit lamp examinations and the IOP maintained stable during the study period in CsA and control groups. CsA concentration in the vitreous (ng/ml) was 257.07 ± 117.23, 271.15 ± 98.96, 296.66 ± 86.25, 256.27 ± 99.22, 304.50 ± 88.18, 326.35 ± 105.24, 491.25 ± 119.90 and 589.93 ± 132.55 after 1, 2, 3, 4, 5, 6, 7 and 8 weeks of implantation, respectively. At the end of the study, 21.67 % of mass loss was found. The retina did not show any histological alteration in either group, but a significant reduction in dark-adapted b-wave amplitude was observed in the CsA group, with no changes in a-wave amplitude. CONCLUSIONS These data show that the PLGA system is safe, but the selective reduction in ERG b-wave amplitude indicates that the PLGA with 350 µg CsA causes retinal function impairment, specifically on the rod postreceptor pathway, 8 weeks after implantation. These ERG changes were not associated with any histological damage as seen at the light microscopy level.
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Affiliation(s)
- Felipe Piacentini Paes de Almeida
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Jefferson Augusto Santana Ribeiro
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Rubens Camargo Siqueira
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Sílvia L Fialho
- Pharmaceutical Research and Development, Ezequiel Dias Foundation, Belo Horizonte, Brazil
| | - Armando Silva-Cunha
- Faculty of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Rodrigo Jorge
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Andre Messias
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil. .,Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, Avenida Bandeirantes, 3900, Ribeirão Preto, SP, 14049-900, Brazil.
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9
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Malalana F, Stylianides A, McGowan C. Equine recurrent uveitis: Human and equine perspectives. Vet J 2015; 206:22-9. [PMID: 26188862 DOI: 10.1016/j.tvjl.2015.06.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 06/22/2015] [Accepted: 06/30/2015] [Indexed: 12/31/2022]
Abstract
Equine recurrent uveitis (ERU) is a spontaneous disease characterised by repeated episodes of intraocular inflammation. The epidemiology of ERU has not been fully elucidated, but the condition appears to be much more common in horses than is recurrent uveitis in humans, especially in certain breeds and geographical regions. Both humans and horses show a similarly altered immune response and a marked autoimmune response as the primary disease pathophysiology. However, an inciting cause is not always clear. Potential inciting factors in horses include microbial agents such as Leptospira spp. Microbial factors and genetic predisposition to the disease may provide clues as to why the horse appears so susceptible to this disease. The aim of this review is to discuss the immunology and genetics of ERU, compare the disease in horses with autoimmune anterior uveitis in humans, and discuss potential reasons for the increased prevalence in the horse.
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Affiliation(s)
- Fernando Malalana
- The Philip Leverhulme Equine Hospital, The University of Liverpool, Leahurst Campus, Neston, Wirral, CH64 7TE, UK.
| | - Amira Stylianides
- St. Paul's Eye Unit, Royal Liverpool University Hospital, Prescot Street, Liverpool, L7 8XP, UK
| | - Catherine McGowan
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic disease, The University of Liverpool, Leahurst Campus, Neston, Wirral, CH64 7TE, UK
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Edelmann ML, McMullen R, Stoppini R, Clode A, Gilger BC. Retrospective evaluation of phacoemulsification and aspiration in 41 horses (46 eyes): visual outcomes vs. age, intraocular lens, and uveitis status. Vet Ophthalmol 2014; 17 Suppl 1:160-7. [DOI: 10.1111/vop.12185] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Michele L. Edelmann
- College of Veterinary Medicine; North Carolina State University; 1060 William Moore Drive Raleigh NC 27607 USA
- College of Veterinary Medicine; Cornell University Hospital for Animals; 930 Campus Road Ithaca NY 14853 USA
| | - Richard McMullen
- College of Veterinary Medicine; North Carolina State University; 1060 William Moore Drive Raleigh NC 27607 USA
- Pferdeklinik Munich-Riem; Graf-Lehndorf-Street 36 Munich 81929 Germany
| | - Riccardo Stoppini
- Solo Practitioner; Via Belvedere, 17 Calvagese D/R Brescia 25080 Italy
| | - Alison Clode
- College of Veterinary Medicine; North Carolina State University; 1060 William Moore Drive Raleigh NC 27607 USA
| | - Brian C. Gilger
- College of Veterinary Medicine; North Carolina State University; 1060 William Moore Drive Raleigh NC 27607 USA
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11
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Leptospirosis in horses. Vet Microbiol 2013; 167:61-6. [DOI: 10.1016/j.vetmic.2013.04.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 04/04/2013] [Accepted: 04/09/2013] [Indexed: 11/24/2022]
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Verma A, Stevenson B. Leptospiral uveitis - there is more to it than meets the eye! Zoonoses Public Health 2013; 59 Suppl 2:132-41. [PMID: 22958257 DOI: 10.1111/j.1863-2378.2011.01445.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Leptospirosis, caused by pathogenic species of genus Leptospira, is a highly prevalent zoonotic disease throughout many parts of the world, and an important emerging disease within the United States. Uveitis is a common complication of systemic infection in humans. A similar condition in horses is characterized by recurrent bouts of inflammation. In this article, we review advances in our understanding of leptospiral uveitis and its pathogenic mechanisms.
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Affiliation(s)
- A Verma
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY 40536-0298, USA.
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Gilger BC, Stoppini R, Wilkie DA, Clode AB, Pinto NH, Hempstead J, Gerding J, Salmon JH. Treatment of immune-mediated keratitis in horses with episcleral silicone matrix cyclosporine delivery devices. Vet Ophthalmol 2013; 17 Suppl 1:23-30. [DOI: 10.1111/vop.12087] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Brian C. Gilger
- Department of Clinical Sciences; North Carolina State University; 1060 William Moore Drive Raleigh NC 27607 USA
| | | | - David A. Wilkie
- Department of Veterinary Clinical Sciences; The Ohio State University; 601 Vernon Tharp Street Columbus OH 43210 USA
| | - Alison B. Clode
- Department of Clinical Sciences; North Carolina State University; 1060 William Moore Drive Raleigh NC 27607 USA
| | - Nelson H. Pinto
- Department of Clinical Sciences; North Carolina State University; 1060 William Moore Drive Raleigh NC 27607 USA
| | - Julie Hempstead
- Department of Clinical Sciences; North Carolina State University; 1060 William Moore Drive Raleigh NC 27607 USA
| | - Joseph Gerding
- Department of Clinical Sciences; North Carolina State University; 1060 William Moore Drive Raleigh NC 27607 USA
| | - Jacklyn H. Salmon
- Department of Clinical Sciences; North Carolina State University; 1060 William Moore Drive Raleigh NC 27607 USA
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A new drug delivery system inhibits uveitis in an animal model after cataract surgery. Int J Pharm 2013; 443:254-61. [DOI: 10.1016/j.ijpharm.2012.12.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 12/19/2012] [Accepted: 12/20/2012] [Indexed: 11/21/2022]
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15
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Mao HQ, Shipanova-Kadiyala I, Zhao Z, Dang W, Brown A, Leong KW. Biodegradable poly(terephthalate-co-phosphate)s: synthesis, characterization and drug-release properties. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 16:135-61. [PMID: 15794482 PMCID: PMC2376812 DOI: 10.1163/1568562053115426] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To develop biodegradable polymers with favorable physicochemical and biological properties, we have synthesized a series of poly(terephthalate-co-phosphate)s using a two-step poly-condensation. The diol 1,4-bis(2-hydroxyethyl) terephthalate was first reacted with ethylphosphorodichloridate (EOP), and then chain-extended with terephthaloyl chloride (TC). Incorporation of phosphate into the poly(ethylene terephthalate) backbone rendered the co-polymers soluble in chloroform and biodegradable, lowered the Tg, decreased the crystallinity and increased the hydrophilicity. With an EOP/TC molar feed ratio of 80: 20, the polymer exhibited good film-forming property, yielding at 86.6 +/- 1.6% elongation with an elastic modulus of 13.76 +/- 2.66 MPa. This polymer showed a favorable toxicity profile in vitro and good tissue biocompatibility in the muscular tissue of mice. In vitro the polymer lost 21% of mass in 21 days, but only 20% for up to 4 months in vivo. It showed no deterioration of properties after sterilization by gamma-irradiation at 2.5 Mrad on solid CO2. Release of FITC-BSA from the microspheres was diffusion-controlled and exceeded 80% completion in two days. Release of the hydrophobic cyclosporine-A from microspheres was however much more sustained and near zero-ordered, discharging 60% in 70 days. A limited structure-property relationship has been established for this co-polymer series. The co-polymers became more hydrolytically labile as the phosphate component (EOP) was increased and the side chains were switched from the ethoxy to the methoxy structure. Converting the methoxy group to a sodium salt further increased the degradation rate significantly. The chain rigidity as reflected in the Tg values of the co-polymers decreased according to the following diol structure in the backbone: ethylene glycol > 2-methylpropylene diol > 2,2-dimethylpropylene diol. The wide range of physicochemical properties obtainable from this co-polymer series should help the design of degradable biomaterials for specific biomedical applications.
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Affiliation(s)
- Hai-Quan Mao
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, 726 Ross Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, 102 Maryland Hall, 3400 N. Charles Street, MD 21218, USA
| | - Irina Shipanova-Kadiyala
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, 726 Ross Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - Zhong Zhao
- Guilford Pharmaceuticals Inc., 6611 Tributary Street, Baltimore, MD 21224, USA
| | - Wenbin Dang
- Guilford Pharmaceuticals Inc., 6611 Tributary Street, Baltimore, MD 21224, USA
| | - Angela Brown
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, 726 Ross Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
| | - Kam W. Leong
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, 726 Ross Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
- To whom correspondence should be addressed. Tel.: (1-410) 614-3741. Fax: (1-410) 955-0549. E-mail:
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Mathes RL, Burdette EL, Moore PA, Myrna KE. Concurrent clinical intraocular findings in horses with depigmented punctate chorioretinal foci. Vet Ophthalmol 2011; 15:81-5. [DOI: 10.1111/j.1463-5224.2011.00940.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
This review covers both noninvasive and invasive ophthalmic drug delivery systems that can have application to therapy of veterinary ophthalmic diseases. Noninvasive approaches include gel technologies, permeation enhancement via pro-drug development, solubilization agents and nanoparticle technologies, iontophoresis, microneedles, drug-eluting contact lenses and eye misters, and microdroplets. More invasive systems include both eroding implants and noneroding technologies that encompass diffusion based systems, active pumps, intraocular lenses, suprachoroidal drug delivery, and episcleral reservoirs. In addition to addressing the physiologic challenges of achieving the necessary duration of delivery, tissue targeting and patient compliance, the commercial development factors of biocompatibility, sterilization, manufacturability and long-term stability will be discussed.
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Choonara YE, Pillay V, Danckwerts MP, Carmichael TR, du Toit LC. A review of implantable intravitreal drug delivery technologies for the treatment of posterior segment eye diseases. J Pharm Sci 2010; 99:2219-39. [PMID: 19894268 DOI: 10.1002/jps.21987] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Intravitreal implantable device technology utilizes engineered materials or devices that could revolutionize the treatment of posterior segment eye diseases by affording localized drug delivery, responding to and interacting with target sites to induce physiological responses while minimizing side-effects. Conventional ophthalmic drug delivery systems such as topical eye-drops, systemic drug administration or direct intravitreal injections do not provide adequate therapeutic drug concentrations that are essential for efficient recovery in posterior segment eye disease, due to limitations posed by the restrictive blood-ocular barriers. This review focuses on various aspects of intravitreal drug delivery such as the impediment of the blood-ocular barriers, the potential sites or intraocular drug delivery device implantation, the various approaches employed for ophthalmic drug delivery and includes a concise critical incursion into specialized intravitreal implantable technologies for the treatment of anterior and posterior segment eye disease. In addition, pertinent future challenges and opportunities in the development of intravitreal implantable devices is discussed and explores their application in clinical ophthalmic science to develop innovative therapeutic modalities for the treatment of various posterior segment eye diseases. The inherent structural and functional properties, the potential for providing rate-modulated drug delivery to the posterior segment of the eye and specific development issues relating to various intravitreal implantable drug delivery devices are also expressed in this review.
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Affiliation(s)
- Yahya E Choonara
- Department of Pharmacy and Pharmacology, University of the Witwatersrand, 7 York Road, Parktown, 2193, Johannesburg, Gauteng, South Africa
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Abstract
Equine recurrent uveitis (ERU) is a disease with high prevalence and relevance for the equine population, since it results in blindness. Over the last decade, important advancements have been made in our understanding of the underlying immune responses in this disease. ERU is mediated by an autoaggressive Th1 response directed against several retinal proteins. Interphotoreceptor-retinoid binding protein (IRBP) and cellular retinaldehyde-binding protein (CRALBP) are capable to induce ERU-like disease in experimental horses, with the unique possibility to activate relapses in a well-defined manner. Further, proteomic evidence now suggests that retinal Mueller glial cells (RMG) may play a fatal role in uveitic disease progression by directly triggering inflammation processes through the expression and secretion of interferon-gamma. Ongoing relapses in blind eyes can be associated with stable expression of the major autoantigens in ERU retinas. This review briefly summarizes the most significant developments in uveitis immune response research.
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Affiliation(s)
- Cornelia A Deeg
- Institute of Animal Physiology, LMU Munich, Munich, Germany.
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Alpha-tocopherol protects against oxidative damage to lipids of the rod outer segments of the equine retina. Vet J 2008; 182:463-8. [PMID: 18829353 DOI: 10.1016/j.tvjl.2008.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 06/30/2008] [Accepted: 08/13/2008] [Indexed: 01/12/2023]
Abstract
Oxidative stress is a possible risk factor for eye diseases. Lipid peroxidation is one of the major events induced by oxidative stress and is particularly active in polyunsaturated fatty acid (PUFA)-rich biomembranes. This work evaluated endogenous lipid antioxidants, in vitro non-enzymatic lipid peroxidation of rod outer segment membranes (ROS), the fatty acid composition during oxidative damage of total lipids from equine retina and ROS, and the protective action of alpha-tocopherol (alpha-Toc). The major lipid soluble antioxidant was alpha-Toc followed by retinoids and carotenoids. The retina contained a high percentage of PUFAs, mainly docosahexaenoic acid (22:6n-3) and arachidonic acid (20:4n-6). Lipid peroxidation of the equine ROS, induced by Fe(2+)-ascorbate, was monitored using chemiluminescence (CL) with or without pre-treatment with alpha-Toc. With alpha-Toc pre-treatment, CL values were significantly decreased. The most abundant fatty acid was 22:6n-3. After 3h incubation, 95% of total PUFAs were destroyed by peroxidation, whereas in alpha-Toc pre-treated ROS the percentage was significantly decreased. The results show that the retina has an endogenous lipid soluble antioxidant system. ROS were highly sensitive to oxidative damage, since their fatty acid composition was markedly modified during the lipid peroxidation process. The protective role of alpha-Toc as an antioxidant was evident and it could be used in the treatment of equine ocular diseases in which free radicals are involved.
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Gasthuys F, Pockelé K, Vervaet C, Weyenberg W, De Prijck K, Pille F, Vlaminck L, Nelis H, Remon JP. Evaluation of the in vivo behaviour of gentamicin sulphate ocular mini-tablets in ponies. J Vet Pharmacol Ther 2007; 30:470-6. [PMID: 17803741 DOI: 10.1111/j.1365-2885.2007.00890.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The in vivo behaviour of 5% gentamicin sulphate ocular mini-tablets (2-mm diameter, 6.525 mg weight) was compared with gentamicin eye drops in six ponies. Two mini-tablets were inserted on the bulbar conjunctiva of the right eye while a similar dose of gentamicin was administered via eye drops in the left eye. Irritation induced by the mini-tablets and the eye drops was evaluated using a visual analogue scale (0-10). Tears were sampled with ophthalmologic absorption triangles for 1 min for the determination of the concentration of gentamicin sulphate using a microbiological plate diffusion method. Irritation induced by the tablets was minor and clinically acceptable (overall median score of 1.7 +/- 1.4). Eye drops induced a sharp increase in gentamicin sulphate concentration (364.4 microg/mL after 5 min) followed by a fast decline (10.8 microg/mL after 60 min). The increase in concentration induced by the ocular mini-tablets was less pronounced (up to 56.2 microg/mL after 30 min) and followed by a gradual decrease; the concentration remained above 15 microg/mL for 8 h. Ocular 5% gentamicin sulphate mini-tablets are clinically well-tolerated in ponies, assuring a constant concentration in the tears for at least 8 h.
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Affiliation(s)
- F Gasthuys
- Department of Surgery and Anaesthesiology of Domestic animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
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He Y, Wang JC, Liu YL, Ma ZZ, Zhu XA, Zhang Q. Therapeutic and toxicological evaluations of cyclosporine a microspheres as a treatment vehicle for uveitis in rabbits. J Ocul Pharmacol Ther 2006; 22:121-31. [PMID: 16722798 DOI: 10.1089/jop.2006.22.121] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
AIM This study was undertaken to investigate the therapeutic efficacy and the toxicity of the intravitreal biodegradable poly(dl-lactide-co-glycolide)co-polymer microspheres containing cyclosporin A (CsA-PLGA-MS) on experimental uveitis in rabbits. METHODS CsA-PLGA-MS that had been prepared by a solvent evaporation approach were characterized for morphology, particle size, entrapment efficiency, and in vitro release profile of CsA-PLGA-MS. Therapeutic efficacy of the CsA-PLGA-MS was evaluated by scoring of the inflammation, aqueous leukocyte counting, aqueous protein determination, and histological examination in the experimental rabbits with artificial uveitis induced by the injection of lipopolysaccharide. The toxicity was investigated by slit-lamp examination, indirect ophthalmoscopy, and electroretinography (ERG) in the noninflamed rabbit eye. RESULTS The CsA-PLGA-MS were spherical in shape, with an average particle size of nearly 50 microm and an entrapment efficiency of more than 80%. The compositions of the formulation that was most effective in the in vivo studies included CsA, PLGA, and 3% Pluronic F68. In vitro released cyclosporine A from the optimized microspheres was approximately 25% during the 60-day incubation at 37 degrees C. It was demonstrated that the intravitreal injection of the optimized CsA-PLGA-MS decreased significantly the severity of the inflammatory signs, cellular infiltrate, aqueous leukocyte counts, and protein levels in the eyes of experimental rabbits with uveitis, compared to other formulations. Also, the preparation did not cause obvious toxicity in the noninflamed eyes of rabbits, except that the ERG b-wave amplitude for the test eyes was reversibly depressed, compared to those of the control eyes at 2 weeks, which almost recovered at the end of 6 weeks. CONCLUSIONS The CsA-PLGA-MS preparation might be useful in the treatment of patients with severe chronic posterior uveitis who cannot tolerate systemic or periocular therapy.
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Affiliation(s)
- Yuan He
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
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Gerard MP, Wotman KL, Komáromy AM. Infections of the Head and Ocular Structures in the Horse. Vet Clin North Am Equine Pract 2006; 22:591-631, x-xi. [PMID: 16882488 DOI: 10.1016/j.cveq.2006.03.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Infectious conditions of the equine head are commonly encountered in clinical practice. Pathogenic bacterial, viral, and fungal organisms may localize in the extensive nasal passages, paranasal sinuses, and guttural pouches, creating a range of clinical signs and conditions that can be severe enough to lead to unexpected fatality. Renewed interest in equine dentistry has led to a greater recognition of dental disease that is associated with infection. This article focuses on bacterial and fungal infections of the main anatomic regions of the equine head, where advances in diagnosis and management have been made or consolidated in recent years. It also addresses recent advances made in the area of infectious equine corneal disease, including bacterial, viral, and fungal etiologies. Recent developments in equine recurrent uveitis as it relates to infectious diseases and ocular manifestations of systemic disease are also discussed.
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Affiliation(s)
- Mathew P Gerard
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606, USA.
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Dong X, Shi W, Yuan G, Xie L, Wang S, Lin P. Intravitreal implantation of the biodegradable cyclosporin A drug delivery system for experimental chronic uveitis. Graefes Arch Clin Exp Ophthalmol 2005; 244:492-7. [PMID: 16163496 DOI: 10.1007/s00417-005-0109-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Accepted: 08/03/2005] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The purpose was to evaluate the efficacy of the intravitreal implantation of the biodegradable cyclosporin A (CsA) drug delivery system (DDS) for experimental chronic uveitis. METHODS The DDS was prepared by formulating CsA into glycolide-co-lactide-co-caprolactone copolymer (PGLC). Right eyes of 30 New Zealand white rabbits were used to establish a model of uveitis and randomized into control, intravitreal non-medicated DDS, oral CsA (15 mg/kg daily), and intravitreal CsA-PGLC DDS (each containing 2 mg CsA) groups. The progress of ocular inflammation, results of electroretinography, and histopathological examination of ocular, renal, and hepatic functions were recorded. Intravitreal CsA levels were measured in another 13 rabbits receiving an implant of the CsA-PGLC DDS. RESULTS Chronic uveitis was successfully induced in all 30 eyes. The inflammation in the eyes with no treatment, non-medicated implant, and oral CsA was more severe than those with the CsA-PGLC DDS at each timepoint. The electroretinography b-wave was depressed much less in the CsA-PGLC DDS group than in the other three groups (p<0.05). No renal or hepatic tissue damage was found in eyes with the CsA-PGLC DDS. The mean intravitreal CsA level was 102.2~145.5 ng/ml at 1~3 weeks after CsA-PGLC DDS implantation, 491.0~575.2 ng/ml at 4~10 weeks, and 257.3 ng/ml at 14 weeks; no toxicity was detected. CONCLUSION Intravitreal implantation of the biodegradable CsA-PGLC DDS may effectively reduce the intraocular inflammation in rabbits with no toxicity, which provides a potentially safe and convenient approach for the treatment of chronic uveitis.
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Gilger BC, Reeves KA, Salmon JH. Ocular parameters related to drug delivery in the canine and equine eye: aqueous and vitreous humor volume and scleral surface area and thickness. Vet Ophthalmol 2005; 8:265-9. [PMID: 16008707 DOI: 10.1111/j.1463-5224.2005.00401.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To measure the ocular surface area, scleral thickness, and the aqueous and vitreous humor volumes in the canine and equine eye. Animals studied Fourteen canine and 16 equine cadaver eyes. PROCEDURE Eyes were measured either fresh or following fixation in formalin. Ocular surface area was calculated using the fluid displacement method. Globes were hemisected and aqueous and vitreous humor were collected and quantitated. Scleral thickness was measured by digital caliper, by image projection, and by ultrasonic biomicroscopy (UBM). RESULTS Mean +/- standard deviation (SD) scleral surface areas in canine and equine eyes were 12.87 +/- 2.24 and 57.23 +/- 5.63 cm2, respectively. Mean +/- SD aqueous humor volume was 0.77 +/- 0.24 in the dog and 3.04 +/- 1.27 mL in the horse. Mean vitreous humor volume was 1.7 +/- 0.86 mL for the canine eye and 26.15 +/- 4.87 mL for the equine eye. In canine and equine eyes, the sclera was thinnest at the ocular equator: 0.34 +/- 0.13 mm (canine) and 0.53 +/- 0.1 (equine). There were no significant differences between the direct caliper and projected thickness measurements or differences between measurements in the superior, inferior, nasal, and temporal quadrants of the eye. Scleral thickness in fresh tissue was greater than in fixed tissue at most sites. CONCLUSIONS The UBM measurement method appeared to be most consistent and reproducible when compared to direct measurement techniques. Formalin fixation of the eyes was associated with significantly thinner scleral tissue than with fresh ocular tissue.
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Affiliation(s)
- Brian C Gilger
- College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.
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Gilger BC, Michau TM. Equine recurrent uveitis: new methods of management. Vet Clin North Am Equine Pract 2004; 20:417-27, vii. [PMID: 15271431 DOI: 10.1016/j.cveq.2004.04.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Equine recurrent uveitis (ERU) is one of the most common causes of blindness in horses. Until recently, treatment of this condition consisted only of symptomatic therapy, typically with steroidal and nonsteroidal medications. A better understanding of the disease process(es) has permitted new medical and surgical therapies that have recently been described. This article highlights clinical features of ERU, the causes of ERU, and new management and treatment options for horses with ERU.
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Affiliation(s)
- Brian C Gilger
- Department of Ophthalmology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.
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Lallemand F, Felt-Baeyens O, Besseghir K, Behar-Cohen F, Gurny R. Cyclosporine A delivery to the eye: a pharmaceutical challenge. Eur J Pharm Biopharm 2004; 56:307-18. [PMID: 14602172 DOI: 10.1016/s0939-6411(03)00138-3] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Systemic administration of cyclosporine A (CsA) is commonly used in the treatment of local ophthalmic conditions involving cytokines, such as corneal graft rejection, autoimmune uveitis and dry eye syndrome. Local administration is expected to avoid the various side effects associated with systemic delivery. However, the currently available systems using oils to deliver CsA topically are poorly tolerated and provide a low bioavailability. These difficulties may be overcome through formulations aimed at improving CsA water solubility (e.g. cyclodextrins), or those designed to facilitate tissue drug penetration using penetration enhancers. The use of colloidal carriers (micelles, emulsions, liposomes and nanoparticles) as well as the approach using hydrosoluble prodrugs of CsA have shown promising results. Solid devices such as shields and particles of collagen have been investigated to enhance retention time on the eye surface. Some of these topical formulations have shown efficacy in the treatment of extraocular diseases but were inefficient at reaching intraocular targets. Microspheres, implants and liposomes have been developed to be directly administered subconjunctivally or intravitreally in order to enhance CsA concentration in the vitreous. Although progress has been made, there is still room for improvement in CsA ocular application, as none of these formulations is ideal.
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Affiliation(s)
- F Lallemand
- School of Pharmacy, University of Geneva, Geneva, Switzerland
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Abstract
This article highlights factors that must be kept in mind when dealing with species other than cats, dogs, and horses. Diseases of the eye are similar regardless of whether they occur in humans or domestic or exotic species. There are unique conditions in exotic species that reflect differences in anatomy, physiology, pharmacology, and pathophysiology compared with domestic species.
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Affiliation(s)
- Nicholas J Millichamp
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Texas A&M University, College Station, TX 77843, USA.
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Smith JR, Rosenbaum JT. Management of uveitis: a rheumatologic perspective. ARTHRITIS AND RHEUMATISM 2002; 46:309-18. [PMID: 11840433 DOI: 10.1002/art.503] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Justine R Smith
- Casey Eye Institute, Oregon Health Sciences University, 3375 Terwilliger Blvd., Portland, OR 97201-4197, USA.
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Gilger BC, Wilkie DA, Davidson MG, Allen JB. Use of an intravitreal sustained-release cyclosporine delivery device for treatment of equine recurrent uveitis. Am J Vet Res 2001; 62:1892-6. [PMID: 11763177 DOI: 10.2460/ajvr.2001.62.1892] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the use of an intravitreal sustained-release cyclosporine (CsA) delivery device for treatment of horses with naturally occurring recurrent uveitis. ANIMALS 16 horses with recurrent uveitis. PROCEDURES Horses with frequent recurrent episodes of uveitis or with disease that was progressing despite appropriate medication were selected for this study. Additional inclusion criteria included adequate retinal function as determined by use of electroretinography, lack of severe cataract formation, and no vision-threatening ocular complications (eg, retinal detachment, severe retinal degeneration, and posterior synechia). Sustained-release CsA delivery devices (4 microg of CsA/d) were implanted into the vitreous through a sclerotomy at the pars plana. Reexaminations were performed 1, 3, 6, and 12 months after implantation, then continued annually. Ophthalmic changes, number of recurrent episodes of uveitis, and vision were recorded. RESULTS The rate of recurrent episodes after device implantation (0.36 episodes/y) was less than prior to surgery (75 episodes/y). In addition, only 3 horses developed episodes of recurrent uveitis after surgery. Vision was detected in 14 of 16 affected eyes at a mean follow-up time of 13.8 months (range, 6 to 24 months). CONCLUSIONS AND CLINICAL RELEVANCE This intravitreal sustained-release CsA delivery device may be a safe and important tool for long-term treatment of horses with chronic recurrent uveitis.
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Affiliation(s)
- B C Gilger
- Comparative Ophthalmology Research Laboratories, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA
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