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Arana E, Gonzalo A, Andollo N, Goñi-de-Cerio F, Gómez-Fernández P, Salado C, Hernández G, Suárez-Cortés T. The new preservative-free ophthalmic formulation of bilastine 0.6% preserves the ocular surface epithelial integrity in a comparative in vitro study. Sci Rep 2024; 14:9598. [PMID: 38671063 PMCID: PMC11053002 DOI: 10.1038/s41598-024-59190-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
Allergic conjunctivitis (AC) is the most common form of allergic eye disease and an increasingly prevalent condition. Topical eye drop treatments are the usual approach for managing AC, although their impact on the ocular surface is not frequently investigated. The aim of this study was to perform a comparative physicochemical characterization, and in vitro biological evaluations in primary conjunctival and corneal epithelial cells of the new multidose preservative-free bilastine 0.6% and main commercially available eye drops. MTT assay was used to measure cell viability; oxidative stress was analyzed with a ROS-sensitive probe; and apoptosis was evaluated monitoring caspase 3/7 activation. Differences in pH value, osmolarity, viscosity and phosphate levels were identified. Among all formulations, bilastine exhibited pH, osmolarity and viscosity values closer to tear film (7.4, 300 mOsm/l and ~ 1.5-10 mPa·s, respectively), and was the only phosphates-free solution. Single-dose ketotifen did not induce ROS production, and single-dose azelastine and bilastine only induced a mild increase. Bilastine and single-dose ketotifen and azelastine showed high survival rates attributable to the absence of preservative in its formulation, not inducing caspase-3/7-mediated apoptosis after 24 h. Our findings support the use of the new bilastine 0.6% for treating patients with AC to preserve and maintain the integrity of the ocular surface.
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Affiliation(s)
- Eider Arana
- Research, Development and Innovation Department (R&D+I Department), Faes Farma, Av. Autonomía 10, 48940, Leioa, Bizkaia, Spain
- Department of Cell Biology and Histology, School of Medicine and Nursing, University of the Basque Country, Leioa, Spain
| | - Ana Gonzalo
- Research, Development and Innovation Department (R&D+I Department), Faes Farma, Av. Autonomía 10, 48940, Leioa, Bizkaia, Spain
| | - Noelia Andollo
- Department of Cell Biology and Histology, School of Medicine and Nursing, University of the Basque Country, Leioa, Spain
- Biobizkaia Health Research Institute, Barakaldo, Spain
| | - Felipe Goñi-de-Cerio
- Biotechnology Area, GAIKER Technology Centre, Basque Research and Technology Alliance, Zamudio, Spain
| | - Paloma Gómez-Fernández
- Biotechnology Area, GAIKER Technology Centre, Basque Research and Technology Alliance, Zamudio, Spain
| | - Clarisa Salado
- Innoprot SL, Bizkaia Technology Park, Derio, Bizkaia, Spain
| | - Gonzalo Hernández
- Research, Development and Innovation Department (R&D+I Department), Faes Farma, Av. Autonomía 10, 48940, Leioa, Bizkaia, Spain
| | - Tatiana Suárez-Cortés
- Research, Development and Innovation Department (R&D+I Department), Faes Farma, Av. Autonomía 10, 48940, Leioa, Bizkaia, Spain.
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Glasco DL, Ho NHB, Mamaril AM, Bell JG. 3D Printed Ion-Selective Membranes and Their Translation into Point-of-Care Sensors. Anal Chem 2021; 93:15826-15831. [PMID: 34812620 DOI: 10.1021/acs.analchem.1c03762] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This technical note describes a method for fabricating ion-selective membranes (ISMs) for use in potentiometric sensing by using 3D printing technology. Here, we demonstrate the versatility of this approach by fabricating ISMs and investigating their performance in both liquid-contact and solid-contact ion-selective electrode (ISE) configurations. Using 3D printed ISMs resulted in highly stable (drift of ∼17 μV/h) and highly reproducible (<1 mV deviation) measurements. Furthermore, we show the seamless translation of these membranes into reliable, carbon fiber- and paper-based potentiometric sensors for applications at the point-of-care. To highlight the modifiability of this approach, we fabricated sensors for bilirubin, an important biomarker of liver health; benzalkonium, a common preservative used in the pharmaceutical industry; and potassium, an important blood electrolyte. The ability to mass produce sensors using 3D printing is an attractive advantage over conventional methods, while also decreasing the time and cost associated with sensor fabrication.
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Affiliation(s)
- Dalton L Glasco
- Department of Chemistry, Washington State University, Pullman, Washington 99163, United States
| | - Nguyen H B Ho
- Department of Chemistry, Washington State University, Pullman, Washington 99163, United States
| | - Art Matthew Mamaril
- Department of Chemistry, Washington State University, Pullman, Washington 99163, United States
| | - Jeffrey G Bell
- Department of Chemistry, Washington State University, Pullman, Washington 99163, United States
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Sedlak L, Świerczyńska M, Borymska W, Zych M, Wyględowska-Promieńska D. Impact of dorzolamide, benzalkonium-preserved dorzolamide and benzalkonium-preserved brinzolamide on selected biomarkers of oxidative stress in the tear film. BMC Ophthalmol 2021; 21:319. [PMID: 34470600 PMCID: PMC8411550 DOI: 10.1186/s12886-021-02079-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 08/14/2021] [Indexed: 11/26/2022] Open
Abstract
Background Long-term use of topical, especially benzalkonium chloride (BAC)-preserved, antiglaucoma medications can cause a negative impact on the ocular surface. The aim of the study was to assess the effect of topical carbonic anhydrase inhibitors (CAIs) on selected oxidative stress biomarkers in the tear film. Methods The patients were divided into four sex-matched groups: group C (n = 25) – control group – subjects who did not use topical antiglaucoma medications, group DL (n = 14) – patients using preservative-free dorzolamide, group DL + BAC (n = 16) – patients using topical BAC-preserved dorzolamide, group BL + BAC (n = 17) – patients using BAC-preserved brinzolamide. Subjects in all the study groups have been using the eye drops two times daily for 6–12 months. The oxidative stress biomarkers in the tear film samples were measured: total protein (TP) concentration, advanced oxidation protein products (AOPP) content, total sulfhydryl (-SH) groups content, the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as Total Oxidant Status (TOS), Total Antioxidant Response (TAR), and Oxidative Stress Index (OSI). Results The advanced oxidation protein products content, Total Oxidant Status as well as superoxide dismutase and catalase activities in the group DL + BAC and BL + BAC were higher in comparison with the group C. The total sulfhydryl groups content was lower in the group DL + BAC and BL + BAC when compared to group C. Oxidative Stress Index was higher in the groups DL + BAC and BL + BAC in comparison with the groups DL and C. Conclusions Use of topical benzalkonium chloride-preserved carbonic anhydrase inhibitors increases oxidative stress in the tear film.
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Affiliation(s)
- Lech Sedlak
- Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland.,Department of Ophthalmology, Kornel Gibiński University Clinical Center, Medical University of Silesia in Katowice, Katowice, Poland
| | - Marta Świerczyńska
- Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland. .,Department of Ophthalmology, Kornel Gibiński University Clinical Center, Medical University of Silesia in Katowice, Katowice, Poland.
| | - Weronika Borymska
- Department of Pharmacognosy and Phytochemistry, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia in Katowice, Sosnowiec, Poland
| | - Maria Zych
- Department of Pharmacognosy and Phytochemistry, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia in Katowice, Sosnowiec, Poland
| | - Dorota Wyględowska-Promieńska
- Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland.,Department of Ophthalmology, Kornel Gibiński University Clinical Center, Medical University of Silesia in Katowice, Katowice, Poland
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Walsh K, Jones L. The use of preservatives in dry eye drops. Clin Ophthalmol 2019; 13:1409-1425. [PMID: 31447543 PMCID: PMC6682755 DOI: 10.2147/opth.s211611] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/03/2019] [Indexed: 12/14/2022] Open
Abstract
Topical ocular preparations are widely recommended by health care professionals, or chosen by patients, to help manage dry eye disease (DED). The chronic and progressive nature of DED may result in the administration of topical products several times a day, over a period of many years. Given DED is a condition that by definition affects the ocular surface, it is important to understand how the repeated use of eye drops may impact the ocular surface, influence clinical signs, affect symptoms, and impact the overall disease process of dry eye. The component in topical preparations with the greatest potential to adversely affect the ocular surface is the preservative. This paper reviews the literature in relation to the use of preservatives in formulations for dry eye. The ocular effects of benzalkonium chloride (BAK) are summarised and compared to the performance of alternative preservatives and preservative-free formulations. Use of preserved and preservative-free drops in relation to the management of varying stages of DED is discussed.
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Affiliation(s)
- Karen Walsh
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, N2L 3G1, Canada
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, N2L 3G1, Canada
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Marek V, Mélik-Parsadaniantz S, Villette T, Montoya F, Baudouin C, Brignole-Baudouin F, Denoyer A. Blue light phototoxicity toward human corneal and conjunctival epithelial cells in basal and hyperosmolar conditions. Free Radic Biol Med 2018; 126:27-40. [PMID: 30040995 DOI: 10.1016/j.freeradbiomed.2018.07.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/12/2018] [Accepted: 07/19/2018] [Indexed: 12/28/2022]
Abstract
AIMS The ocular surface is the very first barrier between the visual system and external environment. It protects the eye from the exposure to various light sources that significantly emit in blue spectrum. However, the impact of blue light on the ocular surface has been poorly explored so far. In this study, we investigated in vitro the phototoxicity of blue light illumination in human epithelial cells of the ocular surface. We worked either in basal conditions or under hyperosmolar stress, in order to mimic dry eye disease (DED) that is the most common disease involving the ocular surface. RESULTS Corneal and conjunctival epithelial cells suffered the most from violet-blue light but also from longer-wave blue light. Exposure to blue wavebands significantly decreased cellular viability, impacted on cellular morphology and provoked reactive oxygen species (ROS) over-production. Conjunctival epithelial cell line had a greater photosensitivity than the corneal epithelial one. Hyperosmolar stress potentiated the blue light phototoxicity, increasing inflammation, altering mitochondrial membrane potential, and triggering the glutathione-based antioxidant system. INNOVATION In human epithelial corneal and conjunctival cells of the ocular surface, we demonstrated the harmful impact of blue light on viability, redox state and inflammation processes, which was modified by hyperosmolarity. CONCLUSION Blue light induced cell death and significant ROS production, and altered the expression of inflammatory genes and operation of the cellular defensive system. We established for the first time that hyperosmolar stress impacted phototoxicity, further suggesting that DED patients might be more sensitive to blue light ocular toxicity.
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Affiliation(s)
- Veronika Marek
- Essilor International, R&D Department, Paris, France; Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France.
| | | | | | - Fanny Montoya
- Essilor International, R&D Department, Paris, France
| | - Christophe Baudouin
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris, France; Versailles-Saint-Quentin-en-Yvelines Université, Versailles, France
| | - Françoise Brignole-Baudouin
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris, France; Sorbonne Paris Cité - Paris Descartes Université, Faculté de Pharmacie de Paris, Département de Toxicologie, Paris, France
| | - Alexandre Denoyer
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris, France; CHU Robert Debré, Université Reims Champagne-Ardenne, Reims, France
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Abstract
Prostaglandins are approved by the European Glaucoma Society guidelines as first-line treatment for glaucoma. This review focuses on latanoprost, an ester prodrug of prostaglandin (PG) F2α, which was the first of the currently available topical PGF2α analogs to be launched for glaucoma or ocular hypertension and which still accounts for the majority of prescriptions. It is better absorbed than the parent compound through the cornea, and peak concentration of the active drug is in the aqueous humor 1–2 hours after topical dosing (15–30 ng/mL). Metabolism occurs mainly in the liver. Latanoprost (0.005%) has been very well studied in clinical trials and meta-analyses that show it to be generally as effective as the other PG analogs (bimatoprost, travoprost, and tafluprost) and more effective than timolol, dorzolamide, and brimonidine. Latanoprost has good short- and long-term safety and tolerability profiles. In common with other prostaglandins, it lacks systemic effects, but can cause ocular adverse events such as conjunctival hyperemia, pigmentation of the iris, periocular skin or eyelashes, hypertrichosis, and ocular surface effects or irritation. Latanoprost is significantly better tolerated than either bimatoprost or travoprost. Patients treated with latanoprost have better compliance and persist with therapy longer than those that are given other drugs. An improved formulation of latanoprost without the preservative benzalkonium chloride has recently been developed. It is as effective as conventional latanoprost, has a lower incidence of hyperemia, and can be stored at room temperature. In conclusion, latanoprost has the best efficacy–tolerability ratio of the PG analogs available for glaucoma treatment, and has good compliance and persistence. These factors should be improved further by the recent development of preservative-free latanoprost.
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Affiliation(s)
- Albert Alm
- Department of Neuroscience, Ophthalmology, University Hospital, Uppsala, Sweden
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Xu M, Sivak JG, McCanna DJ. Comparison of the Effects of Ophthalmic Solutions on Human Corneal Epithelial Cells Using Fluorescent Dyes. J Ocul Pharmacol Ther 2013; 29:794-802. [DOI: 10.1089/jop.2013.0002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Manlong Xu
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Jacob G. Sivak
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - David J. McCanna
- Centre for Contact Lens Research, Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
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McGinnigle S, Eperjesi F, Naroo SA. A preliminary investigation into the effects of ocular lubricants on higher order aberrations in normal and dry eye subjects. Cont Lens Anterior Eye 2013; 37:106-10. [PMID: 24075240 DOI: 10.1016/j.clae.2013.08.156] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 08/22/2013] [Accepted: 08/26/2013] [Indexed: 11/28/2022]
Abstract
PURPOSE To study the effects of ocular lubricants on higher order aberrations in normal and self-diagnosed dry eyes. METHODS Unpreserved hypromellose drops, Tears Again™ liposome spray and a combination of both were administered to the right eye of 24 normal and 24 dry eye subjects following classification according to a 5 point questionnaire. Total ocular higher order aberrations, coma, spherical aberration and Strehl ratios for higher order aberrations were measured using the Nidek OPD-Scan III (Nidek Technologies, Gamagori, Japan) at baseline, immediately after application and after 60 min. The aberration data were analyzed over a 5mm natural pupil using Zernike polynomials. Each intervention was assessed on a separate day and comfort levels were recorded before and after application. Corneal staining was assessed and product preference recorded after the final measurement for each intervention. RESULTS Hypromellose drops caused an increase in total higher order aberrations (p=<0.01 in normal and dry eyes) and a reduction in Strehl ratio (normal eyes: p=<0.01, dry eyes p=0.01) immediately after instillation. There were no significant differences between normal and self-diagnosed dry eyes for response to intervention and no improvement in visual quality or reduction in higher order aberrations after 60 min. Differences in comfort levels failed to reach statistical significance. CONCLUSION Combining treatments does not offer any benefit over individual treatments in self-diagnosed dry eyes and no individual intervention reached statistical significance. Symptomatic subjects with dry eye and no corneal staining reported an improvement in comfort after using lubricants.
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Affiliation(s)
| | - Frank Eperjesi
- School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK
| | - Shehzad A Naroo
- School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK.
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Lim SA, Hwang KY, Chung SH. Niflumic Acid Reduces Histamine-Induced Interleukin-6 and -8 Expression in Human Conjunctival Epithelial Cells. Ophthalmic Res 2013; 50:192-6. [DOI: 10.1159/000354177] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 07/04/2013] [Indexed: 11/19/2022]
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Abstract
Benzalkonium chloride (BAK) is the principal preservative employed in topical ocular hypotensive medications, although alternative compounds recently have begun to be employed or examined. Individual clinical trials have shown that exposure to BAK concentrations contained in ophthalmic solutions does not produce adverse sequelae in the majority of glaucoma patients, but concerns continue with regard to its long-term use. These concerns have resulted from an extensive research effort, including preclinical studies with in vitro and in vivo models, as well as recent clinical investigations dedicated specifically to this issue. The aim of this systematic literature review of both preclinical and clinical data was to determine the relevance of these findings to clinical practice. Most preclinical studies reported negative effects of BAK exposure, but with few exceptions, BAK concentrations and exposure times greatly exceeded those likely to be experienced by patients, given the normal physiological dilution by the tear film. In addition, consistent evidence of BAK-related toxicity did not emerge from our review of dedicated clinical investigations. Thus, taken together, current evidence supports the safety of BAK for most glaucoma patients, although subpopulations with abnormal tearing may benefit from alternative preservative compounds or preservative-free formulations. Further studies to identify these populations are needed.
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Ghasemi H, Ghazanfari T, Yaraee R, Faghihzadeh S, Hassan ZM. Roles of IL-8 in Ocular Inflammations: A Review. Ocul Immunol Inflamm 2011; 19:401-12. [DOI: 10.3109/09273948.2011.618902] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Ayaki M, Iwasawa A, Yaguchi S, Koide R. Preserved and unpreserved 12 anti-allergic ophthalmic solutions and ocular surface toxicity: in vitro assessment in four cultured corneal and conjunctival epithelial cell lines. Biocontrol Sci 2011; 15:143-8. [PMID: 21212507 DOI: 10.4265/bio.15.143] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In the present study, we evaluated the cytotoxicity of anti-allergic ophthalmic solutions in cultured corneal and conjunctival cells, namely SIRC (rabbit corneal epithelium), BCE C/D-1b (bovine corneal epithelial cells), RC-1 (rabbit corneal epithelium), and Chang (human conjunctival cells). The viability of cell cultures was determined following the exposure of cells to 12 commercially available anti-allergic ophthalmic solutions for varying exposure times and at various dilutions using the MTT and neutral red assays. The cell viability score (CVS) was used to compare the toxicity of different drugs. Based on CVS data, the order of cell viability after exposure to the drugs was Zepelin ≥ Tramelas PF ≥ Cumorol PF ≥ Ketotifen PF ≥ Eyevinal = Fumarton ≥ Cumorol > Intal ≥ Rizaben ≥ Tramelas ≥ Patanol Livostin. In conclusion, cell viability was mostly affected by the concentration of benzalkonium chloride rather than the active component and/or the anti-allergic action of the drug. The CVS was useful in comparing the toxicity of different drugs.
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Enríquez-de-Salamanca A, Calonge M. Cytokines and chemokines in immune-based ocular surface inflammation. Expert Rev Clin Immunol 2010; 4:457-67. [PMID: 20477574 DOI: 10.1586/1744666x.4.4.457] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Altered levels of several cytokines and chemokines have been found in different types of inflammatory ocular surface diseases, such as allergy or dry-eye syndrome. It has also been demonstrated that epithelial cells play a key role in the persistence and even initiation of chronic mucosal inflammation. The recent development of 'multiplex detection' technologies has facilitated the identification of specific patterns of expression of these molecules in some ocular immune-based inflammatory disorders. Analysis of these molecules in tissues, cells (in vivo and in vitro) and tears has revealed that not only inflammatory cells but also epithelial and fibroblast resident cells are sources of these molecules. The purpose of this review is to summarize recent studies in this field.
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Affiliation(s)
- Amalia Enríquez-de-Salamanca
- IOBA (Institute of Applied Opthalmobiology), Ocular Surface Group, Campus Miguel Delibes, University of Valladolid, Valladolid, Spain.
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Baudouin C, Labbé A, Liang H, Pauly A, Brignole-Baudouin F. Preservatives in eyedrops: the good, the bad and the ugly. Prog Retin Eye Res 2010; 29:312-34. [PMID: 20302969 DOI: 10.1016/j.preteyeres.2010.03.001] [Citation(s) in RCA: 652] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
There is a large body of evidence from experimental and clinical studies showing that the long-term use of topical drugs may induce ocular surface changes, causing ocular discomfort, tear film instability, conjunctival inflammation, subconjunctival fibrosis, epithelial apoptosis, corneal surface impairment, and the potential risk of failure for further glaucoma surgery. Subclinical inflammation has also been described in patients receiving antiglaucoma treatments for long periods of time. However, the mechanisms involved, i.e., allergic, toxic, or inflammatory, as well as the respective roles of the active compound and the preservative in inducing the toxic and/or proinflammatory effects of ophthalmic solutions, is still being debated. The most frequently used preservative, benzalkonium chloride (BAK), has consistently demonstrated its toxic effects in laboratory, experimental, and clinical studies. As a quaternary ammonium, this compound has been shown to cause tear film instability, loss of goblet cells, conjunctival squamous metaplasia and apoptosis, disruption of the corneal epithelium barrier, and damage to deeper ocular tissues. The mechanisms causing these effects have not been fully elucidated, although the involvement of immunoinflammatory reactions with the release of proinflammatory cytokines, apoptosis, oxidative stress, as well as direct interactions with the lipid components of the tear film and cell membranes have been well established. Preservative-induced adverse effects are therefore far from being restricted to only allergic reactions, and side effects are often very difficult to identify because they mostly occur in a delayed or poorly specific manner. Care should therefore be taken to avoid the long-term use of preservatives, otherwise a less toxic alternative to BAK should be developed, as this weakly allergenic but highly toxic compound exerts dose- and time-dependent effects. On the basis of all these experimental and clinical reports, it would be advisable to use benzalkonium-free solutions whenever possible, especially in patients with the greatest exposure to high doses or prolonged treatments, in those suffering from preexisting or concomitant ocular surface diseases, and those experiencing side effects related to the ocular surface. Indeed, mild symptoms should not be underestimated, neglected, or denied, because they may very well be the apparent manifestations of more severe, potentially threatening subclinical reactions that may later cause major concerns.
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Affiliation(s)
- Christophe Baudouin
- Department of Ophthalmology III, Quinze-Vingts National Ophthalmology Hospital, INSERM, U968, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, CNRS, UMR_7210, Paris F-75012, France.
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Pulmonary irritation after inhalation exposure to benzalkonium chloride in rats. Int J Occup Med Environ Health 2008; 21:157-63. [PMID: 18715840 DOI: 10.2478/v10001-008-0020-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Benzalkonium chloride (BAC) is a quaternary ammonium compound (QAC) with a C8 to C18 chain length of alkyl groups. Since BAC exerts toxic effects on microorganisms, it has been used as an effective germicide and preservative, mostly in cosmetic industry and medicine. However, the toxic potential of BAC may be hazardous to humans, due to the common use of preparations containing BAC as a preservative. MATERIAL AND METHODS To assess the possible toxic effects of BAC, two-stage experiments were performed on female Wistar rats. At first, LC50 after a single exposure to BAC aerosol was determined. Then, the animals were exposed to BAC aerosol at 30 mg/m3 for 6 h, and for 3 days (6 h/day). The controls were unexposed rats. Directly after BAC exposure and 18 h afterwards, BALF concentrations were measured of total protein, Clara cell protein, matrix metalloproteinase-9 (MMP-9), hyaluronic acid (HA), immunoglobulin E (IgE) and cytokines (TF-alpha, IL-6 and MIP-20), lactate dehydrogenase (LDH) and GSH-S-transferase (GST). RESULTS The LC50 value for exposed rats was ca. 53 mg BAC in m3 air for 4 h. All the rats survived single and repeated inhalation exposure to 30 mg/m3 BAC. After single and repeated exposure, lung weight, total protein, HA and LDH activity in BALF of exposed rats were higher than in controls while CC16 levels were decreased. A significantly higher BALF concentration of IL-6 and IgE was noted in animals exposed to single and repeated doses. BALF concentrations of MMP-9, TNF-alpha, and MIP-2 in exposed rats were similar to those in control animals. CONCLUSION BAC may be classified to class I acute inhalation toxicity. It showed a strong inflammatory and irritant activity on the lungs after 6h inhalation and stimulated dynamic patterns of IL-6 and IgE production and protein infiltration from blood vessels to BALF. Continued exposure resulted in cellular destruction, a statistically significant increase in LDH activity and a continuous decrease in CC16 concentration in BALF.
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Bibliography. Current world literature. Genetics and epidemiology. Curr Opin Allergy Clin Immunol 2008; 8:489-93. [PMID: 18769207 DOI: 10.1097/aci.0b013e32830f1c83] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Oxidative and particularly photo-oxidative processes are critical factors many ocular conditions but are often poorly recognized by those investigating ocular disease. The author discusses oxidative stress in inflammatory processes of the conjunctiva, cornea, and uvea; in cataract formation in the lens; in retinal degeneration; and in optic nerve pathologic conditions, inflammatory in optic neuritis and degenerative in glaucoma.
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Affiliation(s)
- David L Williams
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 OES, England, UK; St. John's College, Cambridge CB2 1TP, England, UK.
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Pflugfelder SC, Stern ME. Future directions in therapeutic interventions for conjunctival inflammatory disorders. Curr Opin Allergy Clin Immunol 2007; 7:450-3. [PMID: 17873588 DOI: 10.1097/aci.0b013e3282ef69e3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PURPOSE OF REVIEW To review recent advances in pathogenesis and treatment of conjunctival inflammatory disorders. RECENT FINDINGS The conjunctiva becomes inflamed in a number of conditions, including allergy, atopy, dry eye, mucus membrane pemphigoid, Stevens-Johnson syndrome and surgical manipulation. Basic and clinical studies have identified a number of inflammatory mediators as potential therapeutic targets in these conditions. Additionally, new therapeutic agents and enhanced delivery systems have been evaluated. SUMMARY Increased understanding of the key mediators of conjunctival inflammation coupled with improved drug delivery methods are leading to more effective therapy for conjunctival inflammatory disorders.
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Affiliation(s)
- Stephen C Pflugfelder
- Ocular Surface Center, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA.
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Current World Literature. Curr Opin Allergy Clin Immunol 2007; 7:454-5. [PMID: 17873589 DOI: 10.1097/aci.0b013e3282f0cf23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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