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Hadipour Jahromy M, Qomi M, Fazelipour S, Sami N, Faali F, Karimi M, Adhami Moghadam F. Evaluation of curcumin-based ophthalmic nano-emulsion on atropine-induced dry eye in mice. Heliyon 2024; 10:e29009. [PMID: 38601632 PMCID: PMC11004198 DOI: 10.1016/j.heliyon.2024.e29009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 03/20/2024] [Accepted: 03/28/2024] [Indexed: 04/12/2024] Open
Abstract
Background One of the most efficient treatments for dry eye syndrome (DES) is to use nanocarriers as a potential delivery system. We aim to evaluate curcumin in a nano emulsion formulation. Methods A new formulation containing 5.5% curcuminoid was used. DLS, Zeta potential, TEM, and HPLC tests were performed to determine the size and morphology. First, 30 mice were selected as atropine-induced dry eye models. Next, 25 mice in 5 groups were treated with the nano emulsion at different doses, and corneal tissues were separated for evaluation. Results The DLS test results were indicative of the particles' stability. Nano curcumin appeared to be thoroughly effective in all groups, with the highest dose showing the most similarity to the healthy control group. Conclusions Curcumin-based nano emulsion eye drop is a promising candidate for DES management. However, further investigation is required to evaluate the possible risks in humans.
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Affiliation(s)
- Mahsa Hadipour Jahromy
- Herbal Pharmacology Research Center, School of Medicine, Dept of Pharmacology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Mahnaz Qomi
- Active Pharmaceutical Ingredients Research Center (APIRC), Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
- Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Simin Fazelipour
- School of Medicine, Dept of Histology & Anatomy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Nafiseh Sami
- School of Medicine, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Farzaneh Faali
- School of Medicine, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Mehrnaz Karimi
- Department of Nanotechnology, School of Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Farhad Adhami Moghadam
- School of Medicine, Dept of Ophthalmology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
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Pollalis D, Calle AG, Martinez-Camarillo JC, Ahluwalia K, Hinman C, Mitra D, Lebkowski J, Lee SY, Thomas BB, Ahmed F, Chan V, Junge JA, Fraser S, Louie S, Humayun M. Scaling up polarized RPE cell supernatant production on parylene membrane. Exp Eye Res 2024; 240:109789. [PMID: 38242423 DOI: 10.1016/j.exer.2024.109789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/21/2024]
Abstract
Age-related macular degeneration (AMD), a leading cause of vision loss, primarily arises from the degeneration of retinal pigment epithelium (RPE) and photoreceptors. Current therapeutic options for dry AMD are limited. Encouragingly, cultured RPE cells on parylene-based biomimetic Bruch's membrane demonstrate characteristics akin to the native RPE layer. In this study, we cultivated human embryonic stem cell-derived polarized RPE (hESC-PRPE) cells on parylene membranes at both small- and large-scale settings, collecting conditioned supernatant, denoted as PRPE-SF. We conducted a comprehensive analysis of the morphology of the cultured hESC-RPE cells and the secreted growth factors in PRPE-SF. To evaluate the in vivo efficacy of these products, the product was administered via intravitreal injections of PRPE-SF in immunodeficient Royal College of Surgeons (iRCS) rats, a model for retinal degeneration. Our study not only demonstrated the scalability of PRPE-SF production while maintaining RPE cell phenotype but also showed consistent protein concentrations between small- and large-scale batches. We consistently identified 10 key factors in PRPE-SF, including BMP-7, IGFBP-2, IGFBP-3, IGFBP-4, IGFBP-6, MANF, PEDF, PDGF-AA, TGFβ1, and VEGF. Following intravitreal administration of PRPE-SF, we observed a significant increase in the thickness of the outer nuclear layer (ONL) and photoreceptor preservation in iRCS rats. Furthermore, correlation analysis revealed that IGFBP-3, IGFBP-4, MANF, PEDF, and TGFβ1 displayed positive associations with in vivo bioactivity, while GDF-15 exhibited a negative correlation. Overall, this study highlights the feasibility of scaling up PRPE-SF production on parylene membranes without compromising its essential constituents. The outcomes of PRPE-SF administration in an animal model of retinal degeneration present substantial potential for photoreceptor preservation. Moreover, the identification of candidate surrogate potency markers, showing strong positive associations with in vivo bioactivity, lays a solid foundation for the development of a promising therapeutic intervention for retinal degenerative diseases.
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Affiliation(s)
- Dimitrios Pollalis
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Alejandra Gonzalez Calle
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Juan Carlos Martinez-Camarillo
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Kabir Ahluwalia
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; USC Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Cassidy Hinman
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Debbie Mitra
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Jane Lebkowski
- Regenerative Patch Technologies LLC, Menlo Park, CA 94028, USA
| | - Sun Young Lee
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Biju B Thomas
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Faizah Ahmed
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Victoria Chan
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA
| | - Jason A Junge
- Translational Imaging Center, University of Southern California, Los Angeles, CA 90089, USA
| | - Scott Fraser
- Translational Imaging Center, University of Southern California, Los Angeles, CA 90089, USA
| | - Stan Louie
- USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA; USC Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Mark Humayun
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA; USC Ginsburg Institute for Biomedical Therapeutics, University of Southern California, Los Angeles, CA 90033, USA.
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Gallagher D, Hurley DJ, O'Tuama B, Hughes E, Fulcher T. Quality of vision and tear film osmolarity. Optom Vis Sci 2024; 101:71-77. [PMID: 38350059 DOI: 10.1097/opx.0000000000002095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2024] Open
Abstract
SIGNIFICANCE We evaluate the relationship between tear film osmolarity measurements and quality of vision in patients presenting for routine eye clinic appointments. We found that the hyperosmolar group (>316 mOsm/L) had a worse quality-of-vision score than the normal osmolarity group, with glare being the most problematic symptom. PURPOSE Quality of vision is a perception and measure of real-world vision, which is not measured routinely in a clinical setting. This study aimed to evaluate the relationship between tear film osmolarity measurements and quality of vision in patients presenting for routine eye clinic appointments. METHODS This was an observational nonrandomized study. The participants were placed in groups based on tear film osmolarity (normal, ≤316 mOsm/L; hyperosmolar, >316 mOsm/L; or a difference of >8 mOsm/L between each eye). Thirty-three participants were enrolled in the study, of whom 22 were deemed to have a hyperosmolar tear film. A 30-item questionnaire including 10 symptoms rated on scales of frequency, severity, and bothersomeness was administered to participants in both groups. The quality-of-vision score ranged from 25 to 100 points, with lower scores indicating better quality of vision. RESULTS The hyperosmolar group had a significantly worse quality-of-vision score than the normal osmolarity group across all three scales; mean differences for frequency, severity, and bothersomeness were 12.66 ± 9.75 (p=0.003), 9.44 ± 7.45 (p=0.003), and 11.90 ± 11.14 (p=0.008), respectively. Of the 10 symptoms that were included in the questionnaire, glare was the most problematic in the hyperosmolar group. CONCLUSIONS In this study, we demonstrated a significant relationship between tear film hyperosmolarity and quality of vision, as patients with hyperosmolar tear films had worse quality of vision.
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Affiliation(s)
- David Gallagher
- Department of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland
| | | | - Brian O'Tuama
- Department of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - Emily Hughes
- Department of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - Tim Fulcher
- Department of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland
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Li S, Chen L, Fu Y. Nanotechnology-based ocular drug delivery systems: recent advances and future prospects. J Nanobiotechnology 2023; 21:232. [PMID: 37480102 PMCID: PMC10362606 DOI: 10.1186/s12951-023-01992-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 07/09/2023] [Indexed: 07/23/2023] Open
Abstract
Ocular drug delivery has constantly challenged ophthalmologists and drug delivery scientists due to various anatomical and physiological barriers. Static and dynamic ocular barriers prevent the entry of exogenous substances and impede therapeutic agents' active absorption. This review elaborates on the anatomy of the eye and the associated constraints. Followed by an illustration of some common ocular diseases, including glaucoma and their current clinical therapies, emphasizing the significance of drug therapy in treating ocular diseases. Subsequently, advances in ocular drug delivery modalities, especially nanotechnology-based ocular drug delivery systems, are recommended, and some typical research is highlighted. Based on the related research, systematic and comprehensive characterizations of the nanocarriers are summarized, hoping to assist with future research. Besides, we summarize the nanotechnology-based ophthalmic drugs currently on the market or still in clinical trials and the recent patents of nanocarriers. Finally, inspired by current trends and therapeutic concepts, we provide an insight into the challenges faced by novel ocular drug delivery systems and further put forward directions for future research. We hope this review can provide inspiration and motivation for better design and development of novel ophthalmic formulations.
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Affiliation(s)
- Shiding Li
- Department of Ophthalmology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, 200011, China
| | - Liangbo Chen
- Department of Ophthalmology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, 200011, China
| | - Yao Fu
- Department of Ophthalmology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
- Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, 200011, China.
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Sarmento C, Monteiro H, Paiva A, Duarte ARC, Jesus AR. Using Natural Deep Eutectic Systems as Alternative Media for Ocular Applications. Pharmaceutics 2023; 15:pharmaceutics15051553. [PMID: 37242795 DOI: 10.3390/pharmaceutics15051553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/17/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023] Open
Abstract
The major goal of this work was to study the potential of natural deep eutectic systems (NADES) as new media for ocular formulations. In formulating eye drops, it is important to increase the retention time of the drug on the surface of eye; hence, due to their high viscosity, NADES may be interesting candidates for formulation. Different systems composed of combinations of sugars, polyols, amino acids, and choline derivatives were prepared and then characterized in terms of rheological and physicochemical properties. Our results showed that 5-10% (w/v) aqueous solutions of NADES have a good profile in terms of viscosity (0.8 to 1.2 mPa.s), osmolarity (412 to 1883 mOsmol), and pH (7.4) for their incorporation of ocular drops. Additionally, contact angle and refractive index were determined. Acetazolamide (ACZ), a highly insoluble drug used to treat glaucoma, was used as proof-of-concept. Herein, we show that NADES can increase the solubility of ACZ in aqueous solutions by at least up to 3 times, making it useful for the formulation of ACZ into ocular drops and thereby enabling more efficient treatment. The cytotoxicity assays demonstrated that NADES are biocompatible up to 5% (w/v) in aqueous media, promoting cell viability (above 80%) when compared to the control after 24 h incubation in ARPE-19 cells. Furthermore, when ACZ is dissolved in aqueous solutions of NADES, the cytotoxicity is not affected in this range of concentrations. Although further studies are necessary to design an optimal formulation incorporating NADES, this study shows that these eutectics can be powerful tools in the formulation of ocular drugs.
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Affiliation(s)
- Célia Sarmento
- LAQV-REQUIMTE, Chemistry Department, NOVA-School of Science and Technology, 2829-516 Caparica, Portugal
| | - Hugo Monteiro
- LAQV-REQUIMTE, Chemistry Department, NOVA-School of Science and Technology, 2829-516 Caparica, Portugal
| | - Alexandre Paiva
- LAQV-REQUIMTE, Chemistry Department, NOVA-School of Science and Technology, 2829-516 Caparica, Portugal
| | - Ana Rita C Duarte
- LAQV-REQUIMTE, Chemistry Department, NOVA-School of Science and Technology, 2829-516 Caparica, Portugal
| | - Ana Rita Jesus
- LAQV-REQUIMTE, Chemistry Department, NOVA-School of Science and Technology, 2829-516 Caparica, Portugal
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A novel fixed-combination timolol-netarsudil-latanoprost ophthalmic solution for the treatment of glaucoma and ocular hypertension. Asian J Pharm Sci 2022; 17:938-948. [PMID: 36600899 PMCID: PMC9800952 DOI: 10.1016/j.ajps.2022.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/31/2022] [Accepted: 11/07/2022] [Indexed: 11/19/2022] Open
Abstract
Currently commercial fixed-concomitant three agents have multiple problems such as multiple dosing administration, poor efficacy and side effects. Once-daily fixed-combination timolol-netarsudil-latanoprost ophthalmic solution (FC-TNL) has the ability to treat glaucoma by lowering the intraocular pressure (IOP) with great efficacy and improving patient compliance. However, the commercialized netarsudil dimesylate precipitated when the pH of the solution was above 5.4, or when maleic acid, the salt of commercial timolol maleate, was mixed with netarsudil dimesylate. Consequently, the homologous salt engineering strategy was used to make netarsudil dimesylate soluble in pH 4.8-5.2 solution by synthesizing timolol mesylate. Next, the morphology of timolol mesylate was observed by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and powder X-ray diffraction. The prepared FC-TNL showed good stability during refrigeration storage. Additionally, FC-TNL exerted no influence on the intraocular penetration of each active compounds in the pharmacokinetic study. Importantly, once-daily FC-TNL exerted potent IOP-lowering effect and protective effect on retinal ganglion cells. The FC-TNL was stable, safe and effective, being a promising glaucoma therapeutic.
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Argüeso P. Human ocular mucins: The endowed guardians of sight. Adv Drug Deliv Rev 2022; 180:114074. [PMID: 34875287 PMCID: PMC8724396 DOI: 10.1016/j.addr.2021.114074] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 10/22/2021] [Accepted: 11/30/2021] [Indexed: 01/03/2023]
Abstract
Mucins are an ancient group of glycoproteins that provide viscoelastic, lubricating and hydration properties to fluids bathing wet surfaced epithelia. They are involved in the protection of underlying tissues by forming a barrier with selective permeability properties. The expression, processing and spatial distribution of mucins are often determined by organ-specific requirements that in the eye involve protecting against environmental insult while allowing the passage of light. The human ocular surface epithelia have evolved to produce an extremely thin and watery tear film containing a distinct soluble mucin product secreted by goblet cells outside the visual axis. The adaptation to the ocular environment is notably evidenced by the significant contribution of transmembrane mucins to the tear film, where they can occupy up to one-quarter of its total thickness. This article reviews the tissue-specific properties of human ocular mucins, methods of isolation and detection, and current approaches to model mucin systems recapitulating the human ocular surface mucosa. This knowledge forms the fundamental basis to develop applications with a promising biological and clinical impact.
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Affiliation(s)
- Pablo Argüeso
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States.
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8
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Development of Lutein-Containing Eye Drops for the Treatment of Dry Eye Syndrome. Pharmaceutics 2021; 13:pharmaceutics13111801. [PMID: 34834216 PMCID: PMC8621052 DOI: 10.3390/pharmaceutics13111801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/06/2021] [Accepted: 10/22/2021] [Indexed: 11/17/2022] Open
Abstract
Dry eye syndrome (DES) is a common ophthalmological disease that decreases tear secretion and causes dryness, photophobia, pain, severe corneal rupture, and even blindness. Ocular and lacrimal gland inflammation is one of the pathological mechanisms underlying DES. Therefore, effective suppression of inflammation is a crucial strategy for the treatment of DES. Lutein, commonly found in healthy foods, has anti-inflammatory effects in corneal or retina-related cells and may be a potential therapy for DES. The addition of lutein to artificial tears (AT) as an eye-drop formulation for DES treatment in a mouse model was studied in the present work. Polyvinyl alcohol (PVA) was used as a thickener to increase the viscosity of eye drops to prolong drug retention on the ocular surface. A WST-8 assay in human corneal epithelial cells (HCE-2) showed that a concentration of <5 μM lutein (L5) and <1% PVA (P1) maintained the cell viability at 80%. A real-time PCR showed that the inflamed human corneal epithelial cells (HCECs) cocultured with L5P1 had downregulated expression of inflammatory genes such as IL-1β, IL-6, and TNF-α. In a benzalkonium chloride- (BAC) induced DES mouse model, AT/L5P1 could repair damaged corneas, elevate tear secretion, increase the number of goblet cells, and inhibit the production of inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, in the cornea. In conclusion, we demonstrate that lutein/PVA as eye drops could prolong the drug ocular retention time and effectively to decrease inflammation in DES mice. Therefore, lutein, obtained from eye drops, has a potential therapeutic role for DES.
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Leone G, Pepi S, Consumi M, Mahdizadeh FF, Lamponi S, Magnani A. Phosphorylated xanthan gum-Ag(I) complex as antibacterial viscosity enhancer for eye drops formulation. Carbohydr Polym 2021; 267:118196. [PMID: 34119163 DOI: 10.1016/j.carbpol.2021.118196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/12/2021] [Accepted: 04/27/2021] [Indexed: 01/16/2023]
Abstract
Topical instillation of eye drops represents the treatment of choice for many ocular diseases. Ophthalmic formulations must meet general requirements, i.e. pH, osmolality, transparency and viscosity to ensure adequate retention without inducing irritation and the development of eye infections. We developed a phosphorylated xanthan gum-Ag(I) complex (XGP-Ag) showing pH (pH = 7.1 ± 0.3) and osmolality values (311 ± 2 mOsm/kg) close to that of human tears (pH = 6.5-7.6 and 304 ± 23 mOsm/kg) thanks to the presence of phosphate moieties along the chain. The presence of phosphate groups covalently bound to the XG chains avoids their dispersion in fluid, thus reducing the risk of corneal calcification. 0.02% w/v XGP-Ag solution showed high transparency (higher than 95% along the entire visible range), adequate refractive index (1.334 ± 0.001) and viscosity in the range: γ 1 s-1-10,000 s- 1 (26.4 ± 0.8-2.1 ± 0.4 mPa·s). Its cytotoxicity and capability to hinder bacterial proliferation was also verified.
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Affiliation(s)
- Gemma Leone
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via A. Moro 2, Siena 53100, Italy; INSTM, via G. Giusti 9, 50121 Firenze, Italy.
| | - Simone Pepi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via A. Moro 2, Siena 53100, Italy
| | - Marco Consumi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via A. Moro 2, Siena 53100, Italy; INSTM, via G. Giusti 9, 50121 Firenze, Italy
| | - Fariba Fahmideh Mahdizadeh
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via A. Moro 2, Siena 53100, Italy
| | - Stefania Lamponi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via A. Moro 2, Siena 53100, Italy; INSTM, via G. Giusti 9, 50121 Firenze, Italy
| | - Agnese Magnani
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via A. Moro 2, Siena 53100, Italy; INSTM, via G. Giusti 9, 50121 Firenze, Italy.
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Chiam N, Perara S. Water Gonioscopy: A Technique for Intraoperative Visualization of the Anterior Chamber Angle. J Curr Glaucoma Pract 2021; 15:106-108. [PMID: 35173391 PMCID: PMC8807936 DOI: 10.5005/jp-journals-10078-1314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Aim and objective To describe a technique of lens-free gonioscopy that allows the anterior chamber angle to be visualized intraoperatively, without the use of a gonioscopy lens. Background Minimally invasive glaucoma surgery (MIGS) is an increasingly popular treatment option for mild to moderate glaucoma. We describe a technique of lens-free gonioscopy that allows visualization of the anterior chamber angle without the use of a lens. This simple intraoperative technique may be used to inspect the placement of MIGS devices within the angle. Technique To perform a water gonioscopy, the surgeon sits temporal to the eye. The patient's head is turned 20–45° away from the surgeon, and the operating microscope is tilted 15–30° toward the surgeon. A reservoir of balanced salt solution is allowed to collect in the crater formed by the nose bridge and the bony orbital rim, external to the corneal surface. This body of liquid obliterates the cornea–air interface and hence allows visualization of the anterior chamber. In contrast to gonioscopy using a gonioscopy lens, water gonioscopy offers a lower magnification, ultra-wide field of view for angle visualization. Conclusion Water gonioscopy is a useful technique that anterior segment surgeons might use for quick visualization of the anterior chamber angle without the need for additional equipment. Clinical significance This is a simple technique that surgeons can use to visualize the anterior chamber angles intraoperatively. It is especially useful for MIGS that are placed within the anterior chamber angle, but this technique may also be used during other anterior segment surgeries, such as visualizing the haptics of an anterior chamber intraocular lens or checking for retained lens fragments in the anterior chamber angles. How to cite this article Chiam N, Perara S. Water Gonioscopy: A Technique for Intraoperative Visualization of the Anterior Chamber Angle. J Curr Glaucoma Pract 2021;15(3):106–108.
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Affiliation(s)
- Nathalie Chiam
- Department of Cataract and Comprehensive Ophthalmology, Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore
| | - Shamira Perara
- Department of Glaucoma, Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore
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11
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Beckman KA. Epithelium-on Corneal Collagen Cross-Linking with Hypotonic Riboflavin Solution in Progressive Keratoconus. Clin Ophthalmol 2021; 15:2921-2932. [PMID: 34262252 PMCID: PMC8273905 DOI: 10.2147/opth.s318317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 06/09/2021] [Indexed: 11/23/2022] Open
Abstract
Introduction Epithelium-off cross-linking (epi-off CXL) has long been established as the gold standard treatment for progressive keratoconus. Several protocols for epithelium-on (epi-on) CXL have been proposed to help reduce post-operative pain and facilitate visual recovery, but there is no epi-on treatment approach that is currently approved in the United States. The hydrophilic and macromolecular characteristics of conventional epi-off riboflavin formulations may create clinical challenges for absorption through an intact epithelium. This study investigates the clinical efficacy of a dextran-free hypotonic riboflavin ophthalmic solution (Photrexa, Glaukos, Burlington, MA, USA), approved for epi-off CXL, in a novel epi-on CXL protocol. Methods Twenty-five eyes of 17 patients were treated in this prospective, single-arm study using a hypotonic riboflavin formulation without dextran and low irradiance UVA (3mW/cm2) for epi-on CXL. Visual acuity, as well as refractive and keratometry outcomes, were observed over 12 months. Results At 12 months, Kmax was stable with no clinically or statistically significant change from a mean pre-op of 55.4D to 55.9D (p=0.13). Uncorrected and best corrected logMAR visual acuity significantly improved from 0.77 to 0.62 and from 0.17 to 0.12, respectively. There were no significant adverse safety events. Conclusion Patients who underwent epi-on CXL with dextran-free hypotonic riboflavin demonstrated improvements in uncorrected and best corrected visual acuity with stable keratometry at 12 months post-operatively. The efficacy is consistent with other epi-on studies to date but remains lower than standard epi-off CXL. New technologies, including supplemental oxygen and transepithelial riboflavin ophthalmic solutions, are currently under clinical evaluation and may offer a path forward for epi-on CXL in the USA.
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Affiliation(s)
- Kenneth A Beckman
- Comprehensive EyeCare of Central Ohio, Westerville, OH, USA.,The Ohio State University, Columbus, OH, USA
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12
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Downie LE, Bandlitz S, Bergmanson JPG, Craig JP, Dutta D, Maldonado-Codina C, Ngo W, Siddireddy JS, Wolffsohn JS. CLEAR - Anatomy and physiology of the anterior eye. Cont Lens Anterior Eye 2021; 44:132-156. [PMID: 33775375 DOI: 10.1016/j.clae.2021.02.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 02/01/2021] [Indexed: 02/06/2023]
Abstract
A key element of contact lens practice involves clinical evaluation of anterior eye health, including the cornea and limbus, conjunctiva and sclera, eyelids and eyelashes, lacrimal system and tear film. This report reviews the fundamental anatomy and physiology of these structures, including the vascular supply, venous drainage, lymphatic drainage, sensory innervation, physiology and function. This is the foundation for considering the potential interactions with, and effects of, contact lens wear on the anterior eye. This information is not consistently published as academic research and this report provides a synthesis from all available sources. With respect to terminology, the report aims to promote the consistent use of nomenclature in the field, and generally adopts anatomical terms recommended by the Federative Committee for Anatomical Terminology. Techniques for the examination of the ocular surface are also discussed.
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Affiliation(s)
- Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Australia.
| | - Stefan Bandlitz
- Höhere Fachschule für Augenoptik Köln, Cologne School of Optometry, Germany; School of Optometry, Aston University, Birmingham, UK
| | - Jan P G Bergmanson
- Texas Eye Research and Technology Center, University of Houston College of Optometry, United States
| | - Jennifer P Craig
- Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, New Zealand
| | - Debarun Dutta
- School of Optometry, Aston University, Birmingham, UK
| | - Carole Maldonado-Codina
- Eurolens Research, Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - William Ngo
- Centre for Ocular Research & Education, School of Optometry & Vision Science, University of Waterloo, Waterloo, Canada; Centre for Eye and Vision Research (CEVR), 14W Hong Kong Science Park, Hong Kong
| | | | - James S Wolffsohn
- School of Optometry, Aston University, Birmingham, UK; Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, New Zealand
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13
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Singh M, Bharadwaj S, Lee KE, Kang SG. Therapeutic nanoemulsions in ophthalmic drug administration: Concept in formulations and characterization techniques for ocular drug delivery. J Control Release 2020; 328:895-916. [PMID: 33069743 DOI: 10.1016/j.jconrel.2020.10.025] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/13/2020] [Accepted: 10/13/2020] [Indexed: 12/29/2022]
Abstract
The eye is the specialized part of the body and is comprised of numerous physiological ocular barriers that limit the drug absorption at the action site. Regardless of various efforts, efficient topical ophthalmic drug delivery remains unsolved, and thus, it is extremely necessary to advance the contemporary treatments of ocular disorders affecting the anterior and posterior cavities. Nowadays, the advent of nanotechnology-based multicomponent nanoemulsions for ophthalmic drug delivery has gained popularity due to the enhancement of ocular penetrability, improve bioavailability, increase solubility, and stability of lipophilic drugs. Nanoemulsions offer the sustained/controlled drug release and increase residence time which depend on viscosity, compositions, and stabilization process, etc.; hence, decrease the instillation frequency and improve patient compliance. Further, due to the nanosized of nanoemulsions, the sterilization process is easy as conventional solutions and cause no blur vision. The review aims to summarizes the various ocular barriers, manufacturing techniques, possible mechanisms to the retention and deep penetration into the eye, and appropriate excipients with their under-lying selection principles to prevent destabilization of nanoemulsions. This review also discusses the characterization parameters of ocular drug delivery to spike the interest of those contemplating a foray in this field. Here, in short, nanoemulsions are abridged with concepts to design clinically advantageous ocular drug delivery.
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Affiliation(s)
- Mahendra Singh
- Molecular Genetics Laboratory, Department of Biotechnology, Institute of Biotechnology, College of Life and Applied Sciences, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Shiv Bharadwaj
- Molecular Genetics Laboratory, Department of Biotechnology, Institute of Biotechnology, College of Life and Applied Sciences, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Kyung Eun Lee
- Molecular Genetics Laboratory, Department of Biotechnology, Institute of Biotechnology, College of Life and Applied Sciences, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk 38541, Republic of Korea; Stemforce, 313 Institute of Industrial Technology, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Sang Gu Kang
- Molecular Genetics Laboratory, Department of Biotechnology, Institute of Biotechnology, College of Life and Applied Sciences, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk 38541, Republic of Korea.
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14
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Gelling hypotonic polymer solution for extended topical drug delivery to the eye. Nat Biomed Eng 2020; 4:1053-1062. [PMID: 32895514 PMCID: PMC7655548 DOI: 10.1038/s41551-020-00606-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 07/28/2020] [Indexed: 01/19/2023]
Abstract
Eye-drop formulations should hold as high a concentration of soluble drug in contact with ocular epithelium for as long as possible. However, eye tears and frequent blinking limit drug retention on the ocular surface, and gelling drops typically form clumps that blur vision. Here, we describe a gelling hypotonic solution containing a low concentration of a thermosensitive triblock copolymer, for extended ocular drug delivery. On topical application, the hypotonic formulation forms a highly uniform and clear thin layer that conforms to the ocular surface and resists clearance from blinking, significantly increasing the intraocular absorption of hydrophilic and hydrophobic drugs and extending the drug–ocular-epithelium contact time with respect to conventional thermosensitive gelling formulations and commercial eye drops. We also show that the conformal gel layer allows for therapeutically relevant drug delivery to the eyeball’s posterior segment in pigs. Our findings highlight the importance of formulations that conform to the ocular surface prior to viscosity enhancement, for increased and prolonged ocular-surface contact and drug absorption.
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15
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Snetkov P, Zakharova K, Morozkina S, Olekhnovich R, Uspenskaya M. Hyaluronic Acid: The Influence of Molecular Weight on Structural, Physical, Physico-Chemical, and Degradable Properties of Biopolymer. Polymers (Basel) 2020; 12:E1800. [PMID: 32796708 PMCID: PMC7464276 DOI: 10.3390/polym12081800] [Citation(s) in RCA: 166] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/25/2020] [Accepted: 08/07/2020] [Indexed: 02/07/2023] Open
Abstract
Hyaluronic acid, as a natural linear polysaccharide, has attracted researchers' attention from its initial detection and isolation from tissues in 1934 until the present day. Due to biocompatibility and a high biodegradation of hyaluronic acid, it finds wide application in bioengineering and biomedicine: from biorevitalizing skin cosmetics and endoprostheses of joint fluid to polymeric scaffolds and wound dressings. However, the main properties of aqueous polysaccharide solutions with different molecular weights are different. Moreover, the therapeutic effect of hyaluronic acid-based preparations directly depends on the molecular weight of the biopolymer. The present review collects the information about relations between the molecular weight of hyaluronic acid and its original properties. Particular emphasis is placed on the structural, physical and physico-chemical properties of hyaluronic acid in water solutions, as well as their degradability.
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Affiliation(s)
- Petr Snetkov
- Institute BioEngineering, ITMO University, Kronverkskiy Prospekt, 49A, 197101 St. Petersburg, Russia; (K.Z.); (S.M.); (R.O.); (M.U.)
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16
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Opto-Electronic Refractometric Sensor Based on Surface Plasmon Resonances and the Bolometric Effect. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10041211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The bolometric effect allows us to electrically monitor spectral characteristics of plasmonic sensors; it provides a lower cost and simpler sample characterization compared with angular and spectral signal retrieval techniques. In our device, a monochromatic light source illuminates a spectrally selective plasmonic nanostructure. This arrangement is formed by a dielectric low-order diffraction grating that combines two materials with a high-contrast in the index of refraction. Light interacts with this structure and reaches a thin metallic layer, that is also exposed to the analyte. The narrow absorption generated by surface plasmon resonances hybridized with low-order grating modes, heats the metal layer where plasmons are excited. The temperature change caused by this absorption modifies the resistance of a metallic layer through the bolometric effect. Therefore, a refractometric change in the analyte varies the electric resistivity under resonant excitation. We monitor the change in resistance by an external electric circuit. This optoelectronic feature must be included in the definition of the sensitivity and figure of merit (FOM) parameters. Besides the competitive value of the FOM (around 400 RIU − 1 , where RIU means refractive index unit), the proposed system is fully based on opto-electronic measurements. The device is modeled, simulated and analyzed considering fabrication and experimental constrains. The proposed refractometer behaves linearly within a range centered around the index of refraction of aqueous media, n ≃ 1.33 , and can be applied to the sensing for research in bio-physics, biology, and environmental sciences.
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17
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Chandel L, Sharma R, Rana V. Exploring the Protective Potential of Carboxymethyl Terminalia catappa Polysaccharide on Blue Light Light-Emitting Diode Induced Corneal Damage. ACTA ACUST UNITED AC 2019; 13:310-322. [PMID: 31849292 DOI: 10.2174/1872211314666191218110440] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/14/2019] [Accepted: 11/18/2019] [Indexed: 01/11/2023]
Abstract
BACKGROUND Excessive blue light light-emitting diode (LED) exposure and consequent oxidative stress causes corneal damage and corneal injuries are the major problem arising these days due to excessive use of mobile phone, TV, environment pollution, etc. Objective: In the present investigation, the protectiveness of carboxymethyl Terminalia catappa (CTC) from blue light LED-induced corneal damage was explored. METHODS For this purpose, Terminalia catappa (TC) was functionalized by carboxymethylation and its structural modification was confirmed by spectral attributes. Further, the CTC protective eye drop formulations (0.025-1%, w/v) were prepared and evaluated for their capability of protection from blue light LEDinduced corneal damage as compared to CTC protective eye gel (1.25-7%, w/v). The findings pointed towards excellent protection of CTC gel formulations as compared to CTC eye drop formulations. In addition, the prepared optimized CTC gel had thixotropic behavior as evident from percentage structural recovery which was 1.75 fold higher than marketed formulation (I-Comfort, HPMC 2%, w/v). The safety and non-toxicity of CTC protective eye drop and gel were confirmed by HET-CAM test. Further, a rat eye model was implemented that mimic blue light light-emitting diode induced corneal damage in day to day life to assess the protective effect of CTC protective eye drop and gel. RESULTS The order of protectiveness of CTC formulations was found to be CTC protective eye gel (4%, w/v) (no corneal damage)>marketed eye gel (12.34% corneal damage)=CTC protective eye drop (0.75%, w/v) (17.48% corneal damage)> marketed eye drop (51% corneal damage). The mechanism behind the protective effect of CTC eye drop and gel was associated with good free radical scavenging activity and corneal adhesive property of CTC. It is established from the present work that, carboxymethyl Terminalia catappa has protective action against blue light light-emitting diode induced corneal damage.
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Affiliation(s)
- Lalit Chandel
- Pharmaceutics Division, Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala 147002, India
| | - Radhika Sharma
- Pharmaceutics Division, Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala 147002, India
| | - Vikas Rana
- Pharmaceutics Division, Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala 147002, India
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18
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Aragona P, Simmons PA, Wang H, Wang T. Physicochemical Properties of Hyaluronic Acid-Based Lubricant Eye Drops. Transl Vis Sci Technol 2019; 8:2. [PMID: 31695963 PMCID: PMC6827422 DOI: 10.1167/tvst.8.6.2] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 08/01/2019] [Indexed: 12/19/2022] Open
Abstract
Purpose To assess the physicochemical properties of hyaluronic acid (HA)-based artificial tears. Methods The average molecular weight (MW) and polydispersion index (PDI) of HA in 18 commercially available artificial tears were determined by light scattering/high-performance liquid chromatography. Osmolality, pH, viscosity, and sodium concentration were determined using an osmometer, pH meter, rheometer, and inductively coupled plasma mass spectrometer, respectively. Results The MW of HA varied considerably between formulations. The PDI was >2.0 in two formulations (2.28 and 4.94), suggesting the presence of a copolymer and/or HA size variability. Three formulations exhibited viscosity exceeding the blur threshold at different shear rates. Viscosity at low shear rates was generally highest in formulations containing high-MW HA. Correlations were found between observed viscosity and a predictive/calculated value, except for four copolymer-containing formulations, and osmolality (range, 154–335 mOsm/kg) and sodium concentration (range, 22–183 mM), with two exceptions. Compared with organic osmolytes, adding sodium decreased viscosity, particularly at lower shear rates. Conclusions In the context of the literature, our findings suggest that for most patients with dry eye disease, the ideal HA-based artificial tear should include high-MW HA with a low PDI and exhibit enhanced viscosity at low shear rate (without exceeding the blur threshold). The inclusion of synergistic copolymers and a low sodium concentration may increase viscosity, but whether any of these physicochemical properties or correlations can predict clinical efficacy will require further investigation. Translational Relevance Understanding the properties of HA-based artificial tears will support the development of unique formulations that target specific ocular surface conditions.
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Affiliation(s)
- Pasquale Aragona
- Department of Biomedical Science, Regional Referral Center for Ocular Surface Diseases, University of Messina, Messina, Italy
| | - Peter A Simmons
- Allergan plc, Irvine, CA, USA.,School of Optometry and Vision Science, Faculty of Science, University of New South Wales, Sydney, Australia
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Haber SL, Benson V, Buckway CJ, Gonzales JM, Romanet D, Scholes B. Lifitegrast: a novel drug for patients with dry eye disease. Ther Adv Ophthalmol 2019; 11:2515841419870366. [PMID: 31489402 PMCID: PMC6710705 DOI: 10.1177/2515841419870366] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/26/2019] [Indexed: 11/17/2022] Open
Abstract
The objective of this article is to review the pharmacology, efficacy, and safety of lifitegrast and determine its role relative to other agents in the management of dry eye disease. A PubMed search (1946 to December 2018) using the terms lifitegrast and SAR 1118 was conducted to identify relevant articles. In vitro or in vivo evaluations of lifitegrast published in the English language were eligible for inclusion. Phase II and III trials were selected for review of efficacy and safety. Four randomized controlled trials evaluated the efficacy and safety of lifitegrast 0.5% ophthalmic solution for 12 weeks, and 1 additional trial assessed safety for 1 year. In a majority of the trials, lifitegrast caused statistically significant improvements in inferior corneal fluorescein staining scores and eye dryness scores. The most common adverse effects were eye irritation, dysgeusia, and reduced visual acuity, and most were mild to moderate in severity. Lifitegrast has a novel mechanism of action and is safe and effective for the treatment of dry eye disease. At this time, lifitegrast may be considered as an option for patients who have an inadequate response to artificial tears.
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Affiliation(s)
- Stacy L Haber
- College of Pharmacy-Glendale, Midwestern University, Glendale, AZ, USA
| | - Vera Benson
- College of Pharmacy-Glendale, Midwestern University, Glendale, AZ, USA
| | - Casey J Buckway
- College of Pharmacy-Glendale, Midwestern University, Glendale, AZ, USA
| | | | - David Romanet
- College of Pharmacy-Glendale, Midwestern University, Glendale, AZ, USA
| | - Brittany Scholes
- College of Pharmacy-Glendale, Midwestern University, Glendale, AZ, USA
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20
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Investigating the potential of carboxymethyl pullulan for protecting the rabbit eye from systematically induced precorneal tear film damage. Exp Eye Res 2019; 184:91-100. [DOI: 10.1016/j.exer.2019.04.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 04/09/2019] [Accepted: 04/16/2019] [Indexed: 11/17/2022]
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Patel S, Tutchenko L. The refractive index of the human cornea: A review. Cont Lens Anterior Eye 2019; 42:575-580. [PMID: 31064697 DOI: 10.1016/j.clae.2019.04.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/14/2019] [Accepted: 04/30/2019] [Indexed: 10/26/2022]
Abstract
The refractive index of the cornea and overlying tear film are key factors affecting refraction and overall optical properties of the eye. A figure of 1.376 is often quoted for the refractive index of the human cornea over the visible spectrum. In the 19th century estimates for the average refractive index of the human cornea ranged from 1.335 to 1.4391. Over the last two decades data obtained from either ex or in vivo corneas (under local anaesthesia with or without stromal resection) by contact Abbé refractometry show the refractive index of the cornea changes along its' depth undulating from around 1.400 at the epithelium to 1.380 at Bowman's layer, a low of 1.369 in the mid stroma and 1.373 at the endothelium. The mean refractive index of harvested tear samples is 1.337 rising to 1.482 for the overlying lipid layer. Contemporary measurements obtained in vivo by non-invasive methods reveal the average, or equivalent, refractive index of the tear film-cornea complex along the antero-posterior direction ranges from 1.423 to 1.436. Over the last 200 years calculations, with respect to the optics of the human eye, were based on values for the refractive index of the cornea obtained from invasive techniques. The refractive index of the cornea and overlying tear film appears to be higher than previously accepted and varies from case to case.
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Affiliation(s)
- Sudi Patel
- NHS National Services Scotland, Edinburgh, United Kingdom.
| | - Larysa Tutchenko
- Department of Ophthalmology, Shupyk National Medical Academy of Postgraduate Education, Kyiv, Ukraine; Kyiv City Clinical Ophthalmological Hospital "Eye Microsurgical Center", Kyiv, Ukraine
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22
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Alkholief M, Albasit H, Alhowyan A, Alshehri S, Raish M, Abul Kalam M, Alshamsan A. Employing a PLGA-TPGS based nanoparticle to improve the ocular delivery of Acyclovir. Saudi Pharm J 2018; 27:293-302. [PMID: 30766442 PMCID: PMC6362158 DOI: 10.1016/j.jsps.2018.11.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 11/22/2018] [Indexed: 11/27/2022] Open
Abstract
Delivering drugs via the ocular route has always been a challenge for poorly soluble drugs. The various anatomical and physiological barriers in the eye cavity hinder the residence of drugs within the corneal and precorneal regions. In this study, the nanosystem that could sufficiently deliver the poorly soluble Acyclovir topically via ocular route. Our nanosystem is composed of the biocompatible PLGA polymer stabilized with TPGS which possess a high emulsifying capacity and is also known as P-gp inhibitor. The optimized nanoparticles were prepared with 0.3% TPGS and had particle-size of 262.3 nm, zeta-potential of +15.14 mV. The physicochemical-characterization, ex vivo transcorneal permeation, ocular-irritation and Acyclovir ocular-availability, following topical ocular application of PLGA-NPs in rabbit eyes, were performed. The tested parameters and irritation by Draize's test suggested the suitability and safety of PLGA-NPs for ocular use. An ultrahigh performance liquid chromatographic method was developed, validated, and applied to quantify Acyclovir in aqueous humor which was shown to be significantly higher (p < 0.05) using the developed nanoparticles as compared to Acyclovir-aqueous suspension following their single topical ocular administration. Noticeable 2.78-, 1.71- and 2.2-times increased values of AUC0-24h, t1/2 (h) and MRT0-24h were found, respectively, with the PLGA-TPGS-NPs as compared to ACY-AqS. These results demonstrate the superiority of delivering Acyclovir using a nanosystem compared to conventional methods.
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Affiliation(s)
- Musaed Alkholief
- Nanobiotechnology Unit, Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Hammam Albasit
- Nanobiotechnology Unit, Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Adel Alhowyan
- Nanobiotechnology Unit, Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Sultan Alshehri
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box: 2457, Riyadh 11451, Saudi Arabia
| | - Mohammad Raish
- Department of Pharmaceutics, College of Pharmacy, King Saud University, P.O. Box: 2457, Riyadh 11451, Saudi Arabia
| | - Mohd Abul Kalam
- Nanobiotechnology Unit, Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Aws Alshamsan
- Nanobiotechnology Unit, Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
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23
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Huang HY, Wang MC, Chen ZY, Chiu WY, Chen KH, Lin IC, Yang WCV, Wu CC, Tseng CL. Gelatin-epigallocatechin gallate nanoparticles with hyaluronic acid decoration as eye drops can treat rabbit dry-eye syndrome effectively via inflammatory relief. Int J Nanomedicine 2018; 13:7251-7273. [PMID: 30510416 PMCID: PMC6231513 DOI: 10.2147/ijn.s173198] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Introduction Dry-eye syndrome (DES) is a general eye disease. Eye drops are the common ophthalmological medication. However, the ocular barrier makes it difficult to attain high drug bioavailability. Nanomedicine is a promising alternative treatment for ocular diseases and may increase drug content in the affected eye. Methods To explore this potential, we constructed nanoparticles (NPs) containing an anti-inflammatory agent for DES treatment. The NPs were made of gelatin-epigallocatechin gallate (EGCG) with surface decoration by hyaluronic acid (HA) and designated "GEH". The particle size, surface charge, and morphology were evaluated. The in vitro biocompatibility and anti-inflammation effect of nanoparticles were assayed via culturing with human corneal epithelium cells (HCECs) and in vivo therapeutic effect was examined in a DES rabbit's model. Results The synthesized GEH NPs had a diameter of approximately 250 nm and were positively charged. A coculture experiment revealed that 20 µg/mL GEH was not cytotoxic to HCECs and that an EGCG concentration of 0.2 µg/mL downregulated the gene expression of IL1B and IL6 in inflamed HCECs. Large amounts of GEH NPs accumulated in the cytoplasm of HCECs and the ocular surfaces of rats and rabbits, indicating the advantage of GEH NPs for ocular delivery of medication. Twice-daily topical treatment with GEH NPs was performed in a rabbit model of DES. The ocular surface of GEH-treated rabbits displayed normal corneal architecture with no notable changes in inflammatory cytokine levels in the cornea lysate. The treatment improved associated clinical signs, such as tear secretion, and fluorescein staining recovered. Conclusion We successfully produced GEH NPs with high affinity for HCECs and animal eyes. The treatment can be delivered as eye drops, which retain the drug on the ocular surface for a longer time. Ocular inflammation was effectively inhibited in DES rabbits. Therefore, GEH NPs are potentially valuable as a new therapeutic agent delivered in eye drops for treating DES.
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Affiliation(s)
- Hsin-Yi Huang
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan, .,Department of Biomedical Engineering, Chung Yuan Christian University, Taoyuan City, Taiwan
| | - Ming-Chen Wang
- Department of Biomedical Engineering, Chung Yuan Christian University, Taoyuan City, Taiwan
| | - Zhi-Yu Chen
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan,
| | - Wen-Ying Chiu
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan,
| | - Ko-Hua Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei City, Taiwan.,Department of Ophthalmology, School of Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan
| | - I-Chan Lin
- Department of Ophthalmology, School of Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan.,Department of Ophthalmology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
| | - Wei-Chung Vivian Yang
- PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei City, Taiwan
| | - Chi-Chang Wu
- Department of Electronic Engineering, Feng Chia University, Taichung City, Taiwan
| | - Ching-Li Tseng
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan, .,International PhD Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan, .,International PhD Program in Cell Therapy and Regenerative Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan,
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24
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Montani G, Murphy PJ, Patel S. Immediate effect of a tear enhancer and meibomian gland expression on the corneal surface and whole eye higher order aberrations. JOURNAL OF OPTOMETRY 2018; 11:223-231. [PMID: 29699948 PMCID: PMC6147757 DOI: 10.1016/j.optom.2018.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 11/22/2017] [Accepted: 01/20/2018] [Indexed: 06/08/2023]
Abstract
PURPOSE To investigate changes in higher order ocular aberrations (HOA) induced by the administration of 0.15% sodium hyaluronate tear enhancer (TE) and meibomian gland expression (ME) on the tear film of normal subjects. METHODS HOA values were obtained from the corneal surface (CS) and whole eye (WE), using a corneal topographer and Shack-Hartmann aberrometer, from both eyes of 50 subjects (25 females, mean age±sd 32.5±11.0 years, and 25 males, 33.88±11.2 years) for two pupil sizes (3 and 6mm) in a dark environment. One drop of Blink Contacts™ (Abbott Medical Optics) was instilled into the right eye and HOA measurements repeated after 30s. After 1h, the meibomian glands of the left lower eyelid were gently squeezed and HOA measurements repeated after 30s. RESULTS There was no significant difference for CS and WE root mean square (RMS) HOAs between right and left eyes before (both pupil sizes) and after TE use or ME (3mm pupil). For 6mm pupil, TE use significantly reduced the WE RMS HOA (p<0.05, mean±sd) for Z40 (0.297±0.136 to 0.053±0.069), and Z55 (0.221±0.372 to 0.098±0.121) while ME significantly increased CS RMS HOA (p<0.05, mean±sd) for Z3-3 (0.799±1.178 to 1.302±1.991) and Z44 (0.594±1.184 to 0.988±1.463). In general, the change in HOA was significantly correlated with the initial value before TE use or ME (p<0.05). CONCLUSION There were no detectable differences between right and left eyes. For the 6mm pupil, the tear enhancer tended to improve optical performance of the WE and meibomian gland expression tended to reduce the optical performance at the CS.
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Affiliation(s)
- Giancarlo Montani
- School of Optics and Optometry. University of Salento, Lecce, Italy.
| | - Paul J Murphy
- School of Optometry and Vision Science, University of Waterloo, Canada; School of Optometry and Vision Sciences, Cardiff, UK
| | - Sudi Patel
- NHS National Services Scotland, Edinburgh, UK & Svjetlost University Eye Hospital, Zagreb, Croatia
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25
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AlQattan B, Yetisen AK, Butt H. Direct Laser Writing of Nanophotonic Structures on Contact Lenses. ACS NANO 2018; 12:5130-5140. [PMID: 29688698 PMCID: PMC6107297 DOI: 10.1021/acsnano.8b00222] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 04/20/2018] [Indexed: 05/23/2023]
Abstract
Contact lenses are ubiquitous biomedical devices used for vision correction and cosmetic purposes. Their application as quantitative analytical devices is highly promising for point-of-care diagnostics. However, it is a challenge to integrate nanoscale features into commercial contact lenses for application in low-cost biosensors. A neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (1064 nm, 3 ns pulse, 240 mJ) in holographic interference patterning mode was utilized to produce optical nanostructures over the surface of a hydrogel contact lens. One-dimensional (925 nm) and two-dimensional (925 nm × 925 nm) nanostructures were produced on contact lenses and analyzed by spectroscopy and angle-resolve measurements. The holographic properties of these nanostructures were tested in ambient moisture, fully hydrated, and artificial tear conditions. The measurements showed a rapid tuning of optical diffraction from these nanostructures from 41 to 48°. The nanostructures were patterned near the edges of the contact lens to avoid any interference and obstruction to the human vision. The formation of 2D nanostructures on lenses increased the diffraction efficiency by more than 10%. The versatility of the holographic laser ablation method was demonstrated by producing four different 2D nanopattern geometries on contact lenses. Hydrophobicity of the contact lens was characterized by contact angle measurements, which increased from 59.0° at pristine condition to 62.5° at post-nanofabrication. The holographic nanostructures on the contact lens were used to sense the concentration of Na+ ions. Artificial tear solution was used to simulate the conditions in dry eye syndrome, and nanostructures on the contact lenses were used to detect the electrolyte concentration changes (±47 mmol L-1). Nanopatterns on a contact lens may be used to sense other ocular diseases in early stages at point-of-care settings.
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Affiliation(s)
- Bader AlQattan
- Nanotechnology
Laboratory, School of Engineering, and School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Ali K. Yetisen
- Nanotechnology
Laboratory, School of Engineering, and School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Haider Butt
- Nanotechnology
Laboratory, School of Engineering, and School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, United Kingdom
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26
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Jiang N, Montelongo Y, Butt H, Yetisen AK. Microfluidic Contact Lenses. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1704363. [PMID: 29521022 PMCID: PMC6607692 DOI: 10.1002/smll.201704363] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Indexed: 05/24/2023]
Abstract
Contact lens is a ubiquitous technology used for vision correction and cosmetics. Sensing in contact lenses has emerged as a potential platform for minimally invasive point-of-care diagnostics. Here, a microlithography method is developed to fabricate microconcavities and microchannels in a hydrogel-based contact lens via a combination of laser patterning and embedded templating. Optical microlithography parameters influencing the formation of microconcavities including ablation power (4.3 W) and beam speed (50 mm s-1 ) are optimized to control the microconcavity depth (100 µm) and diameter (1.5 mm). The fiber templating method allows the production of microchannels having a diameter range of 100-150 µm. Leak-proof microchannel and microconcavity connections in contact lenses are validated through flow testing of artificial tear containing fluorescent microbeads (Ø = 1-2 µm). The microconcavities of contact lenses are functionalized with multiplexed fluorophores (2 µL) to demonstrate optical excitation and emission capability within the visible spectrum. The fabricated microfluidic contact lenses may have applications in ophthalmic monitoring of metabolic disorders at point-of-care settings and controlled drug release for therapeutics.
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Affiliation(s)
- Nan Jiang
- School of Engineering and Applied SciencesHarvard UniversityCambridgeMA02138USA
| | - Yunuen Montelongo
- Department of ChemistryImperial College LondonSouth Kensington CampusLondonSW7 2AZUK
- Universidad De La Salle BajíoLeón37150Mexico
| | - Haider Butt
- Nanotechnology LaboratorySchool of EngineeringUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Ali K. Yetisen
- Institute for Measurement Systems and Sensor TechnologyTechnische Universität MünchenTheresienstrasse 9080333MunichGermany
- School of Chemical EngineeringUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
- Institute of Translational MedicineMindelsohn Way, EdgbastonBirminghamB15 2THUK
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King-Smith PE, Begley CG, Braun RJ. Mechanisms, imaging and structure of tear film breakup. Ocul Surf 2017; 16:4-30. [PMID: 28935579 DOI: 10.1016/j.jtos.2017.09.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 08/10/2017] [Accepted: 09/15/2017] [Indexed: 12/14/2022]
Abstract
Tear film breakup (BU) is an important aspect of dry eye disease, as a cause of ocular aberrations, irritation and ocular surface inflammation and disorder. Additionally, measurement of breakup time (BUT) is a common clinical test for dry eye. The current definition of BUT is subjective; here, a more objective concept of "touchdown" - the moment when the lipid layer touches down on the corneal surface - is proposed as an aid to understanding processes in early and late stages of BU development. Models of BU have generally been based on the assumption that a single mechanism is involved. In this review, it is emphasized that BU does not have a single explanation but it is the end result of multiple processes. A three-way classification of BU is proposed - "immediate," "lid-associated," and "evaporative." Five different types of imaging systems are described, which have been used to help elucidate the processes involved in BU and BUT; a new method, "high resolution chromaticity images," is presented. Three directions of tear flow - evaporation, osmotic flow out of the ocular surface, and "tangential flow" along the ocular surface - determine tear film thinning between blinks, leading to BU. Ten factors involved in BU and BUT, both before and after touchdown, are discussed. Future directions of research on BU are proposed.
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28
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Chen HC, Chen ZY, Wang TJ, Drew VJ, Tseng CL, Fang HW, Lin FH. Herbal Supplement in a Buffer for Dry Eye Syndrome Treatment. Int J Mol Sci 2017; 18:ijms18081697. [PMID: 28771187 PMCID: PMC5578087 DOI: 10.3390/ijms18081697] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/28/2017] [Accepted: 07/29/2017] [Indexed: 12/12/2022] Open
Abstract
Dry eye syndrome (DES) is one of the most common types of ocular diseases. There is a major need to treat DES in a simple yet efficient way. Artificial tears (AT) are the most commonly used agents for treating DES, but are not very effective. Herbal extractions of ferulic acid (FA), an anti-oxidant agent, and kaempferol (KM), an anti-inflammatory reagent, were added to buffer solution (BS) to replace ATs for DES treatment. The cytotoxicity and anti-inflammatory effects were examined in vitro by co-culture with human corneal epithelial cells (HCECs) to obtain the optimal concentration of KM and FA for treating HCECs. Physical properties of BS, such as pH value, osmolality, and refractive index were also examined. Then, rabbits with DES were used for therapeutic evaluation. Tear production, corneal damage, and ocular irritation in rabbits’ eyes were examined. The non-toxic concentrations of KM and FA for HCEC cultivation over 3 days were 1 µM and 100 µM, respectively. Live/dead stain results also show non-toxicity of KM and FA for treating HCECs. Lipopolysaccharide-stimulated HCECs in inflammatory conditions treated with 100 µM FA and 1 µM KM (FA100/KM1) showed lower IL-1B, IL-6, IL-8, and TNFα expression when examined by real-time PCR. The BS with FA100/KM1 had neutral pH, and a similar osmolality and refractive index to human tears. Topical delivery of BS + FA100/KM1 showed no irritation to rabbit eyes. The corneal thickness in the BS + FA100/KM1 treated group was comparable to normal eyes. Results of DES rabbits treated with BS + FA100/KM1 showed less corneal epithelial damage and higher tear volume than the normal group. In conclusion, we showed that the combination of FA (100 µM) and KM (1 µM) towards treating inflamed HCECs had an anti-inflammatory effect, and it is effective in treating DES rabbits when BS is added in combination with these two herbal supplements and used as a topical eye drop.
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Affiliation(s)
- Hung-Chang Chen
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 10608, Taiwan.
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan.
| | - Zhi-Yu Chen
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan.
| | - Tsung-Jen Wang
- Department of Ophthalmology, Taipei Medical University Hospital, Taipei 11031, Taiwan.
- Department of Ophthalmology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
| | - Victor J Drew
- International Ph.D. Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan.
| | - Ching-Li Tseng
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan.
- International Ph.D. Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan.
| | - Hsu-Wei Fang
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 10608, Taiwan.
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli 35053, Taiwan.
| | - Feng-Huei Lin
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli 35053, Taiwan.
- Institute of Biomedical Engineering, National Taiwan University, Taipei 10051, Taiwan.
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Deinema LA, Vingrys AJ, Chinnery HR, Downie LE. Optical Coherence Tomography Reveals Changes to Corneal Reflectivity and Thickness in Individuals with Tear Hyperosmolarity. Transl Vis Sci Technol 2017; 6:6. [PMID: 28553560 PMCID: PMC5444496 DOI: 10.1167/tvst.6.3.6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 03/19/2017] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To investigate whether tear hyperosmolarity, a feature of dry eye disease (DED), affects central corneal thickness (CCT), corneal light reflectivity, and/or tear film reflectivity. METHODS This prospective, cross-sectional study involved 48 participants (38 with hyperosmolar tears and 10 controls with normo-osmolar tears). Symptoms and signs of DED (tear osmolarity, sodium fluorescein tear break-up time, ocular surface staining, Schirmer test) were assessed. CCT, and the reflectivity of the cornea and the tear-epithelial interface were quantified relative to background noise using Fourier-domain optical coherence tomography (FD-OCT). RESULTS CCT of eyes with severe tear hyperosmolarity, defined as eyes in the upper quartile of the hyperosmolar group, was less than control eyes (539.1 ± 7.4 vs. 583.1 ± 15.0 μm, P = 0.02) and eyes with less severe tear hyperosmolarity, defined as hyperosmolar eyes in the lower quartile (622.7 ± 5.8 μm, P < 0.0001). CCT showed a negative linear relationship with tear osmolarity for values above 316 mOsmol/L (R2 = 0.17, P = 0.01). Central corneal reflectivity was lower in hyperosmolar eyes than normo-osmolar eyes (45.1 ± 0.3 vs. 48.1 ± 0.6 pixels, P = 0.02); the greatest relative difference was in the anterior stroma, where corneal reflectivity was 4.7 ± 1.9% less in hyperosmolar eyes (P < 0.01). Peak reflectivity of the tear-epithelial interface was 4.8% ± 3.5% higher in the hyperosmolar group than the normo-osmolar tear group (P = 0.04). CONCLUSION Individuals with significant tear hyperosmolarity and clinical signs of symptoms of DED show reduced CCT and altered corneal reflectivity. TRANSLATIONAL RELEVANCE Anterior segment FD-OCT provides novel insight into corneal microstructural differences in individuals with DED.
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Affiliation(s)
- Laura Adelaide Deinema
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry & Health Sciences, The University of Melbourne, Parkville, Victoria, Australia 3010
| | - Algis Jonas Vingrys
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry & Health Sciences, The University of Melbourne, Parkville, Victoria, Australia 3010
| | - Holly Rose Chinnery
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry & Health Sciences, The University of Melbourne, Parkville, Victoria, Australia 3010
| | - Laura Elizabeth Downie
- Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry & Health Sciences, The University of Melbourne, Parkville, Victoria, Australia 3010
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30
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Lallemand F, Schmitt M, Bourges JL, Gurny R, Benita S, Garrigue JS. Cyclosporine A delivery to the eye: A comprehensive review of academic and industrial efforts. Eur J Pharm Biopharm 2017; 117:14-28. [PMID: 28315447 DOI: 10.1016/j.ejpb.2017.03.006] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/09/2017] [Accepted: 03/11/2017] [Indexed: 11/20/2022]
Abstract
Local ocular delivery of cyclosporine A (CsA) is the preferred method for CsA delivery as a treatment for ocular inflammatory diseases such as uveitis, corneal healing, vernal keratoconjunctivitis and dry eye disease. However, due to the large molecular weight and hydrophobic nature of CsA and the natural protective mechanisms of the eye, achieving therapeutic levels of CsA in ocular tissues can be difficult. This review gives a comprehensive overview of the current products available to clinicians as well as emerging drug delivery solutions that have been developed at both the academic and industry levels.
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Affiliation(s)
| | | | - Jean-Louis Bourges
- Department of Ophthalmology, Paris Descartes School of Medicine, Assistance Publique-Hôpitaux de Paris, Cochin-Hôtel-Dieu Hospital, Université Sorbonne Paris Cité, Paris, France
| | - Robert Gurny
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - Simon Benita
- The Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Ein Kerem, Israel
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31
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Deng X, Korogiannaki M, Rastegari B, Zhang J, Chen M, Fu Q, Sheardown H, Filipe CDM, Hoare T. "Click" Chemistry-Tethered Hyaluronic Acid-Based Contact Lens Coatings Improve Lens Wettability and Lower Protein Adsorption. ACS APPLIED MATERIALS & INTERFACES 2016; 8:22064-22073. [PMID: 27509015 DOI: 10.1021/acsami.6b07433] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Improving the wettability of and reducing the protein adsorption to contact lenses may be beneficial for improving wearer comfort. Herein, we describe a simple "click" chemistry approach to surface functionalize poly(2-hydroxyethyl methacrylate) (pHEMA)-based contact lenses with hyaluronic acid (HA), a carbohydrate naturally contributing to the wettability of the native tear film. A two-step preparation technique consisting of laccase/TEMPO-mediated oxidation followed by covalent grafting of hydrazide-functionalized HA via simple immersion resulted in a model lens surface that is significantly more wettable, more water retentive, and less protein binding than unmodified pHEMA while maintaining the favorable transparency, refractive, and mechanical properties of a native lens. The dipping/coating method we developed to covalently tether the HA wetting agent is simple, readily scalable, and a highly efficient route for contact lens modification.
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Affiliation(s)
- Xudong Deng
- Department of Chemical Engineering, McMaster University , Hamilton, Ontario L8S 4L7, Canada
| | - Myrto Korogiannaki
- Department of Chemical Engineering, McMaster University , Hamilton, Ontario L8S 4L7, Canada
| | - Banafsheh Rastegari
- Department of Chemical Engineering, McMaster University , Hamilton, Ontario L8S 4L7, Canada
- Department of Biology, Faculty of Sciences, Shiraz University , Shiraz, Fars 71946-84636, Iran
| | - Jianfeng Zhang
- Department of Chemical Engineering, McMaster University , Hamilton, Ontario L8S 4L7, Canada
| | - Mengsu Chen
- School of Nursing, McMaster University , Hamilton, Ontario L8S 4L8, Canada
| | - Qiang Fu
- Department of Chemical Engineering, McMaster University , Hamilton, Ontario L8S 4L7, Canada
| | - Heather Sheardown
- Department of Chemical Engineering, McMaster University , Hamilton, Ontario L8S 4L7, Canada
| | - Carlos D M Filipe
- Department of Chemical Engineering, McMaster University , Hamilton, Ontario L8S 4L7, Canada
| | - Todd Hoare
- Department of Chemical Engineering, McMaster University , Hamilton, Ontario L8S 4L7, Canada
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32
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Huang J, Hindman HB, Rolland JP. In vivo thickness dynamics measurement of tear film lipid and aqueous layers with optical coherence tomography and maximum-likelihood estimation. OPTICS LETTERS 2016; 41:1981-1984. [PMID: 27128054 DOI: 10.1364/ol.41.001981] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Dry eye disease (DED) is a common ophthalmic condition that is characterized by tear film instability and leads to ocular surface discomfort and visual disturbance. Advancements in the understanding and management of this condition have been limited by our ability to study the tear film secondary to its thin structure and dynamic nature. Here, we report a technique to simultaneously estimate the thickness of both the lipid and aqueous layers of the tear film in vivo using optical coherence tomography and maximum-likelihood estimation. After a blink, the lipid layer was rapidly thickened at an average rate of 10 nm/s over the first 2.5 s before stabilizing, whereas the aqueous layer continued thinning at an average rate of 0.29 μm/s of the 10 s blink cycle. Further development of this tear film imaging technique may allow for the elucidation of events that trigger tear film instability in DED.
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33
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Hayes S, Lewis P, Islam MM, Doutch J, Sorensen T, White T, Griffith M, Meek KM. The structural and optical properties of type III human collagen biosynthetic corneal substitutes. Acta Biomater 2015; 25:121-130. [PMID: 26159106 PMCID: PMC4570929 DOI: 10.1016/j.actbio.2015.07.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 06/03/2015] [Accepted: 07/06/2015] [Indexed: 11/30/2022]
Abstract
The structural and optical properties of clinically biocompatible, cell-free hydrogels comprised of synthetically cross-linked and moulded recombinant human collagen type III (RHCIII) with and without the incorporation of 2-methacryloyloxyethyl phosphorylcholine (MPC) were assessed using transmission electron microscopy (TEM), X-ray scattering, spectroscopy and refractometry. These findings were examined alongside similarly obtained data from 21 human donor corneas. TEM demonstrated the presence of loosely bundled aggregates of fine collagen filaments within both RHCIII and RHCIII-MPC implants, which X-ray scattering showed to lack D-banding and be preferentially aligned in a uniaxial orientation throughout. This arrangement differs from the predominantly biaxial alignment of collagen fibrils that exists in the human cornea. By virtue of their high water content (90%), very fine collagen filaments (2–9 nm) and lack of cells, the collagen hydrogels were found to transmit almost all incident light in the visible spectrum. They also transmitted a large proportion of UV light compared to the cornea which acts as an effective UV filter. Patients implanted with these hydrogels should be cautious about UV exposure prior to regrowth of the epithelium and in-growth of corneal cells into the implants.
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34
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Aranha Dos Santos V, Schmetterer L, Gröschl M, Garhofer G, Schmidl D, Kucera M, Unterhuber A, Hermand JP, Werkmeister RM. In vivo tear film thickness measurement and tear film dynamics visualization using spectral domain optical coherence tomography. OPTICS EXPRESS 2015; 23:21043-63. [PMID: 26367956 DOI: 10.1364/oe.23.021043] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Dry eye syndrome is a highly prevalent disease of the ocular surface characterized by an instability of the tear film. Traditional methods used for the evaluation of tear film stability are invasive or show limited repeatability. Here we propose a new non-invasive fully automated approach to measure tear film thickness based on spectral domain optical coherence tomography and on an efficient delay estimator. Silicon wafer phantom were used to validate the thickness measurement. The technique was applied in vivo in healthy subjects. Series of tear film thickness maps were generated, allowing for the visualization of tear film dynamics. Our results show that the in vivo central tear film thickness measurements are precise and repeatable with a coefficient of variation of about 0.65% and that repeatable tear film dynamics can be observed. The presented approach could be used in clinical setting to study patients with dry eye disease and monitor their treatments.
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35
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Huang J, Yuan Q, Zhang B, Xu K, Tankam P, Clarkson E, Kupinski MA, Hindman HB, Aquavella JV, Suleski TJ, Rolland JP. Measurement of a multi-layered tear film phantom using optical coherence tomography and statistical decision theory. BIOMEDICAL OPTICS EXPRESS 2014; 5:4374-86. [PMID: 25574445 PMCID: PMC4285612 DOI: 10.1364/boe.5.004374] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 11/16/2014] [Accepted: 11/17/2014] [Indexed: 05/07/2023]
Abstract
To extend our understanding of tear film dynamics for the management of dry eye disease, we propose a method to optically sense the tear film and estimate simultaneously the thicknesses of the lipid and aqueous layers. The proposed method, SDT-OCT, combines ultra-high axial resolution optical coherence tomography (OCT) and a robust estimator based on statistical decision theory (SDT) to achieve thickness measurements at the nanometer scale. Unlike conventional Fourier-domain OCT where peak detection of layers occurs in Fourier space, in SDT-OCT thickness is estimated using statistical decision theory directly on the raw spectra acquired with the OCT system. In this paper, we demonstrate in simulation that a customized OCT system tailored to ~1 µm axial point spread function (FWHM) in the corneal tissue, combined with the maximum-likelihood estimator, can estimate thicknesses of the nanometer-scale lipid and micron-scale aqueous layers of the tear film, simultaneously, with nanometer precision. This capability was validated in experiments using a physical phantom that consists of two layers of optical coatings that mimic the lipid and aqueous layers of the tear film.
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Affiliation(s)
- Jinxin Huang
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627,
USA
| | - Qun Yuan
- The Institute of Optics, University of Rochester, Rochester, New York 14627,
USA
- School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094,
China
| | - Buyun Zhang
- The Institute of Optics, University of Rochester, Rochester, New York 14627,
USA
- Department of Optical Engineering, Zhejiang University, Hangzhou, Zhejiang 310027,
China
| | - Ke Xu
- The Institute of Optics, University of Rochester, Rochester, New York 14627,
USA
| | - Patrice Tankam
- The Institute of Optics, University of Rochester, Rochester, New York 14627,
USA
| | - Eric Clarkson
- Department of Radiology, University of Arizona, Tucson, Arizona 85720,
USA
| | - Matthew A. Kupinski
- College of Optical Sciences, University of Arizona, Tucson, Arizona 85720,
USA
| | - Holly B. Hindman
- Flaum Eye Institute, University of Rochester, New York 14642,
USA
| | | | - Thomas J. Suleski
- Department of Physics and Optical Science, The University of North Carolina at Charlotte, Charlotte, North Carolina 28223,
USA
| | - Jannick P. Rolland
- The Institute of Optics, University of Rochester, Rochester, New York 14627,
USA
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36
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Cholkar K, Hariharan S, Gunda S, Mitra AK. Optimization of dexamethasone mixed nanomicellar formulation. AAPS PharmSciTech 2014; 15:1454-67. [PMID: 24980081 DOI: 10.1208/s12249-014-0159-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 05/22/2014] [Indexed: 12/11/2022] Open
Abstract
The purpose of this study was to develop a clear aqueous mixed nanomicellar formulation (MNF) of dexamethasone utilizing both D-α-tocopherol polyethylene glycol-1000 succinate (Vit E TPGS) and octoxynol-40 (Oc-40). In this study, Vit E TPGS and Oc-40 are independent variables. Formulations were prepared following solvent evaporation method. A three level full-factorial design was applied to optimize the formulation based on entrapment efficiency, size, and polydispersity index (PDI). A specific blend of Vit E TPGS and Oc-40 at a particular wt% ratio (4.5:2.0) produced excellent drug entrapment, loading, small mixed nanomicellar size and narrow PDI. Solubility of DEX in MNF is improved by ~6.3-fold relative to normal aqueous solubility. Critical micellar concentration (CMC) for blend of polymers (4.5:2.0) was found to be lower (0.012 wt%) than the individual polymers (Vit E TPGS (0.025 wt%) and Oc-40 (0.107 wt%)). No significant effect on mixed nanomicellar size and PDI with one-factor or multi-factor interactions was observed. Qualitative (1)H NMR studies confirmed absence of free drug in the outer aqueous MNF medium. MNF appeared to be highly stable. Cytotoxicity studies on rabbit primary corneal epithelial cells did not indicate any toxicity suggesting MNF of dexamethasone is safe and suitable for human topical ocular drops after further in vivo evaluations.
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37
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Mafi R, Pelton R, Cui Y, Ketelson H. Weak Gelation of Hydrophobic Guar by Albumin in Simulated Human Tear Solutions. Biomacromolecules 2014; 15:4637-42. [PMID: 25380278 DOI: 10.1021/bm501278g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Roozbeh Mafi
- Department
of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L8, Canada
| | - Robert Pelton
- Department
of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L8, Canada
| | - Yuguo Cui
- Department
of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L8, Canada
| | - Howard Ketelson
- Alcon Research, Ltd., 6201
South Freeway, Fort Worth, Texas 76134-2099, United States
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38
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Abstract
PURPOSE To illustrate surgical outcomes of subepithelial irregularities that were identified incidentally during laser refractive surgery. MATERIALS AND METHODS The study group consisted of 406 patients who underwent 787 surface ablation refractive surgeries. Ophthalmologic evaluations were performed before each procedure and at 1, 3 and 6 months post-operatively. Subepithelial irregularities were evaluated by analyzing still photographs captured from video recordings. Sizes and locations were determined by a calibrated scale located at the major axis of the tracking system's reticle. RESULTS Subepithelial irregularities were identified in 27 eyes during 787 surface ablation refractive surgeries. Most of the subepithelial irregularities did not show any abnormalities in the wavefront aberrometer. However, one case with diameter greater than 1.00 mm and one case of clustered multiple subepithelial irregularities with moderate size were corresponded significant coma (Z31) and increased higher order aberration (HOA) in the HOA gradient map. CONCLUSIONS Corneal subepithelial irregularities may be related to problems that include significantly increased localized HOA and remaining permanent subepithelial opacity. Subepithelial irregularity should be considered even if the surface of the cornea is intact and there are no specific findings measured by corneal topography.
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Affiliation(s)
- Yong Woo Lee
- Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine , Seoul , Korea
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39
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Lu H, Wang MR, Wang J, Shen M. Tear film measurement by optical reflectometry technique. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:027001. [PMID: 24500519 PMCID: PMC3915055 DOI: 10.1117/1.jbo.19.2.027001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 12/31/2013] [Indexed: 05/13/2023]
Abstract
Evaluation of tear film is performed by an optical reflectometer system with alignment guided by a galvanometer scanner. The reflectometer system utilizes optical fibers to deliver illumination light to the tear film and collect the film reflectance as a function of wavelength. Film thickness is determined by best fitting the reflectance-wavelength curve. The spectral reflectance acquisition time is 15 ms, fast enough for detecting film thickness changes. Fast beam alignment of 1 s is achieved by the galvanometer scanner. The reflectometer was first used to evaluate artificial tear film on a model eye with and without a contact lens. The film thickness and thinning rate have been successfully quantified with the minimum measured thickness of about 0.3 μm. Tear films in human eyes, with and without a contact lens, have also been evaluated. A high-contrast spectral reflectance signal from the precontact lens tear film is clearly observed, and the thinning dynamics have been easily recorded from 3.69 to 1.31 μm with lipid layer thickness variation in the range of 41 to 67 nm. The accuracy of the measurement is better than ±0.58% of the film thickness at an estimated tear film refractive index error of ±0.001. The fiber-based reflectometer system is compact and easy to handle.
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Affiliation(s)
- Hui Lu
- University of Miami, Department of Electrical and Computer Engineering, Coral Gables, Florida 33146
| | - Michael R. Wang
- University of Miami, Department of Electrical and Computer Engineering, Coral Gables, Florida 33146
- Address all correspondence to: Michael R. Wang, E-mail:
| | - Jianhua Wang
- University of Miami, Bascom Palmer Eye Institute, Miami, Florida 33136
| | - Meixiao Shen
- University of Miami, Bascom Palmer Eye Institute, Miami, Florida 33136
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Rahman Z, Xu X, Katragadda U, Krishnaiah YSR, Yu L, Khan MA. Quality by Design Approach for Understanding the Critical Quality Attributes of Cyclosporine Ophthalmic Emulsion. Mol Pharm 2014; 11:787-99. [DOI: 10.1021/mp400484g] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ziyaur Rahman
- Division
of Product Quality Research, Office of Testing and Research, Office
of Pharmaceutical Sciences, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Xiaoming Xu
- Division
of Product Quality Research, Office of Testing and Research, Office
of Pharmaceutical Sciences, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Usha Katragadda
- Division
of Product Quality Research, Office of Testing and Research, Office
of Pharmaceutical Sciences, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Yellela S. R. Krishnaiah
- Division
of Product Quality Research, Office of Testing and Research, Office
of Pharmaceutical Sciences, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993, United States
| | - Lawrence Yu
- Office
of Generic Drugs, Center for Drug Evaluation and Research, Food and Drug Administration, Rockville, Maryland 20852, United States
| | - Mansoor A. Khan
- Division
of Product Quality Research, Office of Testing and Research, Office
of Pharmaceutical Sciences, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland 20993, United States
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Shi Y, Queener HM, Marsack JD, Ravikumar A, Bedell HE, Applegate RA. Optimizing wavefront-guided corrections for highly aberrated eyes in the presence of registration uncertainty. J Vis 2013; 13:8. [PMID: 23757512 PMCID: PMC3680305 DOI: 10.1167/13.7.8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 05/03/2013] [Indexed: 11/24/2022] Open
Abstract
Dynamic registration uncertainty of a wavefront-guided correction with respect to underlying wavefront error (WFE) inevitably decreases retinal image quality. A partial correction may improve average retinal image quality and visual acuity in the presence of registration uncertainties. The purpose of this paper is to (a) develop an algorithm to optimize wavefront-guided correction that improves visual acuity given registration uncertainty and (b) test the hypothesis that these corrections provide improved visual performance in the presence of these uncertainties as compared to a full-magnitude correction or a correction by Guirao, Cox, and Williams (2002). A stochastic parallel gradient descent (SPGD) algorithm was used to optimize the partial-magnitude correction for three keratoconic eyes based on measured scleral contact lens movement. Given its high correlation with logMAR acuity, the retinal image quality metric log visual Strehl was used as a predictor of visual acuity. Predicted values of visual acuity with the optimized corrections were validated by regressing measured acuity loss against predicted loss. Measured loss was obtained from normal subjects viewing acuity charts that were degraded by the residual aberrations generated by the movement of the full-magnitude correction, the correction by Guirao, and optimized SPGD correction. Partial-magnitude corrections optimized with an SPGD algorithm provide at least one line improvement of average visual acuity over the full magnitude and the correction by Guirao given the registration uncertainty. This study demonstrates that it is possible to improve the average visual acuity by optimizing wavefront-guided correction in the presence of registration uncertainty.
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Affiliation(s)
- Yue Shi
- Visual Optics Institute, College of Optometry, University of Houston, Houston, TX, USA
| | - Hope M. Queener
- College of Optometry, University of Houston, Houston, TX, USA
| | - Jason D. Marsack
- Visual Optics Institute, College of Optometry, University of Houston, Houston, TX, USA
| | - Ayeswarya Ravikumar
- Visual Optics Institute, College of Optometry, University of Houston, Houston, TX, USA
| | | | - Raymond A. Applegate
- Visual Optics Institute, College of Optometry, University of Houston, Houston, TX, USA
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Verstraelen S, Jacobs A, De Wever B, Vanparys P. Improvement of the Bovine Corneal Opacity and Permeability (BCOP) assay as an in vitro alternative to the Draize rabbit eye irritation test. Toxicol In Vitro 2013; 27:1298-311. [DOI: 10.1016/j.tiv.2013.02.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 02/25/2013] [Accepted: 02/27/2013] [Indexed: 10/27/2022]
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King-Smith PE, Nichols JJ, Braun RJ, Nichols KK. High resolution microscopy of the lipid layer of the tear film. Ocul Surf 2012; 9:197-211. [PMID: 22023815 DOI: 10.1016/s1542-0124(11)70033-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tear film evaporation is controlled by the lipid layer and is an important factor in dry eye conditions. Because the barrier to evaporation depends on the structure of the lipid layer, a high resolution microscope has been constructed to study the lipid layer in dry and in normal eyes. The microscope incorporates the following features. First, a long working distance microscope objective is used with a high numerical aperture and resolution. Second, because such a high resolution objective has limited depth of focus, 2000 images are recorded with a video camera over a 20-sec period, with the expectation that some images will be in focus. Third, illumination is from a stroboscopic light source having a brief flash duration, to avoid blurring from movement of the lipid layer. Fourth, the image is in focus when the edge of the image is sharp - this feature is used to select images in good focus. Fifth, an aid is included to help align the cornea at normal incidence to the axis of the objective so that the whole lipid image can be in focus. High resolution microscopy has the potential to elucidate several characteristics of the normal and abnormal lipid layer, including different objects and backgrounds, changes in the blink cycle, stability and fluidity, dewetting, gel-like properties and possible relation to lipid domains. It is expected that high resolution microscopy of the lipid layer will provide information about the mechanisms of dry eye disorders. Illustrative results are presented, derived from over 10,000 images from 375 subjects.
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Affiliation(s)
- P Ewen King-Smith
- College of Optometry, Ohio State University, Columbus, Ohio 43210, USA.
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Zhong M, Gadek TR, Bui M, Shen W, Burnier J, Barr KJ, Hanan EJ, Oslob JD, Yu CH, Zhu J, Arkin MR, Evanchik MJ, Flanagan WM, Hoch U, Hyde J, Prabhu S, Silverman JA, Wright J. Discovery and Development of Potent LFA-1/ICAM-1 Antagonist SAR 1118 as an Ophthalmic Solution for Treating Dry Eye. ACS Med Chem Lett 2012; 3:203-6. [PMID: 24900456 DOI: 10.1021/ml2002482] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 01/15/2012] [Indexed: 01/09/2023] Open
Abstract
LFA-1/ICAM-1 interaction is essential in support of inflammatory and specific T-cell regulated immune responses by mediating cell adhesion, leukocyte extravasation, migration, antigen presentation, formation of immunological synapse, and augmentation of T-cell receptor signaling. The increase of ICAM-1 expression levels in conjunctival epithelial cells and acinar cells was observed in animal models and patients diagnosed with dry eye. Therefore, it has been hypothesized that small molecule LFA-1/ICAM-1 antagonists could be an effective topical treatment for dry eye. In this letter, we describe the discovery of a potent tetrahydroisoquinoline (THIQ)-derived LFA-1/ICAM-1 antagonist (SAR 1118) and its development as an ophthalmic solution for treating dry eye.
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Affiliation(s)
- Min Zhong
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Thomas R. Gadek
- SARcode Bioscience, Inc., 1000 Marina Boulevard, Suite 250, Brisbane, California
94005, United States
| | - Minna Bui
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Wang Shen
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - John Burnier
- SARcode Bioscience, Inc., 1000 Marina Boulevard, Suite 250, Brisbane, California
94005, United States
| | - Kenneth J. Barr
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Emily J. Hanan
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Johan D. Oslob
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Chul H. Yu
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Jiang Zhu
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Michelle R. Arkin
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Marc J. Evanchik
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - W. Mike Flanagan
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Ute Hoch
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Jennifer Hyde
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Saileta Prabhu
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Jeffrey A. Silverman
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
| | - Jasmin Wright
- Sunesis Pharmaceuticals, Inc., 395 Oyster Point Boulevard, Suite 400, South San
Francisco, California 94080, United States
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Rommel CE, Dierker C, Schmidt L, Przibilla S, von Bally G, Kemper B, Schnekenburger J. Contrast-enhanced digital holographic imaging of cellular structures by manipulating the intracellular refractive index. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:041509. [PMID: 20799787 DOI: 10.1117/1.3449567] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The understanding of biological reactions and evaluation of the significance for living cells strongly depends on the ability to visualize and quantify these processes. Digital holographic microscopy (DHM) enables quantitative phase contrast imaging for high resolution and minimal invasive live cell analysis without the need of labeling or complex sample preparation. However, due to the rather homogeneous intracellular refractive index, the phase contrast of subcellular structures is limited and often low. We analyze the impact of the specific manipulation of the intracellular refractive index by microinjection on the DHM phase contrast. Glycerol is chosen as osmolyte, which combines high solubility in aqueous solutions and biological compatibility. We show that the intracellular injection of glycerol causes a contrast enhancement that can be explained by a decrease of the cytosolic refractive index due to a water influx. The underlying principle is proven by experiments inducing cell shrinkage and with fixated cells. The integrity of the cell membrane is considered as a prerequisite and allows a reversible cell swelling and shrinking within a certain limit. The presented approach to control the intracellular phase contrast demonstrated for the example of DHM opens prospects for applications with other quantitative phase contrast imaging methods.
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Affiliation(s)
- Christina E Rommel
- University of Muenster, Department of Medicine B, Gastroenterological Molecular Cell Biology, Muenster, Germany
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King-Smith PE, Hinel EA, Nichols JJ. Application of a novel interferometric method to investigate the relation between lipid layer thickness and tear film thinning. Invest Ophthalmol Vis Sci 2009; 51:2418-23. [PMID: 20019370 DOI: 10.1167/iovs.09-4387] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The lipid layer of the tear film forms a barrier to evaporation. Evaporation is a major cause of tear thinning between blinks and tear breakup. The purpose of this study was to investigate the relation between tear film thinning and lipid layer thickness before and after instillation of an emulsion eye drop. METHODS Fifty non-contact lens wearers were studied. Spectral interferometry was used to measure the thinning rate of the precorneal tear film for up to 19 seconds after a blink. Simultaneously, lipid layer thickness was measured based on an absolute reflectance spectrum. After a 2-minute recovery, the measurement was repeated. A drop of the lipid emulsion was then instilled; 15 minutes later, two interferometry measurements were performed similarly. RESULTS A histogram of thinning rates was fitted by a bimodal distribution with narrow and broad peaks corresponding to slow and rapid thinning, respectively. The correlation between repeated thinning rate measurements was modest, but repeatability was considerably more significant when analyzed in terms of the slow/rapid dichotomy. Similarly, the correlation between thinning rate and lipid thickness was modest but was more evident when analyzed in terms of the slow/rapid dichotomy. Instillation of an emulsion eye drop significantly increased the thickness of the lipid layer but did not significantly alter the thinning rate. CONCLUSIONS The proposed slow/rapid dichotomy of thinning rates presumably relates to a good/poor barrier to evaporation of the lipid layer. The imperfect correlation between thinning rate and lipid thickness indicates that other factors, such as the composition and structure of the lipid layer, are important (e.g., sufficient polar lipids may be needed to form good interface between nonpolar lipids and the aqueous layer).
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Affiliation(s)
- P Ewen King-Smith
- College of Optometry, The Ohio State University, Columbus, OH 43210, USA.
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Abstract
PURPOSE Given the refractive importance of the human cornea, surprisingly little attention has been directed to the study of local variation in corneal refractive-index. This in vitro and in vivo study measures the refractive-index of different portions of the bovine and human cornea. METHODS Fifty fresh bovine corneas (obtained from an abattoir) and 10 human subjects were used for the study. The refractive-index of the central, nasal, and temporal corneal epithelium was measured with a bench-top Abbe refractometer in the case of bovine corneas and with a hand-held refractometer with humans. RESULTS The mean (+/-standard deviation) refractive-indices of the central, nasal, and temporal bovine corneal epithelium were 1.3760 (+/-0.003), 1.3757 (+/-0.002), and 1.3746 (+/-0.002), respectively. Refractive-indices of the anterior and posterior bovine corneal stroma were 1.3731 (+/-0.002) and 1.3708 (+/-0.004), respectively. The mean (+/-standard deviation) refractive-index in the central, nasal, and temporal periphery of the human cornea epithelium were 1.3970 (+/-0.001), 1.3946 (+/-0.001), and 1.3940 (+/-0.001), respectively. CONCLUSION There are small local differences in the refractive-index of the bovine and human corneal epithelium and the refractive-index of the epithelium is higher than that of the anterior and posterior stroma of the bovine cornea.
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Huang LC, Redfern RL, Narayanan S, Reins RY, McDermott AM. In vitro activity of human beta-defensin 2 against Pseudomonas aeruginosa in the presence of tear fluid. Antimicrob Agents Chemother 2007; 51:3853-60. [PMID: 17724155 PMCID: PMC2151451 DOI: 10.1128/aac.01317-06] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa causes vision-threatening keratitis and is difficult to treat due to emerging resistance. Human beta-defensin 2 (hBD-2) is an antimicrobial peptide expressed by ocular surface epithelia with broad-spectrum activity against various pathogens, including P. aeruginosa. The activity of hBD-2 against P. aeruginosa in the presence of human tears or NaCl was studied. In some experiments, tears were heat-inactivated, filtered, and separated into cationic/anionic fractions or mucin MUC5AC was removed by immunoprecipitation before use. Immunoprecipitation was performed to study the interaction between hBD-2 and MUC5AC. hBD-2 activity was reduced by 40 to 90% in the presence of 17.5 to 70% (vol/vol) tears. NaCl reduced hBD-2 activity, but at most it could account for only 36% of the inhibitory effect of tears. Heat inactivation and filtration attenuated the ability of tears to inhibit hBD-2 activity by 65 and 68%, respectively. Anionic tear fractions significantly reduced (86%) the activity of hBD-2, whereas only a 22% reduction was observed with the cationic fractions. In the absence of MUC5AC, the activity of hBD-2 was restored by 64%. Immunoprecipitation studies suggested that the loss of hBD-2 activity in tears is due to a direct binding interaction with MUC5AC. Our data showed that the antimicrobial activity of hBD-2 is sensitive to the presence of human tears and that this is partly due to the salt content and also the presence of MUC5AC. These data cast doubt on the effectiveness of hBD-2 as an antimicrobial peptide, and additional studies are required to conclusively elucidate its role in innate immunity at the ocular surface in vivo.
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Affiliation(s)
- Ling C Huang
- College of Optometry, University of Houston, 505 J. Davis Armistead Building, 4901 Calhoun Road, Houston, TX 77204-2020, USA
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Khanal S, Tomlinson A, Pearce EI, Simmons PA. Effect of an oil-in-water emulsion on the tear physiology of patients with mild to moderate dry eye. Cornea 2007; 26:175-81. [PMID: 17251808 DOI: 10.1097/ico.0b013e31802b492d] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the effect of an oil-in-water emulsion eye drop compared with a conventional dry eye supplement (hypromellose) on tear physiology in dry eye. METHODS A randomized parallel, longitudinal, and investigator-masked study of the efficacy of 1.25% castor oil emulsion and 0.32% hypromellose solution was carried out. A total of 53 patients with mild to moderate dry eye (27 in emulsion group and 26 in hypromellose group) were recruited for the study. Patients were enrolled if they reported at least 2 symptoms on a McMonnies Dry Eye Questionnaire together with 1 of the following screening tests: noninvasive tear breakup time (5-10 seconds) and Schirmer test without anesthesia (2-5 mm in 5 minutes). Patients were instructed to use the test solutions 3 times a day for 30 days. Tear production, evaporation, lipid layer structure, and osmolality were measured before and 30 days after use of the drops. RESULTS A statistically significant decrease was seen after 1 month in tear evaporation rates with both emulsion (7.25 +/- 5.43 g/m2/h) and hypromellose (2.02 +/- 4.75 g/m2/h). However, the decrease with emulsion was significantly greater than with hypromellose (P < 0.001). Lipid layer structure improved from day 1 to day 30 of the study with the emulsion but not with the hypermellose. No significant changes were seen in tear production and osmolality with either of the drops. CONCLUSIONS The oil-water emulsion was more effective in reducing tear evaporation than hypromellose after repeated application over a 1-month period. This finding signifies the potential of the emulsion in the management of evaporative dry eye.
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Affiliation(s)
- Santosh Khanal
- Department of Vision Sciences, Glasgow Caledonian University, Glasgow, United Kingdom
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