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Morgan PB, Efron N, Papas E, Barnett M, Carnt N, Dutta D, Hepworth A, Little JA, Nagra M, Pult H, Schweizer H, Shen Lee B, Subbaraman LN, Sulley A, Thompson A, Webster A, Markoulli M. BCLA CLEAR Presbyopia: Management with contact lenses and spectacles. Cont Lens Anterior Eye 2024:102158. [PMID: 38631935 DOI: 10.1016/j.clae.2024.102158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
This paper seeks to outline the history, market situation, clinical management and product performance related to the correction of presbyopia with both contact lenses and spectacles. The history of the development of various optical forms of presbyopic correction are reviewed, and an overview is presented of the current market status of contact lenses and spectacles. Clinical considerations in the fitting and aftercare of presbyopic contact lens and spectacle lens wearers are presented, with general recommendations for best practice. Current options for contact lens correction of presbyopia include soft simultaneous, rigid translating and rigid simultaneous designs, in addition to monovision. Spectacle options include single vision lenses, bifocal lenses and a range of progressive addition lenses. The comparative performance of both contact lens and spectacle lens options is presented. With a significant proportion of the global population now being presbyopic, this overview is particularly timely and is designed to act as a guide for researchers, industry and eyecare practitioners alike.
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Affiliation(s)
- Philip B Morgan
- Eurolens Research, Division of Pharmacy and Optometry, University of Manchester, United Kingdom.
| | - Nathan Efron
- Optometry and Vision Science, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Eric Papas
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | | | - Nicole Carnt
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Debarun Dutta
- Optometry and Vision Science Research Group, Aston University, Birmingham, United Kingdom
| | - Andy Hepworth
- EssilorLuxottica Europe North, Bristol, United Kingdom
| | - Julie-Anne Little
- Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, United Kingdom
| | - Manbir Nagra
- Vision and Eye Research Institute, ARU, Young Street, Cambridge, United Kingdom
| | - Heiko Pult
- Dr Heiko Pult - Optometry and Vision Research, Weinheim, Germany
| | - Helmer Schweizer
- CEO Helmer Schweizer Consulting Group (HSCG), Bassersdorf, Switzerland
| | - Bridgitte Shen Lee
- Vision Optique and Ocular Aesthetics dba Ocular Clinical Trials, Houston, TX, United States
| | | | - Anna Sulley
- CooperVision International Ltd, Chandlers Ford, United Kingdom
| | | | | | - Maria Markoulli
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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Gustafson B, Whaley S, Giedd B, Montaquila S, Edwards B, Subbaraman LN. Short-Term Fit Assessment of a Novel Daily Disposable, Toric, Silicone Hydrogel Contact Lens. Clin Ophthalmol 2022; 16:3721-3730. [PMID: 36407500 PMCID: PMC9673940 DOI: 10.2147/opth.s370151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 10/19/2022] [Indexed: 11/16/2022] Open
Abstract
Purpose The development of new contact lens materials and designs are necessary to minimise patient dropout. A lens material with water surface technology was recently developed to incorporate toric design. The on-eye stability of a toric contact lens is critical to a successful toric lens fitting. In an effort to establish if the new daily disposable verofilcon A toric silicone hydrogel lens provides fast stability for ease of fit, this study assessed the initial and short-term on-eye stability of this new lens. Patients and Methods Habitual full-time wearers of soft contact lenses, aged 18 or over, were enrolled and fit with the verofilcon A toric lens. Study endpoints included lens settling time, axis orientation at specific time-points within 10 minutes after insertion, lens oscillation with blink, lens movement and centration, and scribe mark visibility. Results Thirty-nine subjects completed the study; 67% were female and mean age was 34.1 ± 10.8 years (range 18 to 61). The majority of verofilcon A toric lenses (98.7%) settled on average within 60 seconds. Average lens orientation was 3° from six o’clock position within two minutes of insertion. The lenses showed minimal oscillation with blink; 98.7% of the eyes demonstrated ≤5° oscillation with blink. All lenses showed optimal/acceptable lens movement and centration and the scribe mark was reported as easily visible in 96% of eyes. Practitioners reported a 99% first lens fit success rate. Conclusion The novel verofilcon A toric lens was highly successful with the first lens, had excellent on-eye stability and good fit characteristics. These qualities make this new lens a good option for lens wearers. Furthermore, it fulfills the needs of practitioners who want a toric lens that is easy and predictable to fit.
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Affiliation(s)
| | | | | | | | | | - Lakshman N Subbaraman
- Alcon Research, LLC, Johns Creek, GA, USA
- Correspondence: Lakshman N Subbaraman, Alcon Research, LLC, Clinical Development & Medical Affairs, Johns Creek, GA, 30097, USA, Tel +1 678 415 5316, Email
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Miller J, Giedd B, Subbaraman LN. Clinical Comparison of a Silicone Hydrogel and a Conventional Hydrogel Daily Disposable Contact Lens. Clin Ophthalmol 2021; 15:4339-4345. [PMID: 34744430 PMCID: PMC8565979 DOI: 10.2147/opth.s332651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/19/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose To compare the subjective performances of verofilcon A daily disposable silicone hydrogel contact lenses (CLs) and etafilcon A hydrogel CLs. Methods Successful wearers of spherical soft CLs for distance correction were prospectively randomized to wear verofilcon A or etafilcon A lenses for 1 week and crossed over to the alternative lenses. The primary study objective was a comparison of distance visual acuity (VA). Exploratory endpoints included subjective overall lens preference (5-point scale) and subjective ratings (10-point scales) of end-of-day (EOD) vision, overall handling, insertion comfort, EOD comfort, overall quality of vision, overall comfort, vision throughout the day, lens handling at insertion, and lens handling at removal. Results Of 92 subjects (184 eyes), 46 each were randomized to verofilcon A or etafilcon A lenses and subsequently crossed over to the other lenses. Evaluation of distance VA showed that verofilcon A lenses were noninferior to etafilcon A lenses. Comparison of lens preference showed that 68 (73.9%) subjects somewhat or strongly preferred verofilcon A lenses, whereas 21 (22.9%) somewhat or strongly preferred etafilcon A lenses (p<0.0001). Mean ± SD ratings of EOD vision (8.6±1.5 vs 7.7±1.9), overall handling (8.7±1.5 vs 6.9±2.3), insertion comfort (9.2±1.0 vs 7.7±1.9), and EOD comfort (8.0±1.9 vs 7.0±2.2) were all significantly (p≤0.0001 each) higher for verofilcon A than for etafilcon A lenses. Mean ± SD ratings of overall quality of vision (8.9±1.2 vs 8.2±1.8), overall comfort (8.6±1.5 vs 7.4±1.8), vision throughout the day (8.9±1.3 vs 8.1±1.8), lens handling at insertion (9.0±1.4 vs 6.9±2.5), and lens handling at removal (8.3±2.1 vs 7.7±2.2) were also significantly higher for verofilcon A lenses. No subject experienced any ocular adverse events. Conclusion After 1 week of wear, the study population reported that ratings for subjective endpoints were significantly higher for verofilcon A lenses than for etafilcon A lenses.
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Affiliation(s)
- Jason Miller
- EyeCare Professionals of Powell, Powell, OH, USA
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Heynen M, Ng A, Martell E, Subbaraman LN, Jones L. Activity of Deposited Lysozyme on Contemporary Soft Contact Lenses Exposed to Differing Lens Care Systems. Clin Ophthalmol 2021; 15:1727-1733. [PMID: 33935489 PMCID: PMC8079347 DOI: 10.2147/opth.s296116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/17/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose The amount of protein deposition on soft contact lenses and to what extent the proteins are denatured may have an impact on comfortable wearing times of contact lenses. The purpose of this study was to evaluate the effects of two lens care systems on total protein and the quantity and activity of lysozyme deposited on worn senofilcon A, silicone hydrogel contact lenses. Participants and Methods Thirty symptomatic soft contact lens wearers were enrolled into a 4-week prospective, randomized, bilateral eye, daily-wear, crossover, double-masked study. Participants were fitted with biweekly senofilcon A lenses and were assigned either a polyquaternium-1 and myristamidopropyl dimethylamine-containing system (OPTI-FREE RepleniSH) or a peroxide-based system (CLEAR CARE). After each wear period, proteins were extracted from the lenses and analyzed for total protein, total lysozyme quantity and activity. Results The use of either the peroxide-based system or the polyquaternium-1 and myristamidopropyl dimethylamine-containing system resulted in no difference (P>0.05) to the amount of total protein deposited on the lenses (6.7 ± 2.8 micrograms/lens versus 7.3 ± 2.8 micrograms/lens, respectively) or to the amount of denatured lysozyme deposits (0.8 ± 0.7 versus 0.9 ± 0.7 micrograms/lens), respectively. The total amount of lysozyme deposited on the lenses was significantly lower when using the peroxide-based system (1.3 ± 0.9 micrograms/lens) compared to the polyquaternium-1 and myristamidopropyl dimethylamine-containing system (1.7 ± 1.0 micrograms/lens) (P=0.02). Conclusion The inactivation of lysozyme deposited on senofilcon A lenses when disinfected with the peroxide-based or the polyquaternium-1 and myristamidopropyl dimethylamine-containing systems were neither statistically nor clinically significant and the overall amounts of denatured lysozyme recovered from the lenses were low (<1 microgram/lens).
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Affiliation(s)
- Miriam Heynen
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Alan Ng
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Elizabeth Martell
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Lyndon Jones
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada.,Centre for Eye and Vision Research (CEVR), Hong Kong Science Park, Hong Kong
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Yang M, Ngo W, Srinivasan S, Heynen ML, Dantam J, Subbaraman LN, Jones L, Senchyna M. Optimization of goblet cell density quantification methods. Exp Eye Res 2021; 207:108607. [PMID: 33930401 DOI: 10.1016/j.exer.2021.108607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 04/08/2021] [Accepted: 04/21/2021] [Indexed: 10/21/2022]
Abstract
The purpose of this study was to develop a standardized, accurate and efficient method for estimating conjunctival goblet cell density (GCD) via optimizing sample storage conditions and quantification methods. Conjunctival impression cytology (CIC) membranes were collected from both eyes of 32 participants and were randomized to two storage durations (2-3 weeks, 6-7 weeks) and two storage container types (microcentrifuge tube, flat histology cassette). The CIC membranes were stained and subdivided into 25 areas (5 mm × 5 mm) for imaging and the GCs were counted under 200X magnification using three different methods: (1) full CIC membrane GC count of the 25 images with cell-counting software ("full"; reference method), (2) partial membrane GC count of 9 images with cell-counting software ("partial"), and (3) manual counting of the 25 images ("manual"). In all cases, GCD was determined by dividing the GC count by the counting area. The average time required for quantification was recorded to gauge efficiency. Results showed no significant difference in GC count between the two storage durations (p = 0.745) or storage container types (p = 0.552). The median (interquartile range (IQR)) time required to quantify a CIC membrane for the full, partial, and manual methods of GC counting, was 14.8(17.6), 4.6(5.2) and 5.0 (5.0) minutes, respectively. The agreement of GCD values between the full and manual methods (bias: 0.4, 95% LOA: [-4.6, 5.5]) was stronger than that comparing the full and partial methods (bias: 0.5, 95% LOA: [-18, 17]). All together, through systematic examination of key procedural variables, an optimized method for GCD quantification within 7 weeks of sample collection was outlined. Adaption of procedures described in this paper to facilitate accurate and efficient GCD quantification may serve as a valuable step in clinical trials investigating DED pathophysiology and/or novel DED treatment strategies.
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Affiliation(s)
- Mike Yang
- Centre for Ocular Research and Education, University of Waterloo, School of Optometry & Vision Science, 200 University Avenue West, N2L 3G1, ON, Canada
| | - William Ngo
- Centre for Ocular Research and Education, University of Waterloo, School of Optometry & Vision Science, 200 University Avenue West, N2L 3G1, ON, Canada; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong.
| | - Sruthi Srinivasan
- Centre for Ocular Research and Education, University of Waterloo, School of Optometry & Vision Science, 200 University Avenue West, N2L 3G1, ON, Canada
| | - Miriam L Heynen
- Centre for Ocular Research and Education, University of Waterloo, School of Optometry & Vision Science, 200 University Avenue West, N2L 3G1, ON, Canada
| | - Jaya Dantam
- Centre for Ocular Research and Education, University of Waterloo, School of Optometry & Vision Science, 200 University Avenue West, N2L 3G1, ON, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research and Education, University of Waterloo, School of Optometry & Vision Science, 200 University Avenue West, N2L 3G1, ON, Canada
| | - Lyndon Jones
- Centre for Ocular Research and Education, University of Waterloo, School of Optometry & Vision Science, 200 University Avenue West, N2L 3G1, ON, Canada; Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong
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Qiao H, Luensmann D, Heynen M, Drolle E, Subbaraman LN, Scales C, Riederer D, Fadli Z, Jones L. In vitro Evaluation of the Location of Cholesteryl Ester Deposits on Monthly Replacement Silicone Hydrogel Contact Lens Materials. Clin Ophthalmol 2020; 14:2821-2828. [PMID: 33061266 PMCID: PMC7522414 DOI: 10.2147/opth.s270575] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 08/22/2020] [Indexed: 11/23/2022] Open
Abstract
Purpose The deposition profile of cholesteryl ester on the surface and throughout the matrix of silicone hydrogel contact lens (CL) materials was determined under conditions that mimic a daily wear regimen. Methods In this in vitro study, four SiHy CL materials (senofilcon C, lotrafilcon B, comfilcon A and samfilcon A) were incubated in an artificial tear solution (ATS) for up to 30 days. CL incubation was alternated between the ATS (16 hours) and a multipurpose care regimen (8 hours). The ATS included fluorescently tagged cholesteryl ester (5-cholesten-3ß-ol 6-[(7-nitro-2-1,3-benzoxadiazol-4-yl)amino]caproate; CE-NBD) and confocal laser scanning microscopy visualized the distribution of the lipid through the CLs. Results The distribution of CE-NBD was homogenous from the anterior to posterior surface in senofilcon C and comfilcon A, at all time points. For lotrafilcon B and samfilcon A, CE-NBD localization was heterogeneous, with greater amounts on the surfaces on Day 1 and Day 14 compared to the lens matrix; however, differences in concentration between the surface and bulk diminished by Day 30. Conclusion The distribution of the non-polar lipid CE-NBD varied with lens material chemistry. While some lens materials deposited the lipid primarily on the surface after 16 hours of exposure, all materials exhibited a homogenous distribution after one month.
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Affiliation(s)
- Han Qiao
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Doerte Luensmann
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Miriam Heynen
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Elizabeth Drolle
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Charles Scales
- Johnson & Johnson Vision Care, Inc, Jacksonville, FL, USA
| | | | - Zohra Fadli
- Johnson & Johnson Vision Care, Inc, Jacksonville, FL, USA
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada.,Centre for Eye & Vision Research (CEVR), Hong Kong, People's Republic of China
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Omali NB, Subbaraman LN, Heynen M, Lada M, Canavan K, Fadli Z, Ngo W, Jones L. Lipid deposition on contact lenses in symptomatic and asymptomatic contact lens wearers. Cont Lens Anterior Eye 2020; 44:56-61. [PMID: 32466858 DOI: 10.1016/j.clae.2020.05.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 05/08/2020] [Accepted: 05/11/2020] [Indexed: 11/18/2022]
Abstract
PURPOSE Lipid deposition on contact lenses (CL) has traditionally been believed to reduce comfort during CL wear. The purpose of this study was to quantify lipid deposition on CL in a group of symptomatic and asymptomatic adapted CL wearers. METHODS This was a single-masked, randomized clinical trial. Only confirmed symptomatic (comfortable lens wear time (CWT) < 8 h and a noticeable reduction in comfort over the course of the day) and asymptomatic (CWT > 10 h and minimal reduction in comfort over the course of the day) participants were recruited to participate in the study. Participants wore senofilcon A lenses in combination with a polyquaternium-based care solution (OPTI-FREE Replenish). Worn CL samples were collected on Day 14. Deposited lipid amounts from the lenses (including cholesteryl ester, cholesterol and triolein) were quantified using a liquid chromatography-mass spectrometry technique. RESULTS Lipid deposition was significantly higher in CL extracts of asymptomatic wearers compared to the symptomatic wearers for all lipid types quantified, including cholesteryl ester (2.1 ± 0.6 vs 1.6 ± 0.5 log μg/lens), cholesterol (1.5 ± 0.3 vs 1.1 ± 0.3 log μg/lens) and triolein (0.3 ± 0.2 vs 0.1 ± 0.1 log μg/lens) (all p < 0.002). The amount of cholesteryl ester deposited was greatest (p = 0.0001), followed by cholesterol, then triolein, for both the asymptomatic and symptomatic groups (both p = 0.0001). CONCLUSION This study demonstrated that the asymptomatic group deposited a significantly greater amount of lipid on their CL. Although lipid levels measured are considered low to trigger any observable clinical deposition, they may influence other clinical outcomes, particularly comfort.
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Affiliation(s)
- Negar Babaei Omali
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Miriam Heynen
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Mark Lada
- Johnson and Johnson Vision, Jacksonville, USA
| | | | - Zohra Fadli
- Johnson and Johnson Vision, Jacksonville, USA
| | - William Ngo
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
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Rangarajan R, Ketelson HA, Do R, McCanna DJ, Suko A, Enstone D, Subbaraman LN, Dantam J, Jones LW. Effect of Artificial Tear Formulations on the Metabolic Activity of Human Corneal Epithelial Cells after Exposure to Desiccation. J Vis Exp 2020. [PMID: 32420989 DOI: 10.3791/60812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Artificial lipid-containing tear formulations are developed to reduce tear evaporation by the restoration of a deficient tear lipid layer. Artificial tear formulations that prevent cell desiccation will result in ocular surface protection and the maintenance of cell metabolic activity. During dehydration, cells undergo the process of loss of metabolic activity and subsequently cell death. This work describes a method for assessing the efficacy of artificial tear formulations. The metabolic dye (i.e., alamarBlue) changes from a low fluorescent molecule resazurin to a fluorescent molecule resorufin in viable cells. The biological performance of an artificial tear formulation is measured as the ability of the formulation to (a) maintain cell viability and (b) provide cell protection from desiccation. Growth media and saline are used as controls for the cell viability/desiccation tests. Cells are incubated with test solutions for 30 min and then desiccated for 0 or 5 min at 37 °C and 45% relative humidity. Cell metabolic activity after initial exposure and after cell desiccation is then determined. The results show the comparative effects of eye drop formulations on cell metabolic activity and desiccation protection. This method can be used to test dry eye formulations that are designed to treat individuals with evaporative dry eye.
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Affiliation(s)
| | | | - Richard Do
- Centre for Ocular Research and Education (CORE), School of Optometry & Vision Science, University of Waterloo
| | - David J McCanna
- Centre for Ocular Research and Education (CORE), School of Optometry & Vision Science, University of Waterloo;
| | - Adeline Suko
- Centre for Ocular Research and Education (CORE), School of Optometry & Vision Science, University of Waterloo
| | - Daryl Enstone
- Centre for Ocular Research and Education (CORE), School of Optometry & Vision Science, University of Waterloo
| | | | - Jaya Dantam
- Centre for Ocular Research and Education (CORE), School of Optometry & Vision Science, University of Waterloo
| | - Lyndon W Jones
- Centre for Ocular Research and Education (CORE), School of Optometry & Vision Science, University of Waterloo
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Luensmann D, Omali NB, Suko A, Drolle E, Heynen M, Subbaraman LN, Scales C, Fadli Z, Jones L. Kinetic Deposition of Polar and Non-polar Lipids on Silicone Hydrogel Contact Lenses. Curr Eye Res 2020; 45:1477-1483. [PMID: 32281422 DOI: 10.1080/02713683.2020.1755696] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Purpose: This study investigated kinetic lipid uptake to four silicone hydrogel (SiHy) lenses over a period of four weeks, using an in-vitro radiolabel method. Methods: Four contemporary monthly replacement SiHy lenses (lotrafilcon B, senofilcon C, comfilcon A, samfilcon A) were incubated in three different solutions: 1) An artificial tear solution (ATS) containing 14C-labeled phosphatidylcholine (PC), 2) an ATS containing 14C-cholesteryl oleate (CO) and 3) an ATS containing four 14C-radiolabeled lipids (PC, phosphatidylethanolamine, CO, and cholesterol (total lipid)). After 16 hours, lipids were extracted twice from the lenses with chloroform:methanol and the radioactive counts determined the lipid quantities to simulate 1 day of wear. OPTI-FREE PureMoist (Alcon) was used to clean and disinfect the remaining lenses daily and the lipid quantities were further determined after 2 weeks and 4 weeks. Results: The amount of total lipid increased for all lenses over time (p < .01). After four weeks, total lipid accumulated was 20.26 ± 0.15 µg/lens for senofilcon C, which was significantly higher (p < .01) than all other lens materials (samfilcon A - 17.84 ± 0.21; comfilcon A - 16.65 ± 0.12; lotrafilcon B - 7.41 ± 0.56 µg/lens). CO was highest on lotrafilcon B (1.26 ± 0.13 µg/lens) and senofilcon C attracted the most PC (3.95 ± 0.12 µg/lens) compared to the other materials. Conclusion: The amount of both polar and non-polar lipid deposition on monthly replacement SiHy lenses increased over 4 weeks, with significant differences being seen between lens materials.
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Affiliation(s)
- Doerte Luensmann
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo , Waterloo, Canada
| | - Negar Babaei Omali
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo , Waterloo, Canada
| | - Adeline Suko
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo , Waterloo, Canada
| | - Elizabeth Drolle
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo , Waterloo, Canada
| | - Miriam Heynen
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo , Waterloo, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo , Waterloo, Canada
| | | | - Zohra Fadli
- Johnson & Johnson Vision Care, Inc , Jacksonville, USA
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo , Waterloo, Canada
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Muntz A, Subbaraman LN, Craig JP, Jones L. Cytomorphological assessment of the lid margin in relation to symptoms, contact lens wear and lid wiper epitheliopathy. Ocul Surf 2020; 18:214-220. [DOI: 10.1016/j.jtos.2019.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/24/2019] [Accepted: 12/05/2019] [Indexed: 12/17/2022]
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Dantam J, Subbaraman LN, Jones L. Adhesion of Pseudomonas aeruginosa, Achromobacter xylosoxidans, Delftia acidovorans, Stenotrophomonas maltophilia to contact lenses under the influence of an artificial tear solution. Biofouling 2020; 36:32-43. [PMID: 31973583 DOI: 10.1080/08927014.2019.1710832] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 12/25/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
Corneal infection is a devastating sight-threatening complication that is associated with contact lens (CL) wear, commonly caused by Pseudomonas aeruginosa. Lately, Achromobacter xylosoxidans, Delftia acidovorans, and Stenotrophomonas maltophilia have been associated with corneal infection. This study investigated the adhesion of these emerging pathogens to CLs, under the influence of an artificial tear solution (ATS) containing a variety of components commonly found in human tears. Two different CL materials, etafilcon A and senofilcon A, either soaked in an ATS or phosphate buffered saline, were exposed to the bacteria. Bacterial adhesion was investigated using a radio-labeling technique (total counts) and plate count method (viable counts). The findings from this study revealed that in addition to P. aeruginosa, among the emerging pathogens evaluated, A. xylosoxidans showed an increased propensity for adherence to both CL materials and S. maltophilia showed lower viability. ATS influenced the viable counts more than the total counts on CLs.
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Affiliation(s)
- Jaya Dantam
- Centre for Ocular Research & Education, School of Optometry & Vision Science, University of Waterloo, Waterloo, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education, School of Optometry & Vision Science, University of Waterloo, Waterloo, Canada
| | - Lyndon Jones
- Centre for Ocular Research & Education, School of Optometry & Vision Science, University of Waterloo, Waterloo, Canada
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Cheung S, Subbaraman LN, Ngo W, Jay GD, Schmidt TA, Jones L. Localization of full-length recombinant human proteoglycan-4 in commercial contact lenses using confocal microscopy. J Biomater Sci Polym Ed 2019; 31:110-122. [PMID: 31594478 DOI: 10.1080/09205063.2019.1678454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The aim of this study was to determine the sorption location of full-length recombinant human proteoglycan 4 (rhPRG4) tagged with fluorescein isothiocyanate (FITC) to four silicone hydrogel contact lenses [balafilcon A (PureVision, Bausch + Lomb), senofilcon A (Acuvue Oasys, Johnson & Johnson), comfilcon A (Biofinity, CooperVision), lotrafilcon B (Air Optix, Alcon)] and one conventional hydrogel lens [etafilcon A (Acuvue 2, Johnson & Johnson)], using confocal laser scanning microscopy (CLSM). Lenses (n = 3 each) were incubated under two conditions: (1) FITC-rhPRG4 solution at 300 μg/mL and (2) phosphate-buffered saline, for 1 h at 37 °C in darkness with gentle shaking. The central 4 mm of each lens was removed and viewed with the Zeiss 510 CLSM using an argon laser at 488 nm (FITC excitation 495 nm, emission 521 nm). Depth scans were taken at 1 μm intervals to a maximum depth of 100 μm. All lens materials demonstrated sorption of rhPRG4. Both senofilcon A and balafilcon A revealed FITC-rhPRG4 penetration into the bulk of the lens, generally favoring the surface. rhPRG4 was observed exclusively on the surface of lotrafilcon B, with no presence within the bulk of the lens. rhPRG4 was evenly distributed throughout the bulk of the lens, as well as on the surface, for comfilcon A and etafilcon A. The sorption profile of FITC-rhPRG4 was successfully visualized using CLSM in various contact lens materials. The polymer composition, surface treatment and pore size of the material can influence the sorption of rhPRG4.
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Affiliation(s)
- Steven Cheung
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - William Ngo
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Gregory D Jay
- Department of Emergency Medicine, Alpert Medical School & School of Engineering, Brown University, Providence, Rhode Island, USA
| | - Tannin A Schmidt
- Faculty of Kinesiology & Schulich School of Engineering, University of Calgary, Calgary, Alberta, Canada.,Biomedical Engineering Department, University of Connecticut Health Center, Farmington, Connecticut, USA
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
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Walther H, Subbaraman LN, Jones L. Novel in vitro method to determine pre-lens tear break-up time of hydrogel and silicone hydrogel contact lenses. Cont Lens Anterior Eye 2018; 42:178-184. [PMID: 30442514 DOI: 10.1016/j.clae.2018.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 10/10/2018] [Accepted: 11/04/2018] [Indexed: 10/27/2022]
Abstract
PURPOSE To develop an in vitro model to determine pre-lens non-invasive break-up time (NIBUT) and to subsequently use this method to compare the NIBUT over contemporary daily disposable (DD) contact lenses (CL). METHODS Three silicone hydrogel (SH) and two conventional hydrogel (CH) DD CLs were incubated in an artificial tear solution (ATS). A model blink cell (MBC) was utilised to mimic intermittent air exposure. CLs were repeatedly submerged for 3 seconds (s) and exposed to air for 10 s over periods of 2, 6, 12, and 16 hours (h). NIBUTs (n = 4) were determined out of the blister pack (T0) and at the end of each incubation period. RESULTS Overall, nesofilcon A showed the longest NIBUTs (p < 0.001). At T0, CHs revealed significantly longer NIBUTs (p ≤ 0.001) than SHs. After 2 h, nesofilcon A showed the longest NIBUT, however, this was only statistically significant compared with delefilcon A (p ≤ 0.001). After 6 h, nesofilcon A NIBUT was significantly longer than all other CLs (p ≤ 0.001). Etafilcon A showed a significantly longer NIBUT (p ≤ 0.001) after 12 h and delefilcon A had the longest NIBUT (p ≤ 0.001) after 16 h. Statistically significant (p ≤ 0.05) changes of NIBUT within the lens materials varied between time points. After 16 h, all CLs showed significant reductions in NIBUTs (p ≤ 0.001) in comparison to T0. CONCLUSION NIBUT values reduced gradually over time and varying levels of deposition impacted measured pre-lens NIBUTs. While NIBUT of CH materials are longer immediately out of the blister pack, after tear film exposure, the NIBUTs obtained using this methodology became very similar.
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Affiliation(s)
- Hendrik Walther
- Centre for Ocular Research & Education (CORE, formerly CCLR), School of Optometry and Vision Science, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada.
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE, formerly CCLR), School of Optometry and Vision Science, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE, formerly CCLR), School of Optometry and Vision Science, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada
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Phan CM, Walther H, Smith RW, Riederer D, Lau C, Osborn Lorenz K, Subbaraman LN, Jones L. Determination of the release of PEG and HPMC from nelfilcon A daily disposable contact lenses using a novel in vitro eye model. J Biomater Sci Polym Ed 2018; 29:2124-2136. [PMID: 30157706 DOI: 10.1080/09205063.2018.1514192] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The traditional method to measure release of components from CLs is a vial containing a static volume of PBS (phosphate buffered saline). However, this model does not simulate physiologically relevant tear volume and natural tear flow, air exposure, and mechanical rubbing. These factors can significantly impact release kinetics. We have developed an in vitro eye model (OcuFlow) that simulates these parameters. The aim of the study was to measure the release of PEG (polyethylene glycol), and HPMC (hydroxypropyl methylcellulose) from a daily disposable hydrogel contact lens material (nelfilcon A; Dailies AquaComfort PLUS; DACP;) over 24 hrs using the OcuFlow platform. The elution of PEG and HPMC from DACP lenses was analyzed using LCMS (liquid chromatography mass spectrometry). The release of all wetting agents from the lenses followed a burst release pattern, which occurred within the first 1.5 hrs (P < 0.05). The release of PEG was greater than that of HPMC (P < 0.05). The amount of PEG and HPMC released at any given time was less than 1% of the amount in the blister pack solution. Our results suggest that HPMC and PEG are rapidly released from the CL.
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Affiliation(s)
- Chau-Minh Phan
- a Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR) , School of Optometry and Vision Science , Waterloo , ON , Canada
| | - Hendrik Walther
- a Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR) , School of Optometry and Vision Science , Waterloo , ON , Canada
| | - Richard W Smith
- b University of Waterloo Mass Spectrometry Facility, Department of Chemistry , University of Waterloo , Waterloo , ON , Canada
| | | | - Charis Lau
- c Johnson & Johnson Vision , Jacksonville , FL , USA
| | | | - Lakshman N Subbaraman
- a Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR) , School of Optometry and Vision Science , Waterloo , ON , Canada
| | - Lyndon Jones
- a Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR) , School of Optometry and Vision Science , Waterloo , ON , Canada
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Omali NB, Subbaraman LN, Heynen M, Ng A, Coles-Brennan C, Fadli Z, Jones L. Surface versus bulk activity of lysozyme deposited on hydrogel contact lens materials in vitro. Cont Lens Anterior Eye 2018; 41:329-334. [DOI: 10.1016/j.clae.2018.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 12/15/2017] [Accepted: 03/18/2018] [Indexed: 01/12/2023]
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Oh S, McCanna DJ, Subbaraman LN, Jones LW. Cytotoxic and inflammatory effects of contact lens solutions on human corneal epithelial cells in vitro. Cont Lens Anterior Eye 2018; 41:282-289. [DOI: 10.1016/j.clae.2017.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 10/18/2017] [Accepted: 12/01/2017] [Indexed: 11/28/2022]
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McCanna DJ, Oh S, Seo J, Coles-Brennan C, Fadli Z, Subbaraman LN, Jones LW. The Effect of Denatured Lysozyme on Human Corneal Epithelial Cells. ACTA ACUST UNITED AC 2018; 59:2006-2014. [DOI: 10.1167/iovs.17-22260] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- David J. McCanna
- Centre for Ocular Research & Education, School of Optometry & Vision Science, Waterloo, Ontario, Canada
| | - Sarah Oh
- Centre for Ocular Research & Education, School of Optometry & Vision Science, Waterloo, Ontario, Canada
| | - Junghee Seo
- Centre for Ocular Research & Education, School of Optometry & Vision Science, Waterloo, Ontario, Canada
| | | | - Zohra Fadli
- Johnson & Johnson Vision Care, Inc., Jacksonville, Florida, United States
| | - Lakshman N. Subbaraman
- Centre for Ocular Research & Education, School of Optometry & Vision Science, Waterloo, Ontario, Canada
| | - Lyndon W. Jones
- Centre for Ocular Research & Education, School of Optometry & Vision Science, Waterloo, Ontario, Canada
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Walther H, Phan CM, Subbaraman LN, Jones L. Differential Deposition of Fluorescently Tagged Cholesterol on Commercial Contact Lenses Using a Novel In Vitro Eye Model. Transl Vis Sci Technol 2018; 7:18. [PMID: 29644148 PMCID: PMC5892225 DOI: 10.1167/tvst.7.2.18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 02/17/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose We evaluate the differences in lipid uptake and penetration in daily disposable (DD) contact lenses (CL) using a conventional “in-vial” method compared to a novel in vitro eye model. Methods The penetration of fluorescently labelled 22-(N-(7-Nitrobenz-2-Oxa-1,3-Diazol-4-yl)Amino)-23,24-Bisnor-5-Cholen-3beta-Ol (NBD)–cholesterol on three silicone hydrogel (SH) and four conventional hydrogel (CH) DD CLs were investigated. CLs were incubated for 4 and 12 hours in a vial, containing 3.5 mL artificial tear solution (ATS), or were mounted on an in vitro eye-blink platform designed to simulate physiologic tear flow (2 mL/24 hours), tear volume and “simulated” blinking. Subsequently, CLs were analyzed using laser scanning confocal microscopy and ImageJ. Results Penetration depth and fluorescence intensities of NBD-cholesterol varied between the incubation methods as well as lens materials. Using the traditional vial incubation method, NBD-cholesterol uptake occurred equally on both sides of all lens materials. However, using our eye-blink model, cholesterol penetration was observed primarily on the anterior surface of the CLs. In general, SH lenses showed higher intensities of NBD-cholesterol than CH materials. Conclusions The traditional “in-vial” incubation method exposes the CLs to an excessively high amount of ATS, which results in an overestimation for cholesterol deposition. Our model, which incorporates important ocular factors, such as intermittent air exposure, small tear volume, and physiological tear flow between blinks, provides a more natural environment for in vitro lens incubation. Translational Relevance In vitro measurements of CLs are a common approach to predict their interactions and performance on the eye. Traditional methods, however, are rudimentary. Therefore, this study presents a novel in vitro model to evaluate CLs, which consequently will enhance elucidations of the interactions between CLs and the eye.
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Affiliation(s)
- Hendrik Walther
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Chau-Minh Phan
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE) - formerly Centre for Contact Lens Research (CCLR), School of Optometry and Vision Science, Waterloo, Ontario, Canada
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Samsom M, Korogiannaki M, Subbaraman LN, Sheardown H, Schmidt TA. Hyaluronan incorporation into model contact lens hydrogels as a built-in lubricant: Effect of hydrogel composition and proteoglycan 4 as a lubricant in solution. J Biomed Mater Res B Appl Biomater 2017; 106:1818-1826. [DOI: 10.1002/jbm.b.33989] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 08/11/2017] [Accepted: 08/28/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Michael Samsom
- Biomedical Engineering Graduate Program; University of Calgary; Calgary Alberta Canada
| | - Myrto Korogiannaki
- Faculty of Chemical Engineering; McMaster University; Hamilton Ontario Canada
| | - Lakshman N. Subbaraman
- Centre for Contact Lens Research, School of Optometry & Vision Science; University of Waterloo; Waterloo Ontario Canada
| | - Heather Sheardown
- Faculty of Chemical Engineering; McMaster University; Hamilton Ontario Canada
| | - Tannin A. Schmidt
- Biomedical Engineering Graduate Program; University of Calgary; Calgary Alberta Canada
- Faculty of Kinesiology; University of Calgary; Calgary Alberta Canada
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Heynen M, Babaei Omali N, Fadli Z, Coles-Brennan C, Subbaraman LN, Jones L. Selectivity and localization of lysozyme uptake in contemporary hydrogel contact lens materials. Journal of Biomaterials Science, Polymer Edition 2017; 28:1351-1364. [DOI: 10.1080/09205063.2017.1327751] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Miriam Heynen
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada
| | - Negar Babaei Omali
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada
| | - Zohra Fadli
- Johnson & Johnson Vision Care Inc., Jacksonville, FL, USA
| | | | - Lakshman N. Subbaraman
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada
| | - Lyndon Jones
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada
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Phan CM, Bajgrowicz-Cieslak M, Subbaraman LN, Jones L. Release of Moxifloxacin from Contact Lenses Using an In Vitro Eye Model: Impact of Artificial Tear Fluid Composition and Mechanical Rubbing. Transl Vis Sci Technol 2016; 5:3. [PMID: 27847690 PMCID: PMC5106195 DOI: 10.1167/tvst.5.6.3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 09/10/2016] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The aim of this study was to evaluate and compare the release of moxifloxacin from a variety of daily disposable (DD) contact lenses (CLs) under various conditions using a novel in vitro eye model. METHODS Four commercially available DD conventional hydrogel (CH) CLs (nelfilcon A, omafilcon A, etafilcon A, and ocufilcon B) and three silicone hydrogel (SH) CLs (somofilcon A, narafilcon A, and delefilcon A) were evaluated. These lenses were incubated in moxifloxacin for 24 hours. The release of the drug was measured using a novel in vitro model in three experimental conditions: (1) phosphate buffered saline (PBS); (2) artificial tear solution (ATS) containing a variety of proteins and lipids; and (3) ATS with mechanical rubbing produced by the device. RESULTS Overall, CH CLs had a higher drug release than SH CLs (P < 0.05) under all conditions. Typically, a higher drug release was observed in PBS than ATS (P < 0.05). For CH, drug release was found to be higher in ATS with rubbing than PBS or ATS (P < 0.05). For most lens types, ATS with rubbing produced higher drug release than ATS alone (P < 0.05). Generally, the release kinetics for all conditions were sustained over the 24-hour testing period, and no burst release was observed (P < 0.05). CONCLUSIONS Moxifloxacin release from a CL into ATS is lower when compared to release into PBS. When mechanical rubbing is introduced, the amount of drugs released is increased. TRANSLATIONAL RELEVANCE Results suggest that sophisticated in vitro models are necessary to adequately model on-eye drug release from CL materials.
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Affiliation(s)
- Chau-Minh Phan
- Centre for Contact Lens Research, School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Magdalena Bajgrowicz-Cieslak
- Department of Mechanics, Material Science and Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Lakshman N. Subbaraman
- Centre for Contact Lens Research, School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Lyndon Jones
- Centre for Contact Lens Research, School of Optometry and Vision Science, Waterloo, Ontario, Canada
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Abstract
Few reports on the cellular anatomy of the lid wiper (LW) area of the inner eyelid exist and only one report makes use of cytological methods. The optimization of a method of collecting, staining and imaging cells from the LW region using impression cytology (IC) is described in this study. Cells are collected from the inner surface of the upper eyelid of human subjects using hydrophilic polytetrafluoroethylene (PTFE) membranes, and stained with cytological dyes to reveal the presence of goblet cells, mucins, cell nuclei and various degrees of pre- and para-keratinization. Immunocytochemical dyes show cell esterase activity and compromised cell membranes by the use of a confocal scanning laser microscope. Up to 100 microscopic digital images are captured for each sample and stitched into a high-resolution, large scale image of the entire IC span. We demonstrate a higher sensitivity of IC than reported before, appropriate for identifying cellular morphologies and metabolic activity in the LW area. To our knowledge, this is the first time this selection of fluorescent dyes was used to image LW IC membranes. This protocol will be effective in future studies to reveal undocumented details of the LW area, such as assessing cellular particularities of contact lens wearers or patients with dry eye or lid wiper epitheliopathy.
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Affiliation(s)
- Alex Muntz
- Centre for Contact Lens Research, University of Waterloo;
| | | | | | - Lyndon W Jones
- Centre for Contact Lens Research, University of Waterloo
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Abstract
Currently, in vitro evaluations of contact lenses (CLs) for drug delivery are typically performed in large volume vials, which fail to mimic physiological tear volumes. The traditional model also lacks the natural tear flow component and the blinking reflex, both of which are defining factors of the ocular environment. The development of a novel model is described in this study, which consists of a unique 2-piece design, eyeball and eyelid piece, capable of mimicking physiological tear volume. The models are created from 3-D printed molds (Polytetrafluoroethylene or Teflon molds), which can be used to generate eye models from various polymers, such as polydimethylsiloxane (PDMS) and agar. Further modifications to the eye pieces, such as the integration of an explanted human or animal cornea or human corneal construct, will permit for more complex in vitro ocular studies. A commercial microfluidic syringe pump is integrated with the platform to emulate physiological tear secretion. Air exposure and mechanical wear are achieved using two mechanical actuators, of which one moves the eyelid piece laterally, and the other moves the eyeballeyepiece circularly. The model has been used to evaluate CLs for drug delivery and deposition of tear components on CLs.
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Affiliation(s)
- Chau-Minh Phan
- School of Optometry and Vision Science, University of Waterloo;
| | - Hendrik Walther
- School of Optometry and Vision Science, University of Waterloo
| | | | - Jordan Rossy
- School of Optometry and Vision Science, University of Waterloo
| | | | - Lyndon Jones
- School of Optometry and Vision Science, University of Waterloo
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Omali NB, Subbaraman LN, Coles-Brennan C, Fadli Z, Jones LW. Biological and Clinical Implications of Lysozyme Deposition on Soft Contact Lenses. Optom Vis Sci 2015; 92:750-7. [PMID: 26002002 PMCID: PMC5638422 DOI: 10.1097/opx.0000000000000615] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 02/17/2015] [Indexed: 12/28/2022] Open
Abstract
Within a few minutes of wear, contact lenses become rapidly coated with a variety of tear film components, including proteins, lipids, and mucins. Tears have a rich and complex composition, allowing a wide range of interactions and competitive processes, with the first event observed at the interface between a contact lens and tear fluid being protein adsorption. Protein adsorption on hydrogel contact lenses is a complex process involving a variety of factors relating to both the protein in question and the lens material. Among tear proteins, lysozyme is a major protein that has both antibacterial and anti-inflammatory functions. Contact lens materials that have high ionicity and high water content have an increased affinity to accumulate lysozyme during wear, when compared with other soft lens materials, notably silicone hydrogel lenses. This review provides an overview of tear film proteins, with a specific focus on lysozyme, and examines various factors that influence protein deposition on contact lenses. In addition, the impact of lysozyme deposition on various ocular physiological responses and bacterial adhesion to lenses and the interaction of lysozyme with other tear proteins are reviewed. This comprehensive review suggests that deposition of lysozyme on contact lens materials may provide a number of beneficial effects during contact lens wear.
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Bajgrowicz M, Phan CM, Subbaraman LN, Jones L. Release of Ciprofloxacin and Moxifloxacin From Daily Disposable Contact Lenses From an In Vitro Eye Model. ACTA ACUST UNITED AC 2015; 56:2234-42. [DOI: 10.1167/iovs.15-16379] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Magdalena Bajgrowicz
- Department of Mechanics, Material Science and Engineering, Wroclaw University of Technology, Wroclaw, Poland
| | - Chau-Minh Phan
- Centre for Contact Lens Research, School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Lakshman N. Subbaraman
- Centre for Contact Lens Research, School of Optometry and Vision Science, Waterloo, Ontario, Canada
| | - Lyndon Jones
- Centre for Contact Lens Research, School of Optometry and Vision Science, Waterloo, Ontario, Canada
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Muntz A, Subbaraman LN, Sorbara L, Jones L. Tear exchange and contact lenses: a review. J Optom 2015; 8:2-11. [PMID: 25575892 PMCID: PMC4314619 DOI: 10.1016/j.optom.2014.12.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 11/07/2014] [Accepted: 11/26/2014] [Indexed: 05/29/2023]
Abstract
Tear exchange beneath a contact lens facilitates ongoing fluid replenishment between the ocular surface and the lens. This exchange is considerably lower during the wear of soft lenses compared with rigid lenses. As a result, the accumulation of tear film debris and metabolic by-products between the cornea and a soft contact lens increases, potentially leading to complications. Lens design innovations have been proposed, but no substantial improvement in soft lens tear exchange has been reported. Researchers have determined post-lens tear exchange using several methods, notably fluorophotometry. However, due to technological limitations, little remains known about tear hydrodynamics around the lens and, to-date, true tear exchange with contact lenses has not been shown. Further knowledge regarding tear exchange could be vital in aiding better contact lens design, with the prospect of alleviating certain adverse ocular responses. This article reviews the literature to-date on the significance, implications and measurement of tear exchange with contact lenses.
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Affiliation(s)
- Alex Muntz
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada.
| | - Lakshman N Subbaraman
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada
| | - Luigina Sorbara
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada
| | - Lyndon Jones
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada
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Phan CM, Subbaraman LN, Jones L. In vitrodrug release of natamycin from β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin-functionalized contact lens materials. Journal of Biomaterials Science, Polymer Edition 2014; 25:1907-19. [DOI: 10.1080/09205063.2014.958016] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ng A, Heynen M, Luensmann D, Subbaraman LN, Jones L. Impact of tear film components on the conformational state of lysozyme deposited on contact lenses. J Biomed Mater Res B Appl Biomater 2013; 101:1172-81. [PMID: 23564739 DOI: 10.1002/jbm.b.32927] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 12/06/2012] [Accepted: 01/30/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Alan Ng
- Centre for Contact Lens Research; School of Optometry and Vision Science; University of Waterloo; 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
| | - Miriam Heynen
- Centre for Contact Lens Research; School of Optometry and Vision Science; University of Waterloo; 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
| | - Doerte Luensmann
- Centre for Contact Lens Research; School of Optometry and Vision Science; University of Waterloo; 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
| | - Lakshman N. Subbaraman
- Centre for Contact Lens Research; School of Optometry and Vision Science; University of Waterloo; 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
| | - Lyndon Jones
- Centre for Contact Lens Research; School of Optometry and Vision Science; University of Waterloo; 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
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Abstract
PURPOSE To optimize a fluorescence-based lysozyme activity assay to investigate the conformational state of lysozyme in solution and to determine the impact of extraction and evaporation procedures and the possible interference of contact lens materials on lysozyme activity. METHODS The fluorescence-based lysozyme activity assay, Enzchek (Molecular Probes Inc, Eugene, OR) which utilizes fluorescently quenched Micrococcus lysodeikticus, was compared to the gold standard, classical lysozyme turbidity assay, using four differently concentrated lysozyme samples (20, 10, 5.0 and 2.0 ng/µL). Furthermore, six differently concentrated lysozyme samples (2.0, 1.0, 0.5, 0.25, 0.125 and 0.01 µg/µL) were quantified using the fluorescence-based assay in the presence of extraction solvents consisting of 0.2% and 0.02% trifluroacetic acid/acetonitrile and following evaporation procedures. RESULTS A standard curve was generated by the fluorescence-based assay ranging from 2 to 150 ng. The total active lysozyme quantified in the four lysozyme samples was not significantly different between the two assays (p > 0.05) and the concordance correlation coefficient was determined to be 0.995. However an average discrepancy between the two assays was found to be 0.474 ng, with the turbidity assay typically reporting higher active lysozyme measurements. The sensitivity of the fluorescence-based assay was higher than the classical turbidity assay when quantifying 20 ng or less active lysozyme. Following the extraction and evaporation procedures and the addition of lens extracts, the total active lysozyme recovered was 95% or greater. CONCLUSIONS In comparison to the classical turbidity assay, the fluorescence-based assay is a very sensitive method, making it a favorable technique, particularly when studying contact lens materials that deposit relatively low levels of lysozyme.
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Affiliation(s)
- Alan Ng
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada.
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Weeks A, Subbaraman LN, Jones L, Sheardown H. The Competing Effects of Hyaluronic and Methacrylic Acid in Model Contact Lenses. Journal of Biomaterials Science, Polymer Edition 2012; 23:1021-38. [DOI: 10.1163/092050611x569060] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Andrea Weeks
- a School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7
| | | | - Lyndon Jones
- c School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Centre for Contact Lens Research, University of Waterloo, Waterloo, ON, Canada
| | - Heather Sheardown
- d School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Centre for Contact Lens Research, University of Waterloo, Waterloo, ON, Canada.
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Chow LM, Subbaraman LN, Sheardown H, Jones L. Kinetics of in Vitro Lactoferrin Deposition on Silicone Hydrogel and FDA Group II and Group IV Hydrogel Contact Lens Materials. Journal of Biomaterials Science, Polymer Edition 2012; 20:71-82. [PMID: 19105901 DOI: 10.1163/156856208x393509] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Lisa M. Chow
- a Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Lakshman N. Subbaraman
- b Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Heather Sheardown
- c Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8
| | - Lyndon Jones
- d Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
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Subbaraman LN, Jones L. Kinetics of Lysozyme Activity Recovered from Conventional and Silicone Hydrogel Contact Lens Materials. Journal of Biomaterials Science, Polymer Edition 2012; 21:343-58. [DOI: 10.1163/156856209x415873] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Lakshman N. Subbaraman
- a Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Lyndon Jones
- b Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
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Subbaraman LN, Glasier MA, Senchyna M, Sheardown H, Jones L. Kinetics ofIn VitroLysozyme Deposition on Silicone Hydrogel, PMMA, and FDA Groups I, II, and IV Contact Lens Materials. Curr Eye Res 2009; 31:787-96. [PMID: 17050272 DOI: 10.1080/02713680600888799] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
We sought to compare the kinetics of in vitro lysozyme deposition on silicone hydrogel (SH), polymethyl methacrylate (PMMA), and FDA groups I, II, and IV contact lenses. Lenses were incubated in 125I-labeled lysozyme for time periods ranging from 1 hr to 28 days, and radioactive counts were determined. SH lenses and PMMA deposited less lysozyme than conventional hydrogel lenses (p < 0.05). Lysozyme accumulation on group IV lenses reached a maximum on the seventh day and then plateaued, whereas on groups I, II, and SH lenses, deposition continued to increase across all time periods, reiterating that kinetics of lysozyme deposition is highly material dependent.
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Affiliation(s)
- Lakshman N Subbaraman
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
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Glasier MA, Subbaraman LN, Senchyna M, Jones L. A Solid-Phase Assay for the Quantitation of Total Protein Eluted from Balafilcon, Lotrafilcon, and Etafilcon Contact Lenses. Curr Eye Res 2009; 33:631-40. [DOI: 10.1080/02713680802291537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Mary-Ann Glasier
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
| | - Lakshman N. Subbaraman
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
| | | | - Lyndon Jones
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
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Glasier MA, Keech A, Sheardown H, Subbaraman LN, Jones L. Conformational and Quantitative Characterization of Lysozyme Extracted from Galyfilcon and Senofilcon Silicone Hydrogel Contact Lenses. Curr Eye Res 2009; 33:1-11. [DOI: 10.1080/02713680701830278] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Subbaraman LN, Glasier MA, Senchyna M, Sheardown H, Jones L. Extraction Efficiency of an Extraction Buffer Used to Quantify Lysozyme Deposition on Conventional and Silicone Hydrogel Contact Lens Materials. Eye Contact Lens 2007; 33:169-73. [PMID: 17630622 DOI: 10.1097/01.icl.0000248155.23800.20] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Extracting lysozyme from Food and Drug Administration group IV etafilcon lenses by using 0.2% trifluoroacetic acid and acetonitrile (TFA/ACN) is a well-established procedure. TFA/ACN has been the extraction buffer of choice for extracting proteins from silicone hydrogel contact lenses. The purpose of this study was to determine the efficiency of TFA/ACN in extracting lysozyme from silicone hydrogel and etafilcon lenses by using an in vitro model. METHODS ACUVUE 2, Focus NIGHT & DAY, O2 Optix, PureVision, and ACUVUE Advance lenses were incubated in simple lysozyme solution and a complex artificial tear solution consisting of multiple tear components containing lysozyme labeled with iodine 125. All the silicone hydrogel lenses were incubated for 28 days, whereas the ACUVUE 2 lenses were incubated for 7 days at 37 degrees C with constant rotation. After the incubation period, radioactive counts were determined, and the lenses were placed in an appropriate volume of the buffer for 24 hours in darkness. The lenses were removed from the buffer, and radioactive counts were determined again. RESULTS Extraction efficiencies for lysozyme from the artificial tear solution were 97.2% +/- 1.2% for ACUVUE 2, 64.3% +/- 6.2% for Focus NIGHT & DAY, 62.5% +/- 5.6% for O2 Optix, 53.5% +/- 5.8% for PureVision, and 89.2% +/- 3.4% for ACUVUE Advance. Results were similar for the lysozyme extracted after incubating in the simple lysozyme solution. CONCLUSIONS TFA/ACN is extremely efficient at extracting lysozyme deposited on etafilcon lenses. However, it does not extract all the lysozyme deposited on silicone hydrogel lenses, and alternative extraction procedures should be sought.
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Affiliation(s)
- Lakshman N Subbaraman
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
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Suwala M, Glasier MA, Subbaraman LN, Jones L. Quantity and Conformation of Lysozyme Deposited on Conventional and Silicone Hydrogel Contact Lens Materials Using an In Vitro Model. Eye Contact Lens 2007; 33:138-43. [PMID: 17502748 DOI: 10.1097/01.icl.0000244155.87409.f6] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the activity of hen egg lysozyme (HEL) deposited on conventional and silicone hydrogel contact lens materials by using an in vitro model. METHODS ACUVUE 2 (etafilcon A), PureVision (balafilcon A), ACUVUE Advance (galyfilcon A), Focus NIGHT & DAY (lotrafilcon A), O2 Optix (lotrafilcon B), Proclear (omafilcon A), and ACUVUE OASYS (senofilcon A) contact lenses were deposited in vitro in a phosphate-buffered solution (PBS) containing 2 mg/mL HEL. Lenses were briefly rinsed in PBS to remove unbound material and extracted in a mixture of acetonitrile and trifluoroacetic acid. After lyophilization, extracts were examined for lysozyme activity by micrococcal assay and total protein by Western blot. RESULTS In terms of total protein accumulation, ACUVUE 2 showed the most, with 1,800 microg per lens. Proclear was next, with 68 microg per lens, and Focus NIGHT & DAY showed the least, with 2 microg per lens. ACUVUE Advance, ACUVUE OASYS, and O2 Optix accumulated similar amounts of lysozyme, at approximately 6 microg per lens. Lysozyme deposited on ACUVUE 2 showed the greatest activity (91% +/- 5%), and this result was statistically different from all other lens types (P<0.001). Lysozyme deposited on Focus NIGHT & DAY (24% +/- 5%) and O2 Optix (23% +/- 11%) showed the lowest activity. Lysozyme deposits on other lens materials showed intermediate activity (ACUVUE Advance, 60% +/- 15%; ACUVUE OASYS, 51% +/- 9%; PureVision, 58% +/- 8%; and Proclear, 38% +/- 3%). CONCLUSIONS Silicone hydrogel lenses acquire less lysozyme deposit than conventional group II (Proclear) or group IV (ACUVUE 2) lenses do, and the levels of activity of the lysozyme are highly variable between materials.
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Affiliation(s)
- Maciej Suwala
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
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Subbaraman LN, Bayer S, Glasier MA, Lorentz H, Senchyna M, Jones L. Rewetting Drops Containing Surface Active Agents Improve the Clinical Performance of Silicone Hydrogel Contact Lenses. Optom Vis Sci 2006; 83:143-51. [PMID: 16534456 DOI: 10.1097/01.opx.0000204513.76568.57] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The purpose of this study was to investigate the impact of using a rewetting drop (RWD) containing surface active agents (OPTI-FREE RepleniSH; Alcon, Fort Worth, TX) on the clinical performance and protein deposition when using a continuous-wear (CW) silicone hydrogel (SH) contact lens. METHODS Subjects wore lotrafilcon A SH lenses on a 30-day CW basis for two consecutive 1-month periods while inserting either 0.9% unpreserved unit-dose saline (control) or multidose OPTI-FREE RepleniSH (test RWD). Subjective comfort and symptoms were assessed after 2 and 4 weeks with each product. After 1 month of wear with each product, lenses were collected and analyzed in the laboratory for total protein, total lysozyme, and percentage of denatured lysozyme. RESULTS Symptoms of dryness and comfort varied across the day regardless of drop type (p < 0.001) with dryness being maximal on waking, least in the middle of the day, and increased towards the evening. The test RWD provided greater comfort on insertion (p = 0.02), better visual quality (p < 0.01), and less mucous discharge on waking (p = 0.02) than the control product. Lysozyme deposition was significantly reduced after the use of the test RWD as compared to saline (0.73 +/- 0.5 microg/lens vs. 1.14 +/- 0.7 microg/lens; p < 0.001) as was total protein deposition (1.17 +/- 0.7 microg/lens vs. 1.86 +/- 0.8 microg/lens; p < 0.001). Lysozyme denaturation was also reduced with the use of the test RWD compared with the control (76 +/- 10% vs. 85 +/- 7%; p < 0.01). CONCLUSIONS The use of a RWD containing surface active agents provided greater subjective satisfaction, reduced lysozyme and total protein deposition, and reduced denatured lysozyme than a RWD containing saline alone.
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Affiliation(s)
- Lakshman N Subbaraman
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
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Abstract
PURPOSE Lysozyme deposits extracted from lotrafilcon silicone hydrogel (SH) contact lens materials demonstrate a loss in total mass as a function of storage time when assessed by Western blotting. This loss represents a potential source of error when quantifying total lysozyme deposition on SH lenses. The purpose of this study was to devise a method whereby lysozyme mass would be preserved over time to allow for its accurate quantitation after its removal from SH lenses. METHODS Lysozyme deposits from 12 human worn lotrafilcon lenses were extracted using a 50:50 mixture of 0.2% trifluoroacetic acid and acetonitrile. Extracts were lyophilized to dryness, then resuspended in either reconstitution buffer (10 mM Tris-HCl, 1 mM EDTA) or modified reconstitution buffer (reconstitution buffer + 0.9% saline). BIOSTAB Biomolecule Storage Solution (Sigma-Aldrich) was added to one half of the samples from each buffer group. One microliter of each of the samples was immediately subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting, whereas the remaining volume was aliquoted and stored at -20 degrees C or -70 degrees C and subjected to the same procedures after 48 h of storage. Comparison of lysozyme band intensity in stored vs. fresh samples enabled calculation of percentage mass loss of lysozyme. RESULTS Samples stored at -20 degrees C in reconstitution buffer with no BIOSTAB demonstrated a 33% loss in mass over 48 h of storage. Identical samples stored at -70 degrees C in modified reconstitution buffer with BIOSTAB added demonstrated <1% loss in mass. Statistical analysis indicated that buffer composition (p < 0.001), storage temperature (p = 0.04), and addition of BIOSTAB (p < 0.001) were all important in controlling loss of mass over time. CONCLUSION We have optimized a procedure whereby the extracted mass of lysozyme deposits found on lotrafilcon SH lenses can be preserved, thus enabling accurate quantitation after extraction and resuspension.
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Affiliation(s)
- Lakshman N Subbaraman
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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