Publications

Showing 25 results out of 49 in total.

Cheung,S., Subbaraman,L. N., Ngo,W., Jay,G. D., Schmidt,T. A., Jones,L. Localization of full-length recombinant human proteoglycan-4 in commercial contact lenses using confocal microscopy Journal of Biomaterials Science, Polymer Edition 2020;31(1):110-122 [ Show 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.

Craig J, Jones L, Wolffsohn J. TFOS DEWSII Diagnosis and management of dry eye disease – LIVE! 11th Congreso Anual de Oftalmología, Bogota, Colombia, 2020

Dantam,J., Subbaraman,L. N., 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(1):32-43 [ Show 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.

DeLoss K, van der Worp E, Jones L, Pal S, Steele K, Szczotka-Flynn L. A vision on specialty lens care Global Specialty Lens Symposium, Las Vegas, USA, 2020

Drolle,E., Ngo,W., Leonenko,Z., Subbaraman,L., Jones,L. Nanoscale Characteristics of Ocular Lipid Thin Films Using Kelvin Probe Force Microscopy 2020;9(7):41 [ Show Abstract ]

Purpose: To describe the use of Kelvin probe force microscopy (KPFM) to investigate the electrical surface potential of human meibum and to demonstrate successful use of this instrument on both human meibum and a meibum model system (six-lipid stock [6LS]) to elucidate nanoscale surface chemistry and self-assembly characteristics.

Materials and Methods: 6LS and meibum were analyzed in this study. Mica-supported thin films were created using the Langmuir-Blodgett trough. Topography and electrical surface potential were quantified using simultaneous atomic force microscopy/KPFM imaging.

Results: Both lipid mixtures formed thin film patches on the surface of the mica substrate, with large aggregates resting atop. The 6LS had aggregate heights ranging from 41 to 153 nm. The range in surface potential was 33.0 to 125.9 mV. The meibum thin films at P = 5 mN/m had aggregates of 170 to 459 nm in height and surface poten- tial ranging from 15.9 to 76.1 mV, while thin films at P = 10 mN/m showed an aggregate size range of 147 to 407 nm and a surface potential range of 11.5 to 255.1 mV.

Conclusions: This study showed imaging of the differences in electrical surface poten- tial of meibum via KPFM and showed similarities in nanoscale topography. 6LS was also successfully analyzed, showing the capabilities of this method for use in both in vitro and ex vivo ocular research.

Translational Relevance: This study describes the use of KPFM for the study of ocular surface lipids for the first time and outlines possibilities for future studies to be carried out using this concept.

Efron,N., Brennan,N. A., Chalmers,R. L., Jones,L. W., Lau,C., Morgan,P. B., Nichols,J. J., Szczotka-Flynn,L. B., Willcox,M. D. Thirty years of ‘quiet eye’ with etafilcon A contact lenses Contact Lens Anterior Eye 2020;43(3):285-297 [ Show Abstract ]

Frequent replacement contact lenses made from the etafilcon A hydrogel lens material were introduced onto the market over 30 years ago, and etafilcon A remains the most widely used hydrogel lens material today. Although the prescribing of silicone hydrogel lenses is increasing, millions of lens wearers globally have been wearing hydrogel lenses for many years and exhibit a physiologically-stable ‘quiet eye’, with a low profile of adverse events. Hydrogel lenses are demonstrated to maintain a low inflammatory response and infection risk profile during daily wear, which in the case of etafilcon A, may be related to its low modulus, and the naturally-protective, anti-microbial, non-denatured lysozyme absorbed into the lens from the tear fluid. Although improved corneal physiology from decreased hypoxia with silicone hydrogel lenses is well accepted, equivalent levels of corneal oxygenation are maintained during daily wear of low to medium powered hydrogel lenses, which do not impede the daily corneal de-swelling process, and do not induce clinically significant changes in ocular health. Therefore, hydrogel lenses remain an important alternative for daily wear in modern contact lens practice.

Fadel D, Walsh K.. COVID-19, quando l'uso delle lenti è sicurio B2Eyes 2020;March. [ Show Abstract ]

Recentemente alcuni articoli di giornali sul possibile contagio da coronavirus tramite lenti a contatto e alcune organizzazioni sanitarie che consigliano il passaggio in questa fase agli occhiali anziché l’uso delle lenti a contatto sollevano facilmente la preoccupazione che l'utilizzo delle lac potrebbe non essere sicuro durante la pandemia da Covid-19. Questa inondazione di informazioni fuorvianti ha portato ricercatori di spicco nel panorama internazionale, da Canada, Regno Unito e Stati Uniti, a rispondere. Lyndon Jones, direttore del Center for Ocular Research & Education (CORE) presso l'Università di Waterloo (Canada), Philip Morgan, direttore di Eurolens Research presso l'Università di Manchester (Regno Unito), e Jason Nichols, vicepresidente associato di ricerca e docente all'Università dell'Alabama presso la Birmingham School of Optometry (Stati Uniti) e direttore editoriale di Contact Lens Spectrum, hanno fornito le seguenti informazioni sulla sicurezza dell'uso delle lenti a contatto.

Jones,L., Walsh,K.. COVID-19 and contact lenses - Practice re-entry considerations Optician 2020;August22-28 [ Show Abstract ]

A return to contact lens practice after the COVID-19 lock down requires an enhanced awareness of the risks and possibilities of contamination in the practice, and how to manage these. Patients can be triaged via a survey and telehealth before the appointment, and then precautions taken to assure distancing and protection as far as possible during their time in the practice. Staff need to be trained in new procedures and protected from exposure via screens and masks. Regular, rigorous cleaning of surfaces and equipment needs to be carried out between appointments and re-useable diagnostic lenses will need to be disinfected according to rigorous guidelines. However, with adequate guidance and care, contact lens wear continues to be a good option for patients.

Jones,L., Walsh,K., Willcox,M., Morgan,P., Nichols,J. The COVID-19 pandemic: Important considerations for contact lens practitioners Cont Lens Anterior Eye 2020;43196-203 [ Show Abstract ]

A novel coronavirus (CoV), the Severe Acute Respiratory Syndrome Coronavirus - 2 (SARS-CoV-2), results in the coronavirus disease 2019 (COVID-19). As information concerning the COVID-19 disease continues to evolve, patients look to their eye care practitioners for accurate eye health guidance. There is currently no evidence to suggest an increased risk of contracting COVID-19 through contact lens (CL) wear compared to spectacle lens wear and no scientific evidence that wearing standard prescription spectacles provides protection against COVID-19 or other viral transmissions.

During the pandemic there will potentially be significant changes in access to local eyecare. Thus, it is imperative CL wearers are reminded of the steps they should follow to minimise their risk of complications, to reduce their need to leave isolation and seek care. Management of adverse events should be retained within optometric systems if possible, to minimise the impact on the wider healthcare service, which will be stretched. Optimal CL care behaviours should be the same as those under normal circumstances, which include appropriate hand washing (thoroughly with soap and water) and drying (with paper towels) before both CL application and removal. Daily CL cleaning and correct case care for reusable CL should be followed according to appropriate guidelines, and CL exposure to water must be avoided. Where the availability of local clinical care is restricted, practitioners could consider advising patients to reduce or eliminate sleeping in their CL (where patients have the appropriate knowledge about correct daily care and access to suitable lens-care products) or consider the option of moving patients to daily disposable lenses (where patients have appropriate lens supplies available). Patients should also avoid touching their face, including their eyes, nose and mouth, with unwashed hands and avoid CL wear altogether if unwell (particularly with any cold or flu-like symptoms).

Jones D. Measure Axial Length to Guide Myopia Management Review of Myopia Management 2020;March 1. [ Show Abstract ]

Myopic patients must be managed and monitored closely. Myopia can no longer be considered as a benign refractive error, and it cannot be managed by traditional optical means. With the growing prevalence of myopia, and the increased risk of ocular pathology associated with high myopia, eye care professionals (ECPs) need to assess their patients for risk factors that may lead to its onset.

Jones D. What Myopia Management Is and What It Is Not Review of Myopia Management 2020;July [ Show Abstract ]

Almost without exception, a paper or article written about myopia starts with the alarming statistics and predictions regarding the prevalence of myopia worldwide. Globally, clinicians and researchers are hopefully well aware by now of the projection that by 2050, 50 percent of the world’s population will be myopic. While this traditionally sets the scene for the need for action to combat this epidemic, what exactly does the term myopia management mean, and how can it be put into practice?

Jones D. Myopia Management: What Are the Options? Optometric Management 2020;June [ Show Abstract ]

There have been alarming predictions regarding the rate of increase of myopia for the next three decades. Of particular concern is the predicted increase in high myopia, with reports that almost 10% of the world’s population will exhibit myopia in excess of -5.00 D by 2050. Given the abundance of evidence in the literature that shows myopia progression can be reduced, practitioners need to be proactive with their young patients and introduce the concept of myopia control as soon as there is evidence of a myopic refractive error. Additionally, practitioners need to be familiar with the treatment options available.

Jones L. TFOS DEWS II Epidemiology of dry eye disease report 11th Congreso Anual de Oftalmología, Bogota, Colombia, 2020

Jones L. Contact lens comfort update 2020

Jones L. Lids and Contact Lenses Interactive Webinar. April 9th, 2020

Jones L. Lids and Contact Lenses Interactive Webinar. April 15th, 2020

Jones L. TFOS DEWSII Management of dry eye disease report 11th Congreso Anual de Oftalmología, Bogota, Colombia, 2020

Jones L. Myopia control update 2020

Jones L, Cerenzie A, Goodhew T, Morrison S, O'Grady T. Successfully integrating myopia management into your practice 2020

Jones L, Stahl U, Guthrie S, Yang M, Yee A, Thom M. Contact Lens Compendium: Contact Lenses & Solutions Available in America. Vol 1 2020.

Jones L, Stahl U, Guthrie S, Yang M, Yee A, Thom M. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 46 2020.

Jones L, Walsh K, Willcox M, Morgan P, Nichols J. Key considerations for contact lens practitioners during the coronavirus pandemic. Contact Lens Spectrum 2020;June, 19-26: [ Show Abstract ][ PDF ]

A novel coronavirus (CoV), the Severe Acute Respiratory Syndrome Coronavirus-2 (SARSCoV-2), results in the coronavirus disease 2019 (COVID-19). The World Health Organization (WHO) declared the rapid spread of cases of COVID-19 a pandemic on March 11, 2020.
The global response to COVID-19 has resulted in substantial changes to business and social practices around the world. With concerns existing around the pandemic, many reports relating to how to best limit the chance of infection have been shared via various news outlets and on social media, with significant amounts of misinformation and speculation being reported. Among these, recent rumors have circulated stating that contact lens wear is unsafe, that wearers of contact lenses are more at risk of developing COVID-19, that certain contact lens materials are more “risky” compared with others, and that contact lens wearers should immediately revert to spectacle wear to protect themselves. How true are these statements, and are they supported by evidence? Importantly, are contact lens wearers increasing their risk of contracting COVID-19 by wearing contact lenses? Furthermore, what are the ramifications of a potential reduction in the availability of local ophthalmic care for contact lens wearers during this pandemic?

Jones L, Walsh K, Willcox M, Morgan P, Nichols J. Key considerations for contact lens practitioners during the coronavirus pandemic. Optician 2020;April, 19-25: [ Show Abstract ][ PDF ]

A novel coronavirus (CoV), the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), results in the coronavirus disease 2019 (COVID-19). The World Health Organisation (WHO) declared the rapid spread of cases of COVID-19 a pandemic on March 11, 2020. The global response to COVID-19 has resulted in substantial changes to business and social practices around the world. With concerns existing around the pandemic, many reports relating to how best limit the chance of infection have been shared via various news outlets and on social media, with significant amounts of misinformation and speculation being reported. Among these, recent rumours have circulated stating that contact lens wear is unsafe, that wearers of contact lenses are more at risk of developing COVID-19, that certain contact lens materials are ‘riskier’ than others and that contact lens wearers should immediately revert to spectacle wear to protect themselves. How true are these statements, and are they supported by evidence? Importantly, are contact lens wearers increasing their risk of contracting COVID-19 by wearing contact lenses? Furthermore, what are the ramifications of a potential reduction in the availability of local ophthalmic care for contact lens wearers during this pandemic?

Jones L, Walsh K, Wolffsohn J. Contemporary dry eye disease practice Global Specialty Lens Symposium, Las Vegas, USA, 2020

Luensmann,D., Omali,N. B., Suko,A., Drolle,E., Heynen,M., Subbaraman,L. S., Scales,C., Fadli,Z., Jones,L. Kinetic Deposition of Polar and Non-polar Lipids on Silicone Hydrogel Contact Lenses Current Eye Research 2020;Online ahead of print [ Show 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.