Sullivan,D. A., Rocha,E. M., Aragona,P., Clayton,J. A., Ding,J., Golebiowski,B., Hampel,U., McDermott,A. M., Schaumberg,D. A., Srinivasan,S., Versura,P., Willcox,M. D. P. TFOS DEWS II Sex, Gender, and Hormones Report Ocular Surface 2017;15(3):284-333 [ Show Abstract ]

One of the most compelling features of dry eye disease (DED) is that it occurs more frequently in women than men. In fact, the female sex is a significant risk factor for the development of DED. This sex-related difference in DED prevalence is attributed in large part to the effects of sex steroids (e.g. androgens, estrogens), hypothalamic-pituitary hormones, glucocorticoids, insulin, insulin-like growth factor 1 and thyroid hormones, as well as to the sex chromosome complement, sex-specific autosomal factors and epigenetics (e.g. microRNAs). In addition to sex, gender also appears to be a risk factor for DED. “Gender” and “sex” are words that are often used interchangeably, but they have distinct meanings. “Gender” refers to a person's self-representation as a man or woman, whereas “sex” distinguishes males and females based on their biological characteristics. Both gender and sex affect DED risk, presentation of the disease, immune responses, pain, care-seeking behaviors, service utilization, and myriad other facets of eye health. Overall, sex, gender and hormones play a major role in the regulation of ocular surface and adnexal tissues, and in the difference in DED prevalence between women and men. The purpose of this Subcommittee report is to review and critique the nature of this role, as well as to recommend areas for future research to advance our understanding of the interrelationships between sex, gender, hormones and DED. © 2017 Elsevier Inc.

Sullivan,D., da Costa,A. X., Del Duca,E., Doll,T., Grupcheva,C. N., Lazreg,S., Liu,S-H., McGee,S. R., Murthy,R., Narang,P., Ng,A. Y., Nistico,S., O'Dell,L., Roos,J., Shen,J., Markoulli,M. TFOS lifestyle: Impact of cosmetics on the ocular surface Ocular Surface 2023;29(July):77-130 [ Show Abstract ]

In this report the use of eye cosmetic products and procedures and how this represents a lifestyle challenge that may exacerbate or promote the development of ocular surface and adnexal disease is discussed. Multiple aspects of eye cosmetics are addressed, including their history and market value, psychological and social impacts, possible problems associated with cosmetic ingredients, products, and procedures, and regulations for eye cosmetic use. In addition, a systematic review that critically appraises randomized controlled trial evidence concerning the ocular effects of eyelash growth products is included. The findings of this systematic review highlight the evidence gaps and indicate future directions for research to focus on ocular surface outcomes associated with eyelash growth products.

Suwala,M., Glasier,M. -A, Subbaraman,L. N., Jones,L. Quantity and conformation of lysozyme deposited on conventional and silicone hydrogel contact lens materials using an in vitro model Eye and Contact Lens 2007;33(3):138-143 [ Show 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.

Szczotka-Flynn,L., Benetz,B. A., Lass,J., Albright,M., Gillespie,B., Kuo,J., Fonn,D., Sethi,A., Rimm,A. The association between mucin balls and corneal infiltrative events during extended contact lens wear Cornea 2011;30(5):535-542 [ Show Abstract ]

PURPOSE:: To determine the association between mucin ball formation and corneal infiltrative events (CIEs) during continuous wear with lotrafilcon A silicone hydrogel contact lenses. METHODS:: Subjects (n = 205) in the Longitudinal Analysis of Silicone Hydrogel Contact Lens Study wore lotrafilcon A contact lenses for 12 months of continuous wear. The primary outcome was a CIE. Kaplan-Meier methods were used to estimate the unadjusted cumulative incidence of remaining CIE free stratified by mucin ball presence. Cox proportional hazards regression was used to model the hazard of developing a CIE as a function of mucin ball formation and other covariates. RESULTS:: Over half (54.2%) of the subjects displayed some presence of mucin balls during at least 1 visit and about one third (32.8%) displayed repeated episodes. Mucin ball scores were correlated between the 2 eyes and weakly correlated with corneal curvature (P ≤ 0.005). Univariate analyses revealed that the relative hazard for a CIE was 0.35 [95% confidence interval (CI), 0.19-0.68] if a single episode of mucin balls was detected and 0.17 (95% CI, 0.06-0.43) if repeated episodes were detected. Upon multivariate analysis, repeated presence of mucin balls was associated with an 84% decreased hazard of experiencing a CIE (hazard ratio: 0.16; 95% CI, 0.06-0.44). CONCLUSIONS:: The presence of mucin balls is significantly associated with a decreased incidence of CIEs, and the effect is greatest when they are repeatedly present over time. We hypothesize that the mucin ball presence represents a more concentrated or viscous mucus layer, which prevents upregulation of the immune response against bacterial ligands. Copyright © 2011 by Lippincott Williams & Wilkins.

Tanti,N. C., Jones,L., Gorbet,M. B. Impact of multipurpose solutions released from contact lenses on corneal cells Optometry and Vision Science 2011;88(4):483-492 [ Show Abstract ]

Purpose. To assess, in vitro, the effect of the release of contact lens multipurpose solutions (MPS) from two silicone hydrogel lenses on human corneal epithelial cells. Methods. A monolayer of immortalized human corneal epithelial cells was seeded in a 24-well plate in keratinocyte serum-free medium. Lotrafilcon A (LA) and balafilcon A (BA) lenses were placed on top of the adherent cells for 8 and 24 h, after being soaked in MPS, borate-buffered (Unisol) or phosphate-buffered saline overnight. Cells were assayed for viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay or for α3, β1, and β4 integrin expression and caspase activation by flow cytometry. Results. After 8 h, LA lenses soaked in Unisol, Opti-Free Express (OFX), and ReNu MultiPlus (ReNu) showed decrease in cell viability. LA and BA soaked in Complete Moisture Plus (Complete) had similar viability at around 85% of control. After 24 h, a further decrease in viability was observed with all MPS-soaked lenses; LA soaked in OFX significantly reduced viability compared with Unisol-soaked lenses. In addition, reduced levels of integrin expression for lenses soaked in OFX and ReNu, and for BA soaked in Complete were observed. At 24 h, only LA soaked in OFX led to an increase in caspase activation. Conclusions. Our results indicate an increase in cytotoxicity with borate-based MPS solutions in vitro when compared with both phosphate-buffered saline and borate-exposed lenses, suggesting that biocides and/or additives play a role in the observed cell reaction. Moreover, the mechanism of in vitro solution-induced toxicity appeared to be mediated by lens type, suggesting differences in the preferential adsorption/release profile of certain compounds. Copyright © 2011 American Academy of Optometry.

Teichroeb,J. H., Forrest,J. A., Jones,L. W., Chan,J., Dalton,K. Quartz crystal microbalance study of protein adsorption kinetics on poly(2-hydroxyethyl methacrylate) Journal of colloid and interface science 2008;325(1):157-164 [ Show Abstract ]

The interaction of macromolecules with artificial biomaterials may lead to potentially serious complications upon implantation into a biological environment. The interaction of one of the most widely used biomaterials, polyHEMA, with lysozyme, bovine serum albumin (BSA), and lactoferrin was investigated using quartz crystal microbalance (QCM). The concentration dependence of adsorption was measured for the aforementioned proteins individually as well as for lysozyme-BSA, and lysozyme-lactoferrin combinations. An extension of Voinova's viscoelastic model to n layers was used to create thickness-time graphs for adsorption. For each of lactoferrin and lysozyme, two distinctly different timescales of adsorption could be differentiated. However, the mechanisms of adsorption appeared to differ between the two. Negative dissipation shifts were measured for low concentrations of lysozyme, trending to positive dissipation at higher concentrations. This suggested that lysozyme was adsorbed initially into the matrix, stiffening the hydrogel, and later onto the surface of polyHEMA. Additionally, trials with commercial no-rub cleaning solutions indicated little added effectiveness over buffer solutions. Mixtures of proteins showed behaviour which differed in some cases from the simple combination of single protein adsorption experiments. Crown Copyright © 2008.

Teichroeb,J. H., Forrest,J. A., Ngai,V., Jones,L. W. Anomalous thermal denaturing of proteins adsorbed to nanoparticles European Physical Journal E 2006;21(1):19-24 [ Show Abstract ]

We have used localized surface plasmon resonance (LSPR) to monitor the structural changes that accompany thermal denaturing of bovine serum albumin (BSA) adsorbed onto gold nanospheres of size 5nm-60nm. The effect of the protein on the LSPR was monitored by visible extinction spectroscopy. The position of the resonance is affected by the conformation of the adsorbed protein layer, and as such can be used as a very sensitive probe of thermal denaturing that is specific to the adsorbed protein. The results are compared to detailed calculations and show that full calculations can lead to significant increases in knowledge where gold nanospheres are used as biosensors. Thermal denaturing on spheres with diameter > 20 nm show strong similarity to bulk calorimetric studies of BSA in solution. BSA adsorbed on nanospheres with d ≤ 15nm shows a qualitative difference in behavior, suggesting a sensitivity of denaturing characteristics on local surface curvature. This may have important implications for other protein-nanoparticle interactions. © EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2006.

Thite,N., Desiato,A., Shinde,L., Wolffsohn,J. S., Naroo,S. A., Santodomingo Rubido,J., Cho,P., Jones,D., Villa-Collar,C., Carrillo,G., Chan,O., Wang,H., Iomdina,E., Tarutta,E., Proskurina,O., Fan,C. S., Zeri,F., Bakkar,M. M., Barodawala,F., Dabral,N., Lafosse,E., Lee,C., Nichols,J. J., Chan, J., Park,K., Nair,V., Van Der Worp,E., Vankudre,G., Maseedupally,V., Bhattarai,Y., Nagzarkar,D., Brauer,P., Gil-Cazorla,R. Differences in Practitioner Experience, Practice Type, and Profession in Attitudes Toward Growing Contact Lens Practice Eye & Contact Lens 2022;48(9):369-376 [ Show Abstract ]

Objective: To investigate eye care practitioners' attitudes and perceptions toward potential interventions that can enhance contact lens (CL) practice across the world, and how this is influenced by their practice setting.

Methods: A self-administered, anonymized survey was constructed in English and then forward and backward translated into six more languages. The survey was distributed online via social media platforms and mailing lists involving reputed international professional bodies.
Results: In total, 2,222 responses from 27 countries with sufficient responses were analyzed (53% females, median age- 37 years). Most of the respondents were optometrists (81.9%) and 47.6% were from stand-alone/independent practices. Median working experience in CL prescribing was 11.0 years (IQR: 18.0, 4-22 years). Over two-third of them declared themselves to be very hopeful (22.9%) or hopeful (45.1%) about the future of their CL practice. Among the potential interventions proposed, continuous update of knowledge and skills and competently managing CL-related complications were rated the most important (median score: 9/10 for each). Practitioners working in national/regional retail chains expressed higher proactivity in recommending CLs (9/10) than those in local chains, hospitals, and universities (for all 8/10, P<0.05). National differences were also identified in eye care practitioner attitudes and perceptions (P<0.05).

Conclusions: The study provided important information to delineate a variety of elements characterizing CL practice across the world. These insights can serve as a basis to design strategies at national and international levels

Thite,N., Desiato,A., Shinde,L., Wolffsohn,J. S., Naroo,S. A., Santodomingo-Rubido,J., Cho,P., Jones,D., Villar-Collar,C., Carillo,G., Chan,O., Wang,H., Iomdina,E., Tattura,E., Proskurina,O., Shing Fan,C., Zeri,F., Bakkar,M. M., Barodawala,F., Dabral,N., Lafosse,E., Lee,C., Nichols,J. J., Chan,J., Park,K., Nair,V., van der Worp,E., Vankudre,G., Maseedupalli,V., Bhattarai,Y., Nagzarkar,D., Brauer,P., Gil-Cazorla,R. Opportunities and threats to contact lens practice: A global survey perspective Contact Lens Anterior Eye 2021;44(6):101496 [ Show Abstract ]

Aim
To understand the views of contact lens (CL) practitioners across the globe regarding what they perceive as opportunities and threats in CL practice.

Methods
A self-administered anonymised questionnaire, constructed in English and translated in six more languages, was distributed through reputed international professional bodies and academic institutions worldwide. The questionnaire included items on demographic characteristics, type of practice, and questions designed to explore practitioners’ perspective on the future of their CL practice over the next five years.

Results
A total of 2408 valid responses were analysed. Multifocal CLs for presbyopia, CLs for myopia control, use of daily disposable (DD) CLs for occasional wear, and biocompatible materials to improve comfort were identified as promising areas of opportunities by practitioners (all 8/10). Respondents from North America, and Europe valued DDCLs for occasional wear moderately more favourable (Median: 9/10 for all) as compared to colleagues in Asia (Median: 8/10, p < 0.001), South America (Median: 8/10, p < 0.01), and Africa (Median: 8/10p < 0.01). Multifocal CLs for presbyopia was perceived as a better opportunity by practitioners in North America and Europe (Median: 9/10 for both), as well as in Australasia (Median: 8/10), in comparison to Asia, Africa, and Middle East (for all Median: 6/10, p < 0.001). Practitioners expressed concerns about the availability of CLs and CL prescriptions online without direct professional involvement (both 9/10).

Conclusions
Overall, the most appealing opportunities for CL practice growth were identified in occasional use of DD CLs, biocompatible materials to reduce CL discomfort, multifocal CLs for presbyopia correction and management of myopia control with CLs. Lack of regulation in CL sales, especially online, seemed to be a constant threat. The insights from this study can be used to design targeted strategies to enhance CL practice across the globe and in specific geographical areas.

Tichenor,A., Cofield,S., Gann,D., Elder,M., Ng,A. Y., Walsh,K., Jones,L., Nichols,J. Frequency of Contact Lens Complications Between Contact Lens Wearers Using Multipurpose Solutions Versus Hydrogen Peroxide in the United States and Canada Eye & Contact Lens 2021;47(5):277-282 [ Show Abstract ]

Objectives: To retrospectively compare frequency of contact lens (CL) complications in soft CL users of hydrogen peroxide (H2O2) and multipurpose solutions (MPS).

Methods: This was a multicenter, retrospective chart review of CL records from each patient's three most recent eye examinations at academic and private practices. Patients must have used the same solution type for at least 3 years. Univariate analyses were conducted using t tests, and chi-square or Fisher's exact test for categorical measures.

Results: There were 1,137 patients included, with 670 (59%) using MPS and 467 (41%) H2O2. In total, 706 (62%) experienced at least one complication; 409 used MPS and 297 used H2O2. There was no difference in the proportion of patients experiencing at least one complication between MPS (61%) and H2O2 (64%) (P=0.38). Multipurpose solutions users were more likely to report discomfort compared with H2O2 users (P=0.04). Presumed microbial keratitis was experienced by 16 MPS and nine H2O2 users (P=0.60).

Conclusions: No significant differences were found in the frequency of CL complications between MPS and H2O2. H2O2 users were less likely to report discomfort and thus switching to a H2O2 system may be an alternative in CL users with discomfort.

Tonge,S., Jones,L., Goodall,S., Tighe,B. The ex vivo wettability of soft contact lenses Current eye research 2001;23(1):51-59 [ Show Abstract ]

Purpose. To investigate the ex vivo wettability of Etafilcon A contact lenses over an eight hour period of wear and observe the influence of surfactant pre-treatment. Methods. Etafilcon A hydrogel lenses, comprising poly[2-hydroxyethyl methacrylate-co-methacrylic acid] and 58% water, were soaked for 12 hours in either 0.9% saline (control) or a 1% aqueous solution of poloxamine 1107 (treated). The advancing and receding contact angles were subsequently determined ex vivo after various periods of wear in six adapted contact lens wearers using a single-blind, randomised protocol. Contact angles were measured with a dynamic contact angle tensiometer, using the Wilhelmy plate technique. Patient comfort scores were recorded and the static surface tensions of the probe fluids assessed. Results. Control lenses exhibited no change in wetting angles over time, indicating a lack of surface modification by components within the tear film. Treated lenses exhibited a significantly reduced advancing angle (p > 0.001) and hysteresis angle (p < 0.001) when compared with control lenses. In addition, treated lenses were consistently rated as being more comfortable than control lenses (p = 0.04). Conclusions. This study has shown clearly that new Etafilcon A lenses do not exhibit significant changes in wettability during the initial four hour wearing period. Pre-treatment of such lenses with a polymeric surfactant results in wetting of the lenses due to the adsorption of surfactant. The surfactant is retained by the lens for at least eight hours of wear, resulting in significant improvements in subjective comfort, especially over the first 30 minutes of wear.

Troilo,D., Smith,E. L. 3rd, Nickla,D. L., Ashby,R., Tkatchenko,A. V., Ostrin,L. A., Gawne,T. J., Pardue,M. T., Summers,J. A., Kee,C. S., Schroedl,F., Wahl,S., Jones,L. IMI - Report on Experimental Models of Emmetropization and Myopia Invest Ophthalmol Vis Sci 2019;60(3):M31-M88 [ Show Abstract ]

The results of many studies in a variety of species have significantly advanced our understanding of the role of visual experience and the mechanisms of postnatal eye growth, and the development of myopia. This paper surveys and reviews the major contributions that experimental studies using animal models have made to our thinking about emmetropization and development of myopia. These studies established important concepts informing our knowledge of the visual regulation of eye growth and refractive development and have transformed treatment strategies for myopia. Several major findings have come from studies of experimental animal models. These include the eye's ability to detect the sign of retinal defocus and undergo compensatory growth, the local retinal control of eye growth, regulatory changes in choroidal thickness, and the identification of components in the biochemistry of eye growth leading to the characterization of signal cascades regulating eye growth and refractive state. Several of these findings provided the proofs of concepts that form the scientific basis of new and effective clinical treatments for controlling myopia progression in humans. Experimental animal models continue to provide new insights into the cellular and molecular mechanisms of eye growth control, including the identification of potential new targets for drug development and future treatments needed to stem the increasing prevalence of myopia and the vision-threatening conditions associated with this disease.

Tse,J., Rizwan,M., Rasmussen,J., Jones,L., Yim,E. K. F. Gelatin Methacrylate as an Enzyme-Controlled Release Vehicle of Hyaluronic Acid for the Treatment of Recurrent Corneal Erosion Applied Bio Materials 2020;3(9):6214-6223 [ Show Abstract ]

Recurrent corneal erosion (RCE) is a condition where the superficial corneal epithelial cells sporadically shed because of poor attachment to the underlying basement membrane, resulting in pain and discomfort. RCE-afflicted corneas exhibit elevated biological factors and enzymes, such as matrix metalloproteinase (MMP)-9. Soft bandage contact lenses (BCLs) are a commonly recommended treatment as they permit continued vision during recovery. However, they do not outperform alternative treatments as they currently lack active ingredients for ocular surface repair. Development of BCLs with a sustained release of active ingredients to promote RCE wound healing over an extended period of time would be clinically valuable. We fabricated gelatin methacrylate (GelMA) hydrogels with MMP-9-triggered controlled release for further BCL development. GelMA disks were characterized to determine the optimal concentration and methacrylation degree for sustained release in the presence of MMP-9. The chosen active ingredient, 60 kDa hyaluronic acid (HA), was verified to promote wound healing in rabbit corneal epithelial cell and human corneal epithelial cell wound assays. The active ingredient was loaded into GelMA hydrogels, and the bioavailability of the vehicle was determined. The GelMA hydrogels revealed a tunable profile for diffusion and enzyme-mediated controlled release of a model molecule. The 60 kDa HA-loaded GelMA disks showed improvement in wound healing at HA loadings of 150 and 250 μg by improving the wound healing rates by 28% (68.7% wound closure) and 26% (67.9% wound closure), respectively, compared to the control (50.5% wound closure) at 24 h. The HA-loaded GelMA disks with 150 and 250 μg HA also exhibited shortened wound closure time of 75 h compared to >147 h with a bolus daily delivery of HA for wound closure. Overall, we demonstrated that the fabricated GelMA hydrogels offered an enzyme-triggered option as a sustained release material for future RCE treatments.

Ulkuseven,E., McCanna,D. J., Subbaraman,L. N., Jones,L. W. The Effect of Antimicrobial Peptides on the Viability of Human Corneal Epithelial Cells Probiotics and Antimicrobial Proteins 2021;13(2):518-526 [ Show Abstract ]

Antimicrobial peptides are polypeptides composed of less than 100 amino acids and are a class of antibiotics with strong activity against some infectious bacteria. This study examined the safety of four chosen antimicrobial peptides using primary human corneal epithelial cells (HCEC) and explored their potential therapeutic use. The efficacy of the peptides was also studied by evaluating the minimum inhibitory concentrations (MIC) against Gram-negative and Gram-positive bacteria. One of the peptides (polymyxin E) was found to have antibacterial efficacy against a common Gram-negative bacterium (MIC 1.56 μg/mL for Pseudomonas aeruginosa), and another one (nisin) was found to have antibacterial efficacy against a common Gram-positive bacterium (MIC 125 μg/mL for Staphylococcus aureus). Metabolic activity and live/dead/apoptotic effects were measured with fluorescent dyes after HCEC were exposed to the peptides for 30 min. Three of the peptides exhibited lower toxicity against HCEC than a currently marketed eye drop product. Regarding both efficacy and safety, two of the peptides (polymyxin E and nisin) were found to have potential use for treating ocular infections.

Van Beek,M., Jones,L., Sheardown,H. Hyaluronic acid containing hydrogels for the reduction of protein adsorption Biomaterials 2008;29(7):780-789 [ Show Abstract ]

Recently, new contact lens materials have been introduced which are reported to improve comfort by incorporating wetting agents either in a releasable or nonreleasable form. In the present work, model lens materials based on poly(2-hydroxyethyl methacrylate) (pHEMA) were developed which incorporate releasable or crosslinked and therefore physically entrapped hyaluronic acid (HA) of various molecular weights as a wetting agent. Crosslinked HA, despite being only present in very small amounts, resulted in consistently lower water contact angles over 4 h in comparison to controls, indicating that HA is present at the interface and was not being released over time. The presence of HA in the material was further confirmed by increases in the glass transition temperature measured by differential scanning calorimetry (DSC), and small increases in the stiffness as measured by Instron testing. This crosslinking procedure appeared to have no effect on optical transparency using 35 kDa HA, whereas small decreases in optical transparency at higher wavelengths were noted for the 169 kDa HA crosslinked material, as measured by UV spectrophotometry. Most importantly, protein adsorption results indicated that the adsorption of all proteins studied was considerably decreased by the presence of the small amount of crosslinked HA. The results provide insight into the mechanisms of comfort improvement with commercially available lens materials and suggest that HA containing materials may have significant potential for use in contact lens applications. © 2007 Elsevier Ltd. All rights reserved.

van der Worp,E., Wolffsohn,J., Jones,L. When was the last time you fitted a soft lens? Cont Lens Anterior Eye 2020;43(5):415-417 [ Show Abstract ]

A recent webinar “discussing the topic of soft lenses, examining dropout rates and putting forward suggestions for how eye care practitioners can ‘get control’ over their fitting” was hosted by the British Contact Lens Association (BCLA). However, the webinar and this editorial addresses much more than merely’ lens fitting’ and ‘dropouts.’ It seems that the profession is almost at a crossroads in which its future is defined by whether the profession stands as contact lens fitters and specialists or whether contact lenses are simply a commodity that can be sold over the internet.

Varikooty J., Srinivasan S., Subbaraman L., Woods C.A., Fonn D., Simpson T.L., Jones L.W. Variations in observable lid wiper epitheliopathy (LWE) staining patterns in wearers of silicone hydrogel lenses Contact Lens and Anterior Eye 2015;38(6):471-476

Varikooty,J., Keir,N., Richter,D., Jones,L. W., Woods,C., Fonn,D. Comfort response of three silicone hydrogel daily disposable contact lenses Optometry and Vision Science 2013;90(9):945-953 [ Show Abstract ]

PURPOSE: To evaluate subjective ocular comfort across the day with three silicone hydrogel daily disposables (SHDDs) in a group of adapted lens wearers. METHODS: Masked subjects (asymptomatic or symptomatic of end-of-day (EOD) dryness with habitual lenses) wore three SHDDs: DAILIES TOTAL1 (DT1), Clariti 1day (C1D), or 1-DAY ACUVUE TRUEYE (AVTE), each for 3 days. On day 2, wearing time (WT) and comfort ratings after insertion, at 4, 8, and 12 hours, and at EOD were recorded. Because not all subjects wore lenses for 12 hours, comfort was analyzed across the day (up to 8 hours, 8 to 12 hours), and a new variable ("cumulative comfort" [CC]) was calculated for EOD. RESULTS: One hundred four subjects completed the study (51 asymptomatic, 53 symptomatic). The two groups had different WTs (mean WT, 14.0 and 12.7 hours, respectively; p < 0.001). Ocular comfort was rated higher in the asymptomatic group throughout the day (p < 0.001). One hundred four subjects wore all three SHDDs for at least 8 hours, whereas 74 (45 asymptomatic, 29 symptomatic) subjects wore them for 12 hours or longer. Comfort ratings were higher with DT1 (least square means [LSM] = 91.0) than with C1D (LSM = 86.5; p < 0.001) and AVTE (LSM = 87.7; p = 0.011) for the first 8 hours and lower with C1D compared with DT1 (p = 0.012) from 8 to 12 hours. Mean EOD (± SD) comfort with the C1D lens was 72 ± 21, lower than both DT1 (mean, 79 ± 17; p = 0.001) and AVTE (mean, 78 ± 21; p = 0.010). Mean CC was higher in the asymptomatic group (mean, 1261 ± 59) compared with that in the symptomatic group (mean, 1009 ± 58; p < 0.001) and higher for DT1 (mean, 1184 ± 258) than C1D (mean, 1094 ± 318; p = 0.002) and AVTE (mean, 1122 ± 297; p = 0.046). CONCLUSIONS: All three SHDDs had average WTs of 12 hours or longer for 1 day. Comfort during the first 12 hours was highest with DT1 (similar to AVTE between 8 and 12 hours) and lowest with C1D. End-of-day comfort was lowest with C1D, and CC was highest for DT1. Cumulative comfort may be a valuable new metric to assess ocular comfort during the day. © 2013 American Academy of Optometry.

Varikooty,J., Keir,N., Simpson,T. Estimating tear film spread and stability through tear hydrodynamics Optometry and Vision Science 2012;89(8):e1119-e1124 [ Show Abstract ]

PURPOSE.: The stability and ease of spread of the tear-film over the contact lens surface may be an indicator of contact lens surface dewetting. The present in vivo methods of determining lens dewetting are complex. This study introduces a novel and objective way of determining the upward spread and stability of the tear-film through measurement of tear-film particle dynamics. METHODS.: Ten adapted contact lens wearers wore the same type of contact lens. Using a video camera mounted to a slit-lamp, the tear-film spread over the lens surface was recorded after a blink, at 8× magnification and capture rate of 30 frames per second, at morning after lens insertion, and after 8 h of lens wear. Images from 20 videos, without blinks and without an observable change in fixation were analyzed without any further postprocessing of the images. Using a customized calibrated ImageJ macro for particle tracking, the velocity of naturally occurring reflective particles was determined. The results were analyzed using the R program and ProFit. RESULTS.: The results established that the upward particle velocity was highest immediately after a blink and declined with time. The spread of the tear film measured through upward particle velocity was different on lens insertion than after 8 h of lens wear (p ≤ 0.001). The exponential time constants ± SE were 346.02 ± 29.0 for lens insertion at morning and 1413.13 ± 419.6 after 8 h of lens wear. CONCLUSIONS.: A novel and non-invasive way to measure in vivo spread and stability of the prelens tear-film has been developed. Additional studies are needed to understand whether this simple measure is able to differentiate the performance of different soft contact lenses and how this method may help in the understanding other aspects of lens performance such as non-invasive tear breakup time, surface deposition, and lens comfort. Copyright © 2012 American Academy of Optometry.

Varikooty,J., Keir,N., Woods,C. A., Fonn,D. Measurement of the refractive index of soft contact lenses during wear Eye and Contact Lens 2010;36(1):2-5 [ Show Abstract ]

Purpose: To determine whether the refractive index (RI) of a soft contact lens can be evaluated using refractometry while the lens remains on the eye and to compare this with more traditional ex vivo RI measurements. Methods: A slitlamp apparatus was modified to incorporate a customized Atago hand refractometer. With a double-masked study design, nine adapted symptomatic soft contact lens wearers wore a contact lens in each eye (lotrafilcon B and etafilcon A) in a randomized order. In vivo RI was determined from the relative Brix scale measurements immediately after lens insertion and after 1 and 10 hr of lens wear. Ex vivo refractometry was performed after 10 hr of lens wear for comparison. Means ± standard errors of the means are reported. Results: In vivo RI values at baseline were 1.422 ± 0.0004 (lotrafilcon B) and 1.405 ± 0.0021 (etafilcon A); after 1 hr of lens wear, values were 1.423 ± 0.0006 and 1.408 ± 0.0007, respectively; and after 10 hr of lens wear, values were 1.424 ± 0.0004 and 1.411 ± 0.0010, respectively. Ex vivo RI values at the end of the 10 hr wearing period were 1.424 ± 0.0003 (lotrafilcon B) and 1.412 ± 0.0017 (etafilcon A). The change in in vivo RI across the day was statistically significant for the etafilcon A lens (repeated-measures analysis of variance, P0.05). Conclusions: This novel adaptation of refractometry was able to measure the RI of soft contact lenses during wear (without lens removal). End of day RI measurements using in vivo and ex vivo refractometry were comparable with each other. Future work is required to determine whether this in vivo method can improve our understanding of the relationships between soft contact lens RI, hydration, on-eye lens performance, and symptomology. Copyright © Contact Lens Association of Ophthalmologists, Inc.

Varikooty,J., Schulze,M. M., Dumbleton,K., Keir,N., Woods,C. A., Fonn,D., Jones,L. W. Clinical performance of three silicone hydrogel daily disposable lenses Optometry and Vision Science 2015;92(3):301-311 [ Show Abstract ]

Purpose. To determine the clinical performance of DAILIES TOTAL1 (DT1), Clariti 1Day (C1D), and 1-DAY ACUVUE TruEye (AVTE) silicone hydrogel daily disposable contact lenses (SiHy DDCLs). Methods. Eligible participants, subdivided into asymptomatic and symptomatic groups, wore each SiHy DDCLs for three consecutive days. Each participant attended three visits (on day 1 at 0 hours; on days 1 and 3 after 8 hours ofwear) per lens type. The order of lens wear was randomized, with at least 1 day washout between lenses. Lens-related performance was evaluated by assessing lens surface deposits, wettability, pre-lens noninvasive tear breakup time, lens movement, and centration; ocular response assessments included conjunctival redness, corneal staining, and conjunctival staining and indentation. Results. Fifty-one asymptomatic and 53 symptomatic participantscompleted the study. For all visits, themeannoninvasive tear breakup timewas about 1 second longer withDT1 than withC1DandAVTE (p < 0.01).Overall, thewettability of all three lenses was good; however, DT1 was graded marginally better than the other lenses (both p < 0.01). On day 3, eyes wearing AVTE had significantly more dehydration-induced corneal staining compared with DT1 (AVTE, 24%; DT1, 11%; p < 0.01). After 8 hours, conjunctival staining was different between lenses (greatest with C1D and least with DT1; all p < 0.01). Conjunctival indentation was more prevalent with the C1D lenses (n = 70) compared with DT1 (n = 1; p < 0.01) and AVTE (n = 11; p < 0.01). Therewere no differences between asymptomatic and symptomatic lenswearers for any of the clinical parameters (all p 9 0.05). Conclusions. Each of the three SiHy DDCLs performed well. Noninvasive tear breakup time was longest and wettability was greater with DT1. C1D had the most conjunctival staining conjunctival indentation. There was no difference between asymptomatic and symptomatic wearers with regard to ocular response and contact lensYrelated parameters. These results suggest that SiHy DDCLs may be an excellent contact lens modality for the symptomatic patient.

Varikooty,J., Simpson,T. L. The interblink interval I: The relationship between sensation intensity and tear film disruption Investigative Ophthalmology and Visual Science 2009;50(3):1087-1092 [ Show Abstract ]

PURPOSE. To find the relationship between tear film drying and sensation during the interblink period. METHODS. One eye was taped shut, and after a blink the subjects were required to keep the other eye open. Digital video images of the ocular surface (with fluorescein) were obtained using a slit lamp biomicroscope while 23 subjects rated the intensity of the ocular surface sensation by adjusting a one-turn potentiometer to represent the strength of the sensation. They were trained to use the potentiometer before the data were collected. In addition, the characteristics of the sensation as spoken by the subject were recorded. RESULTS. The sensation was generally triphasic, with initial constant sensation and a subsequent biphasic period, with intensity increasing slowly followed by a rapid increase before the subjects blinked (correlations were all r > 0.95). Tear film drying dynamics were also biphasic, and drying and sensation were strongly associated, with a correlation of 0.94 between the break in the bilinear functions of sensation and drying. CONCLUSIONS. The method provides novel information about the development of ocular sensation during ocular surface drying. As evidenced by the complex functions required to adequately describe the relationships, tear film drying and ocular surface sensations are associated in complex ways. © Association for Research in Vision and Ophthalmology.

Varikooty,J., Srinivasan,S., Jones,L. Atypical manifestation of upper lid margin staining in silicone hydrogel lens wearers with symptoms of dry eye Contact Lens and Anterior Eye 2008;31(1):44-46 [ Show Abstract ]

Purpose: To report an atypical manifestation of upper lid margin staining (ULMS) that occurred in adapted silicone hydrogel (SH) contact lens wearers who complained of ocular surface dryness. Methods: Sequential staining with sodium fluorescein (FL) and lissamine green (LG) strips was performed in 38 SH lens wearers. The "wiper area" of the upper lid was examined with the slit lamp, at 8× and 12× magnifications. Results: Four out of 38 subjects (10.5%) showed fimbriated or "feathery" extensions from the superior margin of the subtarsal fold onto the upper tarsal plate. The extent of these feathery extensions varied between subjects, with a mean (±S.D.) length of 2 ± 0.8 mm. In all cases a broad band of staining with both FL and LG was demonstrated, which extended along the entire length of the lid margin. Conclusion: The staining patterns shown on the subjects' upper lid margins and tarsal plates suggest that ULMS may include more complex variants. The putative tissue damage revealed through the staining, points to a mechanism not simply restricted to the upper lid margin. © 2007 British Contact Lens Association.

Vega,J. A., Simpson,T. L., Fonn,D. A noncontact pneumatic esthesiometer for measurement of ocular sensitivity: A preliminary report Cornea 1999;18(6):675-681 [ Show Abstract ]

Purpose. The aim of this investigation was to evaluate a prototype noncontact pneumatic esthesiometer for measuring sensitivity of the eye. Methods. To evaluate the instrument's repeatability, central corneal sensitivity was recorded on two separate occasions with a 24-h interval between the two measures. In a separate experiment, corneal edema was induced with a thick hydrogel lens, and the eye was closed and patched. Corneal sensitivity was measured before wearing the lenses for 3 h, immediately after lens removal, and 15 min later. Corneal sensitivity also was measured before the instillation of a single drop of proparacaine (Alcaine, 0.5%) and at 2 and 18 min later. Sensitivity was measured at the corneal apex and at a temporal conjunctival location 3 mm from the limbus. Results. A high correlation was found between clays 1 and 2 (r = 0.90; p = 0.0001). The coefficient of repeatability (COR = 0.87 mm Hg) showed that 95% of the difference between test and retest measures were between ±0.87 mm Hg. Corneal sensitivity decreased by 55% after lens-induced corneal swelling and by 159% after instillation of the topical anesthetic. Central corneal sensitivity was found to be significantly higher than that of the temporal conjunctiva (p = 0.0001). Conclusion. We conclude that this pneumatic esthesiometer provides repeatable and reliable measures of ocular-surface sensitivity.

Verma,M. S., Chen,P. Z., Jones,L., Gu,F. X. Branching and size of CTAB-coated gold nanostars control the colorimetric detection of bacteria RSC Advances 2014;4(21):10660-10668 [ Show Abstract ]

Rapid detection of pathogenic bacteria is challenging because conventional methods require long incubation times. Nanoparticles have the potential to detect pathogens before they can cause an infection. Gold nanostars have recently been used for colorimetric biosensors but they typically require surface modification with antibodies or aptamers for cellular detection. Here, CTAB-coated gold nanostars have been used to rapidly (<5 min) detect infective doses of a model Gram-positive pathogen Staphylococcus aureus by an instrument-free colorimetric method. Varying the amounts of gold nanoseed precursor and surfactant can tune the size and degree of branching of gold nanostars as studied here by transmission electron microscopy. The size and morphology of gold nanostars determine the degree and rate of color change in the presence of S. aureus. The optimal formulation achieved maximum color contrast in the presence of S. aureus and produced a selective response in comparison to polystyrene microparticles and liposomes. These gold nanostars were characterized using UV-Visible spectroscopy to monitor changes in their surface plasmon resonance peaks. The visual color change was also quantified over time by measuring the RGB components of the pixels in the digital images of gold nanostar solutions. CTAB-coated gold nanostars serve as a promising material for simple and rapid detection of pathogens. © 2014 The Royal Society of Chemistry.