Jump to:

Peer-reviewed articles

2015

Guthrie,S. E., Jones,L., Blackie,C. A., Korb,D. R. A Comparative Study Between an Oil-in-Water Emulsion and Nonlipid Eye Drops Used for Rewetting Contact Lenses Eye and Contact Lens 2015;41(6):373-377 [ Show Abstract ]

OBJECTIVES: The purpose of this study was to determine the clinical impact of using SYSTANE BALANCE Lubricant Eye Drops (Alcon, Fort Worth, TX), an oil-in-water emulsion, as a rewetting eye drop in symptomatic contact lens wearers.
METHODS: Subjects who had previously experienced contact lens discomfort (CLD), with a mean lens wearing history of 18.6±12.8 years, were randomly assigned to use a Test (SYSTANE BALANCE Lubricant Eye Drops; n=76) or control (habitual nonlipid contact lens rewetting eye drop; n=30) drop over their contact lenses within 5 min of lens insertion and then subsequently at 2 hr intervals up to a maximum of 4 drops per eye daily for a 1-month period. Assessments of subjective comfort, comfortable wearing time, lid wiper epitheliopathy (LWE), and corneal staining were conducted at baseline and after 1 month, after 6 hr of lens wear.
RESULTS: Comfort, wearing time, LWE, and corneal staining all showed statistically significant improvements in the test group using SYSTANE BALANCE Lubricant Eye Drops at the 1-month visit compared with baseline data (all P<0.01) and compared with the control group at the 1-month visit (P<0.01, P=0.01, P<0.01, and P=0.03, respectively).
CONCLUSIONS: The use of SYSTANE BALANCE Lubricant Eye Drops as a rewetting drop in a group of wearers who experienced symptoms of CLD improved subjective comfort scores, increased comfortable wearing time, and reduced signs of LWE and corneal staining, when compared with the use of non–lipid-containing contact lens rewetting eye drops.

2013

Woods,J., Guthrie,S. E., Keir,N., Dillehay,S., Tyson,M., Griffin,R., Choh,V., Fonn,D., Jones,L., Irving,E. Inhibition of defocus-induced myopia in chickens Investigative Ophthalmology and Visual Science 2013;54(4):2662-2668 [ Show Abstract ]

PURPOSE. To determine the effect of wearing a lens with a unique peripheral optical design on the development and progression of defocus-induced myopia in newly hatched chickens.METHODS. Eighty-five newly hatched chickens underwent bilateral retinoscopy and A-scan ultrasound to determine their refractive error and axial length. They were randomly divided into Control and two Test groups, in which each chicken was fitted with a goggle-lens over the right eye, with the left eye remaining untreated. The Control group wore a lens of power - 10.00 diopters (D) of standard spherical optical design. The two Test lenses both had a central optical power -10.00 D, but used different peripheral myopia progression control (MPC) designs. For all groups, retinoscopy was repeated on days 3, 7, 10, and 14; ultrasound was repeated on day 14.RESULTS. On day 0 there was no statistical difference in refractive error (mean +6.92 D) or axial length (mean 8.06 mm) between Test and Control groups or treated and untreated eyes (all P > 0.05). At day 14, 37 (43.5%) of 85 chickens had not experienced goggle detachment and were included in the final analyses. In this cohort there was a significant refractive difference between the treated eyes of the Control group (n = 17) and those of Test 1 (n = 14) and Test 2 (n = 6) groups (both P < 0.01): Control -4.65 ± 2.11 D, Test 1 +4.57 ± 3.11 D, Test 2 +1.08 ± 1.24 D (mean ± SEM). There was also a significant axial length difference (both P < 0.01): Control 10.55 ± 0.36 mm, Test 1 9.99 ± 0.14 mm, Test 2 10.17 ± 0.18 mm.CONCLUSIONS. Use of these unique MPC lens designs over 14 days caused a significant reduction in the development of defocus-induced myopia in chickens; the degree of reduction appeared to be design specific. © 2013 The Association for Research in Vision and Ophthalmology, Inc.

Scientific Presentations

2019

Guthrie S, Moezzi A, Varikooty J, Woods J, Jones L. A bilateral dispensing evaluation of two different toric lens geometries
BCLA Conference, Manchester, UK, 2019

2018

Woods J, Ng AY, Luensmann D, Guthrie S, Jones L. Short-term comfort comparison of two daily disposable contact lenses of different material and modulus Invest Ophthalmol Vis Sci 2018;E-Abstract 1753 [ Show Abstract ][ PDF ]

Purpose: Daily disposable contact lenses (DDs) are now widely available in both silicone hydrogel (SH) and hydrogel (H) materials. The higher oxygen transmissibility of SH materials provides many benefits, but their higher modulus has been linked with reduced lens comfort compared to H lenses. This randomized, double-masked clinical trial assessed the short-term comfort of two DDs of differing modulus, yet similar water content (WC): a SH-DD (somofilcon A; clariti® 1 day; CooperVision; 0.50MPa modulus, 56% WC) and a H-DD (etafilcon A; 1-Day Acuvue® Moist®; Johnson & Johnson; 0.29MPa modulus, 57% WC).

Methods: 120 subjects wore the lenses contralaterally, over one day. Targeted recruitment meant that 60 subjects were habitual H-DD wearers (all adapted wearers of 1-Day Acuvue Moist), 60 were non-DD habitual wearers (adapted to various SH and H re-usable lenses). Subjects rated lens comfort on a 0-100 integer scale (100= cannot be felt) at insertion and then hourly until 8hrs. Of particular interest was the comfort at the beginning and end of the 8hr wear period and these data points were tested for equivalence. At the final visit subjects were asked for their lens preference, based on comfort.

Results: Mean subjective comfort was not different between SH-DD and H-DD across the wear period (p>0.05), on insertion (87±14 SH-DD vs 89±14 H-DD; p>0.05) or after 8hrs (82±18 SH-DD vs 83±17 H-DD; p>0.05). Based on equivalency margins of ±5-points, the study lenses showed equivalent comfort at insertion (p=0.03) and at 8hrs (p=0.001). Both lenses exhibited a significant reduction in comfort over the 8hr period (both p<0.001). When subjects’ data was divided according to their habitual lens modality groups (60 H-DD wearers and 60 re-useable wearers), there were also no comfort differences between the study lenses, either across time, or at insertion and 8hrs (all p>0.05). Lens preference was not different between lenses at dispensing or at the final visit (both p>0.05).

Conclusions: Initial and 8hr comfort were not compromised with the SH-DD compared to the H-DD, despite its higher modulus, and there was no difference in the lens preference distribution. The results suggest that lower comfort should not be anticipated when fitting SH-DDs of an appropriate design, thus allowing other material properties such as high oxygen permeability to be considered.

2016

Jones L, Guthrie S, Dumbleton K. Is there a relationship between care system and compliance? Asian Cornea and Contact lens Conference, Hong Kong, 2016 [ PDF ]

Stahl U, Keir N, Guthrie S, Jones L. Effect of monocular lens wear on ocular comfort TFOS conference, Montpelier, France, 2016

2015

Guthrie S, Dumbleton K, Jones L. Is there a relationship between care system and compliance? BCLA Clinical Conference and Exhibition, 2015 [ PDF ]

Guthrie S, Woods J, Dumbleton K, Fonn D, Jones L. Contact lens discomfort management strategies of ECPs Optom Vis Sci 2015;92: E-abstract 155050 [ PDF ]

2014

Dillehay S, Woods J, Situ P, Guthrie S, Paynor R, Griffin R, Tyson M, Jones L. Comparison of Three Power Levels of A Novel Soft Contact Lens Optical Design to Reduce Suspected Risk Factors for the Progression of Juvenile Onset Myopia Invest Ophthalmol Vis Sci 2014;55: E-abstract 3637

2011

Guthrie S, Woods J, Keir N, Dillehay S, Tyson M, Griffin R, Fonn D, Jones L, Irving E. Controlling lens induced myopia in chickens with peripheral lens design Optom Vis Sci 2011;88:E-Abstract 110421

Woods J, Guthrie S, Keir N, Choh V, Fonn D, Jones L, Irving E. Myopia development – what can the chicken tell us? Contact Lens & Anterior Eye 2011;34, Supplement 1:s13

Woods J, Guthrie S, Keir N, Dillehay S, Tyson M, Griffin R, Jones L, Irving E. The effect of a unique lens designed for myopia progression control (MPC) on the level of induced myopia in chicks Invest Ophthalmol Vis Sci 2011;51:E-Abstract 6651

2009

Brodland G, Jones L, Horst C, McDonald M, Guthrie S. A novel method for measuring contact lens tensile properties Optom Vis Sci 2009;86:E-abstract 095818

Dumbleton K, Richter D, Guthrie S, Woods C, Jones L, Fonn D. Patient and practitioner compliance with silicone hydrogel and daily disposable lens replacement CAO (Charlottetown, PEI), 2009

Dumbleton K, Woods C, Jones L, Guthrie S, Fonn D. Patient and practitioner compliance with silicone hydrogel and daily disposable lens replacement Contact Lens & Anterior Eye 2009;32, 5:213

Jones L, Brodland G, Horst C, McDonald M, Guthrie S. A novel method for measuring contact lens tensile properties Contact Lens & Anterior Eye 2009;32, 5:254

2008

Dalton K, Jones L, Guthrie S. pH, Osmolality and viscosity of artificial tears Optom Vis Sci 2008;85: E-abstract 85310

Dalton K, Jones L, Guthrie S. Physical properties of artificial tears Contact Lens & Anterior Eye 2008;31, 5:272

2006

Guthrie S, Simpson T, Varikooty J, Fonn D. Background subtraction and contrast enhancement for interferometric images of the human corneal tear film Invest Ophthalmol Vis Sci 2006;47:E-abstract 2399

Professional Publications

2016

Guthrie S, Dumbleton K, Jones L. Is there a Relationship Between Care System and Compliance? Contact Lens Spectrum 2016;31, April: 40-43

2014

Guthrie S, Dumbleton K, Jones L. Financial Implications of Patient Compliance Contact Lens Spectrum 2014;29, December: 42-45

2011

Guthrie S. Effect of dual-focus soft contact lens wear on axial myopia progression in children - An article review ContactLensUpdate.com 2011

2010

Richter D, Dumbleton K, Guthrie S, Woods C, Jones L, Fonn D. Patient and practitioner compliance with silicone hydrogel and daily disposable lens replacement in Canada Canadian Journal of Optometry 2010;72, 1: 10-19

Books

2019

Jones L, Stahl U, Guthrie S, Luensmann D, Yang M, Thom M. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 45 2019.

2018

Jones L, Sorbara L, Stahl U, Yang M, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 44 2018.

2017

Jones L, Sorbara L, Stahl U, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 43 2017.

2016

Jones L, Sorbara L, Stahl U, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 42 2016.

2015

Jones L, Sorbara L, Stahl U, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 41 2015.

2014

Jones L, Sorbara L, Stahl U, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 40 2014.

2013

Jones L, Sorbara L, Stahl U, Guthrie S, Menzies K, Rossy J, Thom M. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 39 2013.