Peer-reviewed Articles

Please use the year list below to look at past peer-reviewed articles.


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 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.

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 2020;Article in press [ 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.

Muntz,A., Subbaraman,L.N., Craig,J. P., Jones,L. Cytomorphological assessment of the lid margin in relation to symptoms, contact lens wear and lid wiper epitheliopathy 2020;18(2):214-220 [ Show Abstract ]

Purpose: Lid wiper epitheliopathy (LWE) is insufficiently understood from a cytological perspective. This study explored the relationship between lid margin cytomorphology, LWE, contact lens wear, and lens-related symptoms. Methods: Habitual, symptomatic (n = 20) and asymptomatic (n = 20) soft, rigid gas permeable (n = 18) and non-contact lens wearers (n = 19) were enrolled. LWE was graded using lissamine green and the Korb scale. Subjective symptoms were assessed using the Ocular Surface Disease Index and the Contact Lens Dryness Evaluation Questionnaire. Impression cytology samples obtained from the central upper and lower lid margins of both eyes stained histologically to highlight keratinization and imaged using high-resolution microscopy. A masked investigator digitally delimited and measured the average sagittal width of the lid wiper conjunctiva and mucocutaneous junction using ImageJ. Results: The upper lid wiper conjunctiva measured 424 ± 171 μm, 404 ± 75, 667 ± 219 and 266 ± 64 in asymptomatic soft, symptomatic soft, rigid and non-contact lens wearers, respectively. The corresponding lower lid wiper conjunctivae measured 141 ± 57 μm, 232 ± 150, 519 ± 212 and 225 ± 102, which was significantly narrower than that of the upper eyelid in most cases (p < 0.05). Symptoms were not associated with lid margin changes; however, rigid lens wear and clinical LWE were associated with histologically enlarged lid wiper conjunctival areas and increased keratinization. Conclusion: A novel, exploratory account of histological measures of LWE and cytomorphological change associated with contact lens wear suggests mechanical or frictional cellular insult is occurring at the lid wiper conjunctiva.

Wolffsohn,J. S., Calossi,A., Cho,P., Gifford,K., Jones,L., Jones,D., Guthrie,S., Li,M., Lipener,C., Logan,N. S., Malet,F., Peixoto-de-Matos,S. C., González-Méijome,J. M., Nichols,J. J., Orr,J. B., Santodomingo-Rubido,J., Schaefer,T., Thite,N., van der Worp,E., Tarutta,E., Iomdina,E., Ali,B. M., Villa-Collar,C., Abesamis-Dichoso,C., Chen,C., Pult,H., Blaser,P., Parra Sandra Johanna,G., Iqbal,F., Ramos,R., Carrillo Orihuela,G., Boychev,N. Global trends in myopia management attitudes and strategies in clinical practice – 2019 Update 2020;43(1):9-17 [ Show Abstract ]

Purpose: A survey in 2015 identified a high level of eye care practitioner concern about myopia with a reported moderately high level of activity, but the vast majority still prescribed single vision interventions to young myopes. This research aimed to update these findings 4 years later. Methods: A self-administrated, internet-based questionnaire was distributed in eight languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy of available strategies and adoption levels of such strategies, and reasons for not adopting specific strategies. Results: Of the 1336 respondents, concern was highest (9.0 ± 1.6; p < 0.001) in Asia and lowest (7.6 ± 2.2; p < 0.001) in Australasia. Practitioners from Asia also considered their clinical practice of myopia control to be the most active (7.7 ± 2.3; p < 0.001), the North American practitioners being the least active (6.3 ± 2.9; p < 0.001). Orthokeratology was perceived to be the most effective method of myopia control, followed by pharmaceutical approaches and approved myopia control soft contact lenses (p < 0.001). Although significant intra-regional differences existed, overall, most practitioners did not consider single-vision distance under-correction to be an effective strategy for attenuating myopia progression (79.6 %), but prescribed single vision spectacles or contact lenses as the primary mode of correction for myopic patients (63.6 ± 21.8 %). The main justifications for their reluctance to prescribe alternatives to single vision refractive corrections were increased cost (20.6 %) and inadequate information (17.6 %). Conclusions: While practitioner concern about myopia and the reported level of activity have increased over the last 4 years, the vast majority of eye care clinicians still prescribe single vision interventions to young myopes. With recent global consensus evidence-based guidelines having been published, it is hoped that this will inform the practice of myopia management in future.

Yamasaki,K., Mizuno,Y., Kitamura,Y., McCanna,D. J., Ngo,W., Jones,L. W. The efficacy of povidone-iodine, hydrogen peroxide and a chemical multipurpose contact lens care system against Pseudomonas aeruginosa on various lens case surfaces 2020;Epub ahead of print [ Show Abstract ]

To determine the antimicrobial efficacy of a povidone-iodine system (PVP-I; cleadew, OPHTECS Corporation, Kobe, Japan), a peroxide system (AOSEPT Plus with HydraGlyde, Alcon, Fort Worth, TX), and a chemical multipurpose system (renu fresh, Bausch & Lomb, Rochester, NY) on contact lens case surfaces that are both in contact and not in contact with the solutions during lens disinfection.

The surfaces of the inner walls, underside of the lid, and lens holder (if applicable) of the cases were inoculated with P. aeruginosa ATCC 27853. The cases were disinfected with the solutions as per their manufacturer instructions. After disinfection, the inoculated surfaces were swabbed and the amount of surviving P. aeruginosa was determined. Following this experiment, separate cases were inoculated and disinfected as before. This time the cases were agitated after recommended disinfection time and the amount of P. aeruginosa in the disinfecting solution was quantified immediately, and again after resting for 7 days. Experiments were conducted in triplicate (n = 3).

Units are expressed in log CFU. All three solutions significantly reduced P. aeruginosa on direct-contact surfaces (all p < 0.039). On non-contact surfaces, the reduction of P. aeruginosa in the PVP-I system (pre-disinfection: 6.8 ± 0.5, post-disinfection: 1.0 ± 0.0; p < 0.001) was significant, but not for the hydrogen peroxide system (pre-disinfection: 6.3 ± 0.6, post: 5.5 ± 0.5; p = 0.194) and the chemical multipurpose system (pre-disinfection: 6.6 ± 0.1, post-disinfection: 5.6 ± 0.8; p = 0.336). After 7 days post-disinfection, no P. aeruginosa regrowth was observed in the PVP-I system (Day 1: 1.0 ± 0.0, Day 7: 1.0 ± 0.0; p = 1) and the chemical multipurpose system (Day 1: 4.2 ± 0.2, Day 7: 1.8 ± 0.9; p = 0.012), however regrowth was observed in the hydrogen peroxide system (Day 1: 3.4 ± 0.6, Day 7: 6.1 ± 0.4; p = 0.003).

The PVP-I system was more effective against P. aeruginosa on non-contact surfaces than the hydrogen peroxide system or the chemical multipurpose system and is capable of inhibiting regrowth of P. aeruginosa for at least 7 days post-disinfection.