Clinical Investigation of Flat Pack Toric Contact Lenses and Wearer Attitudes to Environmental Impact

Abstract

Objectives: To investigate the performance of a novel flat pack toric daily disposable contact lens compared with traditionally packaged toric lenses in a randomized, crossover study. Environmental attitudes to contact lens wear were also explored.

Methods: Habitual contact lens wearers were recruited to wear a hioxifilcon A (Miru 1 day Flat Pack Toric, Menicon, Nagoya, Japan) test lens and a control lens: either nelfilcon A (Dailies AquaComfort Plus, Alcon, Geneva, Switzerland) or etafilcon A (1-Day Acuvue Moist, Johnson & Johnson, New Brunswick, NJ). Objective lens performance was assessed at fitting, and participants wore lenses in a randomized order for three consecutive days. Subjective measures of lens performance (comfort, vision, and handling) were then assessed by a questionnaire, with further questions on overall lens preference and environmental perceptions.

Results: Objective measures of lens fit were similar for the test and control lenses, except for distance VA which was better with the control lenses ( P <0.05; difference of two logMAR letters). End of day comfort was greater with the test lens, but this did not reach significance. Both lenses demonstrated similar scores for overall satisfaction. 87.5% of participants indicated the environmental impact of contact lenses to be important/extremely important to them, with 100% of participants identifying the flat pack packaging as having a smaller environmental impact.

Conclusion: Overall, the lenses used in the study performed to similar levels. Environmental credentials are important to contact lens wearers, which may contribute to overall lens preference.

FIG. 1.

Distribution of distance visual acuity for the test and control lenses. Open circles indicate outliers extending more than 1.5 box lengths, and asterisks indicate outliers extending more than three box lengths.

FIG. 2.

Distribution of overall comfort scores of the test and control lenses. Open circles indicate outliers extending more than 1.5 box lengths.

FIG. 3.

Distribution of overall satisfaction Likert scores for the test and control lenses. Open circles indicate outliers extending more than 1.5 box lengths.

FIG. 4.

Correlation of subjective vision and comfort scores against overall satisfaction. (a) The correlation between overall vision and overall satisfaction scores. (b) The correlation between overall comfort and overall satisfaction scores. To avoid overlapping data points, random jitter was applied to each of the data points in both x and y directions (80 observations in total).