End of day silicone hydrogel daily disposable contact lens fit

Abstract

Purpose: To quantify the end-of-day silicone-hydrogel daily disposable contact lens fit and its influence of on ocular comfort, physiology and lens wettability. Method: Thirty-nine subjects (22.1±3.5 years) were randomised to wear each of three silicone-hydrogel daily-disposable contact lenses (narafilcon A, delefilcon A and filcon II 3), bilaterally, for oneweek. Lens fit was assessed objectively using a digital video slit-lamp at 8, 12 and 16h after lens insertion. Hyperaemia, noninvasive tearbreak-up time, tearmeniscusheight andcomfortwere also evaluated at these timepoints, while corneal and conjunctival staining were assessed on lens removal. Results: Lens fit assessments were not statistically significantly different between brands (p>0.05), with the exception of the movement at blink; narafilcon A lenses moved further on blink (0.41±0.34mm) than delefilcon A (0.33±0.21mm; p=0.030) and filcon II 3 (0.33±0.25mm; p=0.044) lenses. Overall, lag reduced from 8 to 12h (77±52% vs 69±31%; p=0.046), but remained stable from 8 to 16h (71±31%; p=0.231). Pushup recovery speed increased from 8 to 12h (0.61±0.41mm/s vs 0.76±0.47mm/s; p=0.004), but remained stable from 8 to 16h (0.73±0.40mm; p=0.621). Movement-on-blink was unaffected by wear-time (0.34±0.24mm 8h; 0.35±0.28mm 12h; 0.36±0.28mm 16h; F=0.403, p=0.670). A more mobile lens fit with one brand did not indicate that personwould have amoremobile fitwith another brand (r = 0.060.63). Lens fit was not correlated with comfort, ocular physiology or lens wettability (p>0.01). Conclusions: Among the lenses tested, objective lens fit changed between 8h and 12h of lens wear. The weak correlation in individual lens fit between brands indicates that fit is dependent on more than ocular shape. Consequently, substitution of a different lens brand with similar parameters will not necessarily provide comparable lens fit. Additional studies should be done to further assess the clinical implications of fit.