The influence of end of day silicone hydrogel daily disposable contact lens fit on ocular comfort, physiology and lens wettability

• Three brands of daily disposable silicone hydrogels showed similar average fit.
• Lag reduced, but push-up recovery speed increased from 8 to 12 h.
• Lens fit was not correlated with comfort, ocular physiology or lens wettability.
• The fit of lenses on an individual varied between brands unpredictably.
• Consequently, substitution of lens brand without rechecking fit is Q3 unadvisable.

PurposeTo quantify the end-of-day silicone-hydrogel daily disposable contact lens fit and its influence of on ocular comfort, physiology and lens wettability.MethodsThirty-nine subjects (22.1 ± 3.5 years) were randomised to wear each of 3 silicone-hydrogel daily-disposable contact lenses (narafilcon A, delefilcon A and filcon II 3), bilaterally, for one week. Lens fit was assessed objectively using a digital video slit-lamp at 8, 12 and 16 h after lens insertion. Hyperaemia, non-invasive tear break-up time, tear meniscus height and comfort were also evaluated at these timepoints, while corneal and conjunctival staining were assessed on lens removal.ResultsLens fit assessments were not different between brands (P > 0.05), with the exception of the movement at blink where narafilcon A was more mobile. Overall, lag reduced but push-up speed increased from 8 to 12 h (P < 0.05), but remained stable from 12 to 16 h (P > 0.05). Movement-on-blink was unaffected by wear-time (F = 0.403, P = 0.670). A more mobile lens fit with one brand did not indicate that person would have a more mobile fit with another brand (r = −0.06 to 0.63). Lens fit was not correlated with comfort, ocular physiology or lens wettability (P > 0.01).ConclusionsAmong the lenses tested, objective lens fit changed between 8 h and 12 h 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.