The influence of end of day silicone hydrogel daily disposable contact lens fit on ocular comfort, physiology and lens wettability.
OBJECTIVE
To quantify the end-of-day silicone-hydrogel daily disposable contact lens fit and its influence of on ocular comfort, physiology and lens wettability.


METHODS
Thirty-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 16h 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.


RESULTS
Lens 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 12h (P<0.05), but remained stable from 12 to 16h (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).


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.
Aston University, Life and Health Sciences, Ophthalmic Research Group, Birmingham, UK. Electronic address: j.s.w.wolffsohn@aston.ac.uk.
James
J
Wolffsohn
Visioncare Research Ltd, Farnham, UK.
Lee
L
Hall
University of Plymouth, School of Health Professions, Faculty of Health & Human Sciences, Plymouth, UK.
Stephanie
S
Mroczkowska
Aston University, Life and Health Sciences, Ophthalmic Research Group, Birmingham, UK.
Olivia A
OA
Hunt
Aston University, Life and Health Sciences, Ophthalmic Research Group, Birmingham, UK.
Paramdeep
P
Bilkhu
Aston University, Life and Health Sciences, Ophthalmic Research Group, Birmingham, UK.
Tom
T
Drew
Aston University, Life and Health Sciences, Ophthalmic Research Group, Birmingham, UK.
Amy
A
Sheppard
D003263:Contact Lenses, Hydrophilic; D004209:Disposable Equipment; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D020100:Hydrogels / Q000737:chemistry; D008297:Male; D017060:Patient Satisfaction; D011474:Prosthesis Design; D017755:Prosthesis Fitting / Q000379:methods*; D012030:Refractive Errors / Q000175:diagnosis / Q000534:rehabilitation*; D012828:Silicones / Q000737:chemistry*; D016896:Treatment Outcome; D014792:Visual Acuity; D017155:Wettability; D055815:Young Adult
D020100:Hydrogels; D012828:Silicones
Contact lenses; Daily disposables; Lens substitution; Objective lens fit; Silicone-hydrogel