The Dry Eye Zone

Rebecca's Blog


Abstract: Contact lenses: better doesn't necessarily mean better?

Objective clinical performance of 'comfort-enhanced' daily disposable soft contact lenses.
Cont Lens Anterior Eye. 2010 Apr;33(2):88-92. Epub 2010 Feb 9.
Wolffsohn JS, Hunt OA, Chowdhury A.
Aston University, Aston Triangle, Birmingham, United Kingdom.

PURPOSE: To examine the objective clinical performance of 'comfort-enhanced' daily disposable contact lenses over a 16-h day.

METHODS: Four contact lenses (Hilafilcon B, Etafilcon A Plus, Nelfilcon A and Nelfilcon A Plus) were evaluated in an investigator masked, open label trial at the end of a week's bilateral wear. Pre-lens non-invasive tear break-up time (PL-NITBUT), tear prism height, bulbar hyperaemia and ocular surface temperature (OST) were measured with the lens in situ at 8, 12 and 16h of wear.

RESULTS: There was no difference between how many hours the lenses types were worn each day (F=0.90, p=0.44). The PL-NITBUT decreased with the duration of daily lens wear (F=32.0, p<0.001) and was more stable with Nelfilcon A Plus (F=6.00, p=0.002) than with the other lenses evaluated. Bulbar blood vessels increased in coverage (F=11.5, p<0.001) but not overall redness (F=0.0, p=0.99) with the duration of daily lens wear, but there was no difference between the lenses (p>0.05). The tear prism height decreased with the duration of daily wear (F=27.0, p<0.001) and differed between lenses (F=2.9, p=0.04). The OST decreased with the duration of lens wear (F=119.7, p<0.001) and was reduced by daily disposable lens wear (F=7.88, p<0.001), but did not differ between lenses (F=0.88, p=0.45).

CONCLUSIONS: Objective measures of tear film indicated a difference between the lenses evaluated for PL-NITBUT and tear prism height, but not for wearing time or bulbar conjunctival hyperaemia. Therefore clinical benefits of daily disposable 'comfort enhancing' contact lenses can be measured, but challenges remain in producing contact lenses that do not compromise anterior eye physiology over the whole day.