Effect of Astigmatism on MF CL Visual Performance - Pilot Study
Research type
Research Study
Full title
The Effect of Astigmatism on Multifocal Contact Lens Visual Performance - Pilot Study
IRAS ID
271679
Contact name
Kishan Patel
Contact email
Sponsor organisation
CooperVision, Inc.
Duration of Study in the UK
0 years, 6 months, 3 days
Research summary
The standard of practice when fitting single vision or multifocal soft contact lenses is to disregard astigmatism correction of 0.75DC and fit spherical power contact lenses that do not correct astigmatism but taking into account the spherical equivalence. The practice differs from spectacle prescribing, for which astigmatism is corrected to the nearest 0.25DC. The practice of fitting just spherical soft contact lenses for up to 0.75DC astigmatism has been practiced from the inception of soft contact lenses and all lenses on the market are CE marked for that range of corrections.
Multifocal contact lenses which correct both presbyopia and myopia/hyperopia produce several focus which decrease the intensity of images to see both distance and near vision. It is possible that the reduced image quality due to the combined effect of the multifocal design and uncorrected astigmatism creates more compromised in the quality of vision that leads to multifocal contact lens wearers dissatisfaction and hence discontinuation.
The rationale of the study is to quantify the effect of uncorrected astigmatism on the visual performance of multifocal contact lenses.REC name
West Midlands - Solihull Research Ethics Committee
REC reference
19/WM/0270
Date of REC Opinion
25 Sep 2019
REC opinion
Favourable Opinion