Correction of Low Astigmatism with Soft Contact Lenses
Research type
Research Study
Full title
Correction of Low Level Of Astigmatism with Soft Contact Lenses
IRAS ID
331203
Contact name
Michel Guillon
Contact email
Sponsor organisation
CooperVision International Limited
ISRCTN Number
ISRCTN42235351
Duration of Study in the UK
0 years, 8 months, 1 days
Research summary
Research Summary
People suffer from two main types of vision defects when young: myopia (short sight) and hyperopia (long sight) and when the degree of long or short side is not the same in all directions (e. g. more short sighted in the vertical direction than the horizontal direction) they also suffer from astigmatism.
The correction of astigmatism with spectacles is very precise and any level is corrected (minimal correction ¼ dioptre). With contact lenses, however, the approach has been that the presence of a soft contact lens “masks” some astigmatism and current clinical practice is to start correcting astigmatism only when it is much higher (minimal ¾ to 1 dioptre).
One of the reason for starting to correct astigmatism at a much higher level of defect is that the standard measurement of vision in practice, using test charts with black letters on a white background with good lighting does not show any difference in vision with or without the correction of astigmatism. However, vision demands in every day life is not reduced to this unique situation, when the contrast is lower and / or the light is reduced, such as at night time the visual demand is much higher and and uncorrected astigmatism affects vision quality. Several studies have pointed to the true detrimental effects of uncorrected astigmatism on vision in such conditions.
The study will compare visual performance and vision satisfaction under normal conditions of use of contact lens wearers with low level of astigmatism when their astigmatism is not corrected (the majority of current wearers) and when it is corrected (a small but increasing minority).Summary of Results
The study compared the visual performance and acceptance of MyDay Toric (test) and MyDay Spherical (control) in a population of low astigmats. The results showed that:
i. the test contact lens produced statistically significant higher visual acuity under low (mesopic) light condition [primary endpoint];
ii. vision satisfaction at night was no statistical different between the test and control contact lenses [first secondary endpoint];
iii. the test contact lens produced statistically significant higher visual acuity with the presence of glare [second secondary endpoint].Has the registry been updated to include summary results?: Yes
If yes - please enter the URL to summary results: waiting to receive confirmation from ISRCTN.
If no – why not?:
Did you follow your dissemination plan submitted in the IRAS application form (Q A51)?: Pending
If yes, describe or provide URLs to disseminated materials:
If pending, date when dissemination is expected: 01/12/2025
If no, explain why you didn't follow it:
Have participants been informed of the results of the study?: Yes
If yes, describe and/or provide URLs to materials shared and how they were shared: The participants requested the study results have been emailed the following letter:
Dear .....;
Thank you for taking part in the study which has helped us to better understand how different contact lenses affect vision. In your consent form you indicated that you wanted to be informed of the study results when the study is finished.
The results showed that the test contact lens which corrected astigmatism gave better visual acuity (test chart reading) than the control contact lens that did not correct astigmatism in conditions that mimic both day time and night time.
You will also find further results on the ISRCTN Registry website, the trial reference number is 42235351.REC name
North of Scotland Research Ethics Committee 2
REC reference
23/NS/0081
Date of REC Opinion
11 Aug 2023
REC opinion
Favourable Opinion