MyDay Multifocal Binocular Summation
Research type
Research Study
Full title
Quantification of Binocular Summation of Multifocal and Monovision Contact Lenses
IRAS ID
305799
Contact name
Ruchi Gupta
Contact email
Sponsor organisation
CooperVision International Limited
Duration of Study in the UK
0 years, 9 months, 11 days
Research summary
Research Summary
Multifocal contact lenses are designed to correct both distance and near vision in people over the age of 40 year suffering from presbyopia who otherwise would need reading glasses. To achieve the two different corrections multifocal contact lenses present different corrections at all times within the pupil area, this produces a decrease in the strength of the image focused on the retinas. However, good vision satisfaction has been reported with this type of contact lenses because the brain combines the two images in a single 3D view of the world with superior vision quality. The difference between the performance measured for each eye independently and the performance measured with the two eyes working together is known as “binocular summation”.\n\nIn order to achieve binocular summation, the correction of the two eyes needs to be similarly balanced but different types of multifocal contact lenses involve different strategies to optimise vision such as favouring one eye for distance vision and the other for near vision. The concern is that these approaches may adversely affect binocular summation.\n\nThe alternative to multifocal contact lenses to correct presbyopia is monovision where one eye is corrected for distance vision and the other for near vision using conventional single vision contact lenses. In such cases the brain subconsciously shift the attention between the two eyes but binocular summation is not present.\n\nThe rationale for the current study is to test the efficacy of different multifocal design at maintaining binocular summation compared with monovision. This is achieved by measuring visual acuity at various distances from far to near vision of eye independently and the two eyes together. From these measurements binocular summation is calculated by calculating the difference between binocular and monocular visual acuity.
Summary of Results
The rationale of the study was to measure both visual acuity and binocular status in a group of multifocal contact lens wearers with MyDay® multifocal, two multifocal systems with balance corrections aiming to maintain binocularity and monovision known to affect binocularity.
The study results as follow:
Primary Endpoints
i. MYDAY MF overall binocular summation (mean -0.036logMAR) was non-inferior to both 1DAY ACUVUE MOIST MF (mean -0.051logMAR; 95%CI difference -0.006 to 0.036; p = 0.254) and BIOFINITY MF (mean -0.047logMAR; 95%CI difference -0.005 to 0.036; p = 0.282) demonstrating the first primary hypothesis of non-inferiority in binocular summation between MYDAY MF and the control multifocal corrections.
ii. MYDAY MF overall binocular summation (mean -0.036logMAR) was superior to MYDAY MONOVISION (mean -0.006logMAR; 95%CI difference -0.049 to -0.011; p < 0.001) demonstrating the second primary hypothesis of superiority in binocular summation between MYDAY MF and the control monovision correction.
Secondary Endpoints
i. Horizontal phorias when present were of very low amplitude and below the threshold of clinical significance for all the study contact lenses and not statistically significantly different between the test contact lens and both the control multifocal corrections (p = 0.558 & 0.343) and the control monovision (p = 0.558).
ii. Vertical phorias when present were of very low amplitude and below the threshold of clinical significance for all the study contact lenses and not statistically significantly different between the test contact lens and both the control multifocal corrections (p = 0.161 & 0.940) and the control monovision (p = 0.940).
iii. Horizontal fixation disparity was absent in the vast majority of case for all the study contact lens corrections with a trend towards slightly more anomaly for monovision (no anomaly: BASELINE SPECS 90.5%; MYDAY MF 90.5%; 1DAY ACUVUE MOIST MF 95.2%; BIOFINITY MF 95.2%; MYDAY MONOVISION 81.0%. When present the anomalies were of a very low amplitude.
iv. Vertical fixation disparity was absent in the vast majority of case for all the study contact lens corrections with a trend towards slightly more anomaly for monovision (no anomaly: BASELINE SPECS 95.2%; MYDAY MF 95.2%; 1DAY ACUVUE MOIST MF 95.2%; BIOFINITY MF 100% MYDAY MONOVISION 87.5%. When present the anomalies were of a very low amplitude.
v. Under the conditions of the test distance stereopsis with the MYDAY MF was not significantly different from the stereopsis with the two multifocal control contact lenses MF (Difference from MYDAY MF: 1DAY ACUVUE MOIST MF 95%CI -165 to 115 arcsec - p = 0.720; BIOFINITY MF 95%CI -186 to 69 arcsec – p = 0.596) or with MYDAY MONOVISION (Difference from MYDAY MF -251 to 39 arcsec – p = 0.233).
vi. Under the conditions of the test near stereopsis with the MYDAY MF was not significantly different from the stereopsis with the two multifocal control contact lenses MF (Difference from MYDAY MF: 1DAY ACUVUE MOIST MF 95%CI -52 to 98 arcsec - p = 0.830; BIOFINITY MF 95%CI -26 to 155 arcsec – p = 0.257). or with MYDAY MONOVISION (Difference from MYDAY MF -58 to 122 arcsec – p = 0.830).The objective of the study was to compare binocular functions with MYDAY MF with binocular functions with two multifocal contact lens corrections, 1DAY ACUVUE MOISTMF and BIOFINITY MF and with MYDAY MONOVISION. The primary hypotheses that binocular summation (improvement in binocular visual acuity vs. best monocular visual acuity) with MYDAY MF was non-inferior to that achieved with the two multifocal corrections and superior to monovision was demonstrated. The secondary hypotheses that binocular status achieved with MYDAY MF was non-inferior to that achieved with the two multifocal corrections and superior to monovision was partly demonstrated as equivalent binocular status was demonstrated for all four vison correction modalities. In fact, the study population was shown to have excellent binocular vision characteristics with best spectacle correction, which remained unchanged with MYDAY MF.
REC name
North of Scotland Research Ethics Committee 2
REC reference
21/NS/0131
Date of REC Opinion
14 Oct 2021
REC opinion
Favourable Opinion