Abstract
Purpose:
The purpose of this study was to evaluate the visual performance of DAILIES® Aqua Comfort Plus® (DACP) Multifocal contact lenses compared with monovision correction in a population of established presbyopes.
Methods:
Soft contact lens wearers presenting with normal corrected vision and established presbyopia (near add ≥+1.50) were randomized into a five (±1) days cross over investigation comparing DACP Multifocal (MF) contact lenses with DACP fitted as monovision (MV). Binocular visual performance was measured in terms of areas of focus for the distance, intermediate and near regions calculated from the defocus curves, stereopsis and contrast sensitivity. To generate defocus curves, binocular visual acuity was measured with the Early Treatment Diabetic Retinopathy Study (ETDRS) high-contrast logMAR chart under photopic conditions (85 cd/m2). Binocular distance contrast sensitivity (CS) was measured using the VCTS test (Vistech Consultants Inc) at five spatial frequencies (1.5, 3, 6, 12 and 18cpd). Stereoacuity was determined with the Howard-Dolman system at a distance of 40 cm. Subjective ratings were recorded on a 10 point scale with extreme anchors (1= poor to 10 = excellent) for the subjects’ vision quality at distance, intermediate, near as well as during computer use or while driving, at night.
Results:
In this population of established presbyopes, using defocus curves, the area of focus in the intermediate and near vision range with DACP Multifocal was shown to be significantly larger than with monovision (p=0.007 & p<0.0001). This was associated with a wider range of vision with the multifocal correction. Furthermore, DACP Multifocal was also shown to provide a significantly better stereoacuity than monovision (MV: 84.25(12.96) v DACP MF: 27.17(5.75) sec arc p<0.0001). Subjective evaluations were in favor of the DACP MF correction for all items by at least 1 point on average.
Conclusions:
The area-of-focus metrics used in this study were able to differentiate between multifocal and monovision corrections. DACP Multifocal contact lenses provided better stereoacuity and greater area-of-focus in the intermediate and near zones than monovision. The higher subjective perception associated with the multifocal correction is likely to be due to the lower binocular disruption observed, providing a better real-world visual function.