Abstract
Purpose :
Multifocal contact lenses, work under the principle of simultaneous vision, have been reported to control myopia progression in young myopes, although the mechanisms of operation and the impact of design factors on vision are not well understood. This study evaluates vision with simulated multifocal designs in myopes
Methods :
Multifocal patterns inspired in commercial contact lenses was programmed in a custom polychromatic Adaptive Optics visual simulator. 10 patients (age: 23-35; SE: -0.75-4.25D) performed visual performance (VA, Decimal Visual Acuity 8AFC procedure, tumbling E) and visual perception (Perceptual Score, PS, of a binary image, +10, +5,+1,-10,-5,-1,Max:+50) tests through the simulated patterns, under natural viewing conditions, for far (F) and near (N, -3D). Stimuli were projected in a digital light projector illuminated monochromatically (555 nm). Two patterns (P1:2 zones, Center distance; P2:2 zones, Center Near), with near adds from +1 to +5 D were simulated in a Spatial Light Modulators (SLM). Control measurements included test-retest repeatability, monofocal condition & paralyzed accommodation. The effects of lens design, add, subject’s aberrations, age, pupil diameter was analyzed
Results :
VA ratio monofocal/multifocal lens (F) ranged from 1.08 to 2.79, 1.55 on average across designs,adds & subjects. Average RMS difference between measurements with natural accommodation and paralyzed accommodation was 0.05 (VA, F) and 0.10 (VA, N), 4.15 (PS, F) & 7.21 (PS, N). Average RMS difference between repeated measurements was 0.07 (VA), and 2.73 (PS). Average VA for P1 was 1.18 times better for N than for F, while P2 shows very similar performance for both. In most subjects VA & PS showed a notch for intermediate adds for F, and peaked at around 2-2.5 D for N. Some subjects did not show a higher degradation at N for +5 D, indicating a sustained use of the F peak at all distances. Lens design, subject’s aberrations, age and pupil diameter are not major factors in the effect
Conclusions :
Simultaneous vision simulators are useful to simulate vision with multifocal lenses for myopia progression. The performance is driven by the individual response of the patient to multifocality, regardless of the distribution of zones. The different impact of near add on vision quality appears to be associated with different accommodation dynamics
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.