Extended depth of focus contact lenses vs. two commercial multifocals: Part 1. Optical performance evaluation via computed through-focus retinal image quality metrics

Abstract

Purpose: To compare the computed optical performance of prototype lenses designed using deliberate manipulation of higher-order spherical aberrations to extend depth-of-focus (EDOF) with two commercial multifocals.

Methods: Emmetropic, presbyopic, schematic eyes were coupled with prototype EDOF and commercial multifocal lenses (Acuvue Oasys for presbyopia, AOP, Johnson & Johnson & Air Optix Aqua multifocal, AOMF, Alcon). For each test configuration, the through-focus retinal image quality (TFRIQ) values were computed over 21 vergences, ranging from -0.50 to 2.00D, in 0.125D steps. Analysis was performed considering eyes with three different inherent aberration profiles: five different pupils and five different lens decentration levels.

Results: Except the LOW design, the AOP lenses offered 'bifocal' like TFRIQ performance. Lens performance was relatively independent to pupil and aberrations but not centration. Contrastingly, AOMF demonstrated distance centric performance, most dominant in LOW followed by MED and HIGH designs. AOMF lenses were the most sensitive to pupil, aberrations and centration. The prototypes demonstrated a 'lift-off' in the TFRIQ performance, particularly at intermediate and near, without trading performance at distance. When compared with AOP and AOMF, EDOF lenses demonstrated reduced sensitivity to pupil, aberrations and centration.

Conclusion: With the through focus retinal image quality as the gauge of optical performance, we demonstrated that the prototype EDOF designs were less susceptible to variations in pupil, inherent ocular aberrations and decentration, compared to the commercial designs. To ascertain whether these incremental improvements translate to a clinically palpable outcome requires investigation through human trials.

Keywords: Aberraciones de alto orden; Extended depth of focus contact lenses; Fourier Optics; Higher order aberrations; Lentes de contacto de profundidad de campo ampliada; Presbicia; Presbyopia; Ray tracing simulation; Simulación de trazado de rayos; Óptica de Fourier.

Copyright © 2017 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

Figures

Figure 1

Power profiles of the study lenses. Units of the color scale is in Diopters (D). L: Low; M: Medium; H: High add power.

Figure 2

Log transformed through password-focus retinal image quality values computed as a function of 5 pupil diameters: from 3 to 5 mm in 0.5 mm steps. This data represents computations performed on the schematic eye embedded with Model 2 inherent aberrations. The correcting lens was well-centered over the cornea. A red dashed line across subgraphs indicates the ideal threshold RIQ. The bounded area under the perpendicular lines drawn from X-axis (absolute value) is inscribed at the corner of each sub-graphs indicate the variance of TFRIQ between the five pupil diameters.

Figure 3

Log transformed through-focus retinal image quality values computed as a function of 3 inherent aberration models: Models 1–3. This data represents computations performed on the schematic eye with 4 mm pupil. The correcting lens was well-centered over the cornea. A red dashed line across sub-graphs indicates the ideal threshold RIQ. The bounded area under the perpendicular lines drawn from X-axis (absolute value) is inscribed at the corner of each sub-graphs indicate the variance of TFRIQ between the three aberration models.

Figure 4

Log transformed through-focus retinal image quality values computed as a function of 5 preset lens centration positions: 0.0–0.50 mm in 0.125 mm steps. This data represents computations performed on the schematic eye embedded with Model 2 inherent aberrations (excluding asymmetric HOA) at 3.5 mm pupil diameter. A red dashed line across sub-graphs indicates the ideal threshold RIQ. The bounded area under the perpendicular lines drawn from X-axis (absolute value) is inscribed at the corner of each sub-graphs indicate the variance of TFRIQ between the five decentration levels.