Modified Monovision With Spherical Aberration to Improve Presbyopic Through-Focus Visual Performance

Abstract

PURPOSE.To investigate the impact on visual performance of modifying monovision with monocularly induced spherical aberration (SA) to increase depth of focus (DoF), thereby enhancing binocular through-focus visual performance. METHODS.A binocular adaptive optics (AO) vision simulator was used to correct both eyes' native aberrations and induce traditional (TMV) and modified (MMV) monovision corrections. TMV was simulated with 1.5 diopters (D) of anisometropia (dominant eye at distance, nondominant eye at near). Zernike primary SA was induced in the nondominant eye in MMV. A total of four MMV conditions were tested with various amounts of SA (60.2 and 60.4 lm) and fixed anisometropia (1.5 D). Monocular and binocular visual acuity (VA) and contrast sensitivity (CS) at 10 cyc/deg and binocular summation were measured through-focus in three cyclopledged subjects with 4-mm pupils.RESULTS. MMV with positive SA had a larger benefit for intermediate distances (1.5 lines at 1.0 D) than with negative SA, compared with TMV. Negative SA had a stronger benefit in VA at near. DoF of all MMV conditions was 3.5 6 0.5 D (mean) as compared with TMV (2.7 6 0.3 D). Through-focus CS at 10 cyc/deg was significantly reduced with MMV as compared to TMV only at intermediate object distances, however was unaffected at distance. Binocular summation was absent at all object distances except 0.5 D, where it improved in MMV by 19% over TMV. CONCLUSIONS.Modified monovision with SA improves through-focus VA and DoF as compared with traditional monovision. Binocular summation also increased as interocular similarity of image quality increased due to extended monocular DoF.Keywords: aberrations, presbyopia, monovision, binocular adaptive optics P resbyopia, the age-related loss of accommodation, mostly affects the population aged over approximately 50 years.

Binocular summation and visual function with induced anisocoria and monovision

“…This visual latency can distort the perception of the position and path of moving objects, and thus can lead to hazard in some everyday tasks. Zheleznyak et al [35], studying the impact on visual performance of modified monovision with monocularly induced spherical aberration to increase depth of focus, found a substantial benefit in through-focus visual acuity and binocular depth of focus as compared to traditional monovision. Thus, to take into account the real effects of the induction of anisocoria with artificial pupils, we also need to consider different aspects such as scene luminance, whether or not the task to be evaluated is in movement, the pupil diameter, optical quality of the eye, the Stiles-Crawford function of the individual, and of course, the centration of the inlay.…”

“…For this reason, it is important to avoid generating interocular differences in patients, whether in terms of optical quality (HOA, scattering, Strehl ratio, etc.) or in visual performance through functions as important as discrimination capacity or CSF, since these asymmetries deteriorate binocular visual performance [20,24,35].…”

Testing vision with angular and radial multifocal designs using Adaptive Optics

“…Visual simulation with Adaptive Optics (de Gracia et al, 2010;Piers et al, 2004;Schwarz et al, 2014;Yi et al, 2011;Zheleznyak et al, 2013) allows identifying the optimal multifocal correction for a patient, the effects of interactions of the natural aberrations and a better understanding of the role played by aberrations in perceived visual quality across different multifocal patterns. The Adaptive Optics Visual Simulator developed in the current study allows evaluating vision with any multifocal solution, while controlling the natural aberrations of the subject to allow a better understanding of optical and visual interactions in multifocal simultaneous vision corrections, and to investigate whether these interactions are driven by optical or by neural effects, which is critical to improve intraocular lens design and to select the optimal design for a patient.…”

“…Recently, using an optical design multiconfiguration approach, IOLs with surfaces optimized to enhance retinal image quality over a certain range of focus have been presented (Fernandez, Barbero, Dorronsoro, & Marcos, 2013). Several studies have used Adaptive Optics (AO) to simulate the effects of inducing different levels of spherical aberration in experimental settings (Piers, Fernandez, Manzanera, Norrby, & Artal, 2004;Schwarz et al, 2014;Zheleznyak, Sabesan, Oh, MacRae, & Yoon, 2013). In fact, the use of AO visual simulators has allowed exploring different combinations of high order aberrations (HOAs) to expand DoF (i.e.…”

Temporal integration property of stereopsis after higher-order aberration correction

“…Schwarz et al [23] later found a similar effect of spherical aberration correction on binocular visual acuity and summation in both monochromatic and polychromatic light. Other researches involved the optical effect on stereopsis [16,24] and depth of focus [25]. On the whole, relevant results are limited so far and further efforts are expected in the future.…”