Interaction of Monochromatic and Chromatic Aberrations in Pseudophakic Patients

Abstract

PURPOSE: To measure monochromatic aberrations at various wavelengths in eyes implanted with the Clareon monofocal aspheric intraocular lens (IOL) (Alcon Laboratories, Inc., Fort Worth, TX). The authors estimated longitudinal chromatic aberration (LCA), modulation transfer functions (MTFs), and the impact of interactions between chromatic and monochromatic aberrations on retinal image quality. METHODS: Ten patients (age: 68.4 ± 3.21 years) were measured in two experiments: (1) Hartmann-Shack wave aberrations at five visible wavelengths (480 to 700 nm) and (2) best subjective focus at each wavelength. Objective and psychophysical LCAs were obtained from the Zernike defocus and psychophysical best focus, respectively. MTFs were calculated for the closest wavelengths to the peak sensitivity of the three cone classes (S [480 nm], M [555 nm], and L [564 nm]) using the measured aberrations and chromatic difference of focus. The degradation produced by LCA was estimated as the visual Strehl ratio for green divided by the visual Strehl ratio for blue and red. RESULTS: The root mean square for higher order aberrations (HOAs) ranged from 0.0622 to 0.2084 µm (700 nm, 4.3-mm pupil). Monochromatic visual Strehl ratio was above 0.35 in all patients. LCA was 1.23 ± 0.05 diopters (D) (psychophysical) and 0.90 ± 0.11 D (objective). Visual Strehl ratio decreased by a factor ranging from 1.38 to 3.82 on chromatic defocus from green to blue. There was a significant correlation between native visual Strehl ratio and the degradation produced by LCA (ie, visual Strehl 555 /visual Strehl 480 ). CONCLUSIONS: The Clareon IOL compensates for spherical aberration, with postoperative wave aberrations dominated by astigmatism and other HOAs, being highly subject-dependent. The impact of LCA in blue is largely dependent on the magnitude of monochromatic aberrations. [ J Refract Surg . 2020;36(4):230–238.]

Comparison of visual performance between two aspheric monofocal intraocular lens models

“…patient (19). Regarding chromatic aberration, Marcos et al,(20) recently assessed LCA with a psychophysical test in a group of 10 patients implanted with the Clareon® IOL model; they reported a mean LCA value of 1.23 ± 0.05 D. These values are totally in line with those from our study (1.23 ± 0.49 D, Table…”

Longitudinal Chromatic Aberration in Patients Implanted With Trifocal Diffractive Hydrophobic IOLs

“…This is consistent with a previous study where patients were bilaterally implanted with monofocal IOLs of the same design, but with hydrophobic material in one eye and hydrophilic material in the contralateral eye. 13 In that study, there was a constant offset of 0.15 D between the LCA measured in vivo in eyes implanted with monofocal IOLs of both materials, which compares with the offset in the LCA found between the hydrophobic and hydrophilic trifocal IOL at far (0.17 D). However, the magnitude of the LCA in patients implanted with monofocal IOL designs was higher (1.37 ± 0.08 D for the hydrophobic and 1.2.1 ± 0.08 D for the hydrophilic) than with the corresponding trifocal designs.…”

“…Various studies report the LCA of lenses with different materials, both on bench and once implanted in the eye. [6][7][8][9][10][11][12][13] For example, the psy-chophysical LCA (480 to 700 nm) in phakic eyes has been reported to be 1.52 diopters (D), 5 whereas LCA was 1.37 ± 0.08 D in patients implanted with hydrophobic monofocal IOLs (FineVision hydrophobic raw material) and 1.21 ± 0.08 D in patients implanted with hydrophilic monofocal IOLs (FineVision hydrophilic raw material). 14 Besides the material, the design of the IOL 15 also influences the chromatic aberrations of IOLs.…”

Through-Focus Energy Efficiency and Longitudinal Chromatic Aberration of Three Presbyopia-Correcting Intraocular Lenses

“…Although VA exhibits a robust response under modified chromatic conditions, the authors reported impairment in the predictability of the results with an LCA modified from natural conditions, as the experimental VA values were lower than the predicted. Marcos et al 45 reported in a recent paper that psychophysical LCA was consistently larger than objective LCA in a group of patients implanted with a monofocal IOL. Such reports indicate that clinical applications of in vitro measurements and simulations using eye models are of great interest, and studies are currently proceeding at a rapid pace, although much additional research is required.…”