Optical and clinical simulated performance of a new refractive extended depth of focus intraocular lens.

Objectives: The purpose of this study is to evaluate the optical and expected clinical performance of a new refractive Extended Depth of Focus (EDF) intraocular lens (IOL), TECNIS PureSee™ IOL, designed to maintain a monofocal-like dysphotopsia profile.

Methods: Simulated visual acuity (sVA) with varying defocus was calculated using the area under the Modulation Transfer Function measured in an average eye model and from computer simulations in eye models with corneal higher-order aberrations. Tolerance to defocus was evaluated using computer simulations of the uncorrected distance sVA under defocus.

Influence of decentration and tilt of Tecnis ZCB00 on visual acuity and higher order aberrations.

Background/objectives: To determine the influence of decentration and tilt of a pseudophakic aspheric intraocular lens (IOL) on visual acuity (VA) and higher-order aberrations (HOAs), and to analyze the agreement between pupil center/axis and iridocorneal angles center/axis when assessing IOL decentration and tilt.

Subjects/methods: A prospective interventional case series study including thirty-three patients undergoing Tecnis ZCB00 (Abbott Medical Optics) implantation. IOL decentration and tilt with respect to two reference systems (pupil and iridocorneal angles centers/axes), in cartesian (X,Y) and polar (radius/tilt, polar angle/azimuth) coordinates, were assessed with optical coherence tomography.

The Effect of Retinal Illuminance on the Subjective Amplitude of Accommodation.

Significance: We show that the amplitude of accommodation decreases with retinal illumination even under photopic reading conditions and a constant pupil size. This result provides a basis for clinical approaches that are not based on an optical explanation.

Purpose: We investigated the effect of retinal illuminance on the amplitude of accommodation while the pupil of the eye remained constant.

Aberrations and accommodation.

Modern methods of measuring the refractive state of the eye include wavefront sensors which make it possible to monitor both static and dynamic changes of the ocular wavefront while the eye observes a target positioned at different distances away from the eye. In addition to monitoring the ocular aberrations, wavefront refraction methods allow measurement of the accommodative response while viewing with the eye's habitual chromatic and monochromatic aberrations present, with these aberrations removed, and with specific aberrations added or removed. A large number of experiments describing the effects of accommodation on aberrations and vice versa are reviewed, pointing out the implications for fundamental questions related to the mechanism of accommodation.

Effect of phenylephrine on static and dynamic accommodation.

Purpose: We tested the hypothesis that changes in accommodation after instillation of Phenylephrine Hydrochloride (PHCl) observed in some studies could be caused by changes in optics.

Methods: We performed two experiments to test the effects of PHCl on static and on dynamic accommodation in 8 and 6 subjects, respectively. Objective wavefront measurements were recorded of the static accommodation response to a stimulus at different distances or dynamic accommodation response to a sinusoidally moving stimulus (between 1 and 3 D of accommodative demand at 0.

Amplitude, Latency, and Peak Velocity in Accommodation and Disaccommodation Dynamics.

The aim of this work was to ascertain whether there are differences in amplitude, latency, and peak velocity of accommodation and disaccommodation responses when different analysis strategies are used to compute them, such as fitting different functions to the responses or for smoothing them prior to computing the parameters. Accommodation and disaccommodation responses from four subjects to pulse changes in demand were recorded by means of aberrometry. Three different strategies were followed to analyze such responses: fitting an exponential function to the experimental data; fitting a Boltzmann sigmoid function to the data; and smoothing the data.

Evaluation of the iridocorneal angle with accommodation using optical coherence tomography.

The changes in the iridocorneal angle structure during accommodation are assessed by means of anterior segment optical coherence tomography. Thirteen right eyes were included in the study. The device used for the measurement was the Visante system.

Effect of even and odd-order aberrations on the accommodation response.

Aim: To investigate the potential effect that odd and even-order monochromatic aberrations may have on the accommodation response of the human eye.

Methods: Eight healthy subjects with astigmatism below 1 D, best corrected visual acuity 20/20 or better and normal findings in an ophthalmic examination were enrolled. An adaptive optics system was used in order to measure the accommodation response of the subjects' eyes under different conditions: with the natural aberrations being present, and with the odd and even-order aberrations being corrected.

Human eyes do not need monochromatic aberrations for dynamic accommodation.

Purpose: To determine if human accommodation uses the eye's own monochromatic aberrations to track dynamic accommodative stimuli.

Methods: Wavefront aberrations were measured while subjects monocularly viewed a monochromatic Maltese cross moving sinusoidally around 2D of accommodative demand with 1D amplitude at 0.2 Hz.

Dynamic accommodation without feedback does not respond to isolated blur cues.

The aim of this study was to determine whether dynamic accommodation responds to isolated blur cues without feedback, and without changes in the distance of the object. Nine healthy subjects aged 21-40years were recruited. Four different aberration patterns were used as stimuli to induce blur with (1) the eye's natural, uncorrected, optical aberrations, (2) all aberrations corrected, (3) spherical aberration only, or (4) astigmatism only.

Optical quality of rotationally symmetrical contact lenses derived from their power profiles.

Purpose: To present a methodology for evaluating the optical quality of rotationally symmetrical contact lenses (CLs) from a single power profile.

Methods: Simulated rotationally symmetrical power profiles corresponding to different CLs designs (monofocal, two-zone center-near bifocal, and four-zone center-distance bifocal) were used to calculate the wavefront error profile by means of numerical integration. Then, each lens wavefront error profile was spun around the center to obtain the lens wavefront error surface.

Non-invasive measurements of the dynamic changes in the ciliary muscle, crystalline lens morphology, and anterior chamber during accommodation with a high-resolution OCT.

Purpose: The purpose of the study was to assess non-invasively the changes in the anterior chamber eye, crystalline lens morphology, and ciliary muscle during accommodation by means of an anterior chamber optical coherence tomographer (OCT), and correlate them with vergence.

Methods: Twenty-five eyes of twenty-five healthy subjects, whose mean age was 29.9±7.

Accommodation Responds to Optical Vergence and Not Defocus Blur Alone.

Purpose: To determine whether changes in wavefront spherical curvature (optical vergence) are a directional cue for accommodation.

Methods: Nine subjects participated in this experiment. The accommodation response to a monochromatic target was measured continuously with a custom-made adaptive optics system while astigmatism and higher-order aberrations were corrected in real time.

Objective assessment of the effect of pupil size upon the power distribution of multifocal contact lenses.

Aim: To analytically assess the effect of pupil size upon the refractive power distributions of different designs of multifocal contact lenses.

Methods: Two multifocal contact lenses of center-near design and one multifocal contact lens of center-distance design were used in this study. Their power profiles were measured using the NIMO TR1504 device (LAMBDA-X, Belgium).

Effect of Phenylephrine on the Accommodative System.

Accommodation is controlled by the action of the ciliary muscle and mediated primarily by parasympathetic input through postganglionic fibers that originate from neurons in the ciliary and pterygopalatine ganglia. During accommodation the pupil constricts to increase the depth of focus of the eye and improve retinal image quality. Researchers have traditionally faced the challenge of measuring the accommodative properties of the eye through a small pupil and thus have relied on pharmacological agents to dilate the pupil.

Temporal multiplexing with adaptive optics for simultaneous vision.

We present and test a methodology for generating simultaneous vision with a deformable mirror that changed shape at 50 Hz between two vergences: 0 D (far vision) and -2.5 D (near vision). Different bifocal designs, including toric and combinations of spherical aberration, were simulated and assessed objectively.

Assessing the in vitro optical quality of presbyopic solutions based on the axial modulation transfer function.

Purpose: To present a metric for assessing the in vitro optical quality of rotationally symmetrical optical elements based on volume calculation under the surface defined by the axial modulation transfer function (MTF).

Setting: University of Valencia, Valencia, Spain.

Design: Experimental study.

In vitro optical quality comparison of 2 trifocal intraocular lenses and 1 progressive multifocal intraocular lens.

Purpose: To evaluate the optical quality of 3 multifocal intraocular lenses (IOLs): the Mini Well Ready progressive multifocal aspheric IOL, the AT LISA trifocal diffractive IOL, and the Finevision full diffractive trifocal IOL.

Setting: University of Valencia, Valencia, Spain.

Design: Experimental study.

In vitro optical quality comparison between the Mini WELL Ready progressive multifocal and the TECNIS Symfony.

Purpose: To compare the optical quality between two intraocular lenses (IOLs): the Mini WELL Ready progressive multifocal (SIFI Medtech, Catania, Italy), and the TECNIS Symfony (Abbott Laboratories, Illinois, USA), which both provide a continuous range of vision from far to near positions.

Methods: The in vitro optical quality of each lens was assessed with an instrument conceived for measuring the modulation transfer function (MTF). The optical quality of each lens was described in terms of MTF, through-focus MTF, defocus tolerance, pupil dependence, and Strehl ratio MTF.

Effect of Large Apertures on the Optical Quality of Three Multifocal Lenses.

Purpose: To compare the optical quality under large apertures among three multifocal intraocular lenses (IOLs): the TECNIS Symfony ZXR00 (Abbott Laboratories, Abbott Park, IL), the AT LISA tri 839MP (Carl Zeiss Meditec, Jena, Germany), and the Finevision (PhysIOL, Liège, Belgium).

Methods: The in vitro optical quality of each lens was assessed with an instrument that measured the modulation transfer function (MTF). The optical quality of each lens was described in terms of MTF and through focus average MTF.