Optical bench performance of a novel trifocal intraocular lens compared with a multifocal intraocular lens.

PURPOSE: The purpose of this study is to compare the optical characteristics of the novel PanOptix presbyopia-correcting trifocal intraocular lens (IOL) and the multifocal ReSTOR +3.0 D IOL, through in vitro bench investigations. METHODS: The optical characteristics of AcrySof(®) IQ PanOptix™ (PanOptix) and AcrySof(®) IQ ReSTOR +3.0 D (ReSTOR +3.0 D) IOLs were evaluated by through-focus Badal images, simulated headlight images, and modulation transfer function (MTF) measurements which determine resolution, photic phenomena, and image quality. Through-focus Badal images of an Early Treatment of Diabetic Retinopathy Study chart were recorded at both photopic and mesopic pupil sizes. Simulated headlight images were taken on an MTF bench with a 50-µm pinhole target and a 5.0 mm pupil at the distance focus of the IOL. MTF curves were measured with a 3.0 mm pupil, and spatial frequencies equivalent to 20/40 and 20/20 visual acuities were recorded to illustrate the through-focus MTF curves. Far-, intermediate-, and near-focus MTF values were obtained. RESULTS: Bench Badal image testing and MTF measurements showed that PanOptix has a near focus at a distance of 42 cm and an additional intermediate focus at a distance of about 60 cm. The near focus for ReSTOR +3.0 D is at 45 cm. PanOptix and ReSTOR +3.0 D have comparable photopic distances and near MTF values. Additionally, PanOptix provided a substantial continuous range of vision from distance to intermediate and to near compared with ReSTOR +3.0 D. The halo propensity for PanOptix was slightly higher than that for ReSTOR +3.0 D. CONCLUSION: Laboratory-based in vitro simulations showed that PanOptix trifocal IOL has comparable resolution and image quality performance in distance and near foci compared with ReSTOR +3.0 D IOL. PanOptix showed better resolution and image quality performance at the intermediate focus than ReSTOR +3.0 D IOL.

Ray-tracing optical modeling of negative dysphotopsia.

Negative dysphotopsia is a relatively common photic phenomenon that may occur after implantation of an intraocular lens. The etiology of negative dysphotopsia is not fully understood. In this investigation, optical modeling was developed using nonsequential-component Zemax ray-tracing technology to simulate photic phenomena experienced by the human eye. The simulation investigated the effects of pupil size, capsulorrhexis size, and bag diffusiveness. Results demonstrated the optical basis of negative dysphotopsia. We found that photic structures were mainly influenced by critical factors such as the capsulorrhexis size and the optical diffusiveness of the capsular bag. The simulations suggested the hypothesis that the anterior capsulorrhexis interacting with intraocular lens could induce negative dysphotopsia.

Performance of a new binocular wavefront aberrometer based on a self-imaging diffractive sensor.

PURPOSE: To compare the performance of the Ophthonix Z-View diffractive aberrometer with two different Hartmann-Shack aberrometers. METHODS: The Ophthonix Z-View was compared with the Alcon LADARWave and VISX WaveScan using 4 model eyes and 68 human eyes. Comparisons using three fixed, single-surface model eyes each with a different wavefront pattern were used to determine higher order accuracy. Lower order accuracy, linearity, and higher order repeatability were tested with a fourth model eye with a movable retinal surface. Manifest refraction spherical equivalent and the calculated spherical equivalent refraction of the aberrometers were compared in 68 human eyes. RESULTS: The Z-View was more accurate with lower noise compared to the WaveScan and LADARWave systems for higher order measurements of the fixed model eyes. Total root-mean-square difference from surface topography derived average values for all model eye configurations were 0.48, 0.95, and 0.74 microm for the Z-View, WaveScan, and LADARWave aberrometers, respectively. Average inter-measurement standard deviations for the fixed model eyes were 0.024, 0.025, and 0.034 microm for the Z-View, WaveScan, and LADARWave aberrometers, respectively. Results were similar among the systems for measuring the movable retina surface model eye and comparing manifest refraction spherical equivalent of the patients. CONCLUSIONS: Data gathered using one variable and several fixed-parameter model eyes showed good correlation to predicted values for all of the aberrrometers with one exception. A significant difference was found in the measurement of one individual fixed model eye with one of the three aberrometers. The wavefront refraction provided by the Z-View correlated well with the results of manifest refraction.