Inverted meniscus IOLs reduce image shifts in the periphery compared to biconvex IOLs.

Intraocular lenses (IOLs) are routinely used to replace cataractous crystalline lenses. Most current models have a biconvex design that reduces optical quality in the periphery since they are optimized only for central vision. Inverted meniscus IOLs are optimized to achieve similar optical performance to phakic eyes in the peripheral retina.

Visually relevant on-bench through-focus analysis of intraocular lenses.

Cataract surgery involves the implantation of an intraocular lens (IOL) to replace the opacified crystalline lens. Monofocal IOLs, the most common type, are intended to have the eye in focus at a given distance, usually at infinity. Simultaneous vision IOLs (SVIOLs) and extended depth of focus (EDOF) aim to minimize postoperative dependence on spectacles by providing either multiple foci or an extended depth of focus.

Peripheral Vision in Patients Following Intraocular Lens Implantation: A Systematic Review and Meta-Analysis.

Purpose: To update the literature on peripheral optics and vision following intraocular lens (IOLs) implantation.

Methods: We investigated how current IOLs influence peripheral visual function, peripheral optical quality, and visual perception and performance, in patients following cataract surgery. Peripheral vision is described as vision outside the central foveal region of the eye (beyond 4-5° of eccentricity).

Central and peripheral refraction measured by a novel double-pass instrument.

A novel double-pass instrument and its data analysis method for the measurement of central and peripheral refraction is presented and validated in a group of healthy subjects. The instrument acquires in-vivo, non-cycloplegic, double-pass, through-focus images of the eye's central and peripheral point-spread function (PSF) using an infrared laser source, a tunable lens and a CMOS camera. The through-focus images were analyzed to determine defocus and astigmatism at 0° and 30° visual field.

Inverted meniscus intraocular lens as a better optical surrogate of the crystalline lens.

Current intraocular lenses (IOLs) are designed to substitute the cataractous crystalline lens, optimizing focus at the fovea. However, the common biconvex design overlooks off-axis performance, leading to a reduced optical quality in the periphery of the retina in pseudophakic patients compared to the normal phakic eye. In this work, we designed an IOL to provide better peripheral optical quality, closer in that respect to the natural lens, using ray-tracing simulations in eye models.

Peripheral Refraction and Contrast Detection Sensitivity in Pseudophakic Patients Implanted With a New Meniscus Intraocular Lens.

Purpose: To evaluate peripheral refraction and contrast detection sensitivity in pseudophakic patients implanted with a new type of inverted meniscus intraocular lens (IOL) (Art25; Voptica SL) that was designed to provide better peripheral optics.

Methods: One month after cataract surgery, in 87 eyes implanted with the Art25 IOL, peripheral contrast detection sensitivity was measured psychophysically at 40° visual angle, both horizontally and vertically, and compared with a control group of 51 eyes implanted with standard biconvex IOLs. Thirty-one eyes with the Art25 IOL and 28 eyes from the control group were randomly selected to also measure peripheral refraction using a scanning Hartmann-Shack wavefront sensor along 80° in the horizontal meridian.

Straylight in Different Types of Intraocular Lenses.

Purpose: To show the importance of measuring the angular distribution of straylight as an in vitro test for intraocular lenses (IOLs).

Methods: The optical integration method was implemented to measure the point spread function, up to 5.1°, of IOLs immersed in a wet cell.

Accuracy of dynamic contour tonometry, Goldmann applanation tonometry, and Tono-Pen XL in edematous corneas.

Purpose: To investigate the accuracy of dynamic contour tonometry, Goldmann applanation tonometry, and Tono-Pen XL in edematous corneas.

Methods: Experimental study included 20 freshly enucleated porcine eyes. Epithelium was debrided, and eyes were divided in four groups.

Peripheral image quality in pseudophakic eyes.

The purpose of this work was to evaluate peripheral image quality in the pseudophakic eye using computational, physical, and psychophysical methods. We designed and constructed a physical model of the pseudophakic human eye with realistic dimensions using a corneal phantom and a board-only camera that was pivoted around an axis that matched the anatomical center of a human retina, assuming a radius of curvature of 12 mm, while it was submersed in a 23.4 mm long water filled chamber to emulate human ocular axial length.

Ocular axial length and straylight.

Purpose: Straylight refers to an optical phenomenon that takes places in the eye and leads to a deterioration of the retinal image. Past clinical findings suggest an increase of straylight with the eye's axial length, but the aetiology of the phenomenon was unclear. The purpose of this work is to demonstrate, through raytracing, simple geometrical optics, and the well-established inverse-angle square law for the angular distribution of straylight, why straylight increases when a myopic eye is corrected with spectacles.

Objective method for measuring the macular pigment optical density in the eye.

Macular pigment is a yellowish pigment of purely dietary origin, which is thought to have a protective role in the retina. Recently, it was linked to age-related macular degeneration and improved visual function. In this work, we present a method and a corresponding optical instrument for the rapid measurement of its optical density.

Visual and physiological optics: introduction to the Journal of the Optical Society of America A feature issue.

The 9th European Meeting on Visual Physiological Optics (VPO2018) was held August 29-31, 2018, in Athens, Greece. This issue of the Journal of the Optical Society of America A (JOSA A) is a dedicated feature, including numerous articles that span a large range of visual optics related topics, ranging from geometrical optics to visual psychophysics and from optical metrology to ophthalmic diagnostic technologies. The next VPO meeting will be held August 2020 in Cambridge, UK.

Enhancement-procedure outcomes in patients implanted with the Precisight multicomponent intraocular lens.

Purpose: Eyes that have undergone phacoemulsification with implantation of a multicomponent intraocular lens (MCIOL) may further undergo an enhancement procedure for correction of residual refractive errors. The enhancement procedure is accomplished by exchanging the front lens used in the primary surgery with another lens containing the correct dioptric power. We evaluated the efficacy and safety of enhancement procedures among eyes that received an MCIOL.

Light scattering in the human eye modelled as random phase perturbations.

Light scattering in the eye affects the quality of vision and its effect increases with aging and related pathologies, such as cataracts. Simulating methods were developed in order to reproduce the effects of this phenomenon. We introduce a statistical model of wavefront perturbations at the pupil plane of the eye that replicates the characteristic angular distribution of the light distribution over the retina.

Effect of intraocular scattering in macular pigment optical density measurements.

Fundus reflectometry is a common in-vivo, noninvasive method to estimate the macular pigment optical density (MPOD). The measured density, however, can be affected by the individual's intraocular scattering. Scattering causes a reduction in the contrast of the fundus image, which in turn leads to an underestimation of the measured density.

Performance of a differential contrast sensitivity method to measure intraocular scattering.

Increased intraocular scatter degrades quality of vision, especially in the presence of glare sources. Standard tests, such as visual acuity, are not well suited to capture this condition. There are specific methods to measure intraocular scatter, but require dedicated instruments.

Scattering contribution to the double-pass PSF using Monte Carlo simulations.

Purpose: Scattering in the eye occurs mainly at two sites: the eye's optical media and the deeper retinal layers. Although the two phenomena are often treated collectively, their spatial domain of contribution to the double-pass Point Spread Function (PSF) is different: the fundus effect is limited to the narrow and middle part of the PSF whereas scattering in the eye's optics extends also to wide angles. The objective of this work was to determine the domain of contribution at the double-pass PSF of light scattered in the ocular media and the ocular fundus, using simulated and experimental data for two different wavelengths and for two different pigmentations.

Optical Measurement of Straylight in Eyes With Cataract.

Purpose: To measure straylight in a cohort of patients with cataract using a novel optical instrument and to correlate optical straylight values with clinical grade of cataracts and psychophysical straylight values.

Methods: Measurements were performed on 53 eyes of 44 patients with cataract admitted to the ophthalmology service of the university hospital in Murcia, Spain, and 9 young volunteers with no known ophthalmic pathology. Lens opacities were classified according to the Lens Opacities Classification System Ill (LOCS III) under slit-lamp examination.

Intraocular scattering compensation in retinal imaging.

Intraocular scattering affects fundus imaging in a similar way that affects vision; it causes a decrease in contrast which depends on both the intrinsic scattering of the eye but also on the dynamic range of the image. Consequently, in cases where the absolute intensity in the fundus image is important, scattering can lead to a wrong estimation. In this paper, a setup capable of acquiring fundus images and estimating objectively intraocular scattering was built, and the acquired images were then used for scattering compensation in fundus imaging.

A new endocapsular open ring for prevention of anterior and posterior capsule opacification.

Purpose: The aim of this study is to demonstrate the functionality of a new design of a thick endocapsular open ring for prevention of anterior capsule opacification (ACO) and posterior capsule opacification (PCO).

Setting: The Institute of Vision and Optics, University of Crete and University Hospital of Heraklion, Crete, Greece.

Design: Prospective, interventional pilot study.

Environmental and Genetic Factors Explain Differences in Intraocular Scattering.

Purpose: To study the relative impact of genetic and environmental factors on the variability of intraocular scattering within a classical twin study.

Methods: A total of 64 twin pairs, 32 monozygotic (MZ) (mean age: 54.9 ± 6.

Spatial properties of fundus reflectance and red-green relative spectral sensitivity.

We investigated the spatial characteristics of the diffuse light in the eye at two different wavelengths and the extent to which this may affect red-green relative spectral sensitivity. The fundus reflectance of six subjects was measured for different field sizes ranging from a 0.18° to 7.

Ocular rigidity and outflow facility in nonproliferative diabetic retinopathy.

Purpose: To compare ocular rigidity (OR) and outflow facility (C) in patients with nonproliferative diabetic retinopathy (NPDR) and control subjects.

Methods: Twenty-four patients with NPDR (NPDR group) and 24 controls (control group) undergoing cataract surgery were enrolled. NPDR group was further divided into patients with mild NPDR (NPDR1-group) and patients with moderate and/or severe NPDR (NPDR2-group).

INTRA-SCLERAL PARATHALAMUS IMPLANT: EFFICACY AND SAFETY IN RABBIT EYES.

Purpose: A variety of anti-glaucomatous shunt designs have been proposed so far. This study evaluates the feasibility of a novel shunt design, the intra-scleral parathalamus implant (IPI), in a rabbit eye model.

Methods: Ten healthy albino rabbits were included.