Jacobi-Fourier phase masks as ophthalmic elements to correct presbyopia.

Purpose: Investigations into the correction of presbyopia have considered lens design, clinical implications and the development of objective metrics such as the visual Strehl ratio. This study investigated the Jacobi-Fourier phase mask as an ophthalmic element in the correction of presbyopia. The goal was to develop a contact or intraocular lens whose performance was largely insensitive to changes in pupil diameter.

Think globally, act locally: Quality improvement as a catalyst for COVID-19 related care during the transitional years.

The COVID-19 pandemic has posed distinctive challenges to adolescents and young adults living with spina bifida, especially those from ethic minority populations. With this public health challenge in mind, developing a customized electronic health record to leverage registry data to promote and quantify COVID-19 vaccination uptake among this population is feasible. We provide a brief description of our activities in customizing an electronic health record to track vaccination uptake among adolescents and young adults with spina bifida (AYASB); and the lessons learned, in hopeful support of those scaling-up vaccination delivery across the globe for AYASB as they transition to adult-centered care.

Wavefront coding with Jacobi-Fourier phase masks for retinal imaging.

Wavefront coding is a technique that combines optical phase elements and digital signal processing in order to increase the effective depth of focus of optical systems. The success of wavefront coding lies in the design of a suitable phase mask placed at the system's aperture. This element allows for image formation invariant under the effects of different second-order optical aberrations.

Zernike coefficients from wavefront curvature data.

The concept of curvature sensing is reviewed, and a comprehensive derivation of the curvature polynomials is given, whose inner products with the wavefront curvature data yield the Zernike aberration coefficients of an aberrated circular wavefront. The data consist of the Laplacian of the wavefront across its interior and its outward normal slope at its circular boundary. However, we show that the radial part of the curvature polynomials and their slopes at the boundary of the wavefront have a value of zero, except when the angular frequency of the corresponding Zernike polynomial is equal to its radial degree.

Central blood pressure variability is increased in hypertensive patients with target organ damage.

We aimed to evaluate the association of aortic and brachial short-term blood pressure variability (BPV) with the presence of target organ damage (TOD) in hypertensive patients. One-hundred seventy-eight patients, aged 57 ± 12 years, 33% women were studied. TOD was defined by the presence of left ventricular hypertrophy on echocardiogram, microalbuminuria, reduced glomerular filtration rate, or increased aortic pulse wave velocity.

Pupil size stability of the cubic phase mask solution for presbyopia.

Presbyopia correction involves different types of studies such as lens design, clinical study, and the development of objective metrics, such as the visual Strehl ratio. Different contact lens designs have been proposed for presbyopia correction, but performance depends on pupil diameter. We will analyze the potential use of a nonsymmetrical element, a cubic phase mask (CPM) solution, to develop a contact or intraocular lens whose performance is nearly insensitive to changes in pupil diameter.

Vector polynomials for direct analysis of circular wavefront slope data: erratum.

We provide a correction to Eq. (4) in J. Opt.

Vector polynomials for direct analysis of circular wavefront slope data: publisher's note.

This publisher's note corrects two text errors in J. Opt. Soc.

Vector polynomials for direct analysis of circular wavefront slope data.

In the aberration analysis of a circular wavefront, Zernike circle polynomials are used to obtain its wave aberration coefficients. To obtain these coefficients from the wavefront slope data, we need vector functions that are orthogonal to the gradients of the Zernike polynomials, and are irrotational so as to propagate minimum uncorrelated random noise from the data to the coefficients. In this paper, we derive such vector functions, which happen to be polynomials.

Twenty-four-hour central blood pressure is not better associated with hypertensive target organ damage than 24-h peripheral blood pressure.

Background And Aim: Central blood pressure (BP) is increasingly considered as a better estimator of hypertension associated risks. We aimed to evaluate the association of 24-h central BP, in comparison with 24-h peripheral BP, with the presence of target organ damage (TOD).

Methods: Cross-sectional study of 208 hypertensive patients, aged 57 ± 12 years, 34% women.

Potential use of cubic phase masks for extending the range of clear vision in presbyopes: initial calculation and simulation studies.

Purpose: In this paper we analyse the potential use of a non-symmetrical optical element, a cubic phase mask, for extending the range of clear vision of presbyopic eyes. Additionally, we will discuss the appropriateness of the visual Strehl ratio to analyse this sort of presbyopic solution based on non-symmetrical phase masks contrasted with through-focus retinal images.

Methods: In order to evaluate the performance of the cubic phase mask we employed computational Fourier Optics to compute the different visual Strehl criteria as well as simulate the retinal images.

[Usefulness of the FEV/FEV ratio to detect the prevalence of lung obstruction in hospitalised patients with multiple morbidities].

Background: The prevalence of lung obstruction increases with age and the presence of comorbidities. Although a complete spirometry is necessary to confirm the diagnosis, this may be impractical in elderly patients with cognitive impairment or functional dependence. Recently, the use of portable devices using the FEV/FEV ratio have shown to be useful for assessing the presence of lung obstruction, with greater ease of use, but its usefulness has not been established in the elderly population with multiple morbidities.

Interferometric Local Measurements of High-Order Aberrations in Progressive Addition Lenses.

Purpose: The main goal of this work is to show the principles, design, and performance of a modified point diffraction interferometer (PDI) for evaluating the local higher-order aberrations of progressive addition lenses (PALs). Because aberrations have different impacts in visual perception, we propose a device to provide a customized solution with the best permissible amounts and combinations of aberrations for improving a subject's vision.

Methods: A PDI has been adapted to measure local high-order aberrations in PALs.

Wavefront-coding technique for inexpensive and robust retinal imaging.

We propose a hybrid optical-digital imaging system that can provide high-resolution retinal images without wavefront sensing or correction of the spatial and dynamic variations of eye aberrations. A methodology based on wavefront coding is implemented in a fundus camera in order to obtain a high-quality image of retinal detail. Wavefront-coded systems rely simply on the use of a cubic-phase plate in the pupil of the optical system.

Generation of spherical aberration with axially translating phase plates via extrinsic aberration.

We show that spherical aberration of all orders can be generated as an extrinsic aberration in a system of axially translating plates. Some practical examples are provided. In particular for two phase plates that are 10 mm in diameter it is possible to generate from -10 to 10 waves of fourth-order spherical aberration with an axial displacement of +/- 0.

Lens aberrations and their relationship with lens sutures for species with Y-suture branches.

Work remains to be done to understand the origins of ocular aberrations. We analyze lens aberrations of several species with Y-suture branches (bovine, ovine, and porcine) and their relationship with suture distribution. Aberrations are measured in vitro with a point diffraction interferometer in 10 different eyes of each species.

Progressive addition lens measurement by point diffraction interferometry.

Purpose: Design a device for accurate measurements of local optical properties of progressive addition lenses (PALs).

Methods: A point diffraction interferometer has been adapted to measure local prescriptions of PALs.

Results: The most basic configuration of the interferometer for the measurement of PALs showed in this work presents high dynamic range and accuracy as well as the possibility of choosing the number and position of measurement points.

Optical pressure sensor based on the combined system of a variable liquid lens and a point diffraction interferometer.

We propose an experimental efficient optical pressure sensor based on a variable liquid lens and a modified point diffraction interferometer. The working principle of the sensor is based on the fact that a variation in pressure induces a change in lens curvature and hence in its focal length, which can be tracked and measured with the interferometer. The pressure is then measured by recording and processing the interferometric images.

Low-cost adaptive astigmatism compensator for improvement of eye fundus camera.

In this work we show a conceptually simple and cheap means by which to improve retinal image quality in fundus cameras. We will explain how to build a low-cost variable astigmatism-correcting device with a pair of identical commercial ophthalmic lenses. We have developed and tested a low order aberration compensation device capable of correcting astigmatism prescriptions up to -8.

Adaptive astigmatism-correcting device for eyepieces.

Purpose: We describe how to construct a low-cost and robust variable astigmatism-correcting device manufactured using a pair of identical commercial ophthalmic lenses.

Methods: Variable astigmatism power can be obtained by relative rotation of two cross cylinders with the same prescription (for this work: S = +2.00 D, C = -4.

Phase plates for generation of variable amounts of primary spherical aberration.

We discuss a set of phase plate-pairs for the generation of variable amounts of primary spherical aberration. The surface descriptions of these optical plates are provided, and their aberration-generating properties are verified with real ray-tracing. These plate-pairs are robust in that they allow large tolerances to spacing as well as errors in the relative displacement of the plates.

Relationship between wave aberrations and histological features in ex vivo porcine crystalline lenses.

Wave aberrations of isolated ex vivo porcine crystalline lenses were measured by using a point-diffraction interferometer. This method allowed us to gain greater insight into the detailed aberration structure of eye lenses showing systematic presence of some dominant aberrations. In order of significance, astigmatism together with spherical aberration, coma, and trefoil are the main aberrations present in all lenses.

Wavefront measurements of phase plates combining a point-diffraction interferometer and a Hartmann-Shack sensor.

A dual setup composed of a point diffraction interferometer (PDI) and a Hartmann-Shack (HS) wavefront sensor was built to compare the estimates of wavefront aberrations provided by the two different and complementary techniques when applied to different phase plates. Results show that under the same experimental and fitting conditions both techniques provide similar information concerning the wavefront aberration map. When taking into account all Zernike terms up to 6th order, the maximum difference in root-mean-square wavefront error was 0.