Search results for " Lens"
showing 10 items of 510 documents
New Forceps and Spatula for Easy Retropupillary Implantation of Iris Claw Lenses in Aphakia: Experience in 4 Years of Use
2008
PURPOSE. Retropupillary implantation of an iris claw lens offers a rapid and atraumatic approach for rehabilitation of aphakic eyes. The difficulty in the implantation process arises because of the possibility of losing the intraocular lens (IOL) into the vitreous cavity and the need to change the hand holding the forceps during the enclavation. M ETHODS. The new forceps design radically changes the method of grasping an IOL. It contains an extendable supporting plate with a hook-like end. The instrument achieves a horizontal three-point fixation at the edge of the implant in the 6 and 12 o’clock position in order to prevent slippage into the vitreous cavity during the inclination. The supp…
Visual Performance after AcrySof ReSTOR Aspheric Intraocular Lens Implantation
2008
Purpose: To evaluate distance, intermediate and near visual performance in patients who had undergone implantation of the multifocal aspheric AcrySof ReSTOR intraocular lens (IOL). Methods: Binocular best distance corrected visual acuity (BCVA) at high and low contrast [4 m], best distance corrected near visual acuity (BCNVA) [40 cm], intermediate visual acuity [80 and 60 cm], and distance contrast sensitivity (CS) under photopic [85 cd/m2] and mesopic [3 cd/m2] conditions, were measured in 36 eyes that underwent implantation of the AcrySof ReSTOR Aspheric IOL (SN6AD3). Results: At the 3-month postoperative visit, binocular BCVA was -0.058±0.091, 0.200±0.079, and 0.258±0.071 logMAR, for 100…
New intraocular lens for achromatizing the human eye.
2007
To describe the design of a new intraocular lens (IOL) capable of correcting spherical and chromatic aberrations when implanted in the human eye.University of Murcia, Murcia, and University of Valencia, Valencia, Spain.A hybrid singlet achromatic IOL was designed. The IOL has a combination of a refractive and a diffractive surface, with 1 of the surfaces being aspherical. Optical simulations were used to model the polychromatic modulation transfer function (MTF) in pseudophakic eyes to explain the differences in optical quality afforded by the achromatic IOL. Parameters such as focus shift, optical path difference, through-focus, and robustness to tilt and decentering of achromatic IOLs wer…
Relationship Between Visual Field Sensitivity and Retinal Nerve Fiber Layer Thickness Measured by Scanning Laser Polarimetry and Optical Coherence To…
2009
Purpose: To evaluate the correlation between automated achromatic perimetry (AAP) and the output of two retinal nerve fiber layer (RNFL) analysers: scanning laser polarimetry (GDx-VCC) and optical coherence tomography (OCT). Methods: Quantitative RNFL measurements with GDx-VCC and Stratus-OCT were obtained in one eye from 52 healthy subjects, 38 ocular hypertensive (OHT) patients and 94 glaucomatous patients. All patients underwent a complete examination, including AAP using the Swedish interactive threshold algorithm (SITA). The relationship between RNFL measurements and SITA visual field global indices were assessed by means of the following methods: analysis of variance, bivariate Pearso…
A giant planet beyond the snow line in microlensing event OGLE-2011-BLG-0251
2013
We present the analysis of the gravitational microlensing event OGLE-2011-BLG-0251. This anomalous event was observed by several survey and follow-up collaborations conducting microlensing observations towards the Galactic Bulge. Based on detailed modelling of the observed light curve, we find that the lens is composed of two masses with a mass ratio q=1.9 x 10^-3. Thanks to our detection of higher-order effects on the light curve due to the Earth's orbital motion and the finite size of source, we are able to measure the mass and distance to the lens unambiguously. We find that the lens is made up of a planet of mass 0.53 +- 0.21,M_Jup orbiting an M dwarf host star with a mass of 0.26 +- 0.…
Multifokālo kontaktlēcu lietotāju redzes asums un stereoredze
2018
Bakalaura darbs uzrakstīts uz 37 lapaspusēm, satur 10 zīmējumus, 5 tabulas un 18 literatūras avotus. Darba mērķis ir novērtēt redzes asumu un stereoredzi tuvumā un tālumā pacientiem koriģētiem ar brillēm un multifokālajām kontaktlēcām. Mūsu pētījumi parādīja, ka tāluma binokulārais redzes asums visiem pacientiem ir labs – virs 0,95. Tuvuma redzes asums pacientiem koriģētiem ar brillēm ir labāks un pacienti dod priekšroku brillēm. Tuvuma stereoredze noteikta ar Titmusa mušas testu un Titmusa apļu testu pacientiem koriģētiem ar brillēm un kontaktlēcām bija laba. Tāluma stereoredzes parametriem mēs redzam atšķirību, ar brillēm stereoredze ir labāka, bet rezultātu atšķirība nav statistiski būti…
The effect of blue-light-blocking lenses on retinal straylight
2021
Sometimes yellow-tinted lenses are recommended to help improve visual quality. As yellow lenses filter blue light, it is believed that their use could decrease the intensity of scattered light in the eye (retinal straylight). However, the results of some studies have contradicted this assumption (Van Os et al. 2017). Currently various nontinted blue-light-blocking lenses are used to protect the eyes from short-wavelength light. The objective of this study was to determine whether blue-light-blocking lenses affect the levels of retinal straylight in the eye. A straylight meter (C-Quant, Oculus) was used for retinal straylight measurements. The measurements were performed under four different…
Euclid preparation: XI. Mean redshift determination from galaxy redshift probabilities for cosmic shear tomography
2021
Ilbert, O., et al. (Euclid Collaboration)
Optical quality of hyperopic and myopic phakic intraocular lenses
2013
Aims: To assess and compare the optical quality of the myopic and hyperopic implantable collamer lens (ICL) from its wavefront aberrations for different powers and pupil diameters. Settings and Design: Prospective study. Material and Methods: The wavefront aberrations of two myopic (−3 and −6 diopters (D)) and two hyperopic V4b ICLs (+3 and +6D) were measured in vitro . To assess and compare the optical quality of different powers of ICLs, we analyzed the root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration at 3- and 4.5-mm pupil. In addition, the point spread functions (PSFs) of each ICL evaluated were ca…
IMI Prevention of Myopia and Its Progression
2021
The prevalence of myopia has markedly increased in East and Southeast Asia, and pathologic consequences of myopia, including myopic maculopathy and high myopia-associated optic neuropathy, are now some of the most common causes of irreversible blindness. Hence, strategies are warranted to reduce the prevalence of myopia and the progression to high myopia because this is the main modifiable risk factor for pathologic myopia. On the basis of published population-based and interventional studies, an important strategy to reduce the development of myopia is encouraging schoolchildren to spend more time outdoors. As compared with other measures, spending more time outdoors is the safest strategy…