Search results for "Lens implant"
showing 10 items of 145 documents
Intraocular lens centration and stability: efficacy of current technique and technology
2008
Purpose of review The manuscript presents a review of recently published studies analyzing different methodologies to assess centration and stability of intraocular lenses after implantation. Recent findings Considering that there is no current gold standard for centration and stability of intraocular lenses after implantation, we have summarized the different techniques used clinically for intraocular lenses centration and stability estimation. We have described the use of Scheimpflug imaging, the anterior segment optical coherence tomography and photography analysis used for lens position estimation. Techniques used to assess lens rotation are based on image analysis on digital retroillum…
Analysis of the possible benefits of aspheric intraocular lenses: review of the literature.
2008
We reviewed recently published studies that analyzed the visual and optical quality in eyes with different spherical and aspheric intraocular lenses (IOLs). Recent studies focused on visual quality metrics, such as visual acuity and contrast sensitivity, under photopic and mesopic lighting conditions and optical metrics, such as wavefront aberrations, especially spherical aberration. The results in this review were used in an attempt to understand whether there is a visual and/or optical benefit of implanting aspheric IOLs over implanting spherical IOLs.
In vitro optical performance of nonrotational symmetric and refractive-diffractive aspheric multifocal intraocular lenses: impact of tilt and decentr…
2012
Purpose To evaluate the optical quality of Acrysof Restor SN6AD1 refractive–diffractive +3.00 D and Lentis Mplus LS-312 nonrotational symmetric +3.00 D aspheric multifocal intraocular lenses (IOLs) and analyze the effect of tilt and decentration. Setting University of Valencia, Valencia, and University of Murcia, Murcia, Spain. Design Experimental study. Methods An artificial model eye was used to measure wavefront aberrations of both IOL models. The modulation transfer function (MTF) and point-spread function (PSF) were calculated for a 5.0 mm pupil and under 5 situations: centered, 0.2 mm and 0.4 mm decentered, and 2 degrees and 4 degrees tilted. Results The refractive–diffractive IOL had…
Subjective photic phenomena with refractive multifocal and monofocal intraocular lenses. results of a multicenter questionnaire.
2001
Abstract Purpose To compare the incidence and severity of photic phenomena after the implantation of the Array® (Allergan) refractive multifocal intraocular lens (MIOL) and a monofocal IOL. Setting Multicenter study at Kiel, Mainz, Karlsruhe, and Bremerhaven, Germany. Methods The study comprised 231 randomly selected patients from 4 study centers. The patients had had uneventful phacoemulsification with implantation of a refractive MIOL (n = 138) or a monofocal IOL (n = 93). By questionnaire, patients were asked whether they experienced light sensations postoperatively (light streaks, halos, flare, flashes, or glare) that had not been noticed preoperatively. Additional questions evaluated w…
Endothelial cells loss to the hyperopic pacients during phacoemulsification
2018
Introduction The phacoemulsification cataract surgery is the most frequently performed surgery and it generally improves vision in over 90% of the patients. Hyperopic patients are a challenge during phacoemulsification especially because of their short eyeball and shallow anterior chamber. A shallow anterior chamber is associated with overall reduction of the safe zone, which may lead to difficulty in creating the corneal incisions, harder capsulorhexis performing, or endothelial complications. Purpose The aim of the study was to present the endothelial cells loss after the phacoemulsification procedure in the hyperopic patients. Material and methods A number of 1775 patients operated in th…
Determining postoperative anterior chamber depth
2003
Abstract Purpose: To compare measured and calculated postoperative anterior chamber depths (ACDs). Setting: Department of Ophthalmology and Institute of Medical Physics, University of Vienna, Vienna, Austria, and Department of Ophthalmology, University of Mainz, Mainz, Germany. Methods: The postoperative ACD was measured in 189 pseudophakic eyes using a laboratory prototype of partial coherence interferometry (PCI). In 6 intraocular lens (IOL) groups, the mean ACD was calculated by ray tracing based on the best-known A-constants of the SRK formulas. In addition, for each IOL type, each measured ACD was compared with a value calculated using the individual spherical equivalent of the postope…
Implantation of a custom intraocular lens with a 30-diopter torus for the correction of high astigmatism after penetrating keratoplasty.
2003
Abstract We present a 62-year-old woman who had implantation of an intraocular lens (IOL) with a torus of 30.0 diopters (D) in an eye after penetrating keratoplasty. The patient presented with cataract and a best corrected visual acuity of 20/400. Penetrating keratoplasty was performed in 1975 because of decompensated keratoconus. With a clear but inferiorly decentered corneal graft, visual acuity was limited because of keratoplasty-related high corneal astigmatism of 22.5@156 that could not be successfully treated with spectacles or contact lenses. A custom toric IOL with –30.0 D of cylindrical power was implanted in the capsular bag via a sclerocorneal tunnel incision. Additionally, a sph…
Optical analysis to predict outcomes after implantation of a double intraocular lens magnification device.
2007
Purpose To analyze the effect of different optical parameters of the eye on the outcomes of implantation of a double intraocular lens (IOL) magnification device in patients with low vision. Setting Fundacion Oftalmologica del Mediterraneo, Valencia, Spain. Methods The eye's refraction and magnification before and after surgery were evaluated using a theoretical eye model based on paraxial optics approximation. Four parameters on which refraction and magnification are dependent were evaluated: anterior chamber depth (ACD), axial length (AL), mean keratometry (Km), and the distance between the 2 implanted IOLs. The 4 variables were analyzed separately in the first stage. Next, different combi…
Changes in higher-order aberrations after implantation of a foldable iris-claw lens in myopic phakic eyes
2006
Purpose To evaluate the change in higher-order aberrations (HOAs) after implantation of a foldable iris-claw phakic intraocular lens (pIOL) in myopic eyes. Setting Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. Methods This prospective nonrandomized comparative self-controlled trial included 41 eyes that had implantation of a foldable iris-claw pIOL between July 2003 and November 2004. All patient data for HOAs (Zernike coefficient) were measured and calculated using the same pupil size preoperatively and postoperatively, and the root-mean-square (RMS) wavefront error was calculated. Examinations were performed preoperatively as well as 1 week and 3, 6, and 12 m…
Reading ability with 3 multifocal intraocular lens models.
2006
Purpose To prospectively evaluate reading performance with of 3 types of multifocal intraocular lenses (IOLs) under different lighting conditions based on reading acuity and reading speed tests. Setting Augenklinik, Bad Hersfeld, Germany. Methods This randomized study comprised 60 cataract patients (120 eyes) randomly assigned to receive an SA40N IOL (AMO) (Group 1, 20 patients), Tecnis ZM001 IOL (AMO) (Group 2, 20 patients), or AcrySof ReSTOR SA60D3 IOL (Alcon) (Group 3, 20 patients). Pupil size and reading ability at near (visual acuity, reading speed) without correction, with best distance correction, and with best near correction were assessed 6 weeks postoperatively under low-light con…