Search results for "Ophthalmology"
showing 10 items of 1738 documents
On-eye optical quality of daily disposable contact lenses for different wearing times
2012
Purpose To quantify the optical quality of various daily disposable contact lenses in vivo and to ascertain its variation in terms of wearing time by means of objective non-invasive determination of wavefront patterns. Methods The crx1 adaptive-optics system was used to measure the wavefront aberrations in 15 myopic eyes before and at 2-h intervals after contact lens fitting, over a 12-h wearing period. Seven types of contact lenses having different material, water content and lens design were evaluated in this study: Dailies Total1, Dailies AquaComfort Plus, Proclear 1 Day, 1-Day Acuvue TruEye, 1-Day Acuvue moist, SofLens daily disposable and Clariti 1-Day. The aberration data were analyse…
Crystalens HD Intraocular Lens Analysis Using an Adaptive Optics Visual Simulator
2013
PURPOSE To compare visual and optical quality of the Crystalens HD intraocular lens (IOL) with that of a monofocal IOL. METHODS The wavefront aberration patterns of the monocular Akreos Adapt AO IOL and the single-optic accommodating Crystalens HD IOL were measured in a model eye. The Crystalens IOL was measured in its nonaccommodative state and then, after flexing the haptic to produce 1.4 mm of movement, in its accommodative state. Using an adaptive optics system, subjects' aberrations were removed and replaced with those of pseudophakes viewing with either lens. Monocular distance visual acuity (DVA) at high (100%), medium (50%), and low (10%) contrast and contrast sensitivity (CS) were …
Some physiological and psychological characteristics of myopic and non-myopic young men.
2009
As a part of a research project on the health and functional capacity of men at different ages a comparison of selected physiological and psychological characteristics of myopic and non-myopic 31–35 year-old men was made. The random sample studied consisted of 31 myopic and 100 non-myopic men. It was found that the body mass index and fat content were lower among the myopic than among the non-myopic. No significant differences were found in the elastic properties of skin, in blood pressure or in haematological assays studied between the groups. With respect to physical performance it was observed that the myopic had a higher aerobic capacity whereas there were no significant differences in …
Nine Loci for Ocular Axial Length Identified through Genome-wide Association Studies, Including Shared Loci with Refractive Error
2013
Refractive errors are common eye disorders of public health importance worldwide. Ocular axial length (AL) is the major determinant of refraction and thus of myopia and hyperopia. We conducted a meta-analysis of genome-wide association studies for AL, combining 12,531 Europeans and 8,216 Asians. We identified eight genome-wide significant loci for AL (RSPO1, C3orf26, LAMA2, GJD2, ZNRF3, CD55, MIP, and ALPPL2) and confirmed one previously reported AL locus (ZC3H11B). Of the nine loci, five (LAMA2, GJD2, CD55, ALPPL2, and ZC3H11B) were associated with refraction in 18 independent cohorts (n = 23,591). Differential gene expression was observed for these loci in minus-lens-induced myopia mouse …
An alternative clinical routine for subjective refraction based on power vectors with trial frames.
2016
PURPOSE Subjective refraction determines the final point of refractive error assessment in most clinical environments and its foundations have remained unchanged for decades. The purpose of this paper is to compare the results obtained when monocular subjective refraction is assessed in trial frames by a new clinical procedure based on a pure power vector interpretation with conventional clinical refraction procedures. METHODS An alternative clinical routine is described that uses power vector interpretation with implementation in trial frames. Refractive error is determined in terms of: (i) the spherical equivalent (M component), and (ii) a pair of Jackson Crossed Cylinder lenses oriented …
Peripapillary Choroidal Thickness and Choroidal Area in Glaucoma, Ocular Hypertension and Healthy Subjects by SD-OCT.
2015
Background: The exact pathogenesis of open angle glaucoma and ocular hypertension remains unclear. Hemodynamic influences are discussed as potential risk factors and the choroid may play an important role in the pathogenesis of open angle glaucoma or ocular hypertension. The current study investigates peripapillary choroidal thickness and choroidal area in patients with open angle glaucoma, subjects with ocular hypertension and healthy subjects using spectral-domain OCT. It furthermore assesses the association between peripapillary choroidal thickness and age, central corneal thickness, refractive error and intraocular pressure. Patients and Methods: Prospectively recorded data of 213 eyes …
Postoperative astigmatism and rotational stability after Artisan toric phakic intraocular lens implantation
2003
Abstract Purpose To evaluate deviations in the axis (intended versus achieved) and postoperative astigmatism after implantation of an Artisan toric phakic intraocular lens (IOL). Setting University Eye Hospital, Mainz, Germany. Methods This prospective study comprised 29 eyes with high ametropia and astigmatism. All eyes had uneventful implantation of a toric phakic IOL through a superior scleral tunnel incision at 12 o’clock. After a minimum of 6 months, the uncorrected visual acuity (UCVA), best correct visual acuity, refraction, and astigmatism were analyzed in all eyes. A multivariate analysis of postoperative astigmatism was performed. Results After a follow-up of at least 6 months, 95…
Influence of Refraction on Tonometric Readings After Photorefractive Keratectomy and Laser Assisted In Situ Keratomileusis
2000
PURPOSE To determine the decrease of Goldmann tonometry after photorefractive keratectomy (PRK) and laser assisted in situ keratomileusis (LASIK) according to refraction prior to surgery. METHODS Prospective simultaneous comparative case series of 53 myopic eyes (53 patients) that underwent PRK and 50 (50 patients) that underwent LASIK using the Summit Excimed SVS plus (Summit Technology, Inc., Walthan, MA, U.S.A.). PRK and LASIK were subdivided by refractive error into two subgroups of more than or less than -5 diopters (D). Central tonometric readings were taken prior to surgery and 12 months after surgery. RESULTS In LASIK and PRK subgroups of more than -5 D, 85.7% (24) and 69.6% (24), r…
Rate of Cataract Formation in 343 Highly Myopic Eyes After Implantation of Three Types of Phakic Intraocular Lenses
2004
ABSTRACT PURPOSE: To assess the feasibility of using phakic intraocular lenses (PIOL) to treat high myopia, and evaluate the incidence of cataract, comparing three different lens types. METHODS: From 1989 to 2002, we implanted three different phakic intraocular lenses (PIOL) in 343 eyes of 232 patients; 231 eyes recieved an Ophtec (Worst-Fechner model, iris-claw), 89 an Adatomed (silicone posterior chamber), and 23 a Staar (posterior chamber, models V2, V3, V4). Average follow-up was 96.2 months for the Ophtec group, 31.5 months for the Adatomed group, and 19.3 months for Staar group. Eyes that subsequently developed cataract were studied for clinical evolution and had PIOL explantation and…
Photodynamic therapy with verteporfin for subfoveal choroidal neovascularization secondary to pathologic myopia: long-term study.
2006
Purpose: To assess the safety and effectiveness of photodynamic therapy (PDT) with verteporfin for subfoveal choroidal neovascularization (CNV) secondary to pathologic myopia (PM). Methods: Sixty-two patients (62 eyes) with PM underwent PDT according to the guidelines of the Verteporfin in Photodynamic Therapy Study. Clinical evaluations performed at all study visits included measurement of best-corrected Snellen visual acuity, slit-lamp biomicroscopy, and fundus fluorescein angiography. Patients were followed up at 1 month and 3 months after treatment and thereafter at 3-month intervals. Results: The final visual acuity of the study patients, after a median follow-up of 31 months, improved…