Search results for "Dioptre"

2020

Purpose To investigate the retinal nerve fiber layer profile measured by optical coherence tomography and its relation to refractive error and axial length. Methods The Gutenberg Health Study is a population-based study in Mainz, Germany. At the five-year follow-up examination, participants underwent optical coherence tomography, objective refraction and biometry. Peripapillary retinal nerve fiber layer (pRNFL) was segmented using proprietary software. The pRNFL profiles were compared between different refraction groups and the angle between the maxima, i.e., the peaks of pRNFL thickness in the upper and lower hemisphere (angle between the maxima of pRNFL thickness [AMR]) was computed. Mult…

Imbalance Between Oxidative Stress and Growth Factors in Human High Myopia.

2020

Este artículo se encuentra disponible en la siguiente URL: https://www.frontiersin.org/articles/10.3389/fphys.2020.00463/full Myopia is one of the commonest eye pathologies that could affect 2.56 billion people by 2020. Today high myopia is a leading cause of blindness worldwide due to associated ocular illness. Nevertheless, the cellular bases for these diseases to develop are unclear in many areas. We conducted a prospective study of oxidative stress and growth factors in human myopic and non myopic eyes in an attempt to increase our understanding of the underlying physiopathological conditions to adequately early diagnose, prevent and treat the retina problem that derives from myopia. Aq…

Accuracy and accommodation capability of a handheld autorefractor

2000

Purpose: To determine the accuracy of measurement by the Nikon Retinomax handheld autorefractor and its ability to relax accommodation. Setting: Pediatric Section, Department of Ophthalmology, University of Mainz, Germany. Methods: To perform a series of comparative measurements, autorefractor readings were obtained on healthy young adults (students) and on children aged 2 to 12 years. The autorefractor readings were compared with subjective refractions of the young adults and with cycloplegic retinoscopy of the children. Results: In adults, the accuracy of the handheld autorefractor measurements was comparable to that of conventional tabletop autorefractors. In children, the autorefractor …

Simulated prototype of posterior chamber phakic intraocular lens for presbyopia correction.

2014

Purpose To evaluate the visual impact of adding different spherical aberration values to an Implantable Collamer Lens phakic intraocular lens (pIOL) to increase the depth of focus using an adaptive optics visual simulator. Setting University of Valencia, Valencia, Spain. Design Experimental study. Methods Wavefront aberrations in −3.00 D and −6.00 diopter (D) pIOLs were measured in vitro. Afterward, different simulated pIOL experimental prototypes were created along with variances in the spherical aberration. An adaptive optics visual simulator was used to simulate vision after the implantation of the different pIOL prototypes from their wavefront aberrations. The corrected distance visual …

Depth of focus through different intraocular lenses in patients with different corneal profiles using adaptive optics visual simulation

2011

PURPOSE: To evaluate the depth of focus with monofocal intraocular lenses (IOLs) in patients with different corneal profiles using adaptive optics (AO) visual simulation. METHODS: An AO visual simulator (crx1, Imagine Eyes) was used to simulate the aberration pattern of three monofocal IOLs (Acrysof IQ SN60WF [Alcon Laboratories Inc]; Akreos Adapt AO [Bausch & Lomb]; and Triplato [AJL Ophthalmic]) of different optic designs. Five groups were considered: patients without any corneal refractive surgery (normal cornea group) and with prior low and high myopic and hyperopic ablations (low myopic ablation, high myopic ablation, low hyperopic ablation, and high hyperopic ablation groups). De…

Contrast sensitivity and glare disability by halogen light after monofocal and multifocal lens implantation

2000

BACKGROUND—Standard examination of contrast sensitivity under conditions of glare disability is performed with incandescent light. A new halogen glare test that simulates glare as seen with oncoming vehicle headlights was used to measure glare disability in patients implanted with multifocal and monofocal intraocular lenses (IOLs). METHODS—28 patients with an average age of 69 years (SD 12 years) were implanted with a monofocal IOL (SI-40NB, Allergan) and 28 patients with an average of 66 years (12 years) were implanted with a refractive multifocal IOL (Array-SA-40N, Allergan). All patients were followed for 5 months postoperatively. Contrast sensitivity at four spatial frequencies (3, 6, 1…

Intrasubject repeatability of corneal power, thickness, and wavefront aberrations with a new version of a dual rotating Scheimpflug–Placido system

2014

Purpose To determine the intrasubject repeatability of a recently introduced dual-camera rotating Scheimpflug–Placido imaging system (Galilei G4) in determining corneal thickness, power, and wavefront aberrations in young healthy subjects. Setting University of Valencia, Valencia, Spain. Design Prospective evaluation of diagnostic technology. Methods The study comprised right eyes of 25 subjects aged 20 to 40 years with a spherical equivalent ranging from −4.25 to +1.00 diopters. The central corneal thickness, thinnest point value and location, anterior and posterior surface curvatures, total corneal power, and corneal wavefront aberrations were measured for distance vision using the dual S…

Myopia and Cognitive Performance: Results From the Gutenberg Health Study.

2016

Purpose To analyze the association between myopia and cognitive performance. Methods A cohort of the population-based Gutenberg Health Study included 3819 eligible enrollees between 40 and 79 years. We used the Tower of London (TOL) test to assess cognitive performance. Myopia was defined as a spherical equivalent (SE) ≤ -0.5 diopters (D) via noncycloplegic autorefractometry. We conducted linear mixed models with the SE as the dependent variable and the age, sex, duration of education, and TOL score as covariates. Results Complete data were available for 3452 participants (90.4%). The mean TOL score was 14.0 ± 3.9 in the myopes versus 12.9 ± 4.0 in the nonmyopes (P < 0.001). The mean TOL sc…

Medium-term visual, refractive, and intraocular stability after implantation of a posterior chamber phakic intraocular lens to correct moderate to hi…

2011

To evaluate the medium-term refractive and visual outcomes and the complications after implantation of a silicone posterior chamber phakic intraocular lens (PC pIOL) for moderate to high myopia.Oftalmar, Medimar International Hospital, Alicante, Spain.Retrospective case series.Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, and intraocular pressure were evaluated during a medium-term follow-up. Postoperative complications were also studied.The study enrolled 35 eyes (mean preoperative spherical equivalent [SE] -10.25 diopters [D] ± 3.19 [SD]) of 20 patients with a mean age of 31.83 ± 8.87 years and a mean follow-up of 57.34 ± 9.24 months. The mean UDVA improved…

Short-term Follow-up after Implantation of a Foldable Iris-Fixated Intraocular Lens in Phakic Eyes

2005

Objective To evaluate efficiency, predictability, stability, complications, and patient satisfaction after implantation of a foldable iris-fixated phakic intraocular lens (PIOL) for the correction of myopia. Design Prospective, nonrandomized, comparative (self-controlled) trial. Participants Forty-one eyes of 22 myopic patients aged 18 to 56 years (mean, 36 years) with average sphere of −8.2±2.01 diopters (D; range, −12.25 to −3.75 D) and average preoperative cylinder of −0.90±0.62 D (range, −2.50 to 0.00 D) were enrolled in this prospective study. Methods All eyes underwent implantation of a foldable iris-fixated PIOL with an optical zone of 6.0 mm. The follow-up was 6 months in all cases.…