Search results for "emmetrop"
showing 10 items of 39 documents
Long-term results of surgical treatment of high myopia with Worst-Fechner intraocular lenses
1995
Abstract This retrospective study evaluated the results in 90 eyes that had a minus-power anterior chamber intraocular lens implanted to correct high myopia. Preoperative myopia ranged from −7.00 to −24.00 D. Postoperative spherical equivalent was −0.50 D; 80.5% of eyes were within 1.00 D of emmetropia. Two years postoperatively, no cataract formation, retinal detachment, glaucoma, or significant endothelial damage had occurred. We conclude that minus-power lenses can rapidly, safely, and predictably correct high myopia in phakic patients.
Subjective fixation disparity affected by dynamic asymmetry, resting vergence, and nonius bias.
2011
PURPOSE This study was undertaken to investigate how subjectively measured fixation disparity can be explained by (1) the convergent-divergent asymmetry of vergence dynamics (called dynamic asymmetry) for a disparity vergence step stimulus of 1° (60 arc min), (2) the dark vergence, and (3) the nonius bias. METHODS Fixation disparity, dark vergence, and nonius bias were measured subjectively using nonius lines. Dynamic vergence step responses (both convergent and divergent) were measured objectively. RESULTS In 20 subjects (mean age, 24.5 ± 4.3 years, visual acuity, ≥1.0; all emmetropic except for one with myopia, wearing contact lenses), multiple regression analyses showed that 39% of the v…
Anatomic study of the corneal thickness of young emmetropic subjects.
2004
PURPOSE To study the corneal thickness of young emmetropic subjects. METHODS One thousand eyes of 1000 young healthy emmetropic subjects were analyzed with the Orbscan Topography System II (Orbscan, Inc, Salt Lake City, UT) from January 2001 to May 2003. The age of the subjects ranged from 20 to 30 years old (mean +/- SD = 27.12 +/- 2.86). The mean of 5 consecutive measurements of the corneal thickness in the center of the cornea and at temporal, superotemporal, inferotemporal, nasal, inferonasal, and superonasal cornea were recorded. RESULTS The corneal thickness at the following areas ranged as follows: 518 to 589 microm center; 603 to 678 microm nasal; 620 to 689 microm superonasal; 600 …
Quantitative corneal anatomy in emmetropic subjects.
2006
PURPOSE Currently there is little information available about the corneal thickness values of healthy emmetropic subjects. Therefore, the authors decided to analyze the corneal thickness in healthy emmetropic subjects. METHODS The authors analyzed the difference in thickness values between the thinnest corneal site and the central and paracentral cornea in 124 eyes of 124 healthy emmetropic white subjects. RESULTS The mean difference between the thinnest site of the cornea and the thickness values obtained in the areas analyzed was as follows: 12+/-6 microm center; 140+/-19 microm superonasal; 133+/-23 microm nasal; 117+/-26 microm inferonasal; 122+/-19 microm superotemporal ; 89+/-22 micro…
Poor vision accompanied with other sensory impairments as a predictor of falls in older women
2008
Objectives:we studied visual acuity (VA) and co-existing hearing impairment and poor standing balance as predictors of falls. Design: prospective study with 1-year follow-up. Setting: research laboratory and residential environment. Participants: 428 women aged 63‐76 years from the Finnish Twin Study on Aging. Measurements: participants were followed up for incidence of falls over 1 year. VA, hearing ability and standing balance were assessed at the baseline. The incidence rate ratios (IRR) for falls were computed using the negative binomial regression model. Results: during the follow-up, 47% of participants experienced a fall. After adjusting for age and interdependence of twin sisters, p…
Genetic variants associated with human eye size are distinct from those conferring susceptibility to myopia
2021
Purpose: Emmetropization requires coordinated scaling of the major ocular components, corneal curvature and axial length. This coordination is achieved in part through a shared set of genetic variants that regulate eye size. Poorly coordinated scaling of corneal curvature and axial length results in refractive error. We tested the hypothesis that genetic variants regulating eye size in emmetropic eyes are distinct from those conferring susceptibility to refractive error.Methods: A genome-wide association study (GWAS) for corneal curvature in 22,180 adult emmetropic individuals was performed as a proxy for a GWAS for eye size. A polygenic score created using lead GWAS variants was tested for…
Corneal Biomechanics, Retinal Nerve Fiber Layer, and Optic Disc in Children
2014
Purpose. To evaluate the possible associations between corneal biomechanical parameters, optic disc morphology, and retinal nerve fiber layer (RNFL) thickness in healthy white Spanish children. Methods. This cross-sectional study included 100 myopic children and 99 emmetropic children as a control group, ranging in age from 6 to 17 years. The Ocular Response Analyzer was used to measure corneal hysteresis (CH) and corneal resistance factor. The optic disc morphology and RNFL thickness were assessed using posterior segment optical coherence tomography (Cirrus HD-OCT). The axial length was measured using an IOLMaster, whereas the central corneal thickness was measured by anterior segment opti…
Refractive lens exchange with a multifocal diffractive aspheric intraocular lens
2012
PURPOSE: To evaluate the safety, efficacy and predictability after refractive lens exchange with multifocal diffractive aspheric intraocular lens implantation. METHODS: Sixty eyes of 30 patients underwent bilateral implantation with AcrySof® ReSTOR® SN6AD3 intraocular lens with +4.00 D near addition. Patients were divided into myopic and hyperopic groups. Monocular best corrected visual acuity at distance and near and monocular uncorrected visual acuity at distance and near were measured before and 6 months postoperatively. RESULTS: After surgery, uncorrected visual acuity was 0.08 ± 0.15 and 0.11 ± 0.14 logMAR for the myopic and hyperopic groups, respectively (50% and 46.67% of patients ha…
Contrast sensitivity loss in the peripheral visual field following laser in situ keratomileusis.
2007
We report a case of contrast sensitivity loss in the peripheral visual field following laser in situ keratomileusis (LASIK). A 50-year-old white man was referred to us for differences in visual perception in the peripheral field between the right eye, which had had LASIK, and the left eye, which was emmetropic. Linear meridional static perimetry was carried out in the 0- to 180-degree meridian using a Goldmann perimeter to assess the peripheral perimetric thresholds. There was a statistically significantly marked increased threshold in contrast sensitivity in the nasal and temporal fields from 40 degrees of eccentricity in the LASIK eye compared with that in the emmetropic eye. Eyes treated…
Anisometropia of spherical equivalent and astigmatism among myopes: a 23-year follow-up study of prevalence and changes from childhood to adulthood.
2017
Purpose To study anisometropia of spherical equivalent and astigmatism from the onset of myopia at school age to adulthood. Methods A total of 240 myopic schoolchildren (mean age 10.9 years), with no previous spectacles, were recruited during 1983–1984 to a randomized 3-year clinical trial of bifocal treatment of myopia. Examinations with subjective cyclopedic refraction were repeated 3 years later (follow-up 1) for 238 subjects and thereafter at the mean ages of 23.2 (follow-up 2) and 33.9 years (follow-up 3) for 178 and 134 subjects. After exclusions, the 102 subjects who attended all three follow-ups were included in the analyses. Corneal refractive power and astigmatism and anterior cha…