Search results for "ASTIGMATISM"
showing 10 items of 91 documents
Accommodation Responds to Optical Vergence and Not Defocus Blur Alone.
2017
Purpose To determine whether changes in wavefront spherical curvature (optical vergence) are a directional cue for accommodation. Methods Nine subjects participated in this experiment. The accommodation response to a monochromatic target was measured continuously with a custom-made adaptive optics system while astigmatism and higher-order aberrations were corrected in real time. There were two experimental open-loop conditions: vergence-driven condition, where the deformable mirror provided sinusoidal changes in defocus at the retina between -1 and +1 diopters (D) at 0.2 Hz; and blur-driven condition, in which the level of defocus at the retina was always 0 D, but a sinusoidal defocus blur …
Comparison of visual and refractive results of Toric Implantable Collamer Lens with bioptics for myopic astigmatism.
2013
PURPOSE: To compare visual and refractive results of Toric Implantable Collamer Lens (TICL) and bioptics (ICL plus excimer corneal surgery) to treat myopic astigmatism. METHODS: Eighty-one eyes underwent TICL implantation and 83 eyes were treated with bioptics (corneal ablation was performed between 1.5 and 6 months after ICL implantation). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refraction, adverse events, safety, and efficacy were evaluated 12 months postoperatively. RESULTS: At 12 months postoperatively, the mean spherical equivalent was -0.15 ± 0.36 diopters (D) in the TICL group and -0.08 ± 0.26 D in the bioptics group (p = 0.099). Sixty-six …
Iris-fixated toric phakic intraocular lens: Three-year follow-up
2006
Purpose To evaluate the 3-year safety, efficacy, predictability, and stability of iris-fixated toric phakic intraocular lens (pIOL) implantation for the correction of myopia or hyperopia with astigmatism. Setting Department of Ophthalmology, Johannes Gutenberg University, Mainz, and Department of Ophthalmology, University Clinic, Bochum, Germany. Methods A prospective clinical trial of 40 eyes of 23 patients with high ametropia and astigmatism was conducted. Best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity, refraction, astigmatism, intraocular pressure, slitlamp biomicroscopy, and indirect ophthalmoscopy were measured preoperatively and postoperatively. Results Of t…
Association of low birth weight with myopic refractive error and lower visual acuity in adulthood: results from the population-based Gutenberg Health…
2017
PurposeLow birth weight (BW) is linked to impaired organ development in childhood, including altered ocular morphological and functional development. The aim of this study was to evaluate whether low BW has long-term effects on visual acuity and refraction in adulthood.MethodsThe Gutenberg Health Study is a population-based, observational cohort study in Germany, including 15 010 participants aged between 35 and 74 years. These participants were divided into three different BW groups (low: <2500 g; normal: between 2500 and 4000 g; and high: >4000 g). Best-corrected visual acuity and objective refraction were examined. We used multivariable linear regression models with adjustment for …
Prevalence of refractive errors in the European adult population: the Gutenberg Health Study (GHS).
2014
Objective To study the distribution of refractive errors among adults of European descent. Design Population-based eye study in Germany with15 010 participants aged 35–74 years. Methods The study participants underwent a detailed ophthalmic examination according to a standardised protocol. Refractive error was determined by an automatic refraction device (Humphrey HARK 599) without cycloplegia. Definitions for the analysis were myopia +0.5 D, astigmatism >0.5 cylinder D and anisometropia >1.0 D difference in the spherical equivalent between the eyes. Exclusion criterion was previous cataract or refractive surgery. Results 13 959 subjects were eligible. Refractive errors ranged from −21.5 to…
Endothelial cell loss after toric iris-fixated phakic intraocular lens implantation: three-year follow-up.
2007
ABSTRACT PURPOSE: To study quantitative changes in endothelial cell count after implantation of the toric iris-fixated phakic intraocular lens. METHODS: A prospective, non-randomized, self-controlled clinical trial was conducted of 40 eyes (28 myopic, 12 hyperopic) of 23 patients with high ametropia and astigmatism. Non-contact computer-assisted endothelial microscopy was performed before and I1 2, and 3 years after surgery. RESULTS: In the myopic group, mean preoperative endothelial cell count was 3179±531 cells/mm p 2 (range: 1800 to 3900 cells/mm2). The mean intraindividual endothelial cell loss was -1.83±2.25% (range: -9.09% to 0%) in the first year; -1.83+2.95% (range: -7.74% to 3.80%)…
Vision evaluation in people with Down's syndrome.
1994
We tested the colour vision of 72 people with Down's syndrome using the Ishihara test and an anomaloscope. We found that 13 of the subjects, 6 males and 7 females, had defective colour vision according to Pickford's classification. In monocular vision 10 eyes were protan (five simple, three extreme and two deviant), one eye was simple deuteranomalous and the remaining eyes were normal: in binocular vision four of the subjects were protan (two simple and two deviant), two subjects were deutan (one simple and one deviant) and the rest were normal. Many of our subjects had lens opacities, strabismus, nystagmus, hypermetropia, high myopia and astigmatism, confirming literature reports. The cont…
Femtosecond laser–assisted intrastromal corneal ring segment implantation for high astigmatism correction after penetrating keratoplasty
2013
PURPOSE: To assess the visual and refractive outcomes of femtosecond laser-assisted implanta- tion of Ferrara-type intrastromal corneal ring segments (ICRS) in post-penetrating keratoplasty (PKP) eyes. SETTING: Instituto OftalmolFernOviedo, Spain. DESIGN: Cohort study. METHODS: Patients with previous PKP had ICRS implantation after femtosecond laser tunnel creation. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities and residual refractive errors were recorded before and 6 months after ICRS implantation. The power vector method was used to analyze refractive errors preoperatively and postoperatively. RESULTS: This study enrolled 32 eyes of 30 patients. The mean UDVA (Snell…
Analysis of the Corneal Anterior and Posterior Surface in Patients With Peripheral Hypertrophic Subepithelial Corneal Opacification
2019
PURPOSE To characterize the corneal changes in peripheral hypertrophic subepithelial corneal opacification (PHSCO) considering elevation of the anterior and posterior corneal surface, corneal astigmatism, tear secretion, and endothelial cell density. METHODS Thirty-eight eyes of 22 patients with PHSCO on at least 1 eye and 38 eyes of 22 age- and sex-matched healthy subjects were included in this retrospective cross-sectional study. Using the Pentacam system (Oculus, Wetzlar, Germany), measurement of the anterior and posterior corneal surface was performed. In addition, the Schirmer test was conducted, and endothelial cells were counted in the central cornea with a specular microscope (SP-30…
Change in pupil size after implantation of an iris-fixated toric phakic intraocular lens
2005
Purpose To evaluate the changes in pupil size after implantation of an iris-supported toric phakic intraocular lens (TPIOL) for correction of myopia and hyperopia with astigmatism. Setting Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. Methods Twenty-two myopic eyes and 9 hyperopic eyes were included in the study. The mean age of the 2 groups was 34 years and 40 years, respectively. The scotopic pupil size was measured with a handheld infrared pupillometer (Colvard, Oasis Medical) before and 6 months after implantation of the TPIOL. All examinations were performed under scotopic conditions after 2 minutes of dark adaptation with the fellow eye covered. Intraindi…