Search results for "refractive error"
showing 10 items of 125 documents
Prevalence of visual impairment and refractive errors in an urban area of Mexico
2019
AIM: To determine the distribution of refractive errors in a school-age population in Quintana Roo (Mexico) in the framework of an international cooperation campaign for the prevention of blindness. METHODS: A sample of 2647 school-age children (ranging from 5 to 14 years old) with a mean age of 9.1±1.9 years old were tested by trained volunteers for distance visual acuity (VA) and refractive errors. The first screening examination included uncorrected distance visual acuity (UDVA) and VA with a +2.00 D lens. Inclusion criteria for a second complete cycloplegic eye examination performed by an optometrist were UDVA <20/25 (0.10 logMAR or 0.8 decimal) and/or VA with +2.00 D ≥20/25. RESULTS: A…
Heredity of interocular similarities in components of refraction: a population-based twin study among 66- to 79-year-old female twins.
2019
Purpose: To examine genetic influences on interocular similarities in ocular refraction and components of refraction among elderly female twins. Methods: Refraction was assessed in 94 monozygotic (MZ) and 74 dizygotic (DZ) female twins aged 66–78 years. Absolute values of interocular differences (Aniso variables) in spherical refraction (SR), refractive astigmatism (AST), spherical equivalent (SE), corneal refractive power (CR), corneal astigmatism (CAST), anterior chamber depth (ACD) and axial length (AL) were calculated. The differences between sisters in each of the Aniso variables were calculated and graded into two categories, best differentiating the groups, here isometropic and aniso…
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…
<p>Visual And Refractive Outcomes In Hyperopic Pseudophakic Patients Implanted With A Trifocal Intraocular Lens</p>
2019
Purpose To assess visual and refractive results after bilateral implantation of a trifocal intraocular lens (IOL) in patients with hyperopia. Methods In a retrospective nonrandomized study, 196 eyes of 98 patients had bilateral implantation of a trifocal IOL. The Barrett Universal II formula was used for IOL power calculation. Eyes were divided into two groups for their analysis: low-moderate, with IOL power ranging from 22 to 26 D, and high, with IOL power ranging from 25 to 34 D. Refractive error was used to assess predictability, and corrected distance visual acuity (CDVA) and uncorrected distance visual acuity values were used to assess efficacy and safety of the surgery. Results Six mo…
Ergebnisse nach Implantation einer Worst Iris Claw Lens zur Korrektur der hohen Myopie
2001
Fragestellung. Ziel dieser prospektiven klinischen Studie war die Erfassung der Refraktion, des korrigierten Visus und des Vorderkammerreizzustandes nach Implantation einer Worst Iris Claw Lens zur Korrektur der hohen Myopie. Patienten und Methode. Von Dezember 1996 bis Februar 1999 wurde bei insgesamt 44 phaken Augen von 28 Patienten eine Worst Iris Claw Lens implantiert. Es folgte eine Nachbeobachtungszeit von 6 Wochen bzw. 6 Monaten. Ergebnisse. Das mittlere praoperative spharische Aquivalent betrug −17,35±3,57 dpt. Sechs Monate postoperativ lag die Refraktion bei 79% der Augen im Intervall von ±1,0 dpt von der Zielrefraktion entfernt. Der mittlere korrigierte Visus stieg von praoperativ…
Toric phakic intraocular lens
2003
Abstract Objective To evaluate safety, efficacy, predictability, stability, complications, and patient satisfaction after implantation of Artisan toric phakic intraocular lenses (TPIOLs) for the correction of myopia or hyperopia with astigmatism. Design Prospective, nonrandomized, comparative (self-controlled) multicenter trial. Participants Seventy eyes of 53 patients (mean, 35 years; range, 22–59 years) with preoperative spherical equivalent between +6.50 and −21.25 diopters (D) and cylinder between 1.50 and 7.25 D. Methods Seventy eyes underwent implantation of a TPIOL with an optical zone of 5.0 mm (Artisan, Ophtec, Groningen, The Netherlands). The dioptric power of the intraocular lens…
Five-year change in refractive error and its risk factors: results from the Gutenberg Health Study.
2021
Background/AimsTo examine the 5-year change in refractive error in phakic eyes and its risk factors in the general population.MethodsThe Gutenberg Health Study (GHS) is a population-based cohort study including 15 010 participants from Germany aged 35–74 years at baseline examination (2007–2012). After 5 years, a follow-up examination was carried out (83% participation). 5-year change of spherical equivalent (SE) was computed as difference between follow-up and baseline objective refraction. Linear and logistic regression analysis were conducted analysing potential risk factors. Only phakic eyes at follow-up examination were included.ResultsRight eyes of 10 175 subjects were included. An ag…
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…
Evaluation of Shared Genetic Susceptibility to High and Low Myopia and Hyperopia
2021
Importance: Uncertainty currently exists about whether the same genetic variants are associated with susceptibility to low myopia (LM) and high myopia (HM) and to myopia and hyperopia. Addressing this question is fundamental to understanding the genetics of refractive error and has clinical relevance for genotype-based prediction of children at risk for HM and for identification of new therapeutic targets. Objective: To assess whether a common set of genetic variants are associated with susceptibility to HM, LM, and hyperopia. Design, Setting, and Participants: This genetic association study assessed unrelated UK Biobank participants 40 to 69 years of age of European and Asian ancestry. Par…
Variations of OCT measurements corrected for the magnification effect according to axial length and refractive error in children
2018
Purpose: The aim of this paper was to examine the distribution of macular, retinal nerve fiber layer (RNFL) thickness and optic disc parameters of myopic and hyperopic eyes in comparison with emmetropic control eyes and to investigate their variation according to axial length (AL) and spherical equivalent (SE) in healthy children. Methods: This study included 293 pairs of eyes of 293 children (145 boys and 148 girls), ranging in age from 6 to 17 years. Subjects were divided according to SE in control (emmetropia, 99 children), myopia (100 children) and hyperopia (94 children) groups and according to axial AL in 68 short ([Formula: see text]22.00[Formula: see text]mm, 68), medium (from [For…