Search results for "Refractive"
showing 10 items of 559 documents
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…
Effects of multipurpose contact lens solutions on the protein composition of the tear film
2005
Abstract Objectives: To analyze the influence of multipurpose contact lens cleaning solutions on tear proteins. Changes in tear film protein profiles of contact lens wearers who used several marketed brands of multipurpose contact lens care solutions, were assessed by ProteinChip analysis. Methods: Three studies were conducted. Study I was a comparison of Complete and OptiFree multipurpose solutions. Study II was a study with Complete Moisture Plus solution, Study II was a comparison of Renu and Solocare contact lens solutions. Wearers of soft contact lenses were assigned to use the contact lens care solutions for 4 weeks. Non-contact lens wearing patients were used as controls. Tear sample…
Refractive lens exchange with Acri.LISA bifocal intraocular lens implantation.
2011
PURPOSE To assess efficacy, safety, and predictability after refractive lens exchange (RLE) in patients who had bilateral implantation of an Acri.LISA 366D diffractive bifocal intraocular lens (IOL). METHODS Sixty-six eyes of 33 consecutive patients were examined after RLE who had bilateral implantation of an Acri.LISA bifocal 366D IOL. Eyes were divided into myopic and hyperopic groups. Monocular uncorrected distance visual acuity, best-corrected distance visual acuity (BCVA), uncorrected distance near visual acuity, and best distance-corrected near visual acuity (BCNVA) were recorded preoperatively and 6 months after surgery. RESULTS Efficacy indexes were 0.73 for myopic and 0.85 for hype…
Astigmatism in infancy and childhood.
2000
ABSTRACT Purpose: To evaluate the prevalence of astigmatism In infancy and childhood In a Spanish population. Methods: A total of 478 children with astigmatism from Valencia Province, Spain were examined. The patients, ranging in age from 2-1 2 years, were classified into groups according to age. Astigmatism error and axis orientation were determined using noncyclopeglc retlnoscopy over each eye. Results: The overall prevalence of astigmatism (5=1.00 diopter of cylinder) decreased In relation to increasing age from 44.3% to 5.2%. The prevalence of against-the-rule astigmatism decreased from 61.5% (at 2 years) to 33.4% (at 12 years), with-the-rule astigmatism increased In prevalence from 23.…
Relationship among Corneal Biomechanics, Refractive Error, and Axial Length
2014
Purpose To evaluate the relationship between different ocular and corneal biomechanical parameters in emmetropic and ametropic healthy white children. Methods This study included 293 eyes of 293 healthy Spanish children (135 boys and 158 girls), ranging in age from 6 to 17 years. Subjects were divided according to the refractive error: control (emmetropia, 99 children), myopia (100 children), and hyperopia (94 children) groups. In all cases, corneal hysteresis (CH) and corneal resistance factor (CRF) were evaluated with the Ocular Response Analyzer system. Axial length (AL) and mean corneal power were also measured by partial coherence interferometry (IOLMaster), and central corneal thickne…
Refractive changes in nuclear, cortical and posterior subcapsular cataracts. Effect of the type and grade
2015
Purpose: To determine the effect of main morphological types and grades of age-related cataracts on refractive error. Methods: We measured 276 subjects with optical compensation prior to the development of cataract. We evaluated 224 eyes with nuclear cataract, 125 with cortical cataract, and 103 with posterior subcapsular (PSC) cataract classified with LOCSIII. We measured visual acuity (VA) with their spectacles and best-corrected visual acuity (BCVA) with chart in decimal scale to obtain the optimal compensation with cataract. We evaluated the differences between compensations. Results: A significant myopic shift was observed in nuclear cataract from low to mild grade (p = 0.031), the sam…
Optical and visual performance of diffractive intraocular lens implantation after myopic laser in situ keratomileusis
2008
To evaluate the optical and visual quality in eyes with diffractive intraocular lenses (IOLs) after myopic laser in situ keratomileusis (LASIK).Fernández-Vega Ophthalmological Institute, Oviedo, Spain.The best corrected visual acuity (BCVA [distance]) at 12.5%, 25.0%, and 100% contrasts under photopic and mesopic conditions; best distance-corrected near acuity; corneal total higher-order aberrations (HOAs); and optical quality by modulation transfer function (MTF) were measured after myopic LASIK in eyes with a spherical AcrySof ReSTOR SN60D3 IOL or an aspheric Acri.LISA 366D IOL and phakic eyes (control).Under photopic conditions at 100% contrast, the BCVA was 0.1 logMAR or better in all g…
Visual quality after diffractive intraocular lens implantation in eyes with previous hyperopic laser in situ keratomileusis
2010
To evaluate distance, intermediate, and near visual quality in eyes with diffractive intraocular lens (IOL) implantation after previous hyperopic laser in situ keratomileusis (LASIK).Fernández-Vega Ophthalmological Institute, Oviedo, Spain.Cohort study.Corrected distance visual acuity (CDVA) at 12.5%, 25.0%, and 100% contrast levels under photopic and mesopic conditions; uncorrected (UNVA) and distance-corrected (DCNVA) near visual acuity, defocus curves, and corneal higher-order aberrations (HOAs) were measured in eyes that had AcrySof Restor SN60D3 spherical IOL implantation (study group) and in phakic eyes (control group) after hyperopic LASIK.Under photopic conditions at 100% contrast, …
Toric intraocular lens versus opposite clear corneal incisions to correct astigmatism in eyes having cataract surgery.
2009
To compare toric intraocular lens (IOL) implantation with paired opposite clear corneal incisions (OCCIs) for astigmatism correction in patients having cataract surgery.Ophthalmology Service, Donostia Hospital, San Sebastián, Spain.This randomized prospective clinical study comprised eyes with more than 1.00 diopter (D) of preexisting corneal astigmatism. One group had AcrySof toric IOL implantation and the other, paired 2.75 mm/3.20 mm OCCIs in the steep axis with spherical IOL implantation. Uncorrected (UCVA) and best corrected (BCVA) visual acuity, refraction, corneal and total higher-order aberrations (HOAs), photopic and mesopic contrast sensitivity, and toric IOL axis were measured 3 …
Implantation of a toric poly(methyl methacrylate) intraocular lens to correct high astigmatism
1999
Abstract A 57-year-old man experienced a decrease in visual function because of cataract formation. Corneal astigmatism was 13.4 diopters (D) because he had had a penetrating keratoplasty 27 years before. Cataract surgery was planned, and biometric data for toric intraocular lens (IOL) implantation were collected for the manufacture of a custom IOL. After phacoemulsification, a toric poly(methyl methacrylate) (PMMA) IOL of +19.0 D spherical and +12.0 D cylindrical power was implanted via a sclerocorneal tunnel incision. Three months postoperatively, corneal astigmatism was 14.3 D and best corrected visual acuity (BCVA), 20/25. Postoperative refraction (+1.5 −3.0 × 90) and BCVA remained stab…