Search results for "Refractive"
showing 10 items of 559 documents
Prevalence of corneal astigmatism before cataract surgery.
2008
To analyze the prevalence and presentation patterns of corneal astigmatism in cataract surgery candidates.University of Valencia, Valencia, Spain.Refractive and keratometric values were measured before surgery in patients having cataract extraction. Descriptive statistics of refractive and keratometric cylinder data were analyzed and correlated by age ranges.Refractive and keratometric data from 4,540 eyes of 2,415 patients (mean age 60.59 years +/- 9.87 [SD]; range 32 to 87 years) differed significantly when the patients were divided into 10-year subsets. There was a trend toward less negative corneal astigmatism values, except the steepest corneal radius and the J(45) vector component, in…
Characterization of the effect of intracorneal ring segment in corneal ectasia after laser refractive surgery
2018
Purpose: To evaluate the visual, refractive, topographic, pachymetric, and biomechanical outcomes after intracorneal ring segment implantation in corneas with post-LASIK ectasia. Methods: Retrospective longitudinal study enrolling 26 eyes of 22 patients with post-LASIK ectasia and undergoing intracorneal ring segment implantation (KeraRing®, Mediphacos) using a 60-kHz femtosecond laser (IntraLase®, IntraLase Corp.) for corneal tunnelization. Visual, refractive, anterior, and posterior corneal topographic (Pentacam HR, Oculus), pachymetric, and corneal biomechanical changes (Ocular response Analyzer, Reichert) were evaluated during a 12-month follow-up. Vector analysis of astigmatic changes …
Endothelial study of iris-claw phakic lens: four year follow-up.
1998
Abstract Purpose: To study quantitative and morphometric endothelial changes in phakic eyes implanted with the Worst iris-claw lens to correct high myopia. Setting: Department of Ophthalmology, University Hospital “La Fe”, Valencia, Spain. Material and Methods: This retrospective study involved 111 phakic eyes (73 patients) implanted with the Worst iris-claw lens. Noncontact specular microscopy and computer-assisted analysis was performed preoperatively and 6 months and 1, 2, 3, and 4 years postoperatively. Results: The mean cell loss was 3.85% at 6 months, 6.59% at 1 year, 9.22% at 2 years, 11.68% at 3 years, and 13.42% at 4 years. At 2 years, the hexagonality and coefficient variation in …
Refractive lens exchange with the Acri. Twin asymmetric diffractive bifocal intraocular lens system
2009
PURPOSE To evaluate efficacy, safety, and predictability after refractive lens exchange (RLE) in patients who had implantation of asymmetric Acri.Twin bifocal diffractive intraocular lenses. METHODS The study comprised 130 eyes of 65 consecutive patients after RLE who had bilateral implantation of the Acri.Twin system. Eyes were divided into myopic and hyperopic groups. Binocular 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 0.99 for myopic and 0.93 for hyperopic patients at …
Long-term comparison of corneal aberration changes after laser in situ keratomileusis: mechanical microkeratome versus femtosecond laser flap creatio…
2010
Purpose To compute and compare visual acuity, refractive outcomes, and anterior corneal aberration changes after myopic laser in situ keratomileusis (LASIK) with flap creation by a mechanical microkeratome and by a femtosecond laser. Setting Private practice refractive surgery center, Valencia, Spain. Design Comparative case series. Methods Patients were assigned to have LASIK flap creation with a mechanical microkeratome (Carriazo-Barraquer) or a femtosecond laser (IntraLase). The Visx S2 excimer laser was used for myopic ablation in all cases. Main outcome measures included uncorrected and corrected distance visual acuities and the defocus equivalent. Higher-order aberrations (HOAs) were …
Changes in accommodative responses with multifocal contact lenses: a pilot study.
2011
Our aim was to evaluate induced changes in pupil and accommodative response for different accommodative stimuli with three different multifocal contact lenses (CLs). Accommodative and pupil responses with three aspheric multifocal CLs of simultaneous focus center near (PureVision Low Add, PureVision High Add and Focus Progressives) for two accommodative stimuli of -2.5 and -4.00 D were recorded in 10 young subjects. Accommodative response, peak velocity, and time constant of accommodation and pupil constriction were assessed. The measurements were evaluated in all the participants with distance-single vision CLs and with the three multifocal CLs. The monocular measurements were performed in…
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 …
Single versus double femtosecond laser pass for incomplete laser in situ keratomileusis flap in contralateral eyes: Visual and optical outcomes
2011
Purpose To evaluate visual acuity, refractive outcomes, and anterior corneal higher-order aberrations (HOAs) after myopic laser in situ keratomileusis (LASIK) with uneventful single femtosecond laser pass versus double pass performed for intraoperative suction loss. Setting Private refractive surgery center, Valencia, Spain. Design Cohort study. Methods After the LASIK flap was created with a single pass of an Intralase femtosecond laser in 1 eye and a double pass in the fellow eye, the ablation was performed with a Visx S2 laser. At 12 months, the refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, and anterior corneal HOAs were measured with 4.0 mm and 6.0 mm pup…
Corneal Biomechanical Parameters With Corneoscleral Contact Lenses in Post-Laser In Situ Keratomileusis Eyes
2018
Objective: To evaluate corneal biomechanical parameters wearing corneoscleral contact lenses (CScL) in patients with irregular corneas after laser in situ keratomileusis (LASIK). Methods: Data from patients fitted with CScL because of corneal surface irregularities after complicated LASIK surgery were selected by two eye clinics. Previously and after 1 year of CScL fitting, corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc), and central corneal thickness were evaluated. In addition, visual acuity, subjective comfort, and wearing time CScL were reported. Results: The study comprised 27 eyes. Statistically significant differences were fo…
Changes in the visual field following laser in situ keratomileusis for myopia
2007
Purpose: To assess the changes of the visual field (VF) caused by transient intraocular pressure (IOP) peaks during laser in situ keratomileusis (LASIK) surgery for myopia using automated perimetry. Methods: This prospective study involved 94 eyes of 94 patients who underwent a conventional LASIK procedure. A complete eye examination was carried out in which the IOP measurement, and Humphrey 24-2 SITA standard VF were tested prior to LASIK and 6 and 12 months after LASIK. Patients were divided into two subgroups according to their refractive error. VF global indices, Glaucoma Hemifield Test and the number of depressed points deviating at p < 5%, p < 2%, p < 1% and p < 0.5% on the Pattern …