Search results for "Refractive error"
showing 10 items of 125 documents
Mesopic Contrast Sensitivity Function After Laser in situ Keratomileusis
2003
ABSTRACT PURPOSE: To evaluate contrast sensitivity under mesopic conditions in patients who have undergone uncomplicated bilateral laser in situ keratomileusis (LASIK) for myopia. METHODS: Best-corrected monocular contrast sensitivity was measured with the Stereo Optical F.A.C.T. chart at 1.5, 3, 6, 12, and 18 c/deg in 20 patients (20 left eyes) before and after bilateral LASIK (with the Nidek EC-5000 excimer laser and the Automated Corneal Shaper). Mean preoperative refractive error was -6.40 ± 1.28 D (range -4.00 to -8.00 D) and postoperative mean refractive error was -0.41 ± 0.45 D (range -0.75 to +0.50 D). Contrast sensitivity function was measured before and 6 months after surgery usin…
Iris Claw Phakic Intraocular Lens for High Myopia
1997
ABSTRACT BACKGROUND: The implantation of a WorstFechner iris claw intraocular lens (IOL) is one of the surgical procedures used for the correction of high myopia. This technique reduces myopia with stähle refractive results; however, its potential long-term risks have not been evaluated. We report results in 94 eyes with a minimum follow -up of 3 years. METHODS: We studied 94 eyes of 62 patients with myopia 5= -7.00 diopters (D) who underwent Worst-Fechner IOL implantation. Lens decentration, permeability of the blood-aqueous barrier by iris angiography, and changes in corneal endothelial density were analyzed. RESULTS: Mean follow-up time was 48.9 months (range 36 to 72 mo). Three years af…
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.
Excimer laser photorefractive keratectomy for high myopia
1995
Abstract One hundred and thirty-three eyes of 103 patients had photorefractive keratectomy with a slit scan mode excimer laser for myopia ranging from −6.00 to −22.00 diopters (D). The epithelium was removed with 20% ethanol, and the ablation was done with a tapered profile surrounding the optical zone. Patients were divided into two groups based on preoperative myopia: Group A, −6.00 D to −12.00 D (88 eyes); Group B, −12.50 D to −22.00 D (45 eyes). In Group A, mean preoperative refraction was −9.59 ± 1.79 D. Mean postoperative refraction was −0.29 ± 1.47 D at one month, −0.85 ± 1.68 D at three months, −1.17 ± 2.04 D at six months, and −0.56 ± 0.74 D at one year. Anterior stromal haze was g…
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…
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 …
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…
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 …
The relationship of ocular geometry with refractive error in normal and low birth weight adults
2020
Purpose Low birth weight (BW) individuals have an increased risk for myopic refractive error. However, it is unclear which ocular geometric alterations lead to an increase in myopic refractive error. This study aims to evaluate the impact of ocular biometry in interaction with BW on refractive error. Methods Participants of the prospective, observational, population-based Gutenberg Health Study (GHS) with self-reported BW aged 40–80 years and objective refraction and optical biometry were included. Linear regression analyses were conducted to evaluate associations between spherical equivalent with corneal power, anterior chamber depth, lens thickness and axial length and its interaction wit…
Photodynamic therapy with verteporfin for juxtafoveal choroidal neovascularization in pathologic myopia: a long-term follow-up study.
2007
Purpose To assess the effect of verteporfin photodynamic therapy (PDT) in juxtafoveal choroidal neovascularization (CNV) secondary to pathologic myopia (PM). Design Prospective, open-label, consecutive, interventional case series. Methods We prospectively followed a series of 48 consecutive patients (49 eyes) with pathologic myopia (≥ 6 diopters) who received verteporfin PDT for juxtafoveal CNV. This population was divided into two groups based on age (group A ≤ 55 years old, group B >55 years old), in three subgroups based on CNV lesion size, and in three categories based on refractive error at baseline. Results The median follow-up was 32 months (range, 12 to 56 months). Visual acuity (VA…