Results 141 to 150 of about 78,366 (184)

Equation for Corneal Asphericity After Corneal Refractive Surgery

Journal of Refractive Surgery, 2003
ABSTRACT PURPOSE: To determine the exact theoretical asphericity after refractive surgery when the parabolic approximation of the Munnerlyn formula is utilized. METHOD: From a least-square analysis and considering the conicoid model for anterior cornea, we calculated the final asphericity (p '-factor) from the preoperative ...
José R, Jiménez, Rosario G, Anera, Luis, Jiménez del Barco   +2 more
openaire   +2 more sources

Longitudinal Changes in Corneal Asphericity in Myopia

Optometry and Vision Science, 2000
ABSTRACT: Purpose To report the change in shape of the peripheral cornea (asphericity, Q) as it relates to myopia progression in adolescence. Methods Forty‐eight subjects with initial ages between 11 and 13 years of ...
D G, Horner, P S, Soni, N, Vyas, N L, Himebaugh   +3 more
openaire   +2 more sources

Corneal Asphericity and IOL Power Calculation in Eyes With Aspherical IOLs

Journal of Refractive Surgery, 2017
PURPOSE: Given that a previous study found that corneal asphericity influences the refractive outcome of intraocular lens (IOL) power calculation by means of thin-lens formulas in eyes with spherical IOLs, the authors aimed to verify whether such influence can also be observed in eyes with aspherical IOLs.
Giacomo, Savini, Kenneth J, Hoffer, Piero, Barboni, Domenico, Schiano Lomoriello, Pietro, Ducoli   +4 more
openaire   +2 more sources

Corneal Asphericity in Eye Bank Eyes Implanted with the Intrastromal Corneal Ring

Journal of Refractive Surgery, 1997
ABSTRACT OBJECTIVE: To evaluate the effects of the intrastromal corneal ring, a device developed to reduce myopia, on corneal asphericity in a large set of eye bank eyes. METHODS: Forty-one deturgesced eye bank eyes were implanted with intrastromal corneal rings of five different thicknesses, ranging from 0.25 mm to 0.45 mm. Corneal
T E, Burris, D K, Holmes-Higgin, T A, Silvestrini, J A, Scholl, R A, Proudfoot, P C, Baker   +5 more
openaire   +2 more sources

Corneal asphericity after hyperopic laser in situ keratomileusis

Journal of Cataract and Refractive Surgery, 2002
To analyze corneal asphericity after hyperopic laser in situ keratomileusis (LASIK) and its relationship to the clinical outcomes.Corneal and Refractive Surgery Service, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.In a retrospective case series, 23 patients (33 eyes) with hyperopia or hyperopic astigmatism who had LASIK were ...
Chun Chen, Chen, Alexander, Izadshenas, M Ali Asghar, Rana, Dimitri T, Azar   +3 more
openaire   +2 more sources

Asphericity of the anterior human cornea with different corneal diameters

Journal of Cataract and Refractive Surgery, 2007
To measure the anterior corneal asphericity (Q) with different corneal diameters.Department of Physics (Optometry), University of Minho, Braga, Portugal.Thirty-six eyes of 36 patients were evaluated using a videokeratoscope, and the Q-values were recorded.
José Manuel, González-Méijome, César, Villa-Collar, Robert, Montés-Micó, Antonio, Gomes   +3 more
openaire   +2 more sources

Impact of interocular differences in corneal asphericity on binocular summation

American Journal of Ophthalmology, 2003
To evaluate the impact that interocular differences in corneal asphericity (Q) exert on binocular summation measured as the contrast-sensitivity function.Interventional case series.A total of 92 emmetropic subjects took part in the experiment, classified according to the interocular differences in corneal asphericity (deltaQ) measured with an EyeSys ...
José R Jiménez, Raimundo Jiménez, Rosario G Anera   +2 more
exaly   +3 more sources

Three‐year change in corneal asphericity in children at the age of emmetropisation

Ophthalmic and Physiological Optics, 2022
Abstract Purpose To determine the 3‐year changes in anterior and posterior values of corneal asphericity (Q) in 6‐ to 12‐year‐old children. Methods The first and second phases of the study were conducted in 2015 and ...
Hassan Hashemi, Mehdi Khabazkhoob, Alireza Jamali, Mohammad Hassan Emamian, Akbar Fotouhi   +4 more
openaire   +2 more sources

Differences between real and predicted corneal shapes after aspherical corneal ablation

Applied Optics, 2005
We study the differences between real and expected corneal shapes, using an aspherical ablation algorithm with a known equation and avoiding the limitation imposed by most studies of refractive surgery in which the ablation equations are not known. We have calculated the theoretical corneal shape predicted by this algorithm, comparing this shape with ...
Rosario G, Anera, César, Villa, José R, Jiménez, Ramón, Gutiérrez, Luis Jiménez, del Barco   +4 more
openaire   +2 more sources

Posterior Corneal Asphericity and the Refractive Outcome after Combined Phacovitrectomy

Klinische Monatsblätter für Augenheilkunde, 2023
Abstract Background We assessed the correlation of posterior corneal asphericity and the refractive prediction error of the SRK-T and Barrett II Universal formulas for eyes following phacovitrectomy with peeling of the internal limiting membrane (ILM). Patients and Methods We retrospectively analyzed 41 eyes of 41 patients
Mark, Rabinovich, Jean-Marc, Baumgartner, Jerome, Bovet   +2 more
openaire   +2 more sources