Search results for "Keratometer"

2017

Purpose To analyze the effect of birth weight on ocular morphology, refraction and visual function in early adolescents aged 12–15 years. Material and methods We conducted a secondary data analysis using the public use files from the National Health and Nutrition Examination Survey of the period from 1999 to 2008. Study participants aged 12 to 15 years were included with data on birth weight and ophthalmic parameters including presenting distance visual acuity, objective refraction and keratometry. Visual acuity, sphere, astigmatism in power vectors J0 and J45, corneal power and corneal astigmatism were evaluated for an association with birth weight. Linear and logistic regression with adju…

Influence of trifocal intraocular lenses on standard autorefraction and aberrometer-based autorefraction.

2019

To study the agreement between manifest refraction and objective refraction measured with two autorefractor models and an aberrometer in eyes implanted with a trifocal diffractive intraocular lens (IOL).IOA Madrid Innova Ocular, Madrid, Spain.Prospective comparative cohort study.An autorefractor keratometer (KR-8800), based on a Scheiner double pinhole, and a 3-dimension wavefront topography aberrometer system (OPD-Scan III), based on the scanning-slit retinoscopy principle, were used to obtain objective refraction readings. In addition, lower-order Zernike coefficients (Z) were used to calculate objective refraction. A set of 7 different results was obtained in power vector notation (spher…

Anterior Segment Biometry and Their Correlation with Corneal Biomechanics in Caucasian Children.

2018

Purpose: To assess the relationship between the corneal biomechanical parameters and the anterior segment parameters in Caucasian children. Methods: This study included 293 eyes from 293 healthy children aged between 6 and 17 years. Corneal hysteresis (CH) and corneal resistance factor (CRF) were evaluated with the Ocular Response Analyzer, axial length (AL) with IOLMaster and the anterior segment with Pentacam. Anterior segment parameters obtained were the following: central corneal thickness (CCT), corneal volume (CV), anterior chamber depth (ACD), anterior chamber volume (ACV) and mean anterior and posterior keratometry. Two multiple linear regression models were constructed to assess th…

Agreement between 2 swept-source OCT biometers and a Scheimpflug partial coherence interferometer

2020

PURPOSE To evaluate the agreement between different parameters obtained with 2 swept-source optical coherence tomography (SS-OCT)-based biometers and 1 Scheimpflug camera with partial coherence interferometry (PCI). SETTING Single center, Oftalvist, Alicante, Spain. DESIGN Prospective case series. METHODS Biometry was performed in 49 eyes using 3 optical biometers: ANTERION SS-OCT, IOLMaster 700 SS-OCT, and Pentacam AXL PCI. Keratometry (K), J0 and J45 vectors, anterior chamber depth (ACD), central corneal thickness (CCT), white-to-white (WTW), lens thickness (LT), and axial length (AL) were measured with each device. Bland-Altman analysis was applied. RESULTS This study comprises 49 eyes o…

Optical analysis to predict outcomes after implantation of a double intraocular lens magnification device.

2007

Purpose To analyze the effect of different optical parameters of the eye on the outcomes of implantation of a double intraocular lens (IOL) magnification device in patients with low vision. Setting Fundacion Oftalmologica del Mediterraneo, Valencia, Spain. Methods The eye's refraction and magnification before and after surgery were evaluated using a theoretical eye model based on paraxial optics approximation. Four parameters on which refraction and magnification are dependent were evaluated: anterior chamber depth (ACD), axial length (AL), mean keratometry (Km), and the distance between the 2 implanted IOLs. The 4 variables were analyzed separately in the first stage. Next, different combi…

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…

Customized intraocular telescope implanted in high myopic patients with advanced maculopathy

2011

Purpose To evaluate the results of intraocular personalized telescope implantation to improve distance best corrected visual acuity (BCVA) in high myopic patients having cataract surgery. Methods This prospective non randomized observational study included 16 eyes of 9 consecutive patients with advanced maculopathy associate to high myopia having cataract surgery. Bilateral implantation of the intraocular telescope was performed after phacoemulsification in patients having the requisites. The telescope consists of two lenses a positive high power lens is implanted in the anterior chamber and a negative one is implanted in the posterior chamber. The lenses power, magnification and residual r…

Validity of automated refraction after segmented refractive multifocal intraocular lens implantation

2017

Aim To evaluate the clinical utility of automated refraction (AR) and keratometry (KR) compared with subjective or manifest refraction (MR) after cataract or refractive lens exchange surgery with implantation of Lentis Mplus X (Oculentis GmbH) refractive multifocal intraocular lens (IOL). Methods Eighty-six eyes implanted with the Lentis Mplus X multifocal IOL were included. MR was performed in all patients followed by three consecutive AR measurements using the Topcon KR-8000 autorefractor. Assessment of repeatability of consecutive AR before and after dilation with phenylephrine 10%, and comparison of the AR and KR with MR using vector analysis were performed at 3mo follow-up. Results Ana…