This prospective observational study aimed to evaluate the ocular biometry of Japanese people through a multicenter approach. The uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively) in the log minimum angle of resolution (logMAR), subjective and objective spherical equivalent values (SE) of ocular refraction, anterior and posterior corneal curvature (ACC and PCC, respectively), anterior and posterior corneal asphericity (ACA and PCA, respectively), central corneal thickness (CCT), anterior chamber depth (ACD), and ocular axial length (AL) were measured in the eyes of 250 participants (mean age = 46.5 ± 18.
View Article and Find Full Text PDFPurpose: The purpose of this study is to assess changes in tear film stability caused by incomplete blinking.
Methods: Eleven subjects (mean age, 21.3 years) participated in this study.
Introduction And Purpose: To develop a chart for the clinical setting that can quantify ocular dominance by using the modified balancing technique, a method based on binocular rivalry.
Methods: In 100 healthy young volunteers, rightward-tilted and leftward-tilted square-wave gratings were presented to the right and left eye, respectively. A newly designed chart employing balancing techniques based on binocular rivalry was used in conjunction with a viewer.
J Cataract Refract Surg
August 2012
Purpose: To determine the effect of axis orientation on visual performance in astigmatic eyes.
Setting: Department of Ophthalmology, Kitasato University, Kanagawa, Japan.
Design: Investigational simulation.
Objective: To investigate intraocular lens (IOL) and vitreous contact lens (VCL) combinations that provide good central visual field visualization in vitreous surgery.
Method: ZEMAX optical design software was used to perform optical simulations using the ray tracing method on a Gullstrand eye model. The implanted IOL was assumed to consist of material with a refractive index of 1.
Purpose: To assess the effect of aging on optical quality in a normal population.
Methods: We prospectively examined 100 normal eyes of 100 healthy volunteers (50 men, 50 women; ages, 20-69 years; mean age ± standard deviation, 44.6 ± 15.
Purpose: To investigate the factors affecting apparent accommodation in pseudophakic eyes from a clinical viewpoint and the effects of corneal and refractive astigmatism on this accommodation from an optical viewpoint.
Methods: We retrospectively examined 62 eyes of 33 patients who had undergone phacoemulsification with monofocal intraocular lens implantation. We quantitatively assessed the amplitude of apparent accommodation using an accommodometer 3 months after surgery.
Graefes Arch Clin Exp Ophthalmol
June 2012
Background: A modified implantable collamer lens (ICL) with a central hole (diameter, 0.36 mm), a "Hole-ICL", was created to improve aqueous humour circulation. The aim of this study was to investigate the fluid dynamic characteristics of aqueous humour in a Hole-ICL using computational fluid dynamics.
View Article and Find Full Text PDFAim: To determine the effects of pupil size on uncorrected visual acuity (UCVA) in astigmatic eyes.
Methods: The authors examined 20 normal eyes of 20 healthy volunteers (age 26.7±4.
Graefes Arch Clin Exp Ophthalmol
July 2011
Background: A modified implantable collamer lens (ICL) with a central hole (diameter 0.36 mm), "Hole-ICL", was created to improve aqueous humour circulation. The aim of this study is to investigate the effects of ICL power and the relationship between pupil size and modulation-transfer functions (MTFs) in a Hole-ICL in vitro.
View Article and Find Full Text PDFPurpose: To evaluate the relationship between the horizontal ciliary sulcus diameter and anterior chamber diameter measured by 35 MHz ultrasound biomicroscopy (UBM) and the horizontal corneal diameter (white to white [WTW]) measured by scanning-slit topography and to assess the repeatability (intraexaminer difference) of the 2 methods.
Setting: Department of Orthoptics and Visual Science, Kitasato University School, Sagamihara, Japan.
Methods: The repeatability and agreement of UBM and scanning-slit topography were assessed using the intraclass correlation (ICC) and the Bland and Altman method (ie, mean difference and 95% limits of agreement [LoA]).
Purpose: To investigate the effect of pupil size on visual acuity in pseudophakic monovision.
Methods: For the simulation, a modified Liou-Brennan model eye was used. The model eye was designed to include a centered optical system, corneal asphericity, an iris pupil, a Stiles-Crawford effect, an intraocular lens, and chromatic aberration.
Purpose: To compare the repeatability and reproducibility of corneal curvature measurements using the Pentacam eye scanner (Oculus Optikgeräte GmbH) and Keratron corneal topographer (Optikon 2000 SpA).
Methods: Axial topography maps were used to acquire measurements. Twenty-six eyes of 26 healthy patients were measured to determine repeatability and reproducibility.
Purpose: To investigate the modulation transfer function (MTF) of two refractive multifocal intraocular lenses (IOLs).
Methods: The ReZoom and Array (AMO) multifocal IOLs were evaluated using the OPAL Vector system (Image Science Ltd) and a model eye with a variable aperture (2.1 to 5.
Introduction And Purpose: To investigate the effect of exodeviation in spatial visual attention using the illusory line motion paradigm.
Methods: The perception of visual illusion (i.e.
Purpose: To evaluate the repeatability, reproducibility, and agreement in anterior, posterior, and in particular the total corneal power of 2 topography devices, rotating Scheimpflug photography and scanning-slit topography.
Setting: Department of Ophthalmology and Visual Science, Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan.
Methods: Seventeen eyes of 17 subjects (mean age 24.
Purpose: To compare the modulation transfer function and the retinal magnification after myopic correction by replacement of spectacles, laser in situ keratomileusis (LASIK), or phakic intraocular lens (phakic IOL) implantation.
Materials And Methods: Using the ray tracing method, we measured the modulation transfer function and the retinal magnification after these myopic corrections in a Gullstrand eye model.
Results: The modulation transfer function (3-mm pupil, 100 cycles/mm) after phakic IOL implantation for the correction of low, moderate, and high myopia was 45%, 44%, and 44%, respectively.
Purpose: To clarify the role of ocular dominance and to investigate the importance of visual acuity and restriction of the visual field for the visual stabilization of posture.
Methods: The subjects were 31 healthy volunteers ranging in age from 18 to 27 years. The sway of the center of gravity in the upright position was measured by a stabilometer.
J Cataract Refract Surg
June 2007
Purpose: To evaluate a new surgical procedure that uses a decentered intraocular lens (IOL) to correct vertical strabismus in cataract patients.
Setting: Department of Ophthalmology, Kitasato University School of Medicine, Sagamihara, Japan.
Methods: Six patients (11 eyes) with vertical strabismus had small-incision cataract surgery.
Purpose: To develop a new method using binocular rivalry and retinometers to quantitatively examine ocular dominance and to investigate the magnitude of ocular dominance in cataract patients preoperatively and postoperatively.
Setting: Eye Clinic, Kitasato University School of Medicine Hospital, Sagamihara, Kanagawa, Japan.
Methods: The duration of exclusive visibility of the dominant and nondominant eye target in binocular rivalry were measured in 60 healthy volunteers (study 1) and preoperatively and postoperatively in 10 cataract patients (study 2).
Purpose: To evaluate the relationship between corneal aberrations and contrast sensitivity (CS) after hyperopic laser in situ keratomileusis (H-LASIK).
Methods: In 13 patients (13 eyes) who underwent H-LASIK, we measured CS and corneal topography preoperatively and at 1 year postoperatively. Photopic and scotopic CS values were measured at 3, 6, and 12 cycles/degree (cpd) using an MCT-8000 contrast tester.
J Cataract Refract Surg
December 2005
Purpose: To investigate the relationship between pupil size and the modulation transfer function (MTF) of a multifocal intraocular lens (IOL) in vitro and to predict the visual effects in vivo.
Setting: Department of Ophthalmology and Visual Science, Kitasato University Graduate School of Medical Sciences, Kitasato, Japan.
Methods: A refractive multifocal IOL (Array SA-40N, Allergan) and a monofocal IOL (PhacoFlex SI-40NB, AMO) were evaluated using the OPAL Vector system and a model eye with a variable effective aperture.
Purpose: To examine the effect of posture change on corneal aberrations and corneal curvature.
Design: Observational case series.
Methods: The Keratron topographer, improved to measure patients in the supine position, was used to measure the corneal aberrations and the curvature in nine healthy volunteers.