Eye biometry

PURPOSE: To compare intraocular lens (IOL) power prediction accuracy of the Eyestar 900 (EyeS900) and the IOLMaster 700 (IOLM700) based on estimated and measured posterior corneal power DESIGN: Retrospective, inter-instrument reliability study METHODS: Setting: Institutional. PARTICIPANTS: 225 eyes of 225 cataract surgery patients. MEASUREMENTS: Patients underwent measurements by both devices preoperatively. MAIN OUTCOME MEASURES: Spherical Equivalent Prediction Error (SEQ-PE), spread of the SEQ-PE (Precision) and the absolute SEQ-PE (accuracy) of each device using Barrett Universal II (BUII) formula with either estimated posterior keratometry (E-PK) or measured posterior keratometry (M-PK)...

PURPOSE: The purpose of this study was to investigate the effect of the corneal back surface by comparing the keratometric astigmatism (K, derived from the corneal front surface) of a modern optical biometer against astigmatism of Total Keratometry (TK, derived from both corneal surfaces) in a large population with cataractous eyes. The results were then used to define linear prediction models to map K to TK. METHODS: From a large dataset containing bilateral biometric measurements (IOLMaster 700) in 9736 patients prior to cataract surgery, the total corneal astigmatism was decomposed into vectors for K, corneal back surface (BS), and TK...

AIM: To determine the prevalence of some retinal pathologies in people over 60y and their association with demographic and ocular factors. METHODS: A cross-sectional study was conducted in Tehran using multistage cluster sampling. After selecting subjects aged 60 and over, optometric, and ophthalmic examinations were done. For retinal examination, a 90 D lens was used and indirect ophthalmoscopy was performed after instilling tropicamide drops. Biometry was done using the IOL Master for all participants...

AIMS: To document longitudinal changes in spherical equivalent refraction (SER) and related biometric factors during early refractive development. METHODS: This was a prospective cohort study of Chinese children, starting in 2018 with annual follow-ups. At each visit, children received cycloplegic autorefraction and ocular biometry measurements. Lens power (LP) was calculated using Bennett's formula. Children were divided into eight groups based on baseline age: the 3-year-old (n=426, 49...

PURPOSE: To study the visual results and tolerance of a Zeiss CT Lucia 601P intraocular lens (IOL) implanted in the sulcus after complicated cataract surgery or during IOL exchange for clouded IOL. METHODS: In total, 64 patients who underwent sulcus implantation were recalled to the hospital to undergo subjective and objective refraction, best corrected visual acuity measurement, tonometry, optical coherence tomography, laser flare photometry, biometry, and wavefront aberrometry...

PURPOSE: To report a case of phacolytic glaucoma with atypical presentation in a patient which was diagnosed with biometry swept source optical coherence tomography (SS-OCT) and anterior segment spectral domain OCT (SD-OCT). METHODS: A 56-year-old male with a history of cytomegalovirus (CMV) chronic anterior uveitis in the right eye presented with a white cataract, minimal anterior chamber reaction and intraocular pressure (IOP) of 56 mmHg. Visual acuity was light perception...

Objective: To explore the distribution characteristics of peripheral retinal defocus in children and adolescents. Methods: This cross-sectional study included 500 individuals aged 3 to 18 years, who visited the People's Hospital of Lincang, the First Affiliated Hospital of Dali University and Dali Ophthalmology Hospital between January and December 2021. Data of the right eye of each participant was analyzed. There were 226 males (45.20%) and 274 females (54.80%), with an average age of (10.79±3.79) years...

SIGNIFICANCE: Validation of new biometry instruments against the gold standard and establishing repeatability are important before being utilized for clinical and research applications. PURPOSE: This study aimed to investigate intersession repeatability of the MYAH optical biometer and corneal topographer and examine agreement with the Lenstar LS900 optical biometer in healthy young adults. METHODS: Forty participants (mean age, 25.2 ± 3...

PURPOSE: To compare the accuracy of nine conventional and newer-generation formulae in calculating intraocular lens power in eyes with axial myopia. SETTING: Tertiary eye care center, Bengaluru, India. DESIGN: Retrospective cross-sectional, comparative study conducted in India. METHODS: Patients undergoing uneventful phacoemulsification in eyes with axial length >26 mm were included. Preoperative biometry was done using Lenstar LS 900 (Haag-Streit AG, Switzerland)...

PURPOSE: To compare anterior chamber angle (ACA) parameters measured by Anterior Segment Optical Coherence Tomography (ASOCT) and biometric parameters measured by Swept-Source (SS) OCT-based biometry among patients with suspected occludable angles and open angles. METHODS: An analytical, cross-sectional study was performed on subjects attending our ophthalmology outpatient department with suspected occludable angles (van Herick grades 0, 1, and 2) in group 1, and with open angles (van Herick grades 3 and 4) in group 2...

OBJECTIVE: Aim of this study was to use a combination of partial least squares regression and a machine learning approach to predict IOL tilt using pre-operative biometry data. SETTING: Patients scheduled for cataract surgery at the Kepler University Clinic Linz. DESIGN: Prospective single center study. METHODS: Optical coherence tomography, autorefraction and subjective refraction was performed at baseline and 8 weeks after cataract surgery...

The aim of this study was to investigate the anatomical and physiological ocular parameters in adolescents with myopia and to examine the relations between refractive error (SER), ocular biometry, body size and flexibility parameters in myopic adolescents. A cross-sectional study of 184 myopic adolescents, aged 15 to 19 years was conducted. Refractive error and corneal curvature measures of the eye were evaluated using an autorefractometer under cycloplegia. Central corneal thickness was determined by contact pachymetry...

PURPOSE: To identify the rate and characteristics of cataract surgery candidates suitable for multifocal intraocular lens implantation among patients undergoing preoperative evaluation in a public hospital. MATERIALS AND METHODS: Screening was performed based on the patient's medical records, comprehensive ophthalmic examination, optical biometry (Zeiss, IOL Master 700) and optical coherence tomography (OCT) (Heidelberg, OCT Spectralis) in accordance with the relevant indications and contraindications mentioned in the pertinent literature...

BACKGROUND: Anti-vascular endothelial growth factor (anti-VEGF) therapy is used for myopic choroidal neovascularization (mCNV). Patchy chorioretinal atrophy (pCRA) enlargement has been reported in mCNV cases associated with vision loss. Our aim was to compare the long-term effectiveness of anti-VEGF therapy alone versus anti-VEGF followed by posterior scleral reinforcement (PSR) in controlling myopic maculopathy in mCNV eyes. METHODS: We performed a retrospective review of the medical records of 95 high myopia patients (refractive error ≥ 6...

The VEMoS-AXL system is a new optical biometer based on spectral domain optical coherence tomography (SD-OCT) that has been tested in terms of intrasession repeatability and compared with a swept-source optical coherence tomography biometer (SS-OCT), which is recognized as the gold standard for the performance of an agreement analysis. A biometric analysis was performed three consecutive times in 120 healthy eyes of 120 patients aged between 18 and 40 years with the SD-OCT system, and afterwards, a single measurement was obtained with the SS-OCT system...

PURPOSE: To assess vision-related quality of life (VRQoL) in patients with systemic lupus erythematosus (SLE) under treatment with hydroxychloroquine (HCQ), and to find the influencing factors. METHODS: Cross-sectional study enrolling SLE patients for less than ten years (Group 1), SLE patients for more than ten years (Group 2), and healthy controls (Group 3). SLE patients should be under treatment with HCQ but without ophthalmological affection. Schirmer test, best-corrected visual acuity (BCVA), axial length (AL) with optical biometry, and swept-source optical coherence tomography-angiography (OCTA) Triton (Topcon) were performed...

OBJECTIVE: To describe a repeatable method of measuring ocular structures and to establish ocular biometry reference ranges in adult domestic rabbits (Oryctolagus cuniculus) without medical history or imaging findings consistent with ophthalmic disease using a 64-slice multidetector computed tomography scanner. PROCEDURE: In this retrospective and observational anatomic study, 100 eyes from 50 rabbits without medical history or imaging findings consistent with ophthalmic disease who received a head computed tomography scan were selected for measurement of globe length, width, and height using 3D multiplanar reconstruction...

PURPOSE: To evaluate the dynamic changes in anterior segment parameters during accommodation following Implantable Collamer Lens (ICL) implantation with swept-source optical coherence tomography (SS-OCT). METHODS: Under the accommodation of 0.00 diopters (D), 3.00 D, and maximum amplitude, SS-OCT was used to examine the anterior segment parameters, including ICL vault, ICL depth (the distance between the corneal endothelium and the posterior surface of ICL), crystalline lens thickness, anterior chamber depth, and various parameters of the anterior chamber angle, comprising angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle...

PURPOSE: This study aimed to estimate the corneal keratometric index in the eyes of cataract surgery patients who received zero-power intraocular lenses (IOLs). METHODOLOGY: This retrospective study analyzed postoperative equivalent spherical refraction and axial length, mean anterior curvature radius and aqueous humor refractive index to calculate the theoretical corneal keratometric index value (nk ). Data was collected from 2 centers located in France and Germany...

BACKGROUND: The purpose of this study is to compare axial length (AL) and the refractive outcome after phacoemulsification surgery from 2014 to 2019 at Hospital Sultanah Nur Zahirah, Terengganu, Malaysia. METHOD: This was a retrospective record review of all cataract patients who met the inclusion criteria and underwent uneventful superior wound phacoemulsification with nontoric intraocular lens (IOL) by a single surgeon from 2014 to 2019. Using optical biometry or immersion technique, the preoperative AL determined solely via the Sanders, Retzlaff and Kraff 2 (SRK2) formula was selected...