Search results for "Lens thickness"
showing 9 items of 9 documents
Changes in Pupil Area during Low-energy Femtosecond Laser-assisted Cataract Surgery
2018
Purpose: To study the potential changes in pupil area within low-energy femtosecond-laser assisted cataract surgery (FLACS). Methods: A retrospective assessment of the pupil size was performed in the eyes undergoing FLACS using the Ziemer LDV Z8. We measured the pupil diameters as part of the images taken preoperatively and at the completion of laser pretreatment (after releasing the suction). We calculated the pupil area in 40 eyes of 40 patients (14 right and 26 left eyes). The mean ± standard deviation (SD) of age of the patients was 74 ± 7.4 years (range: 51-87). Paired t-test was used for statistical analyses. Subgroups were built with reference to age and preoperative pupil area (smal…
Lens-vault analysis and its correlation with other biometric parameters using swept-source OCT
2021
Purpose To measure lens vault (LV) and to assess its correlation with various ocular parameters in healthy eyes, using for all measurements the same high-resolution swept-source optical coherence tomographer (SS-OCT). Methods We prospectively recruited 67 Caucasian healthy patients whose mean age was 41.9 ± 12.4 years; only their right eye was included in the study. Data were all recorded with the ANTERION SS-OCT and comprised, for each patient, 5 consecutive measurements of LV, anterior chamber depth (ACD), lens thickness (LT), axial length (AL), white-to-white (WTW) distance, central corneal thickness (CCT), anterior chamber volume (ACV) and spur-to-spur (STS) distance. Results Mean LV wa…
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…
Avaliação por OCT in vivo do comprimentos axiais centrais do segmento anterior
2017
ABSTRACT Purpose: To assess changes in anatomic structures in the anterior eye segment in terms of axial lengths with accommodation via optical coherence tomography. Methods: In this observational study, 25 eyes of 25 healthy adults were examined using the Visante® omni optical coherence tomography system. Central corneal thickness, anterior chamber depth, central lens thickness, and anterior segment length were assessed. The evaluated parameters were obtained with accommodation using different stimulus vergences, namely 0.0, -1.0, -2.0, and -3.0 D. Variation of these parameters was compared among different levels of accommodation. Results: Central corneal thickness was not altered at any s…
Ocular biometry with swept-source optical coherence tomography
2020
This study aimed to summarize the outcomes reported when swept-source optical coherence tomography (SS-OCT) is used for ocular biometry. A literature search was performed to identify publications reporting clinical outcomes of patients measured with commercial SS-OCT. Twenty-nine studies were included in this review. A comprehensive analysis of the available data was performed, focusing on parameters used for intraocular lens (IOL) power calculation in cataract surgery, including keratometry, central corneal thickness, white-to-white distance, anterior chamber depth, lens thickness, axial length, IOL power, and pupil diameter. Different metrics for repeatability, reproducibility, and agreem…
Effect of contact lenses on ocular biometric measurements based on swept-source optical coherence tomography
2019
ABSTRACT Purpose: To determine the reliability of swept- source optical coherence tomography in cases in which soft contact lenses cannot be removed when acquiring biometric measurements. Methods: Eight subjects were included and only one eye per participant was analyzed. Each eye was measured six times by swept-source optical coherence tomography with the IOLMaster 700 instrument (Carl Zeiss Meditec, Jena, Germany). Axial length, central corneal thickness, anterior chamber depth, lens thickness, and keratometric measurements were evaluated for the naked eye and while wearing soft contact lenses of three different powers (-1.5, -3.0, and +2.0 D). Results: There were statistically significan…
A simple description of age-related changes in crystalline lens thickness.
2010
Purpose An increase in lens thickness is often described as a linear function of age. However, contradictory opinions exist about whether the lens thickness continues to increase after 50 years of age. Differences in slope exist between this increase in younger and older people, but these findings are inconsistent with the linear behavior of an increase in the lens thickness throughout life. We investigated among different functions, including slope variation, which would be the best to show the relation between lens thickness and age. An available model portraying lens growth could be advantageous in many practical applications. The possibility of differences between sexes in lens thicknes…
Repeatability assessment of biometric measurements with different refractive states and age using a swept-source biometer
2018
Background We aim to assess if refractive error or age may influence the repeatability of measurements using a swept-source biometer. Methods A total of 61 subjects were evaluated with IOLMaster 700 acquiring measurements of axial length (AL), central corneal thickness (CCT), white-to-white distance (WTW), anterior aqueous depth (AQD), lens thickness (LT), and keratometry (K) readings. Repeatability was evaluated classifying the sample according to the refractive state and age by the calculation of the within-subject standard deviation (Sw), coefficient of repeatability, and intraclass correlation coefficient. Results Very similar Sw was acquired among groups for AL, CCT, and WTW. Differenc…
Comparison of partial coherence interferometry and ultrasound for anterior segment biometry.
2008
To assess the performance of a partial coherence interferometry (PCI)-based device for the determination of anterior segment biometry.Clinica Centrofama, Cartagena, Murcia, Spain.Central corneal thickness (CCT), anterior chamber depth (ACD), and lens thickness (LT) were measured with the ACMaster PCI anterior segment biometer and an Echoscan US-1800 ultrasound (US) biometer/pachymeter with and without cycloplegia. To determine the precision of the instruments, the same examiner took 30 consecutive CCT, ACD, and LT measurements in a single subject under the same conditions and with and without cycloplegia. The same measurements were performed in additional subjects.Twenty-one eyes (16 subjec…