Results 51 to 60 of about 93,210 (330)

Study of Prevalence of Preoperative Corneal Astigmatism in Patients with Senile Cataract at a Tertiary Care Institute in South India

Journal of Ophthalmology, 2022
Background. The prevalence of corneal astigmatism in patients with cataract has not been well documented in both rural and urban areas of Indian population. Purpose. The aim of this study was to assess prevalence of corneal astigmatism before cataract
C. Kumar Amruth, P. Ramya Deepthi, K. Sushma   +2 more
doaj   +1 more source

Molecular Layer Deposited Aluminum‐Based Hybrid Resist for High‐Resolution Nanolithography and Direct Ultra‐High Aspect Ratio Pattern Transfer

Advanced Materials Technologies, EarlyView.
This study demonstrates an aluminum‐based hybrid photoresist synthesized via molecular layer deposition (MLD) using trimethylaluminum and hydroquinone. The resist achieves sub‐20 nm resolution and virtually infinite silicon etch selectivity, enabling 40 nm‐wide, micrometer‐tall nanostructures.
Won‐Il Lee, Dan N. Le, Matthew Yen, Melinda Lin, Ashwanth Subramanian, Xiao Tong, Nikhil Tiwale, Jiyoung Kim, Chang‐Yong Nam   +8 more
wiley   +1 more source

Near visual function measured with a novel tablet application in patients with astigmatism

Clinical and Experimental Optometry, EarlyView., 2020
Clinical relevance While the clinical focus of performance metrics is traditionally based on visual acuity, research from the field of visual impairment has demonstrated that metrics such as reading speed and critical print size correlate much more strongly with subjective patient reported outcomes and assessed ability in real‐world tasks.
Ananya Datta, Kathryn Richdale, Erin S Tomiyama, Chuan Hu, Anna‐Kaye M Logan, Kelsea Skidmore, Moriah A Chandler, Eric R Ritchey, James S Wolffsohn   +8 more
wiley   +1 more source

Uso de lentes intraoculares tóricas no tratamento cirúrgico de astigmatismo [PDF]

, 2014
Correction of corneal astigmatism is a key element of cataract surgery, since post-surgical residual astigmatism can compromise the patient's uncorrected visual acuity.
Koch, Douglas D., Robinson, Shaun B., Ventura, Bruna V., Wang, Li, Weikert, Mitchell P.   +4 more
core   +3 more sources

Anterior and Posterior Corneal Astigmatism after Refractive Lenticule Extraction for Myopic Astigmatism

Journal of Ophthalmology, 2015
Purpose. To assess the amount and the axis orientation of anterior and posterior corneal astigmatism after refractive lenticule extraction (ReLEx) for myopic astigmatism. Methods. We retrospectively examined 53 eyes of 53 consecutive patients (mean age ±
Kazutaka Kamiya, Kimiya Shimizu, Mayumi Yamagishi, Akihito Igarashi, Hidenaga Kobashi   +4 more
doaj   +1 more source

Surgical approaches to correct corneal astigmatism at time of cataract surgery: a mini-review [PDF]

International Journal of Ophthalmology
Among refractive errors, astigmatism is the most common optical aberration, where refraction changes in different meridians of the eye. It causes blurred vision at any distance and includes corneal, lenticular, and retinal astigmatism.
Xiao-Lei Yin, Zhi-Yang Ji, Xiu-Xin Li, Xue-Mei Liang, Shu-Xing Ji   +4 more
doaj   +1 more source

Corneal Astigmatism Measurements Comparison among Ray-Tracing Aberrometry, Partial Coherence Interferometry, and Scheimpflug Imaging System

Journal of Ophthalmology, 2020
Purpose. To investigate interdevice agreement among corneal topography/ray-tracing aberrometry (iTrace), partial coherence interferometry (IOLMaster), and Scheimpflug imaging (Pentacam) for the measurement of corneal astigmatism. Methods.
Yaqin Zhang, Jing Dong, Suhua Zhang, Bin Sun, Xiaoliang Wang, Maolong Tang, Xiaogang Wang   +6 more
doaj   +1 more source

Age- and gender-related characteristics of astigmatism in a myopic population

Frontiers in Medicine, 2022
PurposeTo explore age- and gender-related differences of refractive and corneal astigmatism in myopic patients looking for refractive surgery.DesignA retrospective cross-sectional study.Materials and methodsThe medical files of candidates looking for ...
Shan Yang, Yang Jiang, Ge Cui, Ying Li
doaj   +1 more source

Phase Topology Stability of an Optical Vortex via an Electrically Controlled Twist‐Planar Oriented Liquid Crystal Fresnel Lens

Advanced Optical Materials, EarlyView.
A simple and efficient method for determining the stability of optical vortices via Fourier transform using a conventional spherical lens is presented. The theoretical and experimental results demonstrate a practical approach to directly and unambiguously measure the magnitude and sign of the topological charge of a beam without altering an ...
Elena Melnikova, Katsiaryna Pantsialeyeva, Dmitry Gorbach, Alexei Tolstik, Sergei Slussarenko Jr., Alina Karabchevsky   +5 more
wiley   +1 more source

Ritchey-Chretien Telescope [PDF]

, 1973
A Ritchey-Chretien telescope is described which was designed to respond to images located off the optical axis by using two transparent flat plates positioned in the ray path of the image.
Amon, M., Rosin, S.
core   +1 more source