View clinical trials related to Corneal Astigmatism.
Filter by:The purpose of this post-market study is to describe the long-term safety and performance of Clareon Toric Intraocular Lenses (IOLs).
To evaluate the short-term efficacy and safety of scleral contact lens in the clinical treatment of patients with irregular astigmatism after corneal transplantation by analyzing ocular parameters and ocular surface conditions of patients after corneal transplantation.
The goal of this is prospective, computer based randomized clinical trial is to compare the efficacy of reduction of the pre-existing corneal astigmatism at the time of cataract surgery in patients admitted in sohag university hospital. the main questions it aims to answer are : - Is limbal relaxing incisions as effective as the paired opposite 4mm clear corneal incisions technique in reduction of corneal astigmatism at the time of cataract surgery ? - Are both techniques effective in treating mild degrees of corneal Astigmatism ? All participants will have full ophthalmological examination necessary for routine cataract surgery, then randomly divided into 2 groups, clear corneal incision group & limbal relaxing incision group. Researcher will compare difference between both groups regarding the following : - Uncorrected distance visual acuity (UCVA) - Best Corrected visual acuity (BCVA) - keratometry readings
The aim of the study is to compare functional results and complications of 3 methods of cataract phacoemulsification: bimanual 1.4 mm cataract surgery (B-MICS), coaxial 1.8 mm cataract surgery (C-MICS) and coaxial 2.4 mm small incision cataract surgery.
Corneal astigmatism is refractive error that impairs uncorrected visual acuity. When patients undergo cataract surgery, implantation of toric IOL is deemed the most effective choice for correcting corneal astigmatism and reducing postoperative spectacle dependence. Previous studies report that the visual effects and rotational stability of toric IOLs are well maintained over 1- or 2-year follow-up periods. However, the long-term changes in the effects of toric IOLs remain unclear.
The planned clinical investigation will be conducted to acquire raw data for the development of the algorithm. The data acquisition is intended to obtain first impressions of the potential performance of the changed hardware and software components and to confirm the safety profile assessed by risk analysis.
Corneal astigmatism is refractive error that impairs uncorrected visual acuity. When patients undergo cataract surgery, implantation of toric IOL is deemed the most effective choice for correcting corneal astigmatism and reducing postoperative spectacle dependence. The IOL-capsular complex is formed after cataract surgery and intraocular lens (IOL) implantation. Early postoperative mechanical wrapping of the anterior and posterior capsules plays a significant role in preventing IOL decentration and tilt, as well as formation of the IOL-capsular complex which reduces the incidence of posterior cataract opacity. IOL decentration ≥ 0.4 mm or/and IOL tilt ≥7degree were considered clinically significant because of poor post-surgery visual quality especially for optical sophisticated IOLs such as toric IOLs. IOL instability could decrease the curative effect of toric IOL. There are numerous types of toric IOLs; however, AcrySof IQ and TECNIS toric IOL are most frequently used in the Ophthalmology Hospital of Wenzhou Medical University. AcrySof IQ IOL has some differences compared with TECNIS toric IOL. IQ has a modified L haptic design while TECNIS® toric IOL has a modified C haptic design. AcrySof IQ IOL has a discontinuous 360˚ posterior square edge while TECNIS toric IOL has a continuous 360˚ posterior square edge. The AcrySof IQ IOL cylinder power models include 1.00, 1.50, 2.25, 3.00, 3.75, 4.50, 5.25 and 6.00 D. The Tecnis IOL cylinder power models include 1.00, 1.50, 2.25, 3.00 and 4.00 D. Previous study pointed that patients with cataracts with corneal astigmatism achieved comparable improvement in visual acuity, astigmatism correction, CS（sensitive contrast）, rotational stability and satisfaction, following AcrySof and TECNIS toric IOL implantation. However，some other studies found that the Acrysof toric IOL showed significantly greater rotational stability than the Tecnis toric IOL and the rate of surgical IOL repositioning was higher in eyes implanted with TECNIS than with AcrySof toric IOLs for astigmatic correction. Currently, there is no literature guidance to compare the results of cataract surgery combined various types of toric IOLs implantation in patients using CASIA2. The novel anterior segment optical coherence tomography (AS-OCT) device, CASIA2 can accurately evaluate the IOL capsule bending and the lens position after cataract surgery. Also, CASIA2 can be used to documented the dynamic changes of IOL-capsular complex after surgery.
Some parameters, such as a change in the optic tilt and axial decentration, can affect the optical characteristics of intraocular lenses (IOLs) in postoperative period, which leads to residual refractive errors and other complications. The stability of the intraocular lens in the eye is largely dependent on the mechanical design of its haptic support elements. Thus, the new Clareon IOL has a flat haptic with a flexible design that minimizes axial changes and allows the IOL to maintain a stable position in a given plane during compression. Currently there is no published data of the stability for Clareon AutonoMe IOL for long eyes. The purpose of the current study is to evaluate and compare the axis displacement and stability of optical tilt, visual and refractive results in patients after implantation of two different models of intraocular lenses: Clareon AutonoMe (Alcon, USA) and Hoya iSert 251 (Japan) in the long-term postoperative period (after cataract surgery).
The primary objective of this study is to evaluate the performance of the enVista Toric 0.9D vs non-Toric IOL.
This study is a 6-month, prospective, multicenter, randomized (1:1:1), subject-masked and evaluator-masked, bilateral clinical investigation of the TECNIS IOL Models C1V000 and C2V000 versus the TECNIS Eyhance™ Model ICB00 IOL. The study will be conducted at up to 15 sites in EU, AU, NZ and/or AP and will enroll up to 225 subjects to achieve approximately 67 bilaterally implanted subjects in each lens group. Allowing for 10% lost-to-follow-up, this will achieve approximately 60 evaluable subjects in each lens group at 1, 3, and 6 months. The eye implanted first will be considered the primary (monocular) study eye.