View clinical trials related to Astigmatism.
Filter by:Evaluation, at least one-year long-term, of the clinical performance and safety of Mini Toric Ready Intraocular Lens (IOL), a monofocal toric intraocular lens.
The purpose of this Post-Market Clinical Follow-up (PMCF) study is to describe the long-term safety and performance of the AcrySof PanOptix Trifocal toric and non-toric IOL models in subjects bilaterally implanted with these IOLs for 3 to 5 years. This study will be conducted in Spain.
Refractive errors and corneal astigmatism are associated with changes in angle kappa and corneal back elevation at the thinnest point in Pentacam. The purpose of this study is to track: The effect of anterior corneal astigmatism treatment on angle kappa and corneal back elevation.
The purpose of this study is to report the prevalence data for total corneal astigmatism (TCA) in cataract surgery candidates.
Demonstrate that refraction measurements from the device agree with refraction measurements from a phoropter within clinically meaningful limits.
Subjects will undergo SMILE surgery in one eye and LASIK using Contoura with Phorcides on the contralateral eye to correct myopia.
To evaluate the efficacy, safety and accuracy of Contoura topography-guided LASIK & PRK in comparison to Wavefront optimized LASIK & PRK in virgin eyes with astigmatism.
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
Most of the patients presenting for cataract surgery also have pre-existing corneal astigmatism which if left uncorrected can adversely affect visual and refractive outcomes after cataract surgery. Pre-existing astigmatism at the time of cataract surgery can be corrected by either corneal relaxing incisions or implantation of toric IOLs. While the safety and efficacy of these procedures are well established, there are various challenges associated with these techniques that surgeons need to overcome to achieve good outcomes postoperatively. The use of iris registration technology that automatically compensates for cyclotorsion has the potential to improve the alignment accuracy of CRI or toric IOLs. The Cassini Ambient and Catalys Femtosecond Laser incorporate this technology to help cataract surgeons accurately align toric IOLs on the intended axis of implantation or accurately place CRI on the intended meridian. The present study is aimed at evaluating the efficacy of astigmatism correction during femtosecond laser-assisted cataract surgery with Catalys femtosecond laser. The patients will either undergo iris registration guided CRIs or iris registration guided alignment of toric IOLs.
In an aging population, cataract and presbyopia become increasingly common. A cataract is the opacification of the natural crystalline lens inside a person's eye, causing reduction of vision. Presbyopia is an age related condition resulting in loss of reading/near vision which results in requiring reading glasses. Astigmatism is a common condition characterized by an abnormal cornea (the clear tissue at the front of the eye) which results in blurred distance and near vision, again requiring glasses. Cataract surgery is the most common elective surgery worldwide for patients over 65. It is composed of removal the cataract and insertion of a new intraocular lens (IOL). Currently only monofocal IOLs are available on the National Health Service (United Kingdom) - meaning they give good distance or near vision. The majority of patients opt for good distance vision with glasses to read. The investigators are trialling insertion of a new Extended Depth of Focus (enhanced aspheric) Toric IOL (EDoF Toric IOL), which treats all 3 conditions - cataract, presbyopia and astigmatism. All patients attending St Thomas' hospital for treatment of cataracts, who have presbyopia and astigmatism will be considered for invitation to the study. Patients who participate in the study will be randomly selected to receive either the new IOL - the TECNIS Eyhance Toric II IOL, or a well-established IOL the Alcon Acrysof IQ Toric IOL during cataract surgery. Insertion of the Alcon Acrysof IQ Toric IOL is known to treat cataract and astigmatism but not presbyopia. Patients will be assessed and have their surgery performed at St Thomas' Hospital London. They will have 7 appointments over 12 months, plus surgery. The investigators hope to demonstrate better distance, intermediate and near vision and increased spectacle independence in the TECNIS Eyhance Toric II IOL group. EDoF Toric IOLs have the potential to transform cataract surgery outcomes for patients in the NHS.