Active clinical trials for "Astigmatism"

The aim of the study is to present the effect of implanting intrastromal fresh corneal lenticule by SMILE surgery as a new method-approach to correct the corneal shape on purpose to reduce irregular astigmatism and increasing visual acuity after penetrating keratoplasty.

This study aims to compare the clinical performance of two daily disposable toric contact lenses.

The objective of this study is to assess the rate of early intraocular pressure (IOP) increases following implantation of EVO/EVO+ Implantable Collamer Lens (ICL).

Comparison of wear experience with daily disposable and monthly replacement soft contact lenses in contact lens wearers who have astigmatism.

Photorefractive keratectomy (PRK) with excimer laser has been used successfully to treat myopia, hyperopia, and astigmatism in adults for over 35 years. Children with high refractive errors that go untreated will develop severe amblyopia. PRK can normalize high refractive errors and potentially improve the visual acuity in affected children. The purpose of this study is to investigate whether children with high anisometropia or isoametropia with amblyopia that are nonresponsive to standard therapy and receive PRK develop better longterm visual acuity.

This study is evaluating the wear experience of a daily toric contact lens after 10, 12, 14, and 16 hours of lens wear.

This study is to evaluate the patient subjective experiences of two daily disposable toric contact lenses.

The investigators are comparing outcomes of LASIK surgery using a high definition wavefront-guided laser to a wavefront-optimized laser in patients with nearsightedness with and without 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

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.