View clinical trials related to Corneal Astigmatism.
Filter by:This study will be a prospective, multicenter, bilateral, comparative, three-way masked (Sponsor, subject and evaluator), randomized clinical investigation conducted at up to 15 sites. Up to 300 subjects will be enrolled to achieve approximately 270 bilaterally implanted subjects, resulting in approximately 244 evaluable subjects (122 per lens group) at 6 months. After informed consent is obtained and confirmation that all eligibility criteria are met, the eye(s) may be treated according to randomization. After signing the informed consent form, subjects meeting all eligibility criteria will be randomized in a masked fashion to a treatment group: either the investigational IOL Model ZFR00V or the control IOL Model ZCB00. Prior to randomization, the investigator will choose which eye to operate on first for each subject at his/her discretion based on his/her standard clinical practice (e.g., the eye with the worse cataract, poorer best corrected distance vision and/or more severe optical/visual complaints). All subjects are intended to have bilateral cataract surgery with the second eye surgery occurring after the 1-week postoperative exam for the first eye, but no more than 30 days after the first eye surgery. All subjects will be examined through 6 months postoperatively according to the visit schedule
This study is a prospective, multicenter, bilateral, non-randomized, open-label, comparative, 6-month clinical study conducted at up to 50 sites in the USA.
Astigmatic keratotomy (AK) is used to treat numerous refractive disorders, including congenital astigmatism, residual corneal astigmatism at the time of or following cataract surgery, post-traumatic astigmatism, and astigmatism after corneal transplantation. Within the past few years, much consideration has been given to an evolutionary variant of the procedure, the limbal relaxing incision (LRI). By moving the incision farther to the periphery, cataract surgeons can safely and predictably remediate mild to moderate amounts of regular astigmatism at the time of cataract surgery by performing this incisional technique. Recent technological developments have shifted ophthalmologist's attention from manually created LRIs and astigmatic keratotomy procedures to femtosecond laser-guided procedures. Femtosecond lasers offer superior incisional accuracy and reproducibility coupled with minimal effects on collateral tissues, achieving levels of safety and reproducibility exceeding those of mechanical techniques. A major clinical application of the femtosecond laser is for creating arcuate incisions that have a precise and accurate length, depth, angular position, and optical zone.
The aim of the study was to identify whether preoperative corneal astigmatism can influence corneal biomechanics and the assessment of intraocular pressure (IOP) following micro-incision phacoemulsification.
To analyze the effect of femtolaser-assisted keratotomy on corneal astigmatism (anterior, posterior and Total corneal refractive power) measured by Scheimpflug tomography after laser lens surgery.
The purpose of this study was to demonstrate the safety and effectiveness of the HARMONI® Modular Intraocular Lens System with a toric optic in subjects with pre-existing corneal astigmatism in need of cataract surgery.
The purpose of this study was to evaluate the safety and effectiveness of the HARMONI® Modular Intraocular Lens System with a toric optic (HMTIOL) in subjects with pre-existing corneal astigmatism in need of cataract surgery.
The purpose of this study is to characterize the safety and effectiveness of the ACRYSOF IQ ReSTOR +2.5 diopter (D) Multifocal Toric Intraocular Lens (IOL) in subjects at least 3 months and no more than 14 months after IOL implantation.
Abstract Purpose: To evaluate the visual performance and rotational stability of the Tecnis Toric one-piece IOL (AMO, USA) during the first 3 post-operative months Design: Prospective single center study Setting: VIROS - Vienna Institute for Research in Ocular Surgery, a Karl Landsteiner Institute, Hanusch Hospitel, Vienna, Austria Methods: In this prospective study patients with age-related cataract and corneal astigmatism of 1.0 to 3.0 D measured with the IOL-Master 500 (Carl Zeiss Meditec AG, Germany) were included. Pre-operatively, rotating Scheimpflug scans (Pentacam HR, Oculus, Germany) were performed and the cornea was marked in the sitting position at the slit lamp. Patients recieved a single-piece toric hydrophobic acrylic IOL (Tecnis Toric, AMO, USA). Immediately and 3 months after surgery retroillumination photographs were taken to assess the rotational stability of the IOL. Additionally, Autorefraction (Topcon, USA), subjective refraction, uncorrected and distance corrected visual acuity, keratometry, Scheimpflug and ocular wavefront (WASCA, Carl Zeiss Meditec AG, Germany) measurements were performed at the 3 months follow-up.
With increasing demands of patients concerning refractive outcome after cataract surgery, toric intraocular lenses (IOLs) that correct corneal astigmatism have been introduced more widely to cataract surgery. Originally toric IOLs were used mainly for patients with high degrees of astigmatism, especially after corneal surgical procedures such as penetrating keratoplasty. Since a couple of years, toric IOLs are available from numerous manufacturers to correct lower amounts of astigmatism which are much more prevalent with about 30% having a corneal astigmatism of 0.75D or more in the cataract population. This should result in less spectacle dependence of patients due to the astigmatic correction. The alternative method to reduce corneal astigmatism as part of cataract surgery is to make incisions on the steeper axis of the cornea such as limbal relaxing incisions or an additional clear corneal incision opposite (OCCI) to the main cataract opening. These techniques are in use since more than 2 decades and are widely used in clinical routine. As with toric IOLs, precise alignment of the cuts with the axis of astigmatism is essential. The disadvantage of the incisional techniques is the variability of the effect between patients since it depends on factors such as the extent of scaring of the cuts after surgery as well as corneal thickness. The main advantage is the simplicity of the technique and the lower cost. Aim of this study is to compare toric IOL implantation and opposite clear corneal incision during cataract surgery to correct corneal astigmatism.