View clinical trials related to Astigmatism.
Filter by:This study will include patients who will undergo PRK in both eyes, for each patient each eye will be randomly allocated to one of 2 procedures: topography-guided ablation in one eye (group I) and Q-factor customized ablation in the other eye (group II). Alcon/Wavelight Light Laser Technolo¬gie (GmbH, Erlangen, Germany) will be used for photoablation. The wavelight Topolyzer (Wavelight AG, Erlan¬gen, Germany)and CSO Sirius scheimpflug camera combined with Placido corneal topography (CSO, Florence,Italy) will be used before and 1, 3 and 6 months after PRK. Refrac¬tive visual outcomes and corneal aberration changes will be compared between the two treatment modalities.
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.
Evaluate efficacy and safety of the toric IOL implanted into aphakic eye with corneal astigmatism after cataract surgery.
To compare the outcomes of a toric Implantable Collamer Lens (ICL) and a spherical Implantable Collamer Lens combined with astigmatic keratotomy (AK) in the correction of high myopic astigmatism.
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.
Clear-lens extraction has been considered as first-line therapy for primary angle closure glaucoma(PACG) and application of toric intraocular lens (IOLs) leads to better postoperative visual acuity, yet little is known about the prevalence of corneal astigmatism in PACG patients. We intend to make biometry examination for Chinese PACG patients, to obtain keratometry (K) , axial length (AL) and so on, and demographics data will also be recorded. We will study the prevalence of corneal astigmatism before glaucoma surgery in Chinese patients with PACG. Furthermore, differences of corneal astigmatism between primary angle-closure glaucoma and cataract patients will be explored. Finally, the prevalence of corneal astigmatism before glaucoma surgery in Chinese patients with PACG will be portrayed and can be instructive to the IOLs' manufactering.
Irregular astigmatism is one of the most serious and frequent complications of corneal refractive surgery and one of the worst sequelae of other forms of corneal surgery . It is also considered as one of common, serious complications of corneal injuries . Spectacle correction is usually not useful in the correction of corneal irregular astigmatism. Contact lenses represent a good alternative, but their adaptation and stability are limited by the irregular corneal surface and patient discomfort. In recent years, advancements in laser technology have offered better tools for dealing with irregular astigmatism with finding new surgical methods to improve corneal regularity for the correction of irregular astigmatism. Topography-linked excimer laser is a potentially effective technique in the treatment of irregular astigmatism after keratoplasty . In fact, customized ablation was shown to be an effective means of treatment of irregular astigmatism due to different etiologies Such as corneal Injuries , scar , or postoperative. Some of the theoretical advantages of topography-driven photorefractive keratectomy (PRK) are a better astigmatic correction, the possibility of correcting irregular astigmatism, and a smaller ablation volume compared with standard treatments, resulting in better visual performance. Aim of the work To evaluate the efficacy, safety, and predictability of topography-guided photorefractive keratectomy (PRK) to improve refractive status of patient with irregular Cornea.
Bilateral dispensing study of MyDay Toric, 1-day Acuvue Moist for Astigmatism, and Dailies Aquacomfort Plus Toric lenses
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.
This study is to compare the clinical outcome of Precizon toric intraocular lens(IOL) to that of Tecnis toric IOL.