Active clinical trials for "Astigmatism"

To compare the accuracy of the Abulafia-Koch, the Barrett, the Barrett Post ,the EVO , the new Holladay with total surgical-induced astigmatism, the Kane and and the Næser-Savini toric intraocular lens (IOL) power formulas using a large database of toric IOL refractive outcomes

The purpose of this study is to evaluate visual distortions reported by pseudophakic patients.

Purpose of this study is to compare the astigmatic power of the toric IOL obtained from the AcrySof toric calculator, TECNIS toric calculator, and iTrace toric calculator in a group of patients with preoperative with-the-rule (WTR) and against-the-rule (ATR) corneal astigmatism. The study included 100 eyes with cataract and greater than 0.75 diopter of corneal astigmatism, and the subjects were divided into WTR and ATR group. Keratometric value was measured using autokeratometry, IOLMaster partial coherence interferometry (PCI), iTrace incorporating corneal topography and ray-tracing aberrometry. Based on measured values, toric IOL power calculations were performed using AcrySof, TECNIS and iTrace toric calculators.

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.

Keratoconus is a bilateral (but usually asymmetrical) non-inflammatory progressive thinning process of the cornea. It manifests as characteristic cone-like ectasia of the cornea associated with irregular stromal thinning, resulting in a cone-like bulge , which causing irregular astigmatism and vision impairment.

The primary objective of this study is to evaluate the performance of the enVista Toric 0.9D vs non-Toric IOL.

the records of astigmatic children were reviewed and any deviation was investigated at near and distance. refractive errors, stereopsis, convergence insufficiency were also evaluated. children were divided into two groups according to the presence of amblyopia and ocular deviations and other parameters were compared between groups.

Aim of this study is to gain a better understanding of the diurnal changes of the cornea to improve toric IOL power calculations.

The aim of this project: Confirming the modification in corneal astigmatism after trabeculectomy with MMC and intracameral administration of bevacizumab. Medium-term follow up (6 months) of the induced corneal astigmatism. Investigating correlations between postoperative astigmatism, particularly with the postoperative IOP.

This study is an evaluation of visual outcomes of subjects implanted with the AcrySof Toric Intraocular Lenses (IOLs) Models SN60T3, SN60T4, and SN60T5.