View clinical trials related to Astigmatism.
Filter by:The main purpose of this study is to evaluate the use of limbal relaxing incision (LRI) for astigmatic correction. LRI is a procedure where a pair of incisions is made in the peripheral part of the cornea so as to alter its shape and improve the focusing power of the eye.
This study evaluates the intrastromal correction of ametropia with a femtosecond laser made by 20/10 PERFECT VISION. This laser generates a beam of ultrashort, infrared pulses which enables very precise cuts in the cornea. By these cuts lamellae of the cornea are separated locally, and in the consequence the curvature of the cornea is changed, and the correction of the diagnosed ametropia can be achieved. On the contrary to cuts which are generated with a sharp knife, the cuts generated when using a laser can be generated just inside the cornea without opening the surface of the cornea. This means the procedure is minimal-invasive. The study hypothesis is: Different types of ametropia can be corrected safely and on long-term by intrastromal cuts.
In this study, the investigators employed Visante-OCT (Carl Zeiss, USA), an anterior chamber optical coherence tomography, to monitor the change of anterior chamber dimensions. These data were correlated to anterior and posterior curvature changes collected with the Oculus Pentacam (Oculus Inc., Germany), a corneal topographer based on rotating Scheimpflug principle. To minimize the effect of convergence and excyclotorsion during examination, topical cycloplegic medication was used. The investigators hypothesized that if there is a link between ciliary muscle contraction and cornea curvature, installation of cycloplegic should result in widening of anterior chamber angle to angle distance and flattening of the cornea curvature data.
The purpose of this combined retrospective and prospective chart review analysis is to investigate the safety, efficacy, and predictability obtained via Laser-Assisted In Situ Keratomileusis (LASIK) and Advanced Surface Ablation (ASA) over a wide range of refractive errors The working hypothesis is that there will be no difference in clinical outcomes between patients treated with LASIK or ASA.