View clinical trials related to Refractive Error.
Filter by:This study will be a 2-phase, prospective, multicenter, open-label, non-comparative, non-randomized clinical investigation to confirm the safety and effectiveness of the ELITA system.
Conductive keratoplasty (CK) had shown to be a safe and effective procedure for the treatment of low to moderate hypeopia. It had been approved by the U.S. Food and Drug Administration (FDA) to treat presbyope in early 2004. CK appeals to both surgeons and patients as it avoids the need for flap creation, the use of high intraocular pressure (IOP), or tissue ablation. It utilizes "blended vision" rather than the true monovision used with laser in situ keratomileusis (LASIK), which patients tolerate more readily. There is very little reported research about the induction of wavefront aberration by CK. The symptomatology of high order aberrations (HOA) and the way individual Zernike functions were correlated with visual acuity, contrast sensitivity, visual symptoms. This study measured the HOA created by surgically induced myopic shift via CK and LASIK in an effort to better understand the phenomena of regression, multifocality, pseudo-accommodation and monovision.
This study will be a 12-month, prospective, multicenter, open-label, non-comparative, non-randomized clinical investigation conducted at 8 to 14 sites. A total of 383 subjects will be enrolled to achieve approximately 268 treated subjects, resulting in at least 241 evaluable subjects at the point of refractive stability. After signing the informed consent, subjects meeting all inclusion and exclusion criteria in both eyes may be scheduled for surgery. The follow-up visit schedule will be the same for each operative eye.
The study is a 2-phase, prospective, open-label, comparative (phase II) study design that was chosen for the purpose of optimizing the Cheetah settings (phase I), and evaluating the Cheetah system quality of LASIK flap (phase II).
The purpose of this study is to carry out an international multicenter trial to get more convincing and valuable results of the SMILE surgery and compare the outcomes between the SMILE surgery and the FS-LASIK (femtosecond laser assisted-laser in situ keratomileusis) surgery. The investigators hope to investigate the differences between the SMILE and the FS-LASIK surgery comprehensively, including the comparison of visual acuity, refraction, the correction of cylindrical diopter, the high order aberrations, the corneal biomechanics, the corneal ectasia, the characteristics of the changes of central corneal thickness and the complications. To meet the demands of a multi center trial, all the examination equipments should be same in each center, and this will limit the variations within a study
A prospective study to evaluate the safety and efficacy of a piggyback sulcoflex toric intraocular lens in pseudophakic patients for correcting refractive errors following corneal transplantation