Active clinical trials for "Astigmatism"

Cataract surgery is one of the most common procedures performed worldwide. Astigmatism is the most common refractive disorder in adults, hence there is a high prevalence of preexisting astigmatism in cataract patients. Access to astigmatism correction during cataract surgery allows for improved visual outcomes for patients. Toric intraocular lenses (IOLs) are the procedure of choice to correct corneal astigmatism of one diopter or more in cases undergoing cataract surgery. Rotational stability is a key factor for successful outcomes with toric IOLs. Postoperative toric IOL misalignment is the major factor responsible for suboptimal visual outcomes after toric IOL implantation. The TECNIS® Eyhance Toric II 1-piece posterior chamber lens is a new toric IOL which is FDA approved and CE marked. Marketed by Johnson & Johnson Vision, it is indicated for the visual correction of aphakia and pre-existing corneal astigmatism of one diopter or greater in adult patients with or without presbyopia in whom a cataractous lens has been removed by phacoemulsification and who desire reduction in residual refractive cylinder. No study assessing the early rotational stability of the TECNIS® Eyhance Toric II IOL has been published yet.

The purpose of this study is to compare Topography Guided Laser In Situ Keratomileusis (LASIK) corneal surgery to Small Incision Lenticule Extraction (SMILE) corneal surgery for the treatment of myopia with astigmatism.

This study seeks to evaluate the clinical performance of a recently released contact lens designed to correct astigmatism to an established contact lens that has historically been used in these patients.

Corneal astigmatism is refractive error that impairs uncorrected visual acuity. When patients undergo cataract surgery, implantation of toric IOL is deemed the most effective choice for correcting corneal astigmatism and reducing postoperative spectacle dependence. Previous studies report that the visual effects and rotational stability of toric IOLs are well maintained over 1- or 2-year follow-up periods. However, the long-term changes in the effects of toric IOLs remain unclear.

To evaluate the efficacy, safety and accuracy of Contoura topography-guided LASIK & PRK in comparison to Wavefront optimized LASIK & PRK in virgin eyes with astigmatism.

The aim is to evaluate the short-term changes in ocular surface measures and tear inflammatory mediators after lenticule extraction (FLEx) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) procedures.

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.

OVERVIEW Cataract is a clouding of the crystalline lens which causes vision loss and blindness if untreated. Cataract surgery is the most frequently performed surgical intervention in medicine with an incidence of 880 surgeries per 100.000 population in 2010 amounting to a total number of over 160.000 surgeries per year in the Netherlands. Approximately 22% of patients with cataract have a substantial pre-existing corneal astigmatism. Toric IOLs provide the opportunity to correct pre-existing astigmatism, offering the patients optimum distance vision without the use of spectacles or contact lenses. Toric IOLs are increasingly used in cataract and refractive surgery. Since the introduction of toric intraocular lenses (IOLs) in the treatment of cataract in patients with pre-existing corneal astigmatism, numerous studies have shown the importance of accurate positioning of the toric IOL to the intended alignment axis. An error of 5º in toric IOL alignment will decrease the anticipated effect by 17% and thus misalignment will decrease the effectiveness of the astigmatism treatment. There are several methods used to align the toric IOL at the intended axis. Most of these use a 3-step ink-marking procedure and are performed manually. Clinical study showed an average error of 5º in toric IOL alignment when using this method. Two new tools that have recently been introduced to the market are the VERION Measurement Module and VERION Digital Marker. Together, these tools provide integrated digital guidance for alignment of toric IOLs and they have the potential to eliminate the error in horizontal axis marking and the alignment axis marking error. This will lead to an improved visual outcome. So far, there are no published studies using the VERION tools for toric IOL alignment in cataract surgery. Therefore, the investigators will perform this randomized control trial. MAIN HYPOTHESIS The investigators hypothesise that cataract surgery with the implantation of a toric IOL, when using the VERION-tools, compared to manual ink-marking, in patients with corneal astigmatism will lead to: - An increase in accuracy in toric IOL alignment OBJECTIVES Primary Objective: The primary objective of the study is to compare the accuracy in toric IOL alignment when using the VERION-tools for alignment of the toric IOL or the conventional manual ink-marking procedure. Other hypotheses and objectives are available in the detailed description.

The objectives of this study are to evaluate the safety and efficacy of a treatment regimen for high myopia and myopic astigmatism: LASIK followed by crosslinking performed with the KXL Crosslinking-System and VibeX Xtra (Riboflavin Ophthalmic Solution, Avedro, USA), as compared to LASIK alone, with regards to regression of refractive outcome, as measured by manifest refraction spherical equivalent (MRSE) and keratometry.

The aim of this study is to assess visual and refractive outcomes after Toric Trifocal lens implantation and visual outcomes after laser vision correction (LVC) - ReLex Smile to correct residual refraction after 6 months of Toric Trifocal (IOL) implantation.