View clinical trials related to Keratoconus.
Filter by:The purpose of this research study is to evaluate the long tern safety and effectiveness of cross-linking in eyes with keratoconus and ectasia.
Keratoconus and pellucid marginal degenerations are genetically based ocular conditions and post surgical ectasia is an iatrogenic condition. These diseases are characterized by weakening of the front part of the eye that causes thinning and distortion. This distortion results in unevenness of the cornea and produces progressive near-sightedness and irregularity, which causes loss of vision when using eyeglasses. When eyeglasses fail to give enough vision, the the investigators use rigid contact lenses to create an artificial front eye surface. This improves visual acuity in many patients although they eventually fail either because they cannot be tolerated or the surface irregularity has become so severe that they are rejected. At this stage there is usually thinning and loss of clarity of the eye. There has been no treatment for this other than corneal transplantation, a complex surgical procedure with a significant complication rate and a delay in visual recovery. The treatment the investigators wish to perform strengthens the front of the eye by a chemical reaction using light and riboflavin. This technique has been studied over a decade and is widely used throughout the world. The FDA approved multicenter American clinical study is being analyzed in anticipation of its submission to the FDA for PreMarket approval. Because this is a progressive condition, the investigators wish to be able to offer this on a limited basis to patients in need with vision loss. Any treatment that can delay or prevent corneal transplantation is of great benefit. The investigators believe the evidence is compelling that this treatment is the sole alternative to surgical transplantation.
The objectives of this study are to evaluate the safety and efficacy of corneal collagen cross-linking performed with VibeX (riboflavin ophthalmic solution) and the KXL System as compared to placebo in impeding the progression of, and/or reducing, maximum corneal curvature.
The primary objective of this study is to evaluate two different ultraviolet (UV) dosing regimens for corneal collagen cross linking to slow the progressive changes in corneal curvature in eyes with progressive keratoconus or post-refractive surgery ectasia.
The instrument that will be used in the study is the Murcia monocular Adaptive Optics Visual simulator (AOVIS-I). The system provides an objective characterization of the optical quality of the patient's eye by application of wave-front sensing technology. The optical condition of every eye is represented by its wave aberration. This characterization overcomes the current description based only in refractive errors. This provides an accurate description of the optics of the eye based on the assessment of the whole set of ocular aberrations. The particular wave-front sensor is of a Hartmann-Shack type. One characteristics of this wave-front sensor is its high dynamic range allowing measuring highly aberrated eyes, such as patients with keratoconus.
The purpose of this study is to properly analyse the visual and refractive outcomes of implantation of KeraRing intrastromal corneal ring segment (ICRS) at the different stages of keratoconus.
The purpose of this research study is to test the safety, tolerability, and effectiveness of corneal collagen cross-linking (CXL), when used to treat keratoconus.
The purpose of this study is to evaluate the efficacy of ultraviolet-A (UVA)-induced cross-linking of corneal collagen (CXL) as a method to increase the biomechanical and biochemical stability of the cornea by inducing additional cross-links within or between collagen fibers using UVA light and the photo- mediator riboflavin. The purpose of this study is to generate data for presentation at medical meetings and for peer-review publication. The data generated by this study will not be submitted to the FDA to support commercialization of these riboflavin drops.
Transepithelial CXL (performed without epithelial removal) seem to have similar clinical effect on keratoconic eyes compared to the standard CXL (which includes epithelial removal). The current study attempts to prove that hypothesis. A prospective, controlled, randomized, contralateral trial, will involve one eye of the patient to be treated with transepithelial CXL, while the control eye will be treated with the standard CXL. Totally 20 patients (age >18 and <40 years) referred by an ophthalmologist to the eye department of the University Hospital North Norway for CXL treatment of bilateral progressive keratoconus, will be recruited.
Corneal collagen crosslinking (CXL) has been proposed as an effective method of reducing progression of both keratoconus and corneal ectasia after surgery, as well as possibly decreasing the steepness of the cornea in these pathologies. During the CXL procedure, the central corneal thickness has been shown to significantly change. The investigator's believe that better maintenance of corneal thickness potentially could have benefits of better reproducibility of the crosslinking effect with improved predictability of results.