View clinical trials related to Keratoconus.
Filter by:A complete intrastromal ring, MyoRing (Dioptex, GmbH, Linz, Austria), suggested by Albert Daxer in 2007, is a relatively new technique that has been demonstrated to treat keratoconus safely and effectively.Corneal collagen crosslinking (CXL), introduced by Wollensak et al. in 2003, has become a standard treatment for progressive keratoconus to slow or possibly stop progression of disease. The formation of the stromal pocket during MyoRing implantation offers the opportunity for simultaneous introduction of riboflavin 0.1% into the pocket followed by UVA irradiation to provide combined treatment in patients with progressive keratoconus.
Different techniques of deep anterior lamellar keratoplasty (DALK) have been introduced to create a uniform recipient bed, thereby reducing complications, such as interface irregularity and opacification encountered with conventional lamellar keratoplasty. The big-bubble technique provides a planned, safe, quick and consistent baring of Descemet membrane (DM) by injection of air deep into the stroma. Nevertheless, this technique has a long learning curve with a low success rate of big-bubble formation and a high rate of DM perforation when performed by surgeons in training. Different modifications to the original technique using intraoperative instruments such as corneal pachymetry, anterior segment optical coherence tomography (OCT), and femtosecond laser, have been used to increase the chances of achieving a successful DM detachment from the deep stroma by air injection. Even with these innovations, the rate of successful big-bubble formation did not reach 100%. Recently, the investigators described a modification to the original big-bubble DALK in which a 27-gauge needle was inserted into the stroma peripherally from the trephination site towards the limbus. The investigators found that air injection peripheral to the trephination can effectively and reproducibly separate the corneal stroma from the Descemet membrane (DM). This study was aimed to compare the success rate and complications of big-bubble DALK using central versus peripheral air injection performed by senior cornea fellows under the supervision of an experienced faculty member in an academic hospital.
The standard CXL technique involves removal of the epithelium to enable riboflavin to penetrate into stromal tissue, to avoid epithelial debridement and increasing the patient's comfort and safety transepithelial corneal crosslinking (CXL) was suggested. Iontophoresis of riboflavin is one of approach for riboflavin impregnation. In this study, the investigators compared the results of standard corneal crosslinking (CXL) and transepithelial CXL via iontophoresis of riboflavin after 24 months follow up.
The most common causes for irregular cornea (IC) in hospital contact lens practice are Keratoconus (KC) and related cornea thinning disorders. These conditions cause mild to marked impairment of vision and cannot be effectively corrected by spectacles and soft contact lenses. The gold standard in the management of KC is Corneal Rigid Gas Permeable contact lenses (corneal lenses), which correct approximately 90% of the corneal irregularity. Compared with a normal cornea, the cornea in KC is irregular and this results in a compromise to the fit of rigid corneal lenses. Specifically, they bear on the cornea and this, together with the vulnerability of the cornea in KC, are implicated in corneal scarring, and disease progression as well as a significantly reduced vision related quality of life (QoL) in KC compared with corneal lens wearers who have no KC. In cases where the compromise fit of corneal lenses proves problematic, large diameter Scleral RGP contact lenses (scleral lenses) may be used as a problem solver. Unlike the smaller corneal lenses which bear on the cornea, the scleral lenses completely bridge over the cornea and bear on the sclera. The aim of this research is to investigate the performance of scleral lenses in KC participants who habitually wear corneal lenses. The research question: is there a measurable difference in the visual performance and visual quality of life in participants with Irregular cornea disorders like keratoconus and other related conditions, who habitually wear corneal lenses in comparison with scleral lenses.
The measurement of visual acuity is made using black letters of varying size superimposed on a uniform white background. The objective is to determine the smallest letter, or optotype, that can be correctly identified. One limitation of current tests is the variability of measurements, this making it difficult for clinicians to determine if changes in visual acuity are related to ocular disease. This variability has been attributed to the design of current optotypes, in particular their differing legibilities. Our group has recently demonstrated that a new type of letter chart (Moorfields Acuity Chart), containing letters with a black core and a white border presented on a grey background, reduces the variability of visual acuity measurements. In this study the investigators wish to determine if changes in vision owing to keratoconus, a disease that causes the cornea to adopt an irregular shape, may be detected more easily using the Moorfields Acuity Chart compared with conventional letter charts.
The purpose of this retrospective study is to assess corneal changes (keratometry, pachymetry) and change in visual acuity (VA) in keratoconus patients after unilateral crosslinking treatment compared to the untreated fellow eye. The corneal measurements obtained preoperatively and 2 to 14 months postoperatively using a Pentacam rotating scheimpflug camera are analyzed. Furthermore, pre-existing or actual ocular pathology or/and ocular surgeries as potential factors involved in treatment outcome are also evaluated.
The purpose of this study was to determine whether mechanical compression of the cornea during corneal crosslinking for keratoconus using a sutured rigid contact lens can improve the optical outcomes of the treatment.
The gold standard corneal crosslinking (CXL) technique involves the initial step of epithelial removal, in order to achieve a sufficient treatment effect (meaning: stabilisation of progressive keratoconus (KC). Our aim is to evaluate the effects of transepithelial CXL (TE-CXL), whereby the epithelium is left intact and the cornea is instead treated by a solution composed of 0.1% riboflavin, combined with enhancers, after which standard CXL is performed. This solution seems to facilitate riboflavin penetration into the corneal stroma through the intact epithelium. The investigators expect to achieve a similar effect of TE-CXL with the advantage of a faster healing time and less risk of infections.
The purpose of the study is evaluating safety and clinical efficiency of full femtosecond laser-assisted anterior lamellar keratoplasty (FS-ALK) for curing patients with keratoconus and corneal opacities
Young patients with keratoconus face two problems: disease progression and corneal shape irregularity leading to poor vision even in spectacles. Corneal collagen cross-linking (CXL) is a new treatment designed to halt disease progression in keratoconus. The aim is to stiffen the cornea thereby preventing further shape deterioration. Topography or wavefront guided transepithelial photorefractive keratectomy (transPRK) uses the excimer laser (the laser used to correct sight in 'laser eye surgery') to reduce corneal shape irregularity in early stage keratoconus, reducing dependence on contact lenses. In transPRK, the corneal skin layer is removed in a well controlled, no touch procedure, preparing the cornea for CXL. Performing both treatments simultaneously (combining both procedures in one operation) may offer several advantages over performing CXL first then waiting for corneal shape to stabilise before performing transPRK. In particular, visual rehabilitation may be faster. This study aims to evaluate visual recovery after simultaneous CXL and transPRK in progressive early stage keratoconus. Visual recovery in these patients will be compared with results for a similar group of patients with early stage keratoconus who have already been treated with CXL alone.