View clinical trials related to Keratoconus.
Filter by:Keratoconus (KC) is a corneal ectatic disorders, with incidence rate 1 per 50,000 among the population. Hormonal imbalances may be associated with KC as it affects the corneal metabolism. In this study, we aim to examine this clinical association between thyroid gland dysfunction (TGD) and KC.
This pilot study will compare upto 15 patients undergoing femtolaser assisted keratoplasty (using CE[Conformité Européene] approved femtolaser apparatus) with upto 15 patients undergoing conventional keratoplasty with a manual trephine. Patients will be randomly assigned to either group. All keratoplasties will be penetrating keratoplasties. The following aims of this research is detailed below: 1. Does femtosecond laser assisted keratoplasty ( FLAK ) yield faster visual recovery and better long term BCVA (Best Corrected Visual Acuity)? 2. Does FLAK offer a biomechanically stronger cornea and thereby more safety and less risk of wound dehiscence? 3. Is there any difference between FLAK and conventional keratoplasty in terms of graft failure or rejection? Follow up in best corrected visual acuity, various refraction/astigmatism measurements, intraocular pressure, graft rejection/failure rates, pachymetry and corneal hysteresis and resistance factor will be recorded at 1 day, 1 week, 1, 3 and 6 months and 1 year and 18 months postoperatively. This study, to the investigators' knowledge will be the first randomised controlled trial in this area, the first to provide an empirical measurement to biomechanical stability of the cornea with the femtolaser, and the first done in an NHS (National Health Service) setting.
The mechanism by which vision loss in glaucoma occurs is still unknown, but it is clear that increased Intraocular Pressure (IOP) is a major risk factor. It is also thought that the lamina cribrosa (LC) is a site of primary damage during the pathogenesis of the disease. The changes caused by intraocular pressure (IOP) modulation at the level of the optic nerve head and LC will be evaluated in the present study. Subjects with keratoconus exhibit abnormal collagen properties that can impair their LC behavior. By evaluating their lamina biomechanical response we can advance our understanding on the role of the lamina in glaucoma pathogenesis. A better understanding of the process will ultimately lead to improved detection and management of glaucoma. It is hypothesized that subjects with keratoconus have an abnormal biomechanical response of the lamina cribrosa in response to IOP modulation.
This main goal of this study is to improve the detection, classification, monitoring, and treatment of irregular corneas due to keratoconus, warpage, dry eye, scar, stromal dystrophies, and other corneal conditions. The primary goal will be achieved by using optical coherence tomography (OCT) to: 1. Develop an OCT-based system to classify and evaluate corneal-shape irregularities. 2. Develop OCT metrics for more sensitive detection of keratoconus progression. 3. Develop OCT-and-topography guided phototherapeutic keratectomy (PTK) for irregular corneas.
A monocentric, parallel-arm, prospective, randomized therapeutic trial that compares the efficacy of two curative keratoconus treatment techniques by cross-linking collagen (accelerated conventional technique or iontophoresis). The primary endpoint will be the depth of the demarcation line measured by confocal microscopy and OCT at 1 month. This line represents the limit depth between treated and untreated stroma.
The purpose of this study is to investigate changes in the corneal thickness of scleral contact lens wearers in a keratoconic (KC) population and compare to age-matched controls. The hypothesis is that scleral contact lens wear is associated with low levels of corneal hypoxia including measurable changes in corneal thickness. Corneal thickness will be altered post scleral lens wear compared to pre-lens wear and the amount of alteration will correlate to the fitting characteristics in the central zone of the scleral lenses. We propose to take a sample of keratoconic and control participants, fit them in scleral lenses, and to measure topographic corneal thickness after 8-10 hours of scleral lens wear after three weeks of wear, to compare two instruments in the measurement of corneal thickness, and to compare the effects of varying central corneal clearance of the scleral lens on corneal thickness.
The purpose of this study is to determine whether corneal stroma implantation is effective in the treatment of keratoconus.
Keratoconus is a ocular disease classified under ectatic diseases which often results in bilateral and asymmetrical corneal distortion. It usually affects patients at young age and can cause severe visual loss. The overall goal of this study is to assess the prevalence of keratoconus (KC) in children and adolescents in various regions of the world based on modern tomographic imaging methods, and to verify whether the occurrence rates reported from literature should be corrected. Our hypothesis is that the prevalence of the disease is much higher than that traditionally reported. At each site, corneal tomography examinations (Pentacam) will be performed bilaterally in children and adolescents, who are not ill or with any ophthalmological symptom. The population to be studied will be composed of children and adolescents on medical visits for non-ophthalmologic reasons, aged between 6 and 20 years. Multiple cities, from different continents (North America, South America, Asia and Europe) will participate.
Corneal ectasia is characterized by irregularity and thinning of the cornea, causing the cornea to bulge forward and cause distorted vision and impaired visual acuity. Corneal ectasia is a complication after refractive (LASIK) surgery. It is also the primary problem in keratoconus, a gradually progressive inherited condition that typically is manifested in young adulthood, more commonly in women. Treatment approaches to stabilize the cornea's shape include rigid contact lenses, surgical implantation of stiff plastic intrastromal corneal ring segments, a collagen cross-linking procedure and, in severe cases, cornea transplantation. The collagen cross-linking procedure involves topical application of a concentrated riboflavin (vitamin B2) solution after the corneal epithelium is scraped, followed by ultraviolet (UV) light exposure. UV light stimulates riboflavin to form new bonds (cross links) between the cornea's connective tissue, giving the cornea additional strength to maintain its shape and prevent the need for transplantation. The cost of one treatment using this system is $2,500 to $3,500. A small prospective study including 7 patients with keratoconus was started on a trial of oral riboflavin and 15 minutes of natural sunlight exposure daily. These patients reported no adverse effects and preliminary results showed corneal stabilization and/or corneal flattening in all 7 patients It is hypothesized that dietary riboflavin and natural sunlight is as effective in corneal crosslinking as the currently FDA approved Avedro therapy. If the clinical study confirms the investigators' early observations of the benefits of this approach, coupled with animal studies that document corneal cross-linking, the investigators will have data to pursue funding for larger clinical and animal studies. This has the potential to save millions of dollars in health care costs and ease the burden of treatment in patients who require therapy to induce corneal cross-linking to stabilize the cornea's shape.
The goal of this research is to develop measurement tools and simulation technology for characterizing and predicting individual responses to corneal treatments and for advancing understanding of corneal ectasia risk factors. Patients who either 1) have keratoconus and are being evaluated for corneal crosslinking or 2) have refractive error and are being evaluated for refractive surgery procedures such as LASIK will have their eyes imaged to assess their mechanical properties and will have computational simulations performed to predict the response to treatment. One aim of the study is to test the hypothesis that computational models can predict the cornea's shape changes within clinically acceptable limits of error.