View clinical trials related to Keratoconus.
Filter by:CORNEAL LENTICULE IMPLANTATION IN KERATOCONUS DISEASE WITH RELEX SMILE SURGERY
This randomized clinical trial will assess corneal astigmatism and visual outcomes in participants who have undergone corneal transplantation for keratoconus with ex vivo cross-linked donor corneal tissue versus participants who have undergone corneal transplantation for keratoconus with non-cross-linked donor corneas. Crosslinking is a procedure that stabilizes the biomechanical properties of the cornea; as a result, the cornea stiffens. It has been shown that this procedure stabilizes the cornea of patients with keratoconus or corneal ectasias. The FDA currently approves crosslinking for patients with progressive keratoconus and corneal ectasia following refractive surgery. Ex vivo crosslinking of donor corneal tissue for patients with keratoconus undergoing PK or DALK could stabilize the cornea and reduce the risk of high astigmatism and improve vision in patient with keratoconus.
In keratoconic eyes, the corneal epithelium shows a localized thinning over the cone that is surrounded by an annulus of epithelial thickening. It has been postulated that epithelial thickness mapping can be a sensitive tool for the keratoconus diagnosis. In keratoconus screening the 5 mm diameter of the corneal centrum may be sufficient while studies have shown that the cone apex is located in this area. Aim of this study is to assess agreement and repeatability of epithelial thickness measurements using two optical coherence tomography devices in healthy and keratoconus corneas. Secondary objective is to evaluate the differences between healthy and keratoconus eyes using epithelial thickness map data. This is a prospective monocentric study that includes patients divided into two groups: patients with keratoconus and a control group formed out of patients without corneal pathologies. For each patient only one eye will be included and corneal measurements will be performed, focused on the corneal epithelium thickness.
The purpose of this study is to see if OCT technology can optimize scleral contact lens fittings. Subjects with keratoconus, post-penetrating keratoplasty (PK), post-LASIK ectasia, post-radial keratotomy (RK), or a variety of anterior surface disorders requiring scleral lens fittings will be considered for enrollment. For each study eye, a clinically-selected scleral lens fit will be compared against an OCT-selected lens fit. The quality of each lens fit will be determined by flourescein exam at the slit lamp. Apical clearance, limbal clearance, conjunctival compression, and lens edge lift will be assessed. A lens that satisfies all four criteria will be considered satisfactory.
keratoconus is a progressive corneal ectatic disease characterized by paraxial stromal thinning and weakening, resulting in irregular astigmatism, corneal protrusion, and distortion of the anterior corneal surface. It is usually bilateral, although asymmetrical in most cases. Intrastromal corneal rings are polymethylmethacrylate devices successfully used for the management of keratoconus, pellucid marginal degeneration, post-LASIK ectasia and myopia. Intrastromal corneal rings implantation is safe and reversible procedure that does not affect the central corneal area, and hence, avoids interference with visual axis. The goal of intrastromal corneal rings implantation is to improve visual acuity by regulariztion of the anterior corneal surface.
The standard or Dresden protocol was established in 2003 and treats the entire cornea. However, recent ultra-structural research showed that keratoconus is localized. Therefore, treating only the affected zone and minimalizing the risk of damaging surrounding tissues would be beneficial. The objective of this study is to evaluate whether the effectiveness of customized cross-linking (cCXL) is non-inferior to standard accelerated cross-linking (sCXL) in terms of flattening of the cornea and halting keratoconus progression.
KC is a degenerative disorder of the cornea. Keratoconus etiopathogenesis remains unclear and may rely on environmental and genetic factors. Usually considered as a rare disease (<1/2000), but the prevalence is nowadays growing worldwide up to 1/500. In that pathology, cornea progressively gets thinner, and there is a deformation of the corneal surface which can induce high order optical aberrations and visual impairment. Eye rubbing is certainly the main factor in the progression or development of keratoconus (KC), yet it is only very partially evaluated and quantified in current management. Environmental and clinical factors will be collected and associated with a eye rubbing Questionnaire, specifically pointing out eye rubbing.
The aim of this study is to detect the safety and effectiveness of contact lens assisted corneal cross linking in managing progressive keratoconus with thin corneas CACXL was done for 40 eyes of 30 of keratoconic patients presented to cornea outpatient clinic in Kasr Alainy teaching hospital The UDVA ,BDVA KMAX, thinnest corneal thickness pre-operative and 9 months postoperatively and the endothelial cell count was measured preoperative and 3 months postoperative Demarcation line was measured after 1 month by using ASOCT There was statistical significant difference in UDVA and BDVA, there was stabilization of Kmax there was decrease in endothelial cell count but not statistically significant According to results the procedure seems to be effective and safe un managing progressive keratoconus.
The purpose of this study is the investigation of biomechanical properties of the cornea using computer-aided data analysis. Currently, it is known that keratoconus and glaucoma are ocular disease that are associated with biomechanical alterations of the cornea. Corneal ectasia, especially keratoconus, is a corneal disease that leads to an irreversible loss of visual acuity while the cornea becomes steeper, thinner and irregular. For these patients, surgical intervention (e.g. corneal cross-linking) is performed, in case of disease progression. In glaucoma, the information about corneal alterations serves in two ways, first, correct measurement of intra ocular pressure (IOP); second, early diagnosis of suspects before visual field defects are detectable. Especially, the Corvis ST is an air-puff tonometer that measures intraocular pressure, corneal thickness (CCT) as well as dynamic corneal response (DCR) parameters. Most of the DCR parameters are affected by IOP and CCT: Therefore, algorithm are needed to determine parameters without impact of IOP and CCT that are describe the biomechanical properties of the cornea.
The investigators measured IOP by Goldmann applanation tonometry(GAT) before and 6 months after accelerated 8 minutes CXL in using Avedro Kxl ,and correlated with corneal resistance factor(CRF)using ORA, AC angle and CCT using Scheimpflug imaging.