View clinical trials related to Myopia, Degenerative.
Filter by:Orthokeratology lenses (OK-lens) and multifocal contact lenses (MFCL) are optical devices designed to slow down the progression of myopia. Both treatments a long-term commitment from doctors and patients. This study aims to develop a unified index to predict the success probability of myopia control at the early stage of treatment.
The purpose of the study is to determine the effect of Natural View Multifocal lenses, a soft multifocal lens, on retardation of myopia in an optometric student population. Close up work (i.e. reading, computer work, etc.) is thought to play a factor in the progression of myopia in young adults. The progression should be slowed if not stopped through the use of peripheral defocus lenses (Natural View Multifocal) to change the optics of the eye in order to focus the image on the peripheral retina as opposed to behind it.
Myopia has been increasing in prevalence and severity throughout the world over the last 30 years. Increasing levels of myopia are associated with increased frequency and severity of various ocular pathologies. Slowing myopia progression may help to reduce the future risks of these ocular pathologies. Conventional spectacles and contact lenses correct myopia by moving the central focus of the eye from in front of the retina to on the retina centrally. To varying degrees, these lenses allow the light to focus behind the retina, at varying peripheral retinal locations. These findings have led to efforts to design spectacle and contact lenses which correct peripheral hyperopic defocus, to reduce myopia progression. The consensus theory for how both multifocal contact lenses (MFCLs) and orthokeratology can control myopia progression is that they reduce, eliminate, or reverse relative peripheral hyperopic defocus. Existing published studies on the use of multifocal contact lenses to control myopia in humans have utilized lenses with the distance correction in the center with peripheral plus power to correct the peripheral blur. It is possible that one of the mechanisms responsible for myopia progression control with MFCLs is that when the eye is exposed to an image focused on the retina and simultaneously an image anterior to the retina, that this will suppress axial elongation and myopia progression. This mechanism would not be dependent on whether the anterior image is located in the central area of the retina or the peripheral area of the retina. While there are no published human studies demonstrating the effectiveness of near center MFCLs, this author has presented retrospective data showing no differences in myopia progression between near center and distance center MFCLs. Synergeyes, Inc.'s Duette contact lenses are hybrids of rigid gas permeable (RGP) with a silicon hydrogel peripheral portion or "skirt." They now make their MFCLs in both distance center (DC) and near center (NC) designs. This study will analyze the myopia progression of children after being randomly assigned to wear Duette MFCLs or Duette standard single vision contact lenses over a span of two years. Subjects assigned to the MFCL group will wear a DC lens on one eye and a NC lens on the other and will reverse this lens assignment every six months. Refractive changes will be measured by cycloplegic autorefraction and axial lengths will be measured with a laser interference biometer (Zeiss IOLMaster) at six-month intervals.