View clinical trials related to Myopia.
Filter by:The study aims to observe the relationship between the changes of ocular structure parameters and pathological changes among children and adolescents with high myopia. Environmental factors and family history will also be collected to explore their impacts on high myopia progression.
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.
The purpose of this study is to evaluate the overall performance of investigational contact lenses (DD T2) when compared to clariti® 1 day contact lenses.
Effects on Ocular Parameters of Myopic Eyes After Orthokeratology in Myopic Children
Control of myopia progression has become an important goal because of concerns regarding significantly increased risks of retinal degeneration, retinal detachment, glaucoma and cataract associated with high myopia. It is also clear there prevalence of myopia in children and young adults is increasing all over the world. Several methods including use of progressive addition lenses, rigid gas-permeable contact lenses, and life-style modifications (increased outdoor activity) have reported to alter myopia progression with varying efficacy. In general they have yielded clinical results of marginal significance. Atropine sulphate eye drops has consistently been demonstrated to inhibit axial myopia progression in both humans and animal models. Yet it has not found widespread clinical application for myopia control due to ocular side-effects of cycloplegia and pupil dilation. Recently 0.01% atropine has been shown to be effective in arresting myopia progression without side-effects of cycloplegia and near vision impairment and pupil dilatation and increased light sensitivity. Almost all studies on atropine have been carried out on children of Chinese origin. Efficacy (concentration and dosing) and safety need to be established in the population of interest, before routine use can be recommended. We plan to evaluate the efficacy and safety of topical 0.01% atropine eye drops in slowing the progression of myopia and ocular axial elongation in Omani children. A total of 150 children of ages 6-16 years will be randomized to two groups. Intervention group will receive atropine 0.01% once daily in each eye for two years (Phase 1). Control group will not receive any medications. Follow up visits will be scheduled every three months in Phase 1. Subsequently, medication will be stopped and the study patients will be followed up every six months for one year (Phase 2). The progression of myopia (change in refractive error and axial length) will be compared in the two groups by objective methods.
Prospective, comparative, randomized, non-masked clinical study to compare the a digital refraction with LogMAR VA testing utilizing trial lenses, to standard manual refraction using a Phoropter, and LogMAR VA testing, in accuracy of visual acuity measurement.
Evaluation of the clinical performance of an investigational silicone-hydrogel contact lens (test) compared to a marketed lens (control), when worn on a daily basis for 1 month.
The aim of this study is to determine if habitual or adapted wearers of stenfilcon A control contact lenses can be refit into test lenses and be successful after one week of daily wear.
The goal of the study is to quantify wavefront aberration profiles of the eye with and without contact lens across the visual field. This will enable us to investigate the impact of the aberration on retinal image quality.
This study is to evaluate the fitting performance of stenfilcon A contact lens (test) compared to narafilcon A contact lens (control).