Active clinical trials for "Myopia"

The purpose of this study is to evaluate corneal swelling, limbal redness, and endothelial bleb response to wearing galyfilcon A lenses in asian eyes.

The aim of the study was to evaluate visual outcomes, contrast sensitivity, glare testing and high order aberrations induced by different laser technologies and to evaluate differences in aberrometer technology. We hypothesized that there will not be differences among conventional or wavefront guided treatments.

The primary objective of this study is to compare subjective ocular symptoms and corneal staining over time in a group of individuals who wear soft contact lenses on a daily wear basis, whilst they sequentially use two different contact lens care regimens.

The high prevalence of myopia - especially in Asian countries - is well documented, as are the sight-threatening complications of high or degenerative myopia. Retinal detachment, glaucoma, vitreal degeneration and focal retinal changes may occur secondary to the progressive axial elongation of the eye with age. Specialty rigid lenses have long been shown to lessen this progression in the pediatric population; orthokeratology (ortho-k) lenses are worn at night and change the corneal topography to correct low to moderate amounts of myopia. Most of the studies on orthokeratology were conducted on Asian children. To the best of the investigators knowledge, no study has been done on African American (AA) children. The investigators' project seeks to investigate the efficacy of ortho-k in slowing axial elongation and myopic progression in AA children compared to that in other races.

We have identified focussing problems related to myopia getting worse. Our trial uses optical and orthoptic interventions that correct the focussing problems to see if this retards myopia progression.

The purpose of this study is to determine whether bifocal soft contact lenses are effective in controlling the progression of myopia in children and adolescents that exhibit a tendency to excessively cross their eyes while reading (esophoria or eso fixation disparity). Several studies have demonstrated that bifocal or progressive multifocal spectacles are effective in slowing the progression of myopia in children either with near point esophoria and/or with inadequate focusing at near. A prominent theory for one cause of myopia progression is that poorly focused images on the back of the eye (retina) cause the eye to lengthen, causing an increase in myopia. Bifocal contact lenses may reduce this retinal defocus, reducing the stimulus to eye elongation, and thus may reduce myopia progression.

This study will evaluate the ability of toric multifocal contact lens to reduce the change of myopia progression in children (aged 8-12) with myopic astigmatism.

Atropine eye drops are considered to be an effective form of myopia control in human eyes. However, the mechanism by which it exerts it effects are not fully understood. Thickening of the choroid subsequent to atropine administration may play an important role in the mechanisms by which atropine induces myopia control. Literature also notes that choroidal thickness undergoes diurnal variations, which is a variable that will be controlled in this study in order to examine atropine's effects on different baseline choroidal thicknesses. The purpose of the proposed study is to characterize better the influence of atropine on choroid thickness. The study aims are to: Determine the effect of low dose concentration of topical atropine (0.1% and 0.01%) on choroid thickness Determine the effect of topical atropine on choroid thickness in relationship to baseline thickness throughout the day and after one week of daily instillation Hypothesis: Atropine's effect on choroidal thickness will be dependent on the subject's baseline thickness measurements, at a designated time of the day when the choroid is at its thinnest.

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.

In 2020, the overall myopia rate among children and adolescents in my country was 52.7%. The COVID-19 pandemic has increased students' time of indoor eye-using, and it showed that the light exposure intensity of myopic students is lower than that of non-myopia students. Studies have found that the light wave bandwidth has a significant impact on the emmetropization of the eye, and white light can promote emmetropia more than monochromatic light. It shows that outdoor exercise has a protective effect on the occurrence and development of myopia in children and adolescents, but the specific mechanism is still unclear. Retinal blood flow is sensitive to myopic stimuli, and is a short-term indicator of the relationship between light environment and myopia. This study selected retinal blood flow as the primary outcome, aiming to compare the effects of different outdoor light exposure modes on retinal blood flow after 1 hour of intense eye use, and provide clues for the prevention and control of myopia.