Active clinical trials for "Myopia"

To investigate the Safety and Effect of Overnight Orthokeratology and Its Influencing Factors in China

In the interest of improving visual quality after LASIK we have designed a multifaceted study to test the theoretical, physical, biomechanical and functional effects of commercial and independently designed aspherical ablation profiles.

To study the clinical characteristics and inheritance of pathological myopia in Taiwanese patients.

In this prospective study, entitled "The Long-Term Efficacy of Overminus Lens Therapy in Intermittent Exotropia",the investigators examined the long-term impact of overminus lenses on the management of intermittent exotropia (IXT), treatment effect after overminus treatment has been discontinued and also investigated if overminus lenses cause myopia in long-term.

In this study, the investigators aim to perform a prospective, randomized controlled study to compare the myopia development between myopia children using myopia prediction algorithm and myopia children without using myopia prediction algorithm

Myopia, the most common human eye disorder, is a phenomenon characterized by an unconstrained elongation of the eye globe There are number of theories concerning the environmental effect on the emmetropization process, most are related to childhood exposure to outdoor activity, near work and sleep with night light. Studies in lab animals found an association between intensity of ambient lighting and myopia development. In this study, the investigators will examine the ambient light in kindergarten and schools and their relation to refractive error. Diurnal luminance in kindergarten and school class room will be measured and correlated to biometric measures such as refraction, axial length and keratometry.

Myopia has been increasing in prevalence and severity throughout the world over the last 30 years. Increasing levels of myopia are associated with increased frequencies and severity of various ocular pathologies, including cataracts, glaucoma, retinal detachments and other retinal pathologies and myopic maculopathy. Slowing myopia progression at a young age before the eye reaches excessive axial length may help to reduce the future risks of these ocular pathologies. Conventional spectacles and contact lenses are prescribed correct myopia by moving the central focus of the eye for distance viewing from in front of the retina to on the retina centrally, or at the fovea. 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 and orthokeratology can control myopia progression is that they each can 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. Until recently, there have been no daily disposable multifocal lenses in the US market with distance center designs. The NaturalVue contact lens from Visioneering Technologies, Inc. is the first daily disposable distance center multifocal in the US. It has a novel extended depth of focus design where the distance correction is in the center of the optical zone, surrounded by a zone characterized by having a seamless, rapid transition from the distance power to a highly plus power at the edge of the optical zone. This study will analyze the myopia progression of patients in the investigator's practice while wearing their habitual visual corrections for periods up to two years prior to being switched to NaturalVue contact lenses. They will then be followed for up to two years after beginning use of this novel lens design and the differences in their myopia progression after versus before this novel lens will be analyzed. Axial lengths will be measured with the IOLMaster after switching to NaturalVue, at six-month intervals and will be compared to axial lengths which have been collected with habitual corrections.

High myopia retinopathy has become the first cause of irreversible blindness and severe visual impairment in Chinese adults, in order to avoid the blind and visual impairment caused by high myopia retinopathy, it is very necessary to research the mechanism of early visual impairment to prevent and control damages. Our recent research found that the decreasing of macular retina vascular density and subfoveal choroidal thickness, the increasing of Beta Zone area in optic atrophy and the rising of glycosylated hemoglobin in high myopia patients were significantly related to visual impairment, which suggested that the source of visual impairment was the abnormal structure changes surrounding optic and fovea, but so far there is no related study. We will conduct a 5 years prospective cohort study in the population of 2420 high myopia and controls which have established in college student population, working population and aged more than 50 years old population, using the latest OCT-A and SS-OCT to measure macular retina vascular density, subfoveal choroidal thickness, Beta Zone area in optic atrophy, combined with the semiparametric mixed effects model, we will analysis the prediction index between fundus structure parameters, blood biochemical index and individual characteristics prediction to explore the public health management mode of early prevention and treatment during high myopia population.

Effects on Ocular Parameters of Myopic Eyes After Orthokeratology in Myopic Children

This is a prospective study to validate an algorithm for predicting the effect of orthokeratology on myopia progression in children from 8 hospitals in China.