View clinical trials related to Vision Disorders.
Filter by:A) The main purposes of this study are (i) to develop a related virtual reality (VR) environment in order to judge the nighttime driving ability under mesopic and under glare conditions (ophthalmologically healthy subjects and patients with incipient to intermediate cataract, i.e. opacities of the human lens, will participate in this study), (ii) to validate the above-mentioned VR environment with respect to a related on-road driving scenario under mesopic and glare conditions, (iii) to validate clinical photopic and mesopic contrast vision tests and glare tests with respect to the prediction of nighttime driving ability, (iv) to assess the test retest reliability of clinical photopic and mesopic contrast vision tests B) Background: An intact mesopic vision and a glare sensitivity within a normal range are essential pre-requisites for safe driving at nighttime (DOG & BVA, 2011). Anderson & Holiday (1995) have shown that (simulated) opacities of the refractive media (with only minor effects on daytime visual acuity) induce a pronounced impairment of contrast sensitivity under nighttime conditions. Especially under glare conditions by the headlights of traffic on the opposite lane or by stationary street illumination, an impairment of the mesopic vision may cause traffic hazards. The prevalence of impairments of the central visual acuity, the mesopic vision and the glare sensitivity is significantly higher for subjects being involved in nighttime traffic accidents (Lachenmayr, 1998). Furthermore, these impairments occur more frequently in aged drivers and are, among others, related to an increase of age-related media opacities (Aulhorn & Harms, 1970, Babizhayev, 2003). Due to the demographic change, the relevance of nighttime driving ability is increasing in the next years since more and more aged employees will participate at the motorized traffic at night. The German Fahrerlaubnisverordnung (FEV i.e. driving license regulation) specifies pass/fail criteria with regard to mesopic vision and glare sensitivity. The luminance level during nighttime driving is usually between 0.01 and 1 cd/m^2, and therefore can be attributed to the level of mesopic vision. However, over the last years, the attempt was made to introduce photopic contrast sensitivity test to diagnose nighttime driving ability (i.e. testing of contrast vision under daytime conditions without time consuming adaptation procedures). Current research aims at investigating the relationship between contrast tests under various luminance conditions (Wilhelm et al, 2013). It is questionable, whether photopic tests are at all reliable predictors with regard to nighttime driving (Gramberg-Danielsen et al., 1984, Hertenstein et al., Graefe´s Archive of Ophthalmology, 2016).
This study will train participants (young people and older adults) to do a visual task, and will assess whether this results in changes in behavioral assessments. In some participants, we will be also testing whether MRI measures (cortical thickness, functional connectivity) change with training.
This study evaluates the safety and efficacy simultaneous, trans-conjunctival, 25-Gauge vitrectomy and phacoemulsification with intraocular lens implant in patients with metamorphopsia and visual impairment due to idiopathic epiretinal membrane and cataract. All 30 patients recruited underwent complete ocular examination, visual acuity measurement with ETDRS, metamorphopsia assessment with M-Charts and Metamorphometry® and foveal thickness evaluation by sd-OCT preoperatively, at 30, 90, 180 days postoperatively.
This study will determine whether blood biomarker changes predict sight-saving benefits of exercise.
This pilot study aims to assess the interest to add an auditory pathway morphological analysis during the MRI exploration of visual pathway in visually impaired children.
The purpose of the study is to compare the effect of intravitreal injections of ranibizumab and aflibercept on systemic VEGF levels in DME patients in a detailed time course.
The CLEAR study is testing the level of agreement between visual acuity and Amsler grid testing using a mobile vision testing application, Checkup Study, and standard in office methods. In addition the percent of patients able to successfully complete home testing on the digital device will be assessed.
Amblyopia is a significant health problem, affecting up to 4% of the population in the United States. Amblyopia, commonly known as "lazy eye," is a developmental visual disorder in which one or both eyes suffer from poor vision as a result of being disadvantaged in early life. Strabismus, or eye misalignment, such as crossed eyes (esotropia) or wandering eyes (exotropia), and anisometropia, or a power difference between the eyes, are the most common causes of amblyopia. If conventional treatment, such as patching the better seeing eye, is not initiated during the critical period of visual development, lasting visual impairment may persist throughout life. This critical period of visual development has been thought to end around age 10. However, recent research has demonstrated that the critical period of visual development can be extended into adulthood. Complete light deprivation in animal models has restored plasticity in the visual cortex and has demonstrated drastic recovery of vision in amblyopic eyes. The objective of this pilot study is to evaluate the impact of complete light deprivation on visual function in a cohort of human adults with severe amblyopia from anisometropia.
This is a randomised controlled trial with the aim of testing the efficacy of coloured overlays and coloured lenses for the relief of visual stress and reading difficulties in children and young adults.
This study will compare near clinical oculomotor parameters (heterophoria, vergence ranges, AC/A and accommodative findings) measured when lenses and/or prisms are introduced using three different instruments namely: (i) a standard manual phoropter, (ii) an electronic phoropter and (iii) a wearable adaptive refractor (VisionFit).