View clinical trials related to Visual Impairment.
Filter by:In this prospective pilot study without control group children and young adults (10-25 years old) diagnosed with Bardet-Biedl syndrome and treated with Metformin for their adipositas will be evaluated for a possible additional effect of Metformin on visual acuity.
An individual senses the world and reflects feedbacks via independent behaviors. Such precise collaboration of the sensory and behavioral systems is fundamental to survival and evolution. When a sensory modality is altered, the behavioral system has the potential to fit in a substitute modality. However, the specific dynamics of human behaviors in response to sensory loss remain largely unknown due to the paucities of representative situations and large-scale samples. Here, the investigators focused on thousands of human infants who suffered varying degrees of visual stimuli deficiency in early stages, while their behavioral systems remained sensitive and thus retained high behavioral plasticity. Having access to this unique population provides an unprecedented opportunity to investigate the effect of diverse visual conditions on the behavioral system.
As a subtype of major depressive disorder, seasonal affective disorder (SAD) or winter depression causes severe reductions in both quality of life and productivity and results in high morbidity and frequent sick leave (1). SAD is a prevalent disorder with rates as high as 3-5% in central European countries and 8-10% in Scandinavian countries. In our recent screening survey among persons with severe visual impairment or blindness (visual acuity < 6/60), we found a strikingly high prevalence of SAD of 17 % compared to 8% in the fully sighted control group. Persons with maintained light perception had a highly increased SAD prevalence of 18 % whereas no light perception (NLP) respondents had an SAD prevalence of 13 %. Light is unquestionably of great importance in the development and treatment of SAD. It is suggested that a reduced retinal sensitivity to light leads to sub-threshold light input to the brain and consequently to the development of SAD. The novel retinal non-visual photoreceptors, the intrinsically photosensitive retinal ganglion cells (ipRGCs), are involved in the regulation of circadian rhythm and mood and their function are in part independent of the function of the classical rod and cone photoreceptors which form the basis of conscious visual perception. Function of the ipRGCs can be assessed by chromatic pupillometry where the sustained pupillary contractions following blue light stimulation (PIPR) is the main outcome. In persons with SAD without eye disorder the function of the ipRGCs is reduced. We here wish to investigate associations between ipRGC function and SAD symptoms, circadian profile and treatment response to light therapy in persons with visual impairment. Persons with visual impairment (SAD and non-SAD) are assessed for ipRGC function with chromatic pupillometry, for seasonal mood variation by interview and questionnaire and for diurnal melatonin secretion by saliva analysis summer and winter. In winter SAD participants are treated with daily morning bright light for 6 weeks. Reduction in depression scores and tolerability is recorded.
This is a prospective, randomized, single-center clinical study aiming to explore the safety and efficacy of venous stenting for patients with internal jugular vein stenosis (IJVS).
Elderly with visual impairment (VI) who undergo community eye screening often do not attend tertiary follow-up even if significant eye diseases are detected. Investigators evaluate an incentive-care scheme (ICS) to improve the attendance rates of tertiary eye-care visits of participants following community eye screening.
The purpose of this study is to evaluate how visual acuity assessed with Peek Acuity (a cell phone application to check visual acuity) among preschool and school-aged children 3 to less than18 years of age (1) compares to the standard visual acuity exam in the ophthalmology clinic and (2) performs as a screening test for ocular abnormalities that warrant referral for an eye exam.
This pilot study will integrate multi-sensor fusion techniques (software) to effectively combine information obtained from the newly embedded infrared, ultrasound, and stereo-camera-based sensor systems (hardware) that are implemented into the VIS4ION platform. The core of this technology is based on 4 components: (1) a wearable vest with several distinct range and image sensors embedded. These sensors extract pertinent information about obstacles and the environment, which are conveyed to (2) a haptic interface (belt) that communicates this spatial information to the end-user in real-time via an intuitive, ergonomic and personalized vibrotactile re-display along the torso. (3) A smartphone serves as a connectivity gateway and coordinates the core components through WiFi, bluetooth, and/or 4G LTE, (4) a headset that contains both binaural, open-ear, bone conduction speakers (leaving the ear canal patent for ambient sounds) and a microphone for oral communication-based voice recognition during use of a virtual personal assistant (VPA). Blindfolded-sighted, and blind subjects in a real-world, combined obstacle avoidance / navigation task will serve as an independent measure of overall improvements in the system as well as a roadmap for future avenues to enhance performance. Further, a prospective, randomized crossover, controlled, non-blinded phase will be conducted in Thailand as part of this study to compare and evaluate effectiveness of the wearable vest for increasing navigation and quality of life.
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 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.
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.