Active clinical trials for "Refractive Errors"

Experienced soft contact lens wearing subjects will be enrolled in this 1-week, post-market, bilateral, repeated measures, dispensing study. All subjects will be seen for a Screening/Dispensing Visit at which informed consent will be obtained and eligibility will be assessed. If subjects satisfy all eligibility criteria and none of the exclusion criteria, subjects will be fit and dispensed study lenses. If unsuccessful in the dispensed lenses, additional lenses may be trialed. Once vision and lens fit are determined to be acceptable, eligible subjects will wear study lenses in both eyes for at least 8 hours per day (with the exception of the follow-up visits where the lenses should be worn for a minimum of 2 hours), for approximately 1 week (7 days +/-3 days). Measurements will be taken at the insertion visit and at the 7-day follow-up visit.

In a randomized controlled trial, we will establish whether early glasses for high refractive error at age one reduce the development of amblyopia between age one and four. As a secondary outcome early literacy will be compared in groups with and without glasses.

The main objective of the Sierra Leone Sees to Learn (SL2) trial is to assess the educational impact of providing free eyeglasses to students aged 12-15 years with uncorrected refractive error in Sierra Leone. The procedures include baseline questionnaires and educational assessments to collect data on students and schools, and then the provision of free eyeglasses to students who have uncorrected (or undercorrected) refractive error (URE). The questionnaires and student assessments will take 1-2 hours. The duration of the study timeframe is one school year. The end-line questionnaires and student assessments will be administered at the end of the school year.

This study will be a 12-month, prospective, multicenter, open-label, non-comparative, non-randomized clinical investigation conducted at 8 to 14 sites. A total of 383 subjects will be enrolled to achieve approximately 268 treated subjects, resulting in at least 241 evaluable subjects at the point of refractive stability. After signing the informed consent, subjects meeting all inclusion and exclusion criteria in both eyes may be scheduled for surgery. The follow-up visit schedule will be the same for each operative eye.

Chinese children are some of the most short-sighted in the world, but only one in five children in poor areas who needs glasses has them. Our team has already shown in other trials that giving children free glasses leads to better grades and that free glasses have a bigger impact on grades than factors like parents' education level and the amount of money a family has. The effect on grades from glasses is greater than from other health services in school, like giving vitamins. Only about one in three children in rural western China goes on to a regular, non-vocational high school. The investigators would like to show the Chinese government strong evidence of what glasses can do to help children continue their education, in order to help convince the government to carry out national programs to provide free glasses for children who need them. Study Plan: The investigators will choose 130 middle schools at random in Ningxia, western China, and all children in Years 1 and 2 (one class each) at each school will go at random into one of two groups: either a group getting free glasses, with support from teachers to push them to wear the glasses ("Intervention") or a group getting just glasses prescriptions ("Control.") The main study outcome will be the proportion of children going on to academic (as opposed to vocational) high school, and the study is powered to detect a 10% difference in this figure between groups.The study will also assess children's test scores, whether they wear their glasses at school, and how often they use blackboards (which disadvantage short-sighted children) vs textbooks to learn from. These other outcomes will help us to better understand the causal pathway between vision and high school attendance. We will also study the total cost of providing glasses glasses and the teacher support to wear them per additional student attending academic high school. The hypothesis of this study is that providing glasses will increase academic high school attendance.

Approximately 340 participants (680 eyes) will be enrolled in this three-month, two-arm, 1:1 randomized, parallel-group, bilateral, double-masked study at approximately 22 investigative sites in the United States. Participants will be required to wear dispensed study lenses on a daily wear basis for three months with scheduled in-office replacement of study lenses at the 1-Month and 2-Month Follow-Up Visits.

The investigators aim to conduct a mixed-method study in which a randomised controlled trial (RCT) and a descriptive qualitative study will be conducted. The RCT aims to determine whether free near and distance glasses provided to residents in Hyderabad, India, aged ≥ 60 years, with under- or un- corrected refractive error and normal baseline hearing and cognition (HMSE > 18), can improve quality of life, reduce falls, reduce depression, improve social interaction and physical activity cost-effectively over 36 months. The primary qualitative research aim is to a) contextualize the RCT with information on the milieu and culture in which the trial will be conducted; b) provide data on the lived experiences of older adults with reduced vision in the study area, and c) conduct a process evaluation of the trial. The primary outcome measure is the three-year change in cognition measured by LASI- DAD (Longitudinal Aging Study in India(LASI)- Diagnostic Assessment of Dementia(DAD) global cognitive score. Secondary Outcome Measures: Domain-specific cognitive function (orientation, executive function, language/fluency, memory), quality of life (WHOQOL BREF), self-reported visual functioning (INDVFQ), falls, mobility, depression (PHQ9), glasses compliance, cost-effectiveness (total intervention cost per additional quality-adjusted life years(QALY) gained in the intervention group), social interaction/isolation (Social Networking Index, SNI), self-reported physical activity (GPAQ). An additional secondary outcome will be LASI-DAD global cognitive score analysed by excluding any tests determined pre-hoc to depend on visual acuity.

The purpose of this study is to compare the results of vision tests that are algorithmically derived and delivered through a virtual reality headset with those delivered through the existing technology standards (eg. Humphrey for field tests). Tests that the researchers will be conducting include vision field perimetry, Amsler, acuity chart, contrast- sensitivity and currently used office tests.

The purpose of this clinical trial is to confirm the incidence and magnitude of axial length shortening after RLRL therapy in Chinese high myopia children and teenagers.

This prospective non-comparative interventional study aims to analyse the pre-operative factors affecting the range of optimal ICL vaulting. the main question is what is the correlation between age, gender, spherical equivalent, white to white, anterior chamber volume and depth and postoperative vault? participants will do preoperative investigations ( specular microscopy, pentacam and biometry ) then refractive surgery (ICL implantation) followed by follow-up visits to assess the post-operative ICL vault and visual outcome.