View clinical trials related to Refractive Errors.
Filter by:Primary objective of this study is to compare two presbyopia correction surgical techniques, specificaly premium monovision, in which the dominant eye is corrected with an extended depth of field intraocular lens and the non-dominant eye with a trifocal diffractive intraocular lens, and the bilateral implantation of trifocal diffractive intraocular lenses.
The primary purpose of this study is to demonstrate noninferiority in the visual acuity at distance when wearing PRECISION1™ for Astigmatism (P1fA) soft contact lenses compared to another commercially available, soft toric contact lens, MyDay® toric (MDT).
Prospective, multi-center, non-interventional, randomized, comparative clinical study to identify an optimal refractive technique that provides maximum plus refractive endpoint for best corrected distance visual acuity (BCDVA).
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.
Atropine has a ciliary muscle-paralysing effect and causes hyperopic drift. Besides, atropine has been proven to slow the progression of myopia. Many studies have suggested that atropine can increase the thickness of the choroid. However, few studies have discussed changes in the ciliary muscle after treatment with atropine or other cycloplegic agents. This study aimed to assess the difference in ciliary muscle morphology before and after two different cycloplegic agents and to analyze the correlation between the changes of ciliary muscle biological parameters and the changes of eye axis, spherical equivalent, lens diopter, choroidal thickness, etc. One hundred and forty-four children would be randomly assigned 1:1 to the 1% atropine group and the tropicamide group. This study might provide clinical evidence for the role of regulatory factors in the occurrence and development of myopia.
A novel computerized visual acuity test was developed and tested on both healthy persons and patients with ocular conditions. Visual acuity outcomes of the computerized test will be compared to the Early Treatment Diabetic Retinopathy Study (ETDRS) in measures of reproducibility, accuracy and numbers of questions.
To evaluate the safety and effectiveness of Aceclidine/Brimonidine (LNZ101) compared with Aceclidine (LNZ100) and vehicle in the treatment of Presbyopia.
The purpose of this study is to assess the clinical performance of two reusable silicone hydrogel contact lenses when worn on a daily wear basis.
Retrospective collection of data from medical records, multicenter, post-market clinical follow-up study.
This study will include primary school children to evalute their refraction and follow those who will wear glasses to detect their compliance. Visual acuity will be measured using autorefractometer after cycloplegic eye drops 3 times and glasses will be prescribed for those who are needed. Follow up of the students to detect their compliance of wearing correction.