View clinical trials related to Refractive Errors.
Filter by: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 study will investigate efficacy and safety of astaxanthin in 180 volunteers with refraction errors. Visual test, skin test, liver function test, renal function test, and adverse event will be evaluated before and after taking astaxanthin for 1 and 2 months.
Measuring parameters of anterior segment of the eye accurately is important for diagnosing variety of diseases and for cataract surgeries, glaucoma, refractive surgeries and post-operative follow-up. One of the anterior segment parameters is the anterior chamber depth. The anterior chamber depth (ACD) measurement provides valuable information in different fields in ophthalmology. Firstly, it is important for the new theoretical biometric formulas used to calculate the power of intraocular lenses (IOLs) .Secondly, phakic IOL implantation requires precise ACD measurement for both surgical planning and IOL power calculation. Thirdly, the ACD is also implicated as a screening risk factor for glaucoma. Additionally, precise ACD measurement is thought to be important to the accurate determination of the optic zone ablation diameter for keratorefractive surgery, as well as for the analysis of postoperative ACD changes. Different technologies are used in measurement of the anterior chamber depth Such as pentacam and iol maste
A holographic optical coherence tomography (H-OCT) setup is used to detect the wavefront by means of phase reconstruction.
The aim of this study is to evaluate the level of satisfaction, functional vision and quality of life outcome of patients after LASIK surgery.
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.
In this study, the investigators aim to perform a prospective, randomized controlled study to compare the myopia development between children using myopia prediction algorithm and children without using myopia prediction algorithm.
The purpose of the study is to compare the final glasses prescription based on refraction obtained with SVOne device to the final prescription obtained via subjective manifest refraction.
Wavefront scans are a common form of diagnostic test applied in preparing patients for laser eye surgery. An optical map of the eye is created by wavefront scanning, and information from these maps is used to program lasers used to correct focusing errors in the eye. Here the investigators are comparing how repeatable measurements are with a new wavefront scanner and one that is already in widespread use.