Active clinical trials for "Refractive Errors"

The investigators compared long-term refractive and biometric outcomes in children with retinopathy of prematurity who received two different anti-vascular endothelial growth factor agents.

The investigator want to determine the refractive status of 80 children with disabilities and of 81 healthy children from a witness group. The vitamin D level of the children will be dosed for making different correlations with visual acuity status.

The purpose of this study is to determine the average values of human ocular biometry and to correlate these values with visual function.

Self evaluating tools based on smartphone devices are public available on the market for each person. The tools are used to estimate the existing refractive error for each eye of a patient. Hereafter, e.g. ordering glasses via internet could be the next step for this persons. The daily routine within an eye hospital shows, that estimation of the refractive error is a difficult and time consuming procedure. The study compares the results of the measured refractive error using a smartphone based tool with the results of conventional measurement methods.

The purpose of prospective cohort study is to estimate the rate of change in postoperative change after primary IOL implantation among children with congenital cataract(CC) and to explore key factors associated with the rate of change.

To evaluate the refractive outcomes of cataract surgery in PEX syndrome and determine which of the commonly used IOL formulas (SRK/T, Barrett Universal II and Hill-RBF) is the best in predicting postoperative refractive outcomes in PEX.

To investigate the relationship between axis length (AL) and refractive error. eyes of low hyperopia to emmetropia subjects, comprising eyes with moderate to high myopia (-11.00D ≤ SE ≤ -4.00D) were analyzed in this cross-sectional study. Cycloplegic refractive error was measured with the autorefractor, AL was measured with the IOL master. Association between AL and refractive error were evaluated by linear regression analysis. The mean of AL and its correlation with SE, sex, and age were evaluated.

Corneal topography allows the measure of the radii of curvature and of the thickness of the cornea. It is essential for diagnosis in ophthalmology and allows to highlight corneal irregularities such as a keratoconus, or too thin corneas which are a contra-indication for laser refractive surgery. Several types of corneal topographers are commercially available. Some as the Orbscan(r), operate by analyzing the image of the patterns of a Placido disk associated with a light slit, allowing the collection of thousands of points of the anterior and posterior surface of the cornea. More recent systems such as the Pentacam(r) are based on automatic rotary cameras which capture images of the whole anterior segment of the eye. The aim of this study is to compare two topographs, the Pentacam(r) and the Orbscan(r) and, more specifically, the central corneal pachymetry measurements measured pre- and postoperatively.

Myopia has emerged as a major health issue in east Asia, because of its increasingly high prevalence in the past few decades (now 80-90% in school-leavers), and because of the sight-threatening pathologies associated with high myopia, which now aff ects 10-20% of those completing secondary schooling in this part of the world. Similar, but less marked, changes are occurring in other parts of the world. The higher prevalence of myopia in east Asian cities seems to be associated with increasing educational pressures, combined with life-style changes, which have reduced the time children spend outside.

The present research process is a prospective, non-interventional clinical study that will be conducted -under the auspices of the Democritus University of Thrace (DUTH)- in the pre-school students of the city of Alexandroupolis, Greece. The study aims to assess the visual acuity of the kindergarten students. The measurement of monocular best-spectacle corrected visual acuity will be performed using a web-based visual acuity chart