Active clinical trials for "Anisometropia"

Amblyopia is a developmental condition that is characterized by reduced vision of the eye due to the presence of a sensory impediment during visual development, such as strabismus (ocular misalignment) or anisometropia (unequal refractive error), occurring early in life. Recent studies in humans and animals point towards a cortical locus for the processing deficit in amblyopia, revealing sensory deficits at the signal cell level. If changes in retinal neuronal function are also present, is unknown. Like in the brain, blood flow in the retina is coupled to neuronal activity. This phenomenon has been measured by different study groups with non invasive techniques in the brain and retina. It has been shown in previous studies that stimulating the retina with diffuse luminant flickering light increases retinal vessel diameter and blood flow. However, it is unknown whether this is also the case in the retina of amblyopic eyes. Additionally, the introduction of blood oxygen level dependent (BOLD) fMRI also makes it possible to directly access the vascular response in the brain to visual stimuli. Therefore, the aim of the present study is to investigate the effect of luminant flickering light on retinal vessel diameter and retinal blood flow in subjects with amblyopia. Also, oxygen saturation in retinal vessels will be assessed as well as pattern ERG for assessment of retinal function. Additionally, a high resolution image of the visual pathway will be taken with 7 Tesla MRI to investigate whether anatomical or functional alterations are present.

Photorefractive keratectomy (PRK) with excimer laser has been used successfully to treat myopia, hyperopia, and astigmatism in adults for over 35 years. Children with high refractive errors that go untreated will develop severe amblyopia. PRK can normalize high refractive errors and potentially improve the visual acuity in affected children. The purpose of this study is to investigate whether children with high anisometropia or isoametropia with amblyopia that are nonresponsive to standard therapy and receive PRK develop better longterm visual acuity.

Anisometropic amblyopia among children in school age may affects quality of life and educational progress of children.

This was a randomized, masked, controlled study of the effect of a virtual reality, binocular, 3-dimensional video game on visual acuity and stereopsis in adult patients with amblyopia. The trial has been halted as of June 2016 and will not be evaluating any new subjects for enrollment.

The purpose of this study is to determine the safety, efficacy, predictability, and stability of laser in situ keratomileusis (LASIK) to correct high anisometropia in patients 8 to 15 years old in whom conventional treatments have failed.

The purpose of this study is to compare the results of two standard treatments for amblyopia in order to find out if one is more effective than the other. Amblyopia, which develops in childhood, is also called "lazy eye," because one eye is not being used properly. The brain favors the other eye for some reason, such as crossing or turning out of the eyes, and vision in the weak eye is reduced. Amblyopia is treated by forcing the child to use the weak eye. There are two ways to do this: 1) a patch placed over the "good" eye forces the child to use the weak eye; or 2) an eye drop placed in the "good" eye once a day to blur vision in that eye makes the child rely on the weak eye. The success rates with both of these methods have been reported to be about the same; this study will try to identify if one is more effective than the other. Children will be randomly assigned by computer to one of the following two treatment methods: Patch The child initially will wear a patch over the "good" eye for 8 to 12 hours every day. If vision in the weak eye improves, the patching time will be decreased. If vision remains good after 3 months, the patching will be stopped, unless the child's doctor believes treatment should continue. If vision in the weak eye does not improve, the patching time will be increased. Eye Drops The child will be given one drop per day of atropine in the "good" eye. If vision in the weak eye improves, the drops will be given less often. If the vision remains good after 3 months, the drops will be stopped, unless the child's doctor believes treatment should continue. If the initial daily drop does not improve the vision in the weak eye, the child's eyeglasses may be changed to try to further blur the vision in the "good" eye. After 6 months, treatment may be stopped if it has not been successful. If treatment has been successful after 6 months, it may be continued at a reduced amount or stopped. Follow-up visits will be scheduled every 4 weeks for the first 6 months and every 2 to 4 months after that until the end of the 2-year study. During each visit the eyes will be examined for eye movements and vision, and the pupils will be dilated to examine the inside of the eye.

The purpose of this study is to establish if LFR-260 (investigational device) is not inferior in effectiveness to a traditional phoropter (control device) when applied in visual acuity test in subjects undergoing a full routine eye examination. LFR-260 proposes to provide information of the visual capabilities of the patient. The test will be provided and supervised by a qualified eye care provider. The informed consent, screening, randomization (into the order of visual test device used), (visual) device testing (to include precision testing, remote and offsite testing) will all occur at a single visit.

INTRODUCTION. Amblyopia is defined as the loss of visual acuity (VA) in one or both eyes, without any obvious structural or pathological anomalies. Amblyopic eye should be able to regain some VA if treatment is initiated before the age of seven. It is the leading cause of monocular blindness in the 20- to 70-year olds with prevalence 2-5%. Amblyopia is mainly monocular, hence children are general asymptomatic. VA testing is the only reliable method of detecting amblyopia, and the fourth year of life is considered best for vision screening programs. AIM: The purpose of the study is to reduce the preventable vision loss. The main goal of the study is to evidence the problem of amblyopia in Zagreb and to release a model for formal, government directed vision-screening program as a Croatian public health policy. HYPOTHESIS. In Croatia, the prevalence and actual effect of amblyopia and amblyogenic factors, along with treatment efficacy is impossible to quantify, since no population-based studies have been performed regarding this issue. In addition, national screening of preschool children does not exist, while the school-entry screening is prescribed by law. The object of the study is to determine the prevalence of amblyopia in a 4-4.5 year old children of The Town of Zagreb, the efficacy of screening and effectiveness of treatment on reducing amblyopia prevalence. The primary hypothesis is defined: screening of visual acuity monocularly at distance and near in 4-4.5 year old children in Zagreb is effective in detecting amblyopia. PATIENTS AND METHODS: Monocular vision of about 7000 children/ year aged 4-4.5 for whom both parents gave consent is to be tested with Lea chart at near (40cm) and distance (3m) in the kindergartens of The Town of Zagreb. The criterion for referral to complete ophthalmological examination is VA <0.8.

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.

Recently, there has been an increased interest in evaluating binocular therapies (e.g perceptual learning and dichoptic treatment) for amblyopia. They are designed to improve amblyopia through binocular stimulation by unlocking binocular visual function. The objective of the study is to compare the visual and sensory outcome of 2-hour patching to dichoptic stimulation using virtual reality head mounted display in the management of patients with moderate anisometropic amblyopia. The investigators will include children older than 6 years and adults up to the age of thirty five years with anisometropic amblyopia who either had no prior treatment for amblyopia or had prior treatment for amblyopia using patching therapy but with residual amblyopia defined as >= 0.3 logMAR lines between the best-corrected visual acuity in the sound eye and in the amblyopic eye and with moderate amblyopia in the more anisometropic eye defined as best-corrected visual acuity better than 6/60 but =< 6/18. Patients will be randomized into 2 groups according to age using stratified randomization: Group P: (Patching Group): This group will have 2 hours of patching each day for 10 weeks. Group D (Dichoptic Group): This group will have 1 hour of dichoptic stimulation using the virtual reality system twice a week for 10 weeks for a total of 20 hours of training.