Active clinical trials for "Exotropia"

Aim 1: To determine whether use of dichoptic movies for 4 weeks may be helpful in improving control of alignment in children with intermittent exotropia (IXT), thus allowing IXT to be managed non-surgically Aim 2: To determine pre-IXT surgery use of dichoptic movies for 4 weeks post-operatively may be helpful in maintaining successful control of alignment in children who have surgical correction of IXT

The main objective of this randomized trial comparing vision therapy to observation is to determine the short-term effectiveness of vision therapy on distance intermittent exotropia control. The results will help determine whether to proceed to a full-scale, long-term randomized trial.

The study aims to investigate ocular motor and sensory outcomes of two different strategies of lateral rectus recession; symmetric and asymmetric, in management of basic type intermittent exotropia with ocular dominance.

The purpose of this study is to determine the long-term effect and security of the surgical treatment and observation only on ocular alignment, binocular stereopsis, and quality of life in children with moderate intermittent exotropia.

Determine whether full-time patching is more effective than observation for improving distance control of IXT after 3 months of treatment (on-treatment outcome).

This study intends to determine the number and percent of subjects initially diagnosed with divergence excess exotropia which would be reclassified as simulated divergence excess exotropia if tested after 24 hours of monocular occlusion (patching) or after prism adaptation for the distance angle.

The current measurement methods of strabismus include the corneal light reflection method, prism alternate covering, etc., which especially rely on the subjective experience of doctors, and there is a large error between different measurers， leading to serious underestimation of strabismus prevalence and insufficient care for strabismus patients. Here, the investigators established and validated an artificial intelligence system to achieve an automatic diagnosis of strabismus based on patient-sourced videos of programmatic cover tests. Three-dimensional reconstruction methods are used to digitize the parameters of head and eye positions. This system has been integrated into a smartphone platform to be further validated through hospital-based and population-based clinical trials.

Atropine is a non-selective muscarinic acetylcholine (M) receptor antagonist that paralyzes the ciliary muscle, dilates the pupil, and reduces the power of accommodation. Current studies have confirmed the effect of low concentrations of atropine drops in slowing the progression of myopia. In the atropine treatment for myopia (ATOM2) study, there was a rapid and dose-dependent decrease in accommodation after atropine drops: after 2 weeks of use, accommodation decreased from baseline 16.2D to 11.3D (4.9D) in the 0.01% atropine drops group, from baseline 16.7D to 3.8D (12.9D) in the 0.1% atropine group, and from baseline 15.8 D to 2.2 D (13.6 D) in the 0.5% atropine group; one year after withdrawal, there was some recovery of the accommodation in all the three groups, but it was still lower than the baseline values for each group, with a mean decrease of 2.56 D.Similar results were found in the Low-concentration Atropine for Myopia Progression (LAMP) Study by Janson C. Yam, 0.05% atropine drops reduced the accommodation by approximately 2D on average after 1 year of treatment. In general, if accommodation decreases by 2D or more compared to normal values, accommodation insufficiency is considered. There is a linkage between accommodation and convergence called accommodative convergence-to-accommodation (AC/A) which is closely related to exotropia. It was reported that the amount of accommodation required to maintain binocular fusion in patients with intermittent exotropia was greater than that of normal controls. In addition, pupil size and visual acuity are also factors that affect accommodation. In summary, the reduced accommodation amplitude, pupil dilation, and blurred near vision caused by atropine drops would affect the progression of intermittent exotropia and the ocular alignment after the surgery. In most cases, the reduced accommodation and convergence might induce exotropia, but in some patients, they may use more accommodative stimuli to compensate the insufficiency of accommodation, and there may be an increase in convergence or even esotropia. Taken together, due to the effect of atropine drops on pupil size, near visual acuity, and accommodation amplitude, the investigators hypothesize that atropine drops are likely to affect binocular vision and ocular alignment in patients with exotropia and exophoria.

The aim of this study is to evaluate the techniques of combined lateral rectus muscle recession with hang back and combined lateral rectus muscle recession with z-tenotomy in correcting large-angle exotropia.

This is a multi-center, randomized double-blind controlled trial to compare the effectiveness of S-BLR with C-BLR for the treatment of CI-IXT in children. Specific Aim 1 (Primary): To compare the surgical successful rate of S-BLR with C-BLR for the treatment of CI-IXT in children. Specific Aim 2 (Secondary): To study the suboptimal surgical outcomes between S-BLR and C-BLR for the treatment of CI-IXT in children.