Strabism

Strabismic subjects often develop the ability to fixate on a target with either eye. Previous studies have shown that fixation-preference behavior varies systematically depending on spatial location of the target. We hypothesized that, when an eccentric target is presented, oculomotor fixation-preference in strabismus may be accounted for in a competitive decision framework wherein the brain must choose between two possible retinal errors to prepare a conjugate saccade that results in one of the eyes acquiring the eccentric target...

BACKGROUND: Amblyopia was defined as a reduction in the best-corrected visual acuity in one or both eyes with the presence of amblyogenic factors. OBJECTIVE: The aim of this work was to investigate the effect of curfews resulting from the COVID-19 pandemic on amblyopia treatment in children. DESIGN: A prospective longitudinal study. METHODS: The study was conducted in pediatric ophthalmology clinics at a tertiary hospital in Riyadh, Saudi Arabia...

Cyclic strabismus is a rare entity and is unique in that patients follow variable but reliable time cycles where they alternate between orthotropia or "straight" eyes and strabismus, most commonly in the form of esotropia. Despite many theories on the underlying etiology and unique features of this diagnosis, none have been proven and its pathophysiology remains unknown. Four cases of cyclic esotropia diagnosed by pediatric ophthalmologists have been included in this report. The ages of the patients ranged from 10 months to eight years...

INTRODUCTION: In contrast with the well-known and described deletion of the 22q11 chromosome region responsible for DiGeorge syndrome, 22q12 deletions are much rarer. Only a few dozen cases have been reported so far. This region contains genes responsible for cell cycle control, chromatin modification, transmembrane signaling, cell adhesion, and neural development, as well as several cancer predisposition genes. CASE PRESENTATION: We present a patient with cleft palate, sensorineural hearing loss, vestibular dysfunction, epilepsy, mild to moderate intellectual disability, divergent strabism, pes equinovarus, platyspondylia, and bilateral schwannoma...

BACKGROUND: Most Leber hereditary optic neuropathy (LHON) cases are bilateral and sequential; however, there are rare unilateral examples, or those in which the delay of onset of vision loss between one and the other eye is longer. In the case of presumed childhood amblyopia in one eye, vision loss in the good eye may be the only symptom of bilateral disease, which was unnoticed in the previously amblyopic eye, or a preexisting episode of LHON in the "amblyopic" eye. The clinical decision in such cases may be difficult and suggestive of other forms of atypical optic neuropathy until confirmed by genetic testing...

Dichoptic video gaming offers an alternative approach in amblyopia treatment by allowing different information to be presented in the two eyes, resulting to reduced suppression and/or enhanced fusion. The aim of this case report series is to evaluate the outcome of supervised dichoptic training, with the use of video games in a virtual reality (VR) system, on far and near visual acuity (VA), stereoacuity, and the visual evoked response of an adult and two children with strabismic amblyopia. Results suggest that despite the absence of improvement in VA following supervised dichoptic training, a remarkable increase in stereoacuity was evident with a concurrent decrease in phorias...

PURPOSE: To compare the final cycloplegic refraction of tropicamide 1% and cyclopentolate 1% in children 3 to 16 years of age with brown irides. DESIGN: Randomized, controlled, multicenter prospective clinical trial. METHODS: Included patients were randomized to either cyclopentolate 1% or tropicamide 1% in the first visit with autorefraction measurements. Each subject underwent a second cycloplegic refraction using the other agent on a separate visit with a minimum of one-week interval and a maximum of 12 weeks...

PURPOSE: To determine the frequency of potential non-strabismic accommodative-vergence anomalies (NSAVA) and investigate associations between NSAVA, refractive errors and age among children attending a paediatric ophthalmology clinic. METHODS: This study included children and adolescents aged 5-19 years attending an ophthalmology clinic with at least two follow-up visits. At their first visit, children had a comprehensive ophthalmic examination, including refractive error measurement by cycloplegic autorefraction and spectacles were prescribed if necessary...

PURPOSE: To evaluate the effect of previous orbital decompression on outcomes of rectus muscle recession surgery in patients with thyroid-associated ophthalmopathy. METHODS: This retrospective study enrolled 55 eyes of 33 patients treated in our hospital for restrictive strabismus caused by thyroid-associated ophthalmopathy. We performed muscle recession for the obviously restricted extraocular muscles, with 6 weeks of follow-up. Surgical outcomes were compared between the orbital decompression group (DG, n=15) and non-orbital decompression group (NDG, n=18)...

BACKGROUND: To evaluate factors associated with better outcomes from optical treatment alone in amblyopic children from 3 up to 7 years. METHODS: Data extracted from two studies with similar protocols, Amblyopic Treatment Studies 5 (n = 152) and 13 (n = 128) from the Pediatric Eye Disease Investigator Group database, were used to determine by regression analysis the factors associated with improvements in visual acuity in the amblyopic eye, inter-ocular visual acuity difference and stereoacuity...

BACKGROUND: Amblyopia is associated with unbalanced suppression between the two eyes. Existing clinical measures of suppression, such as the Worth 4 Dot test, provide qualitative information about suppression but cannot precisely quantify it. The Synoptophore, a well-established instrument in binocular vision clinics, has historically been used to gauge suppression qualitatively as well but has the capability to quantify suppression. We extended the capability of the Synoptophore through the development of a systematic protocol of illumination manipulation to quantify suppression in amblyopia...

Strabismus is a condition in which one or both eyes do not work in parallel or in harmony. People with strabismus have one eye looking straight ahead while the other eye looks inwards, outwards, upwards or downwards. This condition can affect both eyes. Strabismus is a common eye condition that affects about 4 % of the world's population. Tests such as Hirschberg, Cover and Krimsky are used to detect strabismus. In the Hirschberg test, a light source is held at a distance of 50 cm so that it falls on the centre of each eye...

PURPOSE: To compare amblyopia treatment outcomes between patients with neurodevelopmental disorders and their typically developing peers. METHODS: Of 2,311 patients diagnosed with amblyopia between 2010 and 2014 at Boston Children's Hospital, 460 met inclusion criteria (age 2-12 with anisometropic, strabismic, or mixed amblyopia [interocular difference (IOD) ≥2 lines]). Treatment and visual outcomes were analyzed according to neurodevelopmental status: neurodevelopmental delay (DD) versus typical development (TD)...

We report about a case of a woman in her 50s with a chondrosarcoma of the petrous apex. She has a strabism due to a right-sided amblyopia since childhood and noticed a slowly progressive squint angle in the last months. Her general practitioner (GP) referred her to an ophthalmologist who diagnosed a left abducens paresis and initiated an MRI demonstrating a mass in the left petrous apex. A transnasal endoscopic transsphenoidal biopsy revealed a grade I chondrosarcoma. The patient underwent an endoscopic transsphenoidal anterior petrosectomy approach with complete removal of the tumour...

It is generally believed that the visual acuity of an amblyopic eye cannot improve significantly in adulthood. However, there have been reports of this occurring following visual loss in the fellow eye. Best-corrected visual acuity improvement in amblyopic eyes of children with strabismic amblyopia following strabismus surgery has also been reported. We present the case of an adult whose visual acuity in his amblyopic eye improved 4 Snellen lines over 28 months following strabismus surgery.

AIMS AND OBJECTIVES: To determine the choroidal thickness (mainly subfoveal) using spectral domain optical coherence tomography (SD-OCT) in amblyopic eyes and to compare it with the choroidal thickness (CT) of healthy fellow eyes. MATERIALS AND METHODS: In this prospective study, 140 eyes of 70 patients (aged 5-40 years) with strabismic and anisometropic amblyopia were examined using enhanced depth imaging (EDI) mode in SD-OCT. The CT was measured directly below the fovea and six other locations: 500 μ, 1000 μ, and 1500 μ from fovea in both nasal and temporal quadrants...

The cone of gaze is a looker's range of gaze directions that is accepted as direct by an observer. The present research asks how the condition of mild strabismus, that is, when the two eyes point in slightly different directions, influences the cone of gaze. Normally, both eyes are rotated in a coordinated manner such that both eyes are directed to the same fixation point. With strabismus, there are two fixation points, and, therefore, two directions into which the two eyes point. This raises the question of the direction and the shape (i...

PURPOSE: Amblyopic eyes show impaired visual functions such as poor visual acuity and reduced foveal sensitivity. The purpose of this study was to determine the association between foveal threshold and visual evoked potentials (VEP) in strabismic and anisometropic amblyopia. METHODS: Forty-five subjects (age range: 7-28 years, 43.3% female) including 15 strabismic and 15 anisometropic amblyopes, and 15 age-similar control subjects participated in this study...

PURPOSE: To measure visual crowding, an essential bottleneck on object recognition and reliable psychophysical index of cortex organization, in older children and adults with horizontal concomitant strabismus before and after strabismus surgery. METHODS: Using real-time eye tracking to ensure gaze-contingent display, we examined the peripheral visual crowding effects in older children and adults with horizontal concomitant strabismus but without amblyopia before and after strabismus surgery...

(1) Background: Amblyopia is an ocular condition leading to structural and functional changes. The relationship between these changes is complex and remains poorly understood. (2) Methods: Participants included 31 children aged 5 to 9 years with strabismic ( n = 9), anisometropic ( n = 16) and mixed ( n = 6) unilateral amblyopia, and 14 age-matched non-amblyopic children. The 95% and 63% Bivariate Contour Ellipse Area (BCEA), axial length, Foveal Avascular Zone (FAZ) area, center macular thickness and volume were assessed...