Reading ability of children treated for amblyopia

Associations between the cause of amblyopia and pre-treatment contrast sensitivity, stereoacuity, fixation, and nystagmus

Purpose

To explore the association between the cause of amblyopia and pre-treatment contrast sensitivity, stereoacuity, fixation and nystagmus.

Design

Retrospective cohort study.

Methods

A retrospective review was conducted for 3408 patients with amblyopia who had not yet started amblyopia treatment utilizing a large amblyopia patient database maintained at Zhongshan Ophthalmic Centre. Six amblyogenic factor subtypes were identified: anisometropia, isoametropia, strabismus, anisometropia and strabismus, monocular visual deprivation, and binocular visual deprivation amblyopia. Monocular best corrected visual acuity (BCVA), the contrast sensitivity function (CSF), fixation, and stereopsis were compared between the subtypes before and after propensity score matching (PSM) for age and sex.

Results

The two deprivation groups had poorer BCVA and CSF than the other groups. There were no systematic differences in CSF between the non-deprivation groups. Nystagmus was more common in the bilateral amblyopia groups compared to the monocular amblyopia groups. Eccentric fixation was uncommon with the exception of the anisometropia and strabismus group which had an eccentric fixation rate of 20%. Distance stereoacuity measured without monocular cues was absent for almost all patients. The results were consistent when analyzed using PSM.

Conclusion

Visual deprivation causes more severe amblyopia than other amblyogenic factors. For non-deprivation amblyopia subtypes, individual differences such as variation in the severity of the amblyogenic factor might be more important in determining pre-treatment vision than whether amblyopia was caused by refractive error, strabismus or both.

Motion-Defined Form Perception in Deprivation Amblyopia

Purpose

The purpose of this study was to assess motion-defined form perception, including the association with clinical and sensory factors that may drive performance, in each eye of children with deprivation amblyopia due to unilateral cataract.

Methods

Coherence thresholds for orientation discrimination of motion-defined form were measured using a staircase procedure in 30 children with deprivation amblyopia and 59 age-matched controls. Visual acuity, stereoacuity, fusion, and interocular suppression were also measured. Fixation stability and fellow-eye global motion thresholds were measured in a subset of children.

Results

Motion-defined form coherence thresholds were elevated in 90% of children with deprivation amblyopia when viewing with the amblyopic eye and in 40% when viewing with the fellow eye. The deficit was similar in children with a cataract that had been visually significant at birth (congenital) and in children for whom the cataract appeared later in infancy or childhood (developmental). Poorer motion-defined form perception in amblyopic eyes was associated with poorer visual acuity, poorer binocular function, greater interocular suppression, and the presence of nystagmus. Fellow-eye deficits were not associated with any of these factors, but a temporo-nasal asymmetry for global motion perception in favor of nasalward motion suggested a general disruption in motion perception.

Conclusions

Deficits in motion-defined form perception are common in children with deprivation amblyopia and may reflect a problem in motion processing that relies on binocular mechanisms.

Impact of strabismus and binocular dysfunctions in the developmental eye movement test and test of visual perception skills: A multicentric and retrospective study

PURPOSE

To compare the performance in the Developmental Eye Movement test (DEM) and the Test of Visual Perceptual Skills (TVPS) between three groups: individuals with strabismus and amblyopia, patients with binocular and accommodative dysfunctions, and subjects with normal binocular and accommodative function.

METHODS

A multicentric, retrospective study including 110 children aged 6-14 years old was conducted to investigate the potential impact of strabismus, amblyopia, and different binocular conditions in DEM results (adjusted time in vertical and horizontal parts) and TVPS (percentiles in the seven sub-skills).

RESULTS

No significant differences were found in the different subtests of the vertical and horizontal DEM and all the sub-skills in the TVPS between the three groups of the study. We found high variability of performance in the DEM test between participants with strabismus and amblyopia compared with binocular and accommodative problems.

CONCLUSION

DEM and TVPS scores have not been found to be influenced by the presence of strabismus with or without amblyopia, nor by binocular and accommodative dysfunctions. A slightly correlation tendency with horizontal DEM and degree of exotropia deviation was observed.

Anisometropic amblyopia: A review of functional and structural changes and treatment

Amblyopia is the decreased best-corrected visual acuity (BCVA) in one or both eyes caused by the abnormal processing of visual input during development. One common cause of amblyopia is anisometropia, which has attracted widespread attention. Many structural changes occur in the primary and extrastriate visual areas of the cerebral cortex, as well as in the eyes, in patients with anisometropic amblyopia. Understanding these mechanisms has provided a favorable theoretical basis for treating anisometropic amblyopia. This article reviews the functional and anatomical changes and progress toward the treatment of anisometropic amblyopia.

Amblyopia and the whole child

Amblyopia is a disorder of neurodevelopment that occurs when there is discordant binocular visual experience during the first years of life. While treatments are effective in improving visual acuity, there are significant individual differences in response to treatment that cannot be attributed solely to difference in adherence. In this considerable variability in response to treatment, we argue that treatment outcomes might be optimized by utilizing deep phenotyping of amblyopic deficits to guide alternative treatment choices. In addition, an understanding of the broader knock-on effects of amblyopia on developing visually-guided skills, self-perception, and quality of life will facilitate a whole person healthcare approach to amblyopia.

Reading difficulties in amblyopia: Consequence of visual sensory and oculomotor dysfunction

INTRODUCTION

Reading is a vision-reliant task, requiring sequential eye movements. Binocularly discordant input results in visual sensory and oculomotor dysfunction in amblyopia, which may contribute to reading difficulties. This study aims to determine the contributions of fixation eye movement (FEM) abnormalities, clinical type and severity of amblyopia to reading performance under binocular and monocular viewing conditions.

METHODS

Twenty-three amblyopic patients and nine healthy controls were recruited. Eye movements elicited during fixation and reading of preselected passages were collected for each subject using infrared video-oculography. Subjects were classified as having no nystagmus (n = 9), fusion maldevelopment nystagmus (FMN, n = 5), or nystagmus without structural anomalies that does not meet criteria for FMN or infantile nystagmus (n = 9). Reading rate (words/min), the number of forward and regressive saccades (per 100 words) and fixation duration (s) were computed.

RESULTS

Amblyopic patients with and without nystagmus exhibited greater vergence and fixation instability. In patients without nystagmus, the instability arises from increased amplitude and velocity of fast and slow FEMs respectively. Amblyopic patients with and without nystagmus exhibited lower reading speeds with increased fixation duration, regressive and progressive saccades than controls in all viewing conditions. Mixed etiology, greater amblyopic eye visual acuity and stereopsis deficits were associated with greater reading difficulties under binocular viewing.

CONCLUSIONS

The presence of oculomotor dysfunction and the extent of visual acuity and stereoacuity deficits contribute to reading difficulties in patients with amblyopia, with and without nystagmus. The understanding of reading difficulties is essential to devise accommodations to limit long-term academic and vocational consequences of amblyopia.

Psychosocial needs of Spanish schoolchildren with visual impairment: a mixed methods research

Abstract This study investigates the psychosocial needs of a group of schoolchildren with visual impairments. Based on a CUAN+CUAL mixed methods, it analyzed 26 children, with and without visual impairment, who attended a pediatric ophthalmology consultation with their parents. Several descriptive, mean and variance tests of independence between variables were performed using Pearson’s Chi-square (χ²) and Mann-Whitney U tests. The interviews conducted with the children and/or parents on the impact of their visual impairment on education, leisure activities and peer interaction, as well as the feelings derived from the impairment, underwent discourse analysis. Results show that schoolchildren with severe visual impairments experience greater difficulties regarding physical and emotional well-being, school performance, and peer interaction when compared with those without. These findings suggest the importance of developing comprehensive and joint health and socio-educational interventions to improve these areas.

Identificación de necesidades psicosociales de un grupo de escolares españoles con problemas visuales: un estudio con metodología mixta

Resumen Este estudio presenta un análisis de las necesidades psicosociales de un grupo de escolares españoles que padecen problemas visuales. La investigación utiliza metodología mixta aplicada en una muestra de 26 menores que acuden con sus progenitores a una consulta de oftalmología pediátrica con y sin problemas visuales. Se realizan entrevistas a los niños, adolescentes y/o progenitores sobre las repercusiones de su problema visual en el ámbito educativo, en la realización de actividades de ocio y tiempo libre y en la interacción con sus iguales, además de los sentimientos que les produce su problema visual. A los datos obtenidos se aplican análisis descriptivos, de medias, de varianza y pruebas de independencia entre variables, mediante las pruebas de chi-cuadrado de Pearson (χ²) y de U de Mann-Whitney. Los resultados encontrados indican que el grupo de escolares con problemas visuales graves tienen mayores dificultades que los que no los tienen en el bienestar físico y emocional, en el rendimiento escolar y en la interacción con los otros. Estos resultados sugieren la importancia de programar intervenciones integrales y conjuntas de carácter sanitario y socioeducativo que incidan en la mejora en cada una de las áreas de necesidad.

Analysis of the potential impact of strabismus with and without amblyopia on visual-perceptual and visual-motor skills evaluated using TVPS-3 and VMI-6 tests

PURPOSE

To investigate the potential impact of strabismus and amblyopia on visual-perceptual skills (VPS) and visual-motor skills (VMS) of patients according to the type of strabismus, visual acuity (VA), state of binocularity, and sex.

METHODS

This observational, transverse, prospective study analyzed a sample of 146 children with strabismus (88 male and 58 female) aged 5-15 years from Querétaro, México. To determine the strabismus type, we considered the deviation direction, frequency, binocularity state, and associated and dissociated elements. VPS and VMS were evaluated using the Test of Visual-Perceptual Skills 3rd ed. (TVPS-3) and Visual-Motor Integration Test of Beery 6th ed. (VMI-6).

RESULTS

Sex was the main variable associated with the performance of the analyzed patients on TVPS-3 and VMI-6 (p<0.05); boys obtained better scores than girls in all evaluated aspects. Stereopsis was not a determinant of the patients' performance level but was associated with the far and near angles of deviation in both types of strabismus, esotropia and exotropia. Amblyopia was associated with the spatial relationship (p=0.001) and visual closure abilities (p=0.044). Form constancy skill scores diminished in both types of strabismus (esotropia: p=0.011; exotropia: p=0.004), and VMS were the most affected in patients with strabismus.

CONCLUSIONS

The performance of patients with strabismus with and without amblyopia on TVPS-3 and VMI-6 suggests that they adopt a mechanism to compensate for the impact of strabismus on their VPS and VMS.

The effects of amblyopia on children's reading performance after patching treatment

PURPOSE

The purpose of this study was to evaluate the effects of amblyopia on children's reading performance after the successful patching treatment with 20/20 visual acuity (VA) in the treated eye.

METHODS

The treated amblyopes group included 10 children with strabismic amblyopia diagnosed on the first visit presenting VA equal or better than 0.0 logMAR (20/20 Snellen) in the better vision eye and VA worse than 0.2 logMAR (20/32 Snellen) in the worse eye that underwent patching treatment of amblyopia reaching a final VA  equal to  0.0 logMAR in the treated eye. The control group comprised 10 children matched by age, gender and school-grade with no visual disorders. Reading performance was evaluated according to reading acuity (RA), critical print size (CPS), reading speed (RS) at 0.7 logMAR, and maximum reading speed (MRS) using the MNREAD chart.

RESULTS

Binocular reading performance was compared between groups and no statistically significant differences were found on RA, CPS, RS, or MRS (p > 0.05). When analyzing monocular reading performances of treated amblyopes, a worse RA (p = 0.04) and CPS (p = 0.04) were observed on the previously amblyopic eye when compared to the fellow eye. When comparing the fellow eye from treated amblyopes and a randomly selected eye from controls, no statistically significant differences on RA, CPS, RS, or MRS were found (p > 0.05).

CONCLUSIONS

The results suggest that even patients who reached 20/20 VA in the treated eye after patching treatment for amblyopia may present persistent impaired reading performance. These findings reinforce the importance of reading performance testing as a tool when evaluating the visual function development in amblyopic patients.

Psychomotor, Psychosocial and Reading Skills in Children with Amblyopia and the Effect of Different Treatments

Amblyopia influences psychomotor and psychosocial skills, although not all studies are unanimous. Different treatments coexist, but the effect on those variables is not clear. This study aims to probe whether children with amblyopia have impairments in these areas and if different optometric treatments reduce them effectively. 50 children, diagnosed with amblyopia, and 33 without amblyopia participated in this study. Eye-hand coordination, psychosocial skills and reading abilities, were measured before and after three months of different treatments (patch, patch and near vision activities and perceptual learning). Results revealed lower scores in eye-hand coordination and some reading issues in children with amblyopia, without differences in psychosocial skills in regard to the control group. Moreover, optometric treatments improved eye-hand coordination.

Motor skills in children with strabismus

PURPOSE

To assess the extent to which strabismus in children was associated with motor difficulties and to examine which parameters of strabismus were most closely associated with motor development.

METHODS

The motor skills of children who were suffering from strabismus, were tested binocularly using the Movement Assessment Battery for Children, Second Edition (MABC-2) and compared with the motor performance of monocularly tested healthy controls without any ophthalmologic disease.

RESULTS

A total of 40 children with strabismus (mean, 7.25 ± 3.83 years; 19 females) and 18 controls (mean age, 8.33 ± 5.42 years; 6 females) were tested. According to the MABC-2 test, of the 40, 19 had no motor disability, and 21 were at risk of or already presented significant motor disabilities. Results of the MABC-2 were significantly lower for strabismic children without binocularity compared to those with binocularity (P = 0.002). Lack of binocularity was associated with significantly lower performance for static balance (P = 0.003) as well as for catching tasks (P = 0.042).

CONCLUSIONS

Lack of binocularity and stereopsis in children is associated with significant motor skills impairment, in particular for static balance and catching tasks. These results should be confirmed with a larger sample, including older patients, to assess the compensation mechanisms that develop with age and the actual effects of strabismus on overall motor performance.