Frequency of Visual Deficits in Children With Developmental Dyslexia

Raghuram, Aparna; Gowrisankaran, Sowjanya; Swanson, Emily; Zurakowski, David; Hunter, David G.; Waber, Deborah P.

doi:10.1001/jamaophthalmol.2018.2797

Cited by 43 publications

(70 citation statements)

References 35 publications

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“…Children with developmental dyslexia in general show an increased prevalence of visual deficits including accommodative dysfunction, 21 and the prevalence of AI in children with learning difficulties was reported to be 26%. 22 Similarly, children with Down syndrome are found to have poorer accommodative amplitudes for their age, resulting in a high prevalence of AI ranging between 55% and 76%.…”

Section: Methodsmentioning

confidence: 99%

<p>Accommodative Insufficiency: Prevalence, Impact and Treatment Options</p>

Hussaindeen¹,

Murali²

2020

OPTO

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Purpose Accommodative insufficiency (AI), defined as the inability to stimulate accommodation in pre-presbyopic individuals, has gained much attention over recent years. Despite the enormity of the available information, there is a significant lack of clarity regarding the criteria for definition, methodology adopted for testing and diagnosis, and the varied prevalence across the globe. This review aims to gather evidence that is pertinent to the prevalence, impact and efficacy of available treatment options for AI. Methods PubMed, Google Scholar and Cochrane Collaboration search engines were used with the keywords prevalence, accommodative insufficiency, symptoms, plus lens, vision therapy and treatment. Peer-reviewed articles published between 1992 and 2019 were included in the review. After reviewing the studies for study methodology and robustness, 83 articles were chosen for this literature review. Results The prevalence of AI ranges between <1.00% and 61.6% across studies. The prevalence shows considerable variation across ethnicities and age groups. There is significant variation in the study methodology, diagnostic criteria and number of tests performed to arrive at the diagnosis. Not many studies have explored the prevalence beyond 20 years of age. The prevalence of AI is high among children with special needs. There is no high-quality evidence regarding the standard treatment protocol for AI. Both vision therapy and low plus lenses have shown efficacy in independent studies, and no studies have compared these two treatment options. Conclusion The understanding of AI prevalence is currently limited owing to the lack of a standard set of diagnostic criteria and wide variations in the study methodology. There is a lack of high-quality evidence suggesting the best possible treatment for AI. The current gaps in the literature have been identified and future scope for exploration is elucidated.

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Section: Methodsmentioning

confidence: 99%

<p>Accommodative Insufficiency: Prevalence, Impact and Treatment Options</p>

Hussaindeen¹,

Murali²

2020

OPTO

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“…Both subtests are also a good indication of the level of academic performance 5 , 13 , 14 , reading rate 6 , 15 – 17 , and speed of visual processing 10 . Additionally, children with dyslexia perform worse than typically developing readers 18 . For these reasons, the horizontal and vertical DEM can still be useful in clinical settings when a quick assessment of visual functioning is required 10 , 19 .…”

Section: Introductionmentioning

confidence: 99%

Visual fixations rather than saccades dominate the developmental eye movement test

Tanke

Barsingerhorn

Boonstra

et al. 2021

Sci Rep

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When children have visual and/or oculomotor deficits, early diagnosis is critical for rehabilitation. The developmental eye movement (DEM) test is a visual-verbal number naming test that aims to measure oculomotor dysfunction in children by comparing scores on a horizontal and vertical subtest. However, empirical comparison of oculomotor behavior during the two subtests is missing. Here, we measured eye movements of healthy children while they performed a digital version of the DEM. In addition, we measured visual processing speed using the Speed Acuity test. We found that parameters of saccade behavior, such as the number, amplitude, and direction of saccades, correlated with performance on the horizontal, but not the vertical subtest. However, the time spent on making saccades was very short compared to the time spent on number fixations and the total time needed for either subtest. Fixation durations correlated positively with performance on both subtests and co-varied tightly with visual processing speed. Accordingly, horizontal and vertical DEM scores showed a strong positive correlation with visual processing speed. We therefore conclude that the DEM is not suitable to measure saccade behavior, but can be a useful indicator of visual-verbal naming skills, visual processing speed, and other cognitive factors of clinical relevance.

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“…Dyslexia is a developmental learning disorder that emerges in childhood. The primary deficit involves problems with word recognition, decoding words, and spelling, which translates into slower reading, decreased comprehension, and even difficulty writing 1 , 2 . Though it is a prevalent condition, it is often difficult to describe a clear pathologic presentation of the disorder.…”

Section: Introductionmentioning

confidence: 99%

“…Though traditionally dyslexia has been described as a behavioral issue, there have also been studies that have shown that dyslexics do have physiologic deficits as well: they demonstrate evidence of abnormal visual processing, including abnormal saccadic and vergence eye movements, and visual rehabilitation has been recommended for decades to improve symptoms in dyslexic adolescents 1,[10][11][12][13][14][15] . Though dyslexia is considered a learning disability rooted in phonologic processing deficits, and though studies have shown physiologic problems in coordinating eye movements, there has been no longitudinal or randomized interventional trial that has demonstrated whether these physiologic problems are the consequence of poor reading and spell problems, or the cause of these issues.…”

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confidence: 99%

Differential diagnosis of vergence and saccade disorders in dyslexia

Ward

Kapoula

2020

Sci Rep

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Previous studies suggest vergence and saccade abnormalities in dyslexic adolescents. However, these studies are mainly clinically based and do not provide objective measurements of eye movements, but rather subjectively evaluate vergence using haplosopic conditions in which the two eyes are dissociated (via polarizers, prisms, or intermittent spectacles). Other studies have identified deficits with binocular coordination during reading in dyslexics. Yet, there are few studies that provide objective measurements of eye movements in the dyslexic population to help provide more information regarding if these deficits could be due to an intrinsic motor problem or if they are the consequence of poor reading. 47 dyslexic adolescents (18 female, 29 male; mean age 15.5) and 44 non-dyslexic adolescents (22 female, 22 male; mean age 14.8) wore a head-based eye tracker (PupilCore, Pupil Labs, Berlin) which recorded wide angle saccade and vergence eye movements at 200 Hz. Tests were run using the REMOBI device, which produced a saccade or vergence audiovisual target. Analysis of eye movements was performed with lab-developed software, AIDEAL. The results showed statistically significant abnormalities in vergence and saccades. In vergence, dyslexics displayed a reduced amplitude of the visually driven portion of convergence and a longer duration in the initial phase of divergence. In saccades, dyslexic adolescents demonstrated slower saccades in both directions. They also had an increased disconjugate drift in the first 80 or 160 ms following saccades to the right, suggesting poor binocular coordination. For both vergence and saccades, the peak velocity and time to peak velocity was higher and earlier, respectively, in non-dyslexics compared to dyslexics; yet the average velocity of both movements was lower in dyslexics. Thus, these results indicate peculiar velocity profiles in dyslexics, particularly a slow deceleration phase in both vergence and saccades. The study provides an objective method to diagnose vergence and saccade abnormalities while viewing targets in the real three-dimensional space in a dyslexic population. Vergence abnormalities are demonstrated to be a problem in dyslexics, occurring independently from reading. We hypothesize these disconjugate drifts following saccades are the result of slow vergence capacity. Rehabilitation programs, such as those using REMOBI, should aim to target these deficits in vergence velocity, as this has been shown to improve binocular control.

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Frequency of Visual Deficits in Children With Developmental Dyslexia

Cited by 43 publications

References 35 publications

<p>Accommodative Insufficiency: Prevalence, Impact and Treatment Options</p>

<p>Accommodative Insufficiency: Prevalence, Impact and Treatment Options</p>

Visual fixations rather than saccades dominate the developmental eye movement test

Differential diagnosis of vergence and saccade disorders in dyslexia

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