[Skip to Content]
[Skip to Content Landing]
Original Investigation
October 2018

Frequency of Visual Deficits in Children With Developmental Dyslexia

Author Affiliations
  • 1Department of Ophthalmology, Boston Children’s Hospital, Boston, Massachusetts
  • 2Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
  • 3Department of Anesthesiology, Boston Children’s Hospital, Boston, Massachusetts
  • 4Department of Surgery, Boston Children’s Hospital, Boston, Massachusetts
  • 5Department of Anesthesia, Harvard Medical School, Boston, Massachusetts
  • 6Division of Psychology, Department of Psychiatry, Boston Children’s Hospital, Boston, Massachusetts
  • 7Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
JAMA Ophthalmol. 2018;136(10):1089-1095. doi:10.1001/jamaophthalmol.2018.2797
Key Points

Question  Are deficits in visual function more frequent in children with developmental dyslexia than in typically developing readers?

Findings  In this cohort study, school-aged children with developmental dyslexia exhibited more deficits in visual function—vergence, accommodation, and/or ocular motor tracking—than did a nonrandomized control group of typically developing children.

Meaning  These findings suggest that visual function deficits contribute to reading acquisition in children with developmental dyslexia.

Abstract

Importance  Developmental dyslexia (DD) is a specific learning disability of neurobiological origin whose core cognitive deficit is widely believed to involve language (phonological) processing. Although reading is also a visual task, the potential role of vision in DD has been controversial, and little is known about the integrity of visual function in individuals with DD.

Objective  To assess the frequency of visual deficits (specifically vergence, accommodation, and ocular motor tracking) in children with DD compared with a control group of typically developing readers.

Design, Setting, and Participants  A prospective, uncontrolled observational study was conducted from May 28 to October 17, 2016, in an outpatient ophthalmology ambulatory clinic among 29 children with DD and 33 typically developing (TD) children.

Main Outcomes and Measures  Primary outcomes were frequencies of deficits in vergence (amplitude, fusional ranges, and facility), accommodation (amplitude, facility, and accuracy), and ocular motor tracking (Developmental Eye Movement test and Visagraph eye tracker).

Results  Among the children with DD (10 girls and 19 boys; mean [SD] age, 10.3 [1.2] years) and the TD group (21 girls and 12 boys; mean [SD] age, 9.4 [1.4] years), accommodation deficits were more frequent in the DD group than the TD group (16 [55%] vs 3 [9%]; difference = 46%; 95% CI, 25%-67%; P < .001). For ocular motor tracking, 18 children in the DD group (62%) had scores in the impaired range (in the Developmental Eye Movement test, Visagraph, or both) vs 5 children in the TD group (15%) (difference, 47%; 95% CI, 25%-69%; P < .001). Vergence deficits occurred in 10 children in the DD group (34%) and 5 children in the TD group (15%) (difference, 19%; 95% CI, –2.2% to 41%; P = .08). In all, 23 children in the DD group (79%) and 11 children in the TD group (33%) had deficits in 1 or more domain of visual function (difference, 46%; 95% CI, 23%-69%; P < .001).

Conclusions and Relevance  These findings suggest that deficits in visual function are far more prevalent in school-aged children with DD than in TD readers, but the possible cause and clinical relevance of these deficits are uncertain. Further study is needed to determine the extent to which treating these deficits can improve visual symptoms and/or reading parameters.

×