Abstract
Purpose: :
To begin an examination of the relationship between visual skills and reading in elementary school children.
Methods: :
Students (N=346) in grades 3-6 attending public school in Los Angeles responded to questions on the Convergence Insufficiency Symptom Survey (CISS). Distance acuity, vergence, accommodation, and tracking skill were measured in symptomatic students (CISS > 15), and a subset of them (N=18) participated in a visual skills training program via internet at school. The training program was 30 sessions of 20 minutes each, using anaglyph technology and red/blue glasses. Results were compared to another symptomatic subset (N=30) who did not participate in training.
Results: :
45% (154/346) of the students were symptomatic for CI, a percentage that is similar to what we have found in middle schools in the same school district (41%, 191/461). Of those, about 1/3 (56/154) also failed standard school screening criteria for acuity (>20/30). Nearly all students who failed the CISS scored below "adequate" on one or more visual skill. Following visual skills training, CISS scores improved in 94% of students who participated in training (17/18), compared to 47% (14/30) of those who did not. Average CISS improvement was 11.6 points for participants and 7.8 points for non-participants. Visual skill level improved, on average, in each category. Convergence skill required more sessions to reach adequate levels than other skills. Reading fluency tests administered by the school before and after visual skill training demonstrated improvement in words read correctly per minute in 88% of participants, with magnitudes of 15 to 30% (12 words per minute, on average; p<.001). Five of 7 6th grade students continued to improve fluency by as much as 50% during the 3 months following training.
Conclusions: :
A surprisingly large proportion of students in grade 3 and beyond report symptoms on the CISS. We found that reading scores improved for over 80% of students in elementary school who had adequate acuity but were symptomatic for CISS, following training that targeted dynamic vergence, accommodation, and tracking skills. Symptoms and skill levels improved in over 90% of students. Further studies, with random assignment and matched-sample design, are needed to determine the generalizability of these results..
Clinical Trial: :
www.irb-irc.com 09041-01A
Keywords: binocular vision/stereopsis • learning