Comparison of Reading Speed in Patients with Strabismus versus Controls
CAPOS Award for Best Resident Paper
Authors: Sarah K. Yeo1, Daniel Lamoureux2, Vishaal Bhambhwani3.
1University of Ottawa, 2Northern Ontario School of Medicine, 3Thunder Bay Regional Health Sciences Centre.
Author Disclosure Block: S.K. Yeo: None. D. Lamoureux: None. V. Bhambhwani: None.
Title: Comparison of Reading Speed in Patients with Strabismus versus Controls
Purpose: Reading is an important visual task and affects numerous aspects of daily functioning. Research has indicated reading performance to be a strong predictor of visual ability and vision-related quality of life. Amblyopia has been shown to slow reading speed. However, there is paucity of literature regarding reading speed in individuals with strabismus without amblyopia. The purpose of our study was to compare reading speed in patients with childhood-onset strabismus without amblyopia and normal controls using the International Reading Speed Texts (IReST).
Study Design: Prospective study.
Methods: 48 participants were enrolled, including 12 patients with childhood-onset (onset <8 years of age) strabismus without amblyopia and 36 age- and education level-matched controls. Inclusion criteria were age 14-50 years, education level >9 years, primary language English, best corrected vision >20/30 distance and >N8 near in either eye. Exclusion criteria were presence of other eye conditions (other than refractive error), neurological/cognitive conditions including learning disabilities, which may impact reading speed. IReST charts were used to measure reading speed. Each participant was instructed to read two passages (passage 1 and 8) with a break of two minutes between passages, following all IReST chart instructions. Reading time was measured using a stopwatch. Reading speed in words per minute (WPM) was calculated as = (60/participant reading time in seconds) x (number of words in passage - skipped words - incorrect words).
Results: Mean age for strabismus group was 28.3 +/- 11.1 and control group was 28.2 +/- 11.0 years (p=0.96). Mean education level for strabismus group was 14.2 +/- 2.4 years and control group was 13.8 +/- 2.5 years (p=0.62). Mean reading speed for passage 1 for strabismus group was 192.0 and for control group was 220.0 WPM (p=0.01). Mean reading speed for passage 8 for strabismus group was 201.3 and for control group was 226.2 WPM (p=0.04). There was some learning effect in both strabismus (p=0.04) and control (p=0.02) groups, with reading speed for passage 8 being faster than for passage 1.
Conclusions: In patients with childhood-onset strabismus without amblyopia, average reading speed was slower compared to age- and education-matched controls. This may be due to sub-optimal coordination of eye movements. Further studies with eye tracking may help gain more insight. Strabismus, even without amblyopia, may affect reading performance and consequently vision-related quality of life.