Abstract
Purpose: :
The 15-item Convergence Insufficiency Symptom Survey (CISS), used as the primary outcome measure in the Convergence Insufficiency Treatment Trial, has been shown to be a reliable and valid instrument for measuring symptoms in children with convergence insufficiency (CI). Survey items can be classified as either eye-related or performance-related. This report presents the most commonly reported symptoms by children with symptomatic CI; compares the frequency of eye-related and performance-related symptoms; and examines the effect of age, gender, and parent-reported ADHD on symptoms.
Methods: :
The CISS was administered to 221 children 9-17 years (mean 11.8 yrs) with symptomatic CI (near exophoria at least 4Δ greater than at distance, receded near point of convergence ≥ 6cm, and insufficient positive fusional vergence at near) at baseline. All children had 20/25 or better visual acuity with any significant refractive correction worn for at least 2 weeks.
Results: :
Approximately one-half of the children reported loss of place (50%) or concentration (45%) and re-reading the same line (45%) "always" or "fairly often" while doing near tasks. In fact, performance-related symptoms were rated significantly higher than eye-related symptoms (mean response of 2.3 vs. 1.8, p<0.001). No significant gender effect was detected (p≥0.19 for all comparisons). CISS score increased with age (p=0.046). Although there was no difference with age in performance-related symptoms (p = 0.36), a mean increase in eye-related symptoms was found with age (p=0.031). There was also a significant difference in CISS scores between children with and without parent-reported ADHD (p=0.005). Children with parent-reported ADHD rated performance-related symptoms with greater frequency (average response of 2.8 vs. 2.2, p<0.001); however, there was no difference in the frequency of eye-related symptoms (p=0.29). A greater mean response to performance- versus eye-related items was found for both children with (p<0.001) and without (p<0.001) parent-reported ADHD.
Conclusions: :
Children with symptomatic CI reported performance-related symptoms (e.g. loss of place, loss of concentration, re-reading the same line, reading slowly) significantly more frequently than eye-related symptoms (e.g. blur, headache, diplopia, or asthenopia). With increasing age, performance-related symptoms remain and eye-related symptoms increase. Clinicians should perform a targeted history which addresses both performance- and eye-related symptoms to help identify children with symptomatic CI.
Clinical Trial: :
www.clinicaltrials.gov NCT00338611
Keywords: binocular vision/stereopsis • clinical (human) or epidemiologic studies: outcomes/complications