Binocular reading in children following extraction of a dense congenital or infantile unilateral cataract

Abstract

Reading relies on ocular motor function, requiring sequential eye movements (forward and regressive saccades). Binocularly discordant input from a dense congenital or infantile cataract is associated with ocular motor dysfunction and may affect the development of reading ability. The purpose of this study was to assess silent, binocular reading in children treated for unilateral congenital or infantile cataract. Twenty school-age children (age range, 7-13years) treated for unilateral congenital (n=9) or infantile (n=11) cataract and 49 age-similar control children silently read a grade-appropriate paragraph during binocular viewing. Reading rate (words/min) and the number of forward and regressive saccades (per 100 words) were recorded using the ReadAlyzer. Reading rate in children treated for a unilateral cataract did not differ significantly from controls (174±59 words/min vs 195±54 words/min; P=0.1). However, they did have significantly more forward saccades (101±33 saccades/100 words vs 87±21 saccades/100 words; P=0.03) but not regressive saccades (21±14 saccades/100 words vs 16±8 saccades/100 words; P=0.1) compared with controls. Reading rate was not related to cataract type (congenital vs infantile), visual acuity outcome (poor vs good), or sensory fusion (fail vs pass; all P≥0.1). Reading rate of children treated for a dense unilateral cataract did not differ from that of controls. Increased forward saccades during reading may be due to fixation instability associated with fusion maldevelopment nystagmus prevalent in children following cataract extraction.