Slow Reading in Children with Anisometropic Amblyopia Is Associated with Gaze Instability and Increased Saccades
Krista R. Kelly, PhD; Reed M. Jost, MS; Angie De La Cruz, BS; Lori Dao, MD; Cynthia L. Beauchamp, MD;
David Stager, Jr, MD; Eileen E. Birch, PhD
Retina Foundation of the Southwest
Introduction: Previous studies have reported slow reading in strabismic amblyopia. We recently identified amblyopia, not strabismus, as the key factor in slow reading in children (Kelly et al., 2015). To date, no studies have focused on reading in amblyopic children without strabismus. Here, we assessed whether amblyopic eye visual acuity, stereoacuity, and eye movements were related to slow reading in children with anisometropic amblyopia.
Methods: Reading was assessed in anisometropic children age 7-12 years and age-similar normal controls. Children silently read a grade-appropriate paragraph during binocular viewing while fitted with the ReadAlyzer, an eye movement recording system. Reading rate (words/min) and number of forward and regressive saccades (per 100 words) were recorded. Amblyopic eye best-corrected visual acuity (BCVA), stereoacuity and binocular gaze stability (EyeLink 1000) were also obtained.
Results: Amblyopic anisometropic children read slowly (n=24; mean±standard deviation=148±43 words/min) compared with non-amblyopic anisometropic children (n=13; 206±79 words/min, p=0.0007) and controls (n=24; 195±64 words/min, p=0.009). Non-amblyopic anisometropic children read at a comparable rate to controls (p=0.599). Slow reading in amblyopic anisometropic children was correlated with increased forward saccades (r=‒0.83, p<0.001), increased regressive saccades (r=‒0.80, p<0.001), and fellow eye gaze instability (r=-‒0.51, p=0.023). No relationships were found with BCVA (p=0.52) or stereoacuity (p=0.57).
Discussion: Slow reading in school-age children with anisometropic amblyopia is associated with impaired oculomotor function, including increased frequency of saccades and gaze instability.
Conclusion: Anisometropic amblyopia is associated with slow reading and may hinder academic success. Academic accommodations could alleviate this limitation.
References: Kelly KR, Jost RM, De La Cruz A, Birch EE. Amblyopic children read more slowly than controls under natural, binocular reading conditions. J AAPOS, 2015;19(6):515-20.