Distribution of Visual and Oculomotor Alterations in a Clinical Population of Children with and without Neurodevelopmental Disorders

Abstract

A prospective, non-randomized comparative study was conducted to compare the distribution of oculomotor and visual alterations in children with neurodevelopmental disorders and healthy children without such disorders. Sixty-nine children (aged 6–13 years) were enrolled and divided into three groups: a control group (CG) of 23 healthy children; a group of 18 healthy children with oculomotor abnormalities (OAG); and a group of 28 children with a neurodevelopmental disorder (NDDG), with 15 cases of dyslexia, 7 cases of developmental coordination disorder (DCD) and 6 cases of attention deficit/hyperactivity disorder (ADHD). Significantly worse near stereopsis was found in NDDG compared with CG (p < 0.001) and OAG (p = 0.001). Likewise, a significantly lower amplitude of accommodation was found in NDDG compared with CG in both the right (p = 0.001) and left eyes (p < 0.001). No statistically significant differences between groups were found in the measurement of near and distance phoria (p ≥ 0.557), near point of convergence (p = 0.700) and fusional vergences (p ≥ 0.059). Significantly impaired oculomotor test scores were found in NDDG compared with CG (p < 0.001), with no significant differences between OAG and NDDG (p ≥ 0.063). The comparison between the three types of neurodevelopmental disorders included revealed the presence of a significantly lower amplitude of accommodation in children with DCD compared with dyslexics. Furthermore, less exophoria at near was present in children with dyslexia compared with children with ADHD (p = 0.018) and DCD (p = 0.054). In conclusion, children with dyslexia, ADHD and DCD show an altered oculomotor pattern and a more reduced amplitude of accommodation, not always compatible with the diagnostic criteria of an accommodative insufficiency. Accommodative and binocular vision problems are not always present in these children and cannot be considered an etiologic factor.

Objective and Subjective Evaluation of Saccadic Eye Movements in Healthy Children and Children with Neurodevelopmental Disorders: A Pilot Study

“…Significant differences between CG and NDDG were found in all the categories evaluated with the NSUCO test, with worse outcomes in the group of children with neurodevelopmental disorders, as in previous studies [ 10 , 12 ]. Likewise, significant differences were found in some parameters provided by the eye tracking system, including the number of hypometric saccades and the percentage of hypometric saccades with respect to the number of completed saccades.…”

“…However, the diagnostic criteria defined for the diagnosis of these conditions are not consistent, with no normative data available to be used for diagnostic purposes [ 18 ]. Different authors [ 10 , 11 , 12 , 13 , 14 , 19 , 20 ] have demonstrated the presence of oculomotor anomalies in children with neurodevelopmental disorders, but using different types of tests, parameters and cutoff criteria, being quite difficult a generalization of the diagnostic criteria and how to use this information to analyze the impact of oculomotor anomalies in daily activities, such as reading or playing sports. Furthermore, the scientific evidence of the correlation between subjective and objective tests to analyze oculomotor performance is scarce and showing poor correlation between both types of examination [ 21 ].…”

“…A speech therapist, a psychologist and a pediatrician evaluated all of these children and made a diagnosis of NDD according to the DSM-5 criteria [ 15 ]. According to previous scientific studies, oculomotor abnormalities are expected to be present in these children [ 10 , 11 , 12 , 13 , 14 ]. No comorbidity of neurodevelopmental disorders was present in any case.…”

“…Several studies have demonstrated that oculomotricity can be limited or altered in different health conditions, including neurological [ 9 ] or neurodevelopmental disorders (NDD), such as dyslexia, attention deficit disorder (ADHD) or developmental coordination disorder (DCD) [ 10 ]. In general, problems of ability and precision of saccades have been detected in these three NDDs, with movements of body and head associated [ 10 , 11 ].…”

“…Several studies have demonstrated that oculomotricity can be limited or altered in different health conditions, including neurological [ 9 ] or neurodevelopmental disorders (NDD), such as dyslexia, attention deficit disorder (ADHD) or developmental coordination disorder (DCD) [ 10 ]. In general, problems of ability and precision of saccades have been detected in these three NDDs, with movements of body and head associated [ 10 , 11 ]. Specifically, worse binocular coordination during and after the saccade, but without a stereotyped pattern of disconjugacy (divergence during the saccade and convergence after the saccade), has been reported in children with dyslexia [ 12 ].…”