Clinical Characterization of Oculomotricity in Children with and without Specific Learning Disorders

Abstract

Children with specific learning disorders have been associated with oculomotor problems, with their analysis even suggested to be a potential diagnostic tool. A prospective non-randomized comparative study evaluating 59 children (6–13 years old) divided into three groups was conducted: a control group (CG) including 15 healthy emmetropic children; a group of 18 healthy children with oculomotor abnormalities (OAG); and a group of 26 children diagnosed with specific learning disorders (LDG). In all groups, besides a complete eye exam, oculomotricity was characterized with two clinical tests: Northeastern State University College of Optometry’s Oculomotor (NSUCO) and Developmental Eye Movement (DEM) tests. Concerning the NSUCO test, lower ability, precision, and head/body movement associated scorings were obtained for both smooth pursuits and saccades in OAG and LDG when compared to the CG (p < 0.001). Likewise, significantly longer time needed to read the horizontal sheet of the DEM test and a higher DEM ratio were found in OAG and LDG compared to CG (p ≤ 0.003). No differences between LDG and OAG were found in the performance with the two oculomotor tests (p ≥ 0.141). Oculomotor anomalies can be present in children with and without specific learning disorders, and therefore cannot be used as diagnostic criteria of these type of disorders.

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

“…The results of the current study in terms of oculomotricity are consistent with those reported by previous authors [ 4 , 5 , 6 , 7 , 31 , 32 , 33 , 34 , 35 ]. Mahone et al [ 5 ] found deficits in oculomotor response (response inhibition) in 60 children with ADHD compared with 60 controls.…”

“…A great variety of scientific studies have confirmed the presence of significant alterations in oculomotricity in children with neurodevelopmental disorders [ 4 , 5 , 6 , 7 , 31 , 32 , 33 , 34 , 35 ]. However, these altered oculomotor patterns are not specific to this type of disorders [ 4 ], as they are also present in healthy children, and they have the potential to affect reading [ 36 ]. Therefore, children with oculomotor alterations and reading problems cannot be diagnosed as having a neurodevelopmental disorder, such as dyslexia, as the diagnosis of this type of conditions is very complex and requires a multidisciplinary approach [ 17 ].…”

“…Dyslexia was present in 15 children, ADHD in 7 children, and a diagnosis of the motor disorder DCD was made in the remaining 6 children. According to previous studies, these children were expected to have oculomotor abnormalities in most cases [ 4 , 5 , 6 , 7 , 8 , 9 ]. The same exclusion criteria as those used in the other two groups were considered.…”

“…Among neurodevelopmental motor disorders, DCD is characterized by deficits in the acquisition and execution of coordinated motor skills, and is manifested by clumsiness and slowness or inaccuracy in the performance of motor skills that cause interference with activities of daily living [ 1 ]. All these neurodevelopmental conditions have been associated with different alterations of ocular movements with potential impact on learning and reading activities [ 4 , 5 , 6 , 7 , 8 ], leading in some cases to the establishment of incorrect causal relationships [ 9 ], even though reading difficulties are not relevant for the diagnostic criteria of DCD or ADHD [ 1 ]. Furthermore, there are even doubts about the most adequate criteria for diagnosing oculomotor alterations in this type of disorders [ 9 ].…”

Spotlight on the Developmental Eye Movement (DEM) Test

“…Some procedures, such as gross observations of eye movements, have found a relationship with reading disability. 26 , 27 Compared to the DEM test, the gross observation of eye movements is considered to have a different accuracy (see validity paragraph below). The NSUCO (Northeastern State University College of Optometry) 26 oculomotor test is a standardized method and scoring of observational eye movement testing (saccades and pursuit).…”