Evaluation of the ganglion cell layer thickness in children with attention deficit hyperactivity disorder and comorbid oppositional defiant disorder

Object: We aimed to compare the Retinal Nerve Fiber Layer (RNFL), ganglion cell layer (GCL), and the optic nerve thicknesses (ONT) of children diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) to a healthy control group; and the possible worse effect of the Oppositional Defiant Disorder (ODD). Methods: 31 patients, (n=16 ADHD and n=15 ADHD+ODD) and a control group of 31 participants included. The Conners' Teachers Rating Scale and the Conners' Parent Rating Scale were used for the severity of the symptoms in children. Ophthalmologic measurements performed with optic coherence tomography device. Results: In this study, different ophthalmologic measurements (RNFL, GCL and optic nerve thicknesses) are compared between ADHD children and controls. Results show primarily bilateral thinner GCL in ADHD children compared to controls, which is the first demonstration. Optic nerve thicknesses of right eye inferior quadrant and left eye superior quadrant, as well as mean optic nerve thickness of left eye, and furthermore both eyes total GCL thickness measurement averages with also their thicknesses in superior, inferior area of patient group were found as statistically lower (p<0,05) than control group. The measured thinning of RNFL wasn't statistically significant for both eyes in patient group. Discussion: In patients diagnosed with ADHD, thinning of the GCL and optical nerve thicknesses were found statistically significant compared to the control group, whereas the thinning of RNFL was only numerical. ODD comorbidity was thought to have no additional effect on thinning. This may lead to the idea that the negative effect of the ODD on the neurodegenerative process may be assessed with larger sample studies.