Evaluation of pupillary contraction in adult attention deficit and hyperactivity disorder and its relationship with neurodegeneration: Optical coherence tomography (OCT) study

Attention deficit hyperactivity disorder (ADHD) is a childhood-onset psychiatric disorder characterized by attention problems, hyperactivity and impulsivity. In recent years, there have been serious advances in studies to explain the etiopathogenesis of psychiatric diseases. In particular, studies with neuroimaging methods to show the neurodegenerative process have gained momentum and evidence supporting an increasing amount of neurodegeneration has been found in these studies. Based on the fact that irregular dopamine input in psychiatric disorders may also occur in retinal ganglion cells, which may cause abnormal glutamate synthesis and lead to axonal atrophy, studies are carried out with OCT in psychiatric disorders, especially in schizophrenia. Patients with ADHD have dopamine dysregulation. We aimed to visualize the neurodegeneration findings caused by dopamine dysregulation through glutamate exotoxicity in these patients with OCT, which is a noninvasive method. Based on the previous survey on sensitivity to light, in this study, we performed the measurement of pupillary diameters in patients with ADHD using the pentecam method, aiming to reveal whether the neurodegeneration of the retina affects pupil contraction and causes difficulty in adapting the eye to light compared to healthy individuals. According to DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th edition), in order for the diagnosis to be made in children and adolescents, the onset of symptoms before the age of 12, the presence of 6 or more symptoms in the areas of attention deficit and/or mobility/impulsivity, at least two different It should be observed widely in the social environment, continue for at least 6 months inconsistently with the level of development and impair functionality. For applicants aged 17 and above, the number of symptoms must be at least 5 in any field. In our study, we included those who met 5 or more of the criteria specified in DSM-5 in the patient group, and those who did not meet these criteria were included in the control group. Forty patients and 40 healthy controls who met the diagnostic criteria for ADHD evaluated with the DIVA and Turgay scales were included in this study. The patients included in the study were categorized as the predominant type and the composite type. It was found that the use of sunglasses was higher in the attention-deficit-dominated ADHD and composite ADHD groups compared to the control group, and there was a statistically significant difference. The use of sunglasses in the shade was more and statistically significant in the attention-deficit-dominated ADHD group and the combined ADHD group compared to the control group. There is no information about this in the literature, but an article published in 2014 about light sensitivity in individuals with ADHD was found to be compatible with our data. ADHD is a neurodevelopmental disorder, that is, it is present from birth. The delay or disorder in the development of the prefrontal cortex made us think that this structure, which develops from the neuroectoderm, may also cause symptoms in other tissues, and led us to measure the neuroectoderm-originated eye with OCT methods, which we think may indicate pentecam and nerve damage. When the right and left nerve fiber thicknesses were examined in the control, attention-deficit type and compound type ADHD groups, no statistically significant difference was found between the groups. However, further studies are needed in this area. In summary, nerve fiber thickness was found to be associated with light adaptation in the control group, and as nerve fiber thickness increased, adaptation to light environment and pupil diameter reduction were found to be greater. In the attention deficit dominant type group, nerve fiber thickness and adaptation to light were not found to be associated, and as nerve fiber thickness increased, adaptation to light environment and pupil diameter reduction were not found to be significant. When we look at the combined type ADHD group, although the nerve fiber thickness increased, adaptation to light was impaired and the expected pupil dilation in the absence of light did not occur and the pupil diameter decreased. In this study, nerve fiber thickness was measured with OCT in individuals with ADHD, and it was thought that although the nerve fiber thickness increased, there was deterioration in functionality in individuals with the disease, and data were obtained indicating that this neurodegeneration in the retina affects pupil contraction and causes difficulty in adapting the eye to light compared to healthy individuals. This study suggested that there may be functional disorders, if not morphological, in individuals with ADHD in tissues of common embryonic origin. In future studies, it has been shown that the functions of organs developing from a common embryonic origin should be examined with neuroradiological, neurobiological, histological and biochemical parameters. However, taking into account the patients divided into subgroups and their drug use, it was thought that studying in large samples could bring important information to the literature.