Variations in Macular Pigment Optical Density in Children and Adolescents Depending on Time Spent on Smartphones

Children and teenagers use electronic devices daily, especially smartphones. The use of these devices exposes children and adolescents to excess blue light, which can alter the structures of the eye, especially the retina. As a protective mechanism, the macular region contains pigments represented by lutein, zeaxanthin, and meso-zeaxanthin. In this study, we aimed to analyze the relationship between the Macular Pigment Optical Density (MPOD) levels in the macula and the time spent on smartphones in children and adolescents.

Fifty-seven children and teenagers aged between 8 and 18 were evaluated, with a total of 114 eyes. The patients included in the study were divided into two groups: those who spent less than two hours a day on the device and those who exceeded this period. To determine the amount of macular pigment, the Heterochromatic Flicker Photometry technique was used.

We found a statistically significant difference in screen time between weekdays and weekends in favor of the latter. We compared the different refractive categories with respect to pigment levels and screen time and found no significant differences between groups. When comparing the patients with respect to environment, we found a slight difference in macular pigmentation in the favor of rural areas and also in the screen time which was shorter in rural areas. We found a strong association at all levels between longer screen time (both weekdays and weekend) and lower macular pigment quantities for both eyes. When comparing the groups with more/less than 2 h of screen time, the MPOD was lower for both eyes in the group with over 2 h screen time.

In this study we demonstrated that smartphone use is a risk factor leading to a decrease in MPOD in children and adolescents. The amount of lutein in the retina, brain and serum are correlated, therefore MPOD can be considered a natural biomarker of lutein and zeaxanthin levels in the body.