Decreased sleep quality in high myopia children

Abstract

The aim of the present study was to evaluate sleep quality in myopic children and adults. This cross sectional study surveyed 486 participants aged from 10 to 59 years with refractive errors using a questionnaire containing the Pittsburgh Sleep Quality Index (PSQI) and Hospital Anxiety and Depression Scale (HADS). Children (< 20 years) in the high myopia group exhibited the poorest PSQI scores (P < 0.01), while the adults showed no such correlations. Subscales of PSQI and HADS in children disclosed that the high myopia groups had the shortest sleep duration (P < 0.01), worst subjective sleep scores (P < 0.001), and latest bedtime (P < 0.05). Regression analyses in children significantly correlated myopic errors with PSQI (P < 0.05), sleep duration (P < 0.01), and bedtime (P < 0.01). Sleep efficacy (P < 0.05) and daytime dysfunction (P < 0.05) were significantly better in contact-lens users compared to the respective non-user groups across all participants. In conclusion, sleep quality in children was significantly correlated with myopic error, with the high myopia group worst affected.

Figure 1. Schematic hypothesis of possible factors contributing to sleep disorders in high myopia.

Based on the results of the present study, we hypothesize that sleep disorders in high myopia may be associated with retinal complications and poor unaided vision. High myopia children may suffer blurring and dependence on optical correction including with spectacles and contact lenses. In addition, myopic retina is accompanied by multiple dysfunctions presumably involving intrinsically photosensitive retinal ganglion cells, although evidence is to be further confirmed in human. High myopia children might therefore, consciously or unconsciously, be affected by this distress and disability during both the daytime and night, leading to sleep disorders. ipRGC, intrinsically photosensitive retinal ganglion cell.

Figure 2. Box plots showing the distribution of Pittsburgh Sleep Quality Index (PSQI) global score in the 10–19 y/o group (a), 20–39 y/o group (b), and 40–59 y/o group (c).

Note that highly myopic children are poor sleepers with statistical significance compared with the mild myopia and non-myopia groups (*P < 0.05, Mann-Whitney U test after Bonferroni correction). The horizontal line in each diagram indicates the median score for PSQI. The height, positive error bar, and negative error bar of each box indicate the 25th–75th percentiles, maximum values, and minimum values, respectively.

Figure 3. Box plots showing the distribution of sleep duration (a), bedtime (b), and HADS score (c) in children.

Note that the highly myopic children were poorer sleepers compared with the less myopic groups (*P < 0.05, Mann-Whitney U test after Bonferroni correction). The horizontal line in each diagram indicates the median scores. The height, positive error bar, and negative error bar of each box indicate the 25–75th percentiles, maximum values, and minimum values, respectively.

Figure 4. Sleep efficacy of contact lens users.

Sleep efficacy was significantly better in contact lens users both for children (age, 15–19 years) and adults (age, 20–39 years). *P < 0.05, Mann-Whitney U test.