Post-Illumination Pupil Response and Sleep Quality in Patients With Glaucoma: The LIGHT Study

PURPOSE: This study aimed to investigate whether intrinsically photosensitive retinal ganglion cell function evaluated using post-illumination pupil response (PIPR) in patients with glaucoma is associated with sleep quality. METHODS: This cross-sectional study measured the PIPR in 138 patients with glaucoma (mean age, 70.3 years) using pupil diameter after red and blue light exposure. The net PIPR change was classified into three groups according to tertiles (i.e., low, intermediate, and high groups), with lower net PIPR change indicating lower intrinsically photosensitive retinal ganglion cell (ipRGC) function. Subjective and objective sleep qualities were assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire and actigraphy, respectively, with a total PSQI score of ≥6 indicating sleep disturbance. RESULTS: The prevalence of subjective sleep disturbance significantly increased with decreasing tertile groups of net PIPR change (P = 0.036). Subgroup analysis obtained the same results in the severe glaucoma group (P = 0.004) but not in the non-severe glaucoma group. In the severe glaucoma group, multivariable logistic regression analysis adjusted for potential confounders showed a higher odds ratio for subjective sleep disturbance in the low-tertile group of net PIPR compared with the high-tertile group (odds ratio = 6.22; 95% confidence interval, 1.76–21.90; P = 0.004). Significant associations between PIPR and objective sleep quality (total sleep time, sleep efficiency, and wake after sleep onset) were found in the severe glaucoma group (P = 0.015, P = 0.013, and P = 0.015, respectively). CONCLUSIONS: The PIPR in patients with glaucoma was significantly associated with decreased sleep quality, independent of potential confounders.