Circadian Rhythm Disruption in Bilateral Optic Neuropathies

Recent work has indicated that optic neuropathies can cause death of melanopsin-expressing photosensitive retinal ganglion cells (pRGCs), which entrain mammalian circadian rhythms and align the sleep-wake cycle. It remains unknown whether optic neuropathies cause measurable disruption of sleep or circadian rhythms in humans. We performed a cross-sectional study to evaluate the impact of bilateral optic neuropathies, on subjective and objective measures of sleep quality and circadian rhythms.

269 Circadian rhythm disruption in bilateral optic neuropathies Jovi Wong 1, Neda Pirouzmand 2, Kaitlyn Ramsay 1, Michael Balas 3, Milena Cioana 1, Sabrina Hundal 1, Aaditeya Jhaveri 4, Jonathan Micieli 1 University of Toronto, 2 Temerty Faculty of Medicine University of Toronto, 3 Temerty Faculty of Medicine, University of Toronto, 4 University of Toronto, Temerty Faculty of Medicine 1 Introduction: Recent work has indicated that optic neuropathies can cause death of melanopsin-expressing photosensitive retinal ganglion cells (pRGCs), which entrain mammalian circadian rhythms and align the sleep-wake cycle. It remains unknown whether optic neuropathies cause measurable disruption of sleep or circadian rhythms in humans. We performed a cross-sectional study to evaluate the impact of bilateral optic neuropathies, on subjective and objective measures of sleep quality and circadian rhythms. Methods: Adult patients with confirmed diagnoses of unilateral or bilateral optic neuropathies were recruited. Subjective sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI), a validated sleep questionnaire. Participants were asked to complete ≥ 14 days of continuous non-invasive wristwatch actigraphy, which measures locomotor activity as a surrogate for sleep and activity rhythms. Interdaily stability, which measures the degree of regularity in the activity-rest cycle, was measured from 0 to 1. A value of 0 indicates a total lack of regularity, while 1 indicates a perfectly stable rhythm. Total sleep time, sleep efficiency (total sleep time/time in bed), sleep latency, fragmentation index (degree of sleep fragmentation), and intra-daily variability (degree of fragmentation of activity-rest periods) were also assessed. Results: 19 patients with bilateral optic neuropathies (mean age 48±22 years, 50% female) and 12 patients with unilateral optic neuropathies (mean age 54±16 years, 58% female) completed actigraphy. Bilateral patients (n=19) demonstrated significantly lower interdaily stability than unilateral patients (n=10) (mean difference -0.111; 95% CI: -0.196 to -0.026; p=0.013). Total sleep time, sleep efficiency, sleep latency, fragmentation index, intra-daily variability and PSQI scores were not significantly different between groups. Linear regression analysis confirmed the difference in interdaily stability after adjustment for age and gender. Conclusions: Bilateral optic neuropathy patients demonstrated significantly reduced interdaily stability compared to unilateral optic neuropathy patients, indicating measurable circadian rhythm dysfunction. References: None provided. Keywords: Optic neuropathy Financial Disclosures: The authors had no disclosures. Grant Support: None. Contact Information: Jovi Wong, [e-mail] 2024 Annual Meeting Syllabus | 429