A nationwide cohort analysis conducted in the United States has found patients have an up to 30% higher risk of developing retinal vascular disease in the month following the transition to daylight savings time in the spring.
Conversely, there’s a 20% lower risk of disease in the month following the transition to daylight savings time in autumn, study authors from Northwestern Medicine found in a study published in Scientific Reports.1
Prof Rukhsana Mirza said the study suggested “gaining an hour of sleep may be protective against disease risk”.
“Even one hour of change can impact a patient’s health and perhaps patients who are reporting new symptoms in the period after a change in time, specifically in the spring, may warrant closer evaluation,” Prof Mirza said.2
there was a roughly 20% lower risk of RVO and PDR in the month following the autumn daylight saving time transition
Circadian Rhythm Disruption
Transitions to daylight saving time have been shown to cause disruptions in circadian rhythm, the body’s 24-hour internal clock.
Prof Mirza said the retina plays an important role in circadian rhythm.
“We have seen how daylight savings time transitions, particularly the spring transition when we lose an hour of sleep, are associated with increased rates of heart attack and stroke. This led us to ask if these similar effects would be happening in the retina, which is one of the most metabolically active tissues in the body and contains some of the body’s most complex microvascular networks,” she said.
To better understand how circadian disruption impacts retinal vascular health, Prof Mirza’s team performed a retrospective analysis of health insurance claims data from more than 18 million patients aged 18–64 years who were newly diagnosed with retinal vascular disease.
The study authors found the incidence of newly diagnosed retinal artery occlusion (RAO), retinal vein occlusion (RVO), proliferative diabetic retinopathy (PDR), and neovascular age-related macular degeneration (nAMD) was determined after the autumn daylight saving time transition, spring daylight saving time transition, and a northern summer (July) or northern winter (January) control period.
The data was analysed to determine the effect of variables of interest on new-onset retinal vascular disease during one-week and one-month periods following daylight saving time transition.
From their analysis, the investigators found that with a summer control period, there was a roughly 20% lower risk of RVO and PDR in the month following the autumn daylight saving time transition.
However, there was a nearly 30% increased risk of new diagnosis of PDR and nAMD in the month following the spring daylight saving time transition.
The investigators hope the findings will prompt future studies to investigate the impact of daylight savings transitions and sleep disturbances on a more patient level.
References
- Chan KS, Cheng BT, Mirza RG, et al. Daylight saving time transition and new-onset retinal vascular disease: a nationwide cohort study. Sci Rep. 2026. doi: 10.1038/s41598-026-55281-7.
- Rohman M, Daylight saving time impacts risk of retinal vascular disease, North Western Medicine News Center, available at: news.feinberg.northwestern.edu/2026/07/17/daylight-saving-time-impacts-risk-of-retinal-vascular-disease [accessed July 2027]
