Overview
- A nationwide analysis by Northwestern Medicine, published in Scientific Reports, found up to a roughly 30% higher risk of new retinal vascular disease in the month after the spring move to daylight saving time and about a 20% lower risk in the month after the fall return to standard time.
- The team analyzed insurance claims for more than 18 million commercially insured adults aged 18 to 64 from the Merative MarketScan database for 2012–2014 to identify new diagnoses of retinal artery occlusion, retinal vein occlusion, proliferative diabetic retinopathy and neovascular age-related macular degeneration.
- The largest relative increases after the spring transition occurred for proliferative diabetic retinopathy and neovascular age-related macular degeneration, while the fall return showed lower incidence across several retinal vascular conditions.
- Authors warn the study is observational, depends on claims data rather than clinical measures, covers only three years of records, and therefore cannot prove cause; they call for replication in other, longer or non-overlapping datasets and for studies that measure sleep and circadian disruption directly.
- The findings build on prior evidence that short-term sleep loss and circadian misalignment raise vascular risk and could influence clinical practice and ongoing U.S. policy discussions about changing seasonal clock rules if later studies confirm a causal link.