Colder Ambient Temperatures Independently Raise Intraocular Pressure in Treated Primary Open-Angle Glaucoma

Researchers extracted 2,655 intraocular pressure readings from 154 eyes over a median five-year period and matched them to Japan Meteorological Agency data. Multivariable models adjusted for age, sex, blood pressure, heart rate, and central corneal thickness showed air temperature remained the only climatic variable independently linked to pressure elevation. The association held only among patients with advanced glaucoma or using multiple agents, suggesting disease severity modulates environmental sensitivity.

Prior seasonal studies in healthy populations reported similar winter peaks in intraocular pressure, yet this cohort isolates the effect in pharmacologically stable disease. The 1 mmHg shift is modest but clinically relevant given that each 1 mmHg sustained elevation raises progression risk by approximately 10 percent in treated eyes. Unmeasured confounders such as outdoor time, exercise, and indoor heating use limit causal inference.

Larger prospective cohorts with wearable sensors and daily pressure monitoring are required to test whether temperature-triggered pressure spikes predict visual-field loss. Regulatory and guideline bodies should consider incorporating seasonal counseling into standard glaucoma care pathways if replication confirms the signal.