Intraocular Pressure and Its Relation to Climate Parameters—Results From the Gutenberg Health Study

PURPOSE: To investigate the association between intraocular pressure (IOP) and climate parameters. METHODS: The Gutenberg Health Study (GHS) is a population-based cohort study in Mainz, Germany. Participants underwent two comprehensive ophthalmologic examinations (baseline visit and five-year follow up) including non-contact tonometry, objective refraction, pachymetry, perimetry, and fundus imaging in the time frame of 2007 to 2017. The respective climate parameters were assessed at the University Mainz including temperature, air humidity, and air pressure. Associations of IOP and climatic parameters were computed using component models and cross-correlation plots. Multivariable regression analysis was performed to adjust for age, sex, body mass index, diabetes, central corneal thickness, and systolic blood pressure. To further explore the link between systolic blood pressure, temperature, and IOP, an effect mediation analysis was conducted. RESULTS: A total of 14,632 participants (age 55 ± 11 years at baseline, 49.1% female) were included in this analysis. Mean IOP was 14.24 ± 2.8 mm Hg at baseline. There was a similar periodic change in IOP and in temperature, as shown in the component models. IOP was not associated with air humidity. In univariable and multivariable regression analyses we found a significant association between lower IOP during the summer months with higher air temperature (B = −0.011, P < 0.001). This could be partially explained in mediation analysis by lower systolic blood pressure at higher air temperature. Furthermore, IOP was associated with air pressure in univariable (B = 0.005, P = 0.04.) and multivariable models (B = 0.006, P = 0.03). CONCLUSIONS: There is a periodic annual change of IOP with higher values in winter and lower values in summer supporting the hypothesis of an impact of environmental temperature on IOP, which is partly mediated by lower systolic blood pressure in summer.