Association between Days of the Week and Intraocular Pressure: Japan Ningen Dock Study

Abstract

Précis: The analysis of intraocular pressure by day of the week using the mega database showed a periodic weekly pattern with the highest value on Monday. Purpose: To evaluate intraocular pressure (IOP) by the day of the week. Patients and Methods: Annual health checkup examinees between April 2014 and March 2015 were cross-sectionally evaluated. As a result, 655,818 participants [51.5±10.5 (range, 20-96) years, 40.1% women] from 103 medical centers were included. IOP was measured using a non-contact tonometer. Mean IOPs of each day of the week were compared using multiple comparison test and multiple linear regression analysis. Wednesday was set as the reference. Moreover, weekly IOP variations stratified by sex and age were also evaluated. Results: Mean IOPs from Monday to Sunday were 13.19 ±2.97, 13.06±2.92, 13.05±2.91, 13.05±2.92, 13.12±2.94, 13.10±2.96, and 13.16±2.78 mmHg. IOP was significantly higher on Monday, Friday, and Saturday than those on Wednesday (P<0.001, P<0.001, and P=0.002). After adjusting for factors affecting IOP, the IOPs on Monday and Saturday were higher than those on Wednesday [β=0.097 (95% CI: 0.074 - 0.121), P<0.001; β=0.032 (95% CI: 0.005 - 0.059), P=0.019]. Men had significantly higher IOPs on Monday and Saturday than on Wednesday [β=0.142 (95% CI: 0.110 - 0.173), P<0.001; β=0.053 (95% CI: 0.017 - 0.089), P=0.004], whereas women did not have a significant trend. Participants aged <65 years had higher IOPs on Monday (P<0.001 in under 60 years; P=0.003 in 60–64 years), while those aged ≥65 years did not (P=0.856). Conclusion: IOP values may have a periodic weekly pattern. The high IOP on Monday was more pronounced in men aged <65 years.