Ten-year changes of intraocular pressure in adults: the Liwan Eye Study

IMPORTANCE: Understanding the longitudinal intraocular pressure (IOP) changes and potential risk factors in adults is important for future glaucoma control in the aging society. BACKGROUND: Limited longitudinal studies exist in Asia investigating the longitudinal IOP changes and with varying results. DESIGN: Population-based cohort study. PARTICIPANTS: 1405 baseline participants from the Liwan Eye Study. METHODS: All baseline participants were invited for the 10-year follow-up examination in 2013. IOP (by Tonopen), central corneal thickness (CCT; by ultrasound), refractive error (by autorefractor), blood pressure, height and weight were measured per standardized protocol and the presence of hypertension or diabetes was collected by questionnaire. Follow-up examinations were conducted using the same equipment with proper calibration. Linear regression analysis was used to assess the association between IOP change and potential risk factors. MAIN OUTCOME MEASURES: 10-year IOP change. RESULTS: Of the 791 participants at the 10-year follow-up, IOP data were available for 602 participants with a mean age of 60.9 years (55.5% female). The average IOP change over 10 years was an increase of 1.44 mmHg (95% confidence interval, 1.12-1.75). Linear regression showed that 10-year IOP change was not associated with baseline age, gender, body mass index (BMI), CCT, spherical equivalence (SE), hypertension or diabetes. However, it was positively associated with longitudinal increase of BMI when longitudinal changes of BMI and SE were included in the model (P < 0.001). CONCLUSIONS AND RELEVANCE: We observed a small increase in IOP over 10 years in this adult Chinese population, which was positively related to the longitudinal change in BMI.