Age-Related Changes of Intraocular Pressure in Elderly People in Southern China: Lingtou Eye Cohort Study

Abstract

PurposeTo study age-related changes of intraocular pressure (IOP) and assess the cohort effect in both cross-sectional and longitudinal settings among elderly Chinese adults.MethodsParticipants were enrolled from the Lingtou Eye Cohort Study with Chinese government officials aged 40 years and older at baseline and received physical check-up and ocular examinations from 2010 to 2012. IOP was measured using a non-contact tonometer according to standardized protocols, as well as systolic blood pressure (SBP), diastolic blood pressure (DBP) and body mass index (BMI). Participants who had attended IOP measurements in both 2010 and 2012 were included in this study. Cross-sectional association of IOP with age was assessed using multivariate liner regression analyses and based on the data of 2010. Longitudinal changes in IOP were assessed by paired t-test.ResultsA total of 3372 subjects were enrolled in the current analysis (2010 mean [SD] age, 61.9 [7.1] years; 60.2% men). The mean IOP in 2010 was 15.4±2.3 mmHg for women and 15.2±2.3 mmHg for men with an intersex difference (P = 0.029). Cross-sectional analysis showed that IOP was negatively associated with age (P = 0.003, β = -0.033 for women and P<0.001, β = -0.061 for men) adjusted for baseline SBP, DBP and BMI. Paired t-test suggested that IOP was higher in the year 2012 than 2010 in women (P = 0.006) but did not change significantly in men within 2 years (P = 0.345). In addition, the 2-year changes of IOP were not associated with age adjusted for baseline IOP in 2010 (P = 0.249).ConclusionCross-sectional data suggests that IOP is lower in people with older age. Longitudinal data does not support such findings and thus the identified decreasing pattern with age in cross-sectional analysis is likely caused by cohort effects.

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

“…Mean IOP reported in our study (15.3 AE 3.0 mmHg at baseline) was similar to that reported in other studies based on Chinese populations (15.6 AE 3.0 mmHg in Beijing and 15.3 AE 2.3 mmHg in Guangzhou, using a noncontact pneumotonometer), 18,25 and higher that reported in Japan (11.9 AE 2.5 mmHg, using a noncontact tonometer) and Korea (13.6 AE 2.5 mmHg, using automated non-contact tonometers). 11,13 This discrepancy on IOP distribution may be attributable to ethnicity and different methods of tonometry are used.…”

“…31 Multiple previous studies, either cross-sectional or longitudinal in design, had reported that a higher BMI was associated with a higher risk of glaucoma. 33 Based on our findings and other related longitudinal studies in China, 18,22,25 we suggest that higher BMI could lead to an increase in IOP in Chinese population, and this could be part of reason that younger generations had higher IOP compared to the elderly in cross-sectional analysis. 16 However, data from the Nurses' Health Study and the Health Professionals Follow-up Study showed that women with a higher BMI had a lower risk of primary open angle glaucoma.…”

“…Greater BMI and CCT, as well as self-reported hypertension were associated with a higher IOP in the baseline analysis, which was consistent with other crosssectional studies in the literature. 22,25 This pattern of change suggests that an increase of IOP is the authentic pattern of IOP change with aging, whereas the observed IOP reduction with age in cross-sectional analysis is likely due to cohort effect, for example, the younger birth cohorts have higher IOP in comparison to the older cohorts. Interestingly, we had identified similar results based on another longitudinal cohort of adult population in Southern China, apparent reduction in IOP with age in cross-sectional analysis and an increase of 0.43 mmHg (95% confidence interval, 0.36-0.50) in IOP over 5 years.…”

“…Interestingly, we had identified similar results based on another longitudinal cohort of adult population in Southern China, apparent reduction in IOP with age in cross-sectional analysis and an increase of 0.43 mmHg (95% confidence interval, 0.36-0.50) in IOP over 5 years. 22,25 This pattern of change suggests that an increase of IOP is the authentic pattern of IOP change with aging, whereas the observed IOP reduction with age in cross-sectional analysis is likely due to cohort effect, for example, the younger birth cohorts have higher IOP in comparison to the older cohorts. In the existing literature, longitudinal studies on age-related IOP changes have mainly been based on Caucasian and African populations, and reported an overall increasing trend of IOP with age.…”

Aqueous humour dynamics and biometrics in the ageing Chinese eye

“…Following age-based stratification, the Beijing Eye Study reported an IOP decline over time but only after 75 years of age 42. In the Lingtou Eye Cohort Study,43 a cross-sectional analysis revealed age-associated IOP reduction that was negated by a longitudinal analysis uncovering a possible cohort effect. The effect of age on IOP depends on one’s ethnicity and associated ocular or systemic conditions.…”