The relationship of intraocular pressure with age, systolic blood pressure, and central corneal thickness in an Asian population

Abstract

PURPOSE. To describe the distribution of intraocular pressure (IOP) and its cross-sectional relationship to age, systolic blood pressure (sBP), and central corneal thickness (CCT) in an Asian population. METHODS. This was a population-based, cross-sectional study of 3280 Malay subjects (78.7% response) aged 40 to 80 years residing in Singapore. The participants had a standardized interview, examination, and ocular imaging at a centralized study clinic. IOP was measured with Goldmann applanation tonometry (GAT) before pupil dilation, CCT measurements were obtained with an ultrasound pachymeters, and sBP was taken with participants seated after 5 minutes of rest with an automatic blood pressure monitor. RESULTS. IOP increased with age to the sixth decade, after which a decrease in IOP was seen with further increase in age, resulting in an inverted U pattern. sBP increased linearly with age whereas CCT decreased linearly with age. In regression models, age, CCT, and sBP were all significant determinants of IOP (P < 0.001 for all three). In younger persons aged 40 to 59 years, both CCT and sBP were positively associated with IOP (P < 0.001 for both), but in older persons of 60 to 80 years, only age and sBP had a positive association with of IOP (P = 0.001 for age, P < 0.001 for sBP). CONCLUSIONS. Age, CCT and sBP are significant determinants of IOP in persons aged 40 to 80 years, with CCT being a more important determinant in younger persons. The opposing effects of age-specific changes in sBP and CCT interact to lead to a relatively flat profile of IOP with age, possibly with a subtle inverted U-shaped relationship. © Association for Research in Vision and Ophthalmology.