Abstract
Purpose:
Intraocular pressure (IOP) is a key modifiable risk factor for the development and progression of glaucoma and it is closely associated with systolic blood pressure (SBP). Central aortic systolic pressure (CASP) better reflects systemic arterial tree. The aim of this study is to examine the relationship between CASP and IOP, and to compare the strength of any association with that of peripheral blood pressure and IOP.
Methods:
Adults aged between 40 to 80 years were consecutively recruited from Singapore Chinese Eye Study (n=3353, response rate 72.8%). CASP was measured with a noninvasive wristwatch device (BPro, HealthStats, Singapore). SBP and diastolic blood pressure (DBP) were measured by using a digital automatic blood pressure monitor (Dinamap model Pro Series DP110X-RW, 100V2; GE Medical Systems Information Technologies, Inc., Milwaukee, WI, USA) and IOP using Goldmann applanation tonometry. All participants had a standardized examination including a complete ophthalmic and systemic examination. Multiple-linear regression analyses were performed to examine the relationship between CASP and IOP. Standardized regression coefficients (sβ) were calculated to compare the associations between CASP and SBP with IOP.
Results:
A total of 372 consecutive non-glaucomatous Chinese participants were analyzed. After adjusting for age, gender, body mass index, total cholesterol, use of antihypertensive medication and central corneal thickness, each 10 mmHg increase in CASP was associated with 0.32 mmHg of IOP elevation (95% confidence interval (CI): 0.10 - 0.53, sβ = 0.160, p-value = 0.004). SBP also had a positive but weaker relationship with IOP (β = 0.279, 95% CI: 0.079- 0.479, sβ=0.152, p-value = 0.006). Associations between IOP and CASP, SBP and DBP were similar in participants using anti-hypertensive medication to participant not using antihypertensive medication.
Conclusions:
Increased CASP, as measured by arterial tonometry, is associated with higher IOP. Our results strengthen the relationship between SBP and IOP. Future longitudinal studies are required to determine if a high CASP is a risk factor for raised IOP.