Blood pressure, ocular perfusion pressure, and body mass index in glaucoma patients

Purpose: To investigate relationships between blood pressure (BP), ocular perfusion pressure (OPP), and intraocular pressure (IOP) in patients with open-angle glaucoma (OAG) of different body mass index (BMI) classes. Methods: Data from participants of a prospective, longitudinal, single site, observational study were analyzed. Patients with a prior diagnosis of OAG completed 2 baseline visits (1 week apart) with follow-up visits every 6 months for 2 years. At each visit, BP, weight, height, and IOP were recorded for normal-weight (BMI 18.5-24.9; n = 38), overweight (BMI 25.0-29.9; n = 43), and obese (BMI ≥30; n = 34) patients: The BP was measured using automated ambulatory measurements after 5 minutes rest and IOP was measured using Goldmann applanation tonometry. Results: The IOP decreased from baseline to 2-year measurement in normal-weight (-1.5, 95% confidence interval [CI] -2.7 to -0.4), overweight (-1.9, 95% CI -3.4 to -0.4), and obese (-2.5, 95% CI -3.9 to -1.2) patients with OAG. Systolic BP (SBP) and OPP decreased from baseline to 2-year measurement in all 3 BMI categories, although not reaching statistical significance. In normal-weight patients, there was a significant, positive correlation between changes in IOP and SBP (r = 0.36, p = 0.0431). A significant, negative correlation was observed between changes in IOP and OPP in overweight (r = -0.56, p = 0.0002) and obese (r = -0.38, p = 0.0499) patients. Conclusions: This study demonstrated that in normal-weight individuals with OAG, changes in SBP were positively correlated to changes in IOP. However, this relationship did not exist for overweight or obese patients. Instead, overweight and obese patients displayed a negative correlation between OPP and IOP.