Association of Blood Pressure and Retinal Nerve Fiber Layer Rates of Thinning in Patients with Moderate to Advanced Glaucoma.

PURPOSE

To investigate the influence of baseline blood pressure (BP) on retinal nerve fiber layer (RNFL) rates of change (RoCs) in glaucoma patients with central damage or moderate to severe disease.

DESIGN

Prospective cohort study.

PARTICIPANTS

One hundred ten eyes with ≥ 4 RNFL OCT scans and ≥ 2 years of follow-up.

METHODS

Global RNFL RoCs were modeled with a Bayesian hierarchical model with subject- and sector-level random effects. Influence of baseline systolic and diastolic BP measures and their interactions with intraocular pressure (IOP) on global RNFL RoCs was investigated in prognostic models adjusting for relevant baseline demographic and clinical measures.

MAIN OUTCOME MEASURES

Magnitude and direction of coefficients for BP, IOP, and their interaction for prediction of global RNFL RoCs. One-sided Bayesian P values denote posterior probability that a regression coefficient is greater than or less than zero, with P < 0.025 or P > 0.975 defining significance.

RESULTS

Average (standard deviation) 24-2 visual field mean deviation (MD) at baseline, follow-up time, and number of OCT scans were -8.8 (6.0) dB, 4.3 (0.5) years, and 8.3 (1.4), respectively. In multivariable analyses, female sex, Hispanic ethnicity (vs. White ethnicity), better baseline 24-2 MD, higher contrast sensitivity at 12 cycles per degree, presence of diabetes, and thicker central cornea predicted faster RNFL thinning. Adjusted for covariates, lower diastolic BP combined with higher IOP predicted faster RNFL RoCs. Parallel multivariable models incorporating systolic BP showed similar effects. Among various BP/IOP combinations, eyes with IOP at the 90th percentile and diastolic (systolic) BP at 10th percentile demonstrated the fastest RNFL thinning rates (-0.554 and -0.539 μm/year).

CONCLUSIONS

Low BP and higher IOP at baseline predicted faster (worse) RNFL RoCs in glaucoma patients with central damage or moderate to advanced disease. Although there may be potential benefits to BP management in glaucoma patients, the therapeutic value of BP manipulation in glaucoma patients is yet to be established given the proven benefits of tight BP control in reducing cardiovascular morbidity and mortality.

FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.