Decreased mean, diastolic arterial pressure tied to faster RNFL loss

Lower mean (MAP) and diastolic arterial pressure (DAP) during follow-up significantly correlate with faster rates of retinal nerve fibre layer (RNFL) loss when adjusted for intraocular pressure (IOP), reports a study.

This finding suggests that levels of systemic blood pressure (BP) may be a significant factor in glaucoma progression, according to the investigators.

This retrospective cohort study analysed a total of 7,501 eyes of 3,976 patients with glaucoma or suspected of glaucoma followed over time from the Duke Glaucoma Registry. The investigators used linear mixed models to examine the effects of BP on the rates of RNFL loss from spectral-domain optical coherence tomography (SD-OCT).

Models were adjusted for IOT, gender, race, diagnosis, central corneal thickness (CCT), follow-up time, and baseline disease severity.

Overall, 157,291 BP visits, 45,408 IOP visits, and 30,238 SD-OCT visits were included in the analysis. The mean rate of RNFL change was ‒0.70 μm/year (95 percent confidence interval, ‒0.72 to ‒0.67). In univariate models, MAP, DAP and systolic arterial pressure (SAP) during follow-up did not significantly correlate with rates of RNFL loss.

However, after adjusting for mean IOP during follow-up, each 10-mm Hg decrease in mean MAP (‒0.06 μm/year; p=0.007) and mean DAP (‒0.08 μm/year; p<0.001) significantly correlated with faster rates of RNFL thickness change over time, but not SAP (‒0.01 μm/year; p=0.355).

The effect of arterial pressure metrics persisted even after additional adjustment for baseline age, diagnosis, sex, race, follow-up time, disease severity, and corneal thickness.