U-Shaped Effect of Blood Pressure on Structural OCT Metrics and Retinal Perfusion in Ophthalmologically Healthy Subjects

Abstract

Purpose We wanted to investigate the association of blood pressure (BP) status with the ganglion cell-inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) thickness of nonglaucomatous eyes and to elucidate whether this effect is related to vascular metrics proxying retinal perfusion. Methods For this case-control study, we prospectively included 96 eyes of 96 healthy subjects (age 50–65) from a large-scale population-based cohort in the northern Netherlands (n = 167,000) and allocated them to four groups (low BP, normal BP [controls], treated arterial hypertension [AHT], untreated AHT). We measured macular GCIPL and RNFL (mRNFL) and peripapillary RNFL (pRNFL) thicknesses with optical coherence tomography (OCT). We estimated retinal blood flow (RBF), retinal vascular resistance (RVR), and autoregulatory reserve (AR) from quantitative OCT-angiography, fundus imaging, BP, and intraocular pressure. We compared structural and vascular metrics across groups and performed mediation analysis. Results Compared to controls, GCIPL was thinner in the low BP group ( P = 0.013), treated hypertensives ( P = 0.007), and untreated hypertensives ( P = 0.007). Treated hypertensives exhibited the thinnest mRNFL ( P = 0.001), temporal pRNFL ( P = 0.045), and inferior pRNFL ( P = 0.034). The association of GCIPL thickness with BP was mediated by RBF within the combined low BP group and controls ( P = 0.003), by RVR and AR within the combined treated hypertensives and controls ( P = 0.001, P = 0.032), and by RVR within the combined untreated antihypertensives and controls ( P = 0.022). Conclusions Inner retinal thinning was associated with both tails of the BP distribution and with ineffective autoregulation. Longitudinal studies could clarify whether these defects can explain the reported glaucomatous predisposition of these population groups.

Macular Layer Thickness and Effect of BMI, Body Fat, and Traditional Cardiovascular Risk Factors: The Tromsø Study

“…Blood pressure was inversely associated with the inner retinal layers, which is in accordance with previous studies showing thinner inner retinal layers in persons with hypertension. 30 , 38 Further, we found that women with low blood pressure had thinner GCIPL compared to women with normal blood pressure. This corresponds to results in a recent publication, whereas as noted by the authors, the female proportion in their low blood pressure group was substantially higher than in the reference group with normal blood pressure, and this complicates the interpretation of their results.…”

“…This corresponds to results in a recent publication, whereas as noted by the authors, the female proportion in their low blood pressure group was substantially higher than in the reference group with normal blood pressure, and this complicates the interpretation of their results. 30 A strength of our study was that the sample size allowed sex stratified analyses, which seems important exploring this relationship possibly related to glaucoma risk. 39 …”

“…Post hoc we explored a possible U-shaped relationship with blood pressure with details described in the Appendix ( Supplementary material ). 30 We performed sensitivity analysis on the prediction model excluding persons with drusen.…”

Effects of blood pressure and arterial stiffness on retinal neurodegeneration: Cross-sectional and longitudinal evidence from UK Biobank and Chinese cohorts

“…16,17 Moreover, an inverted U-shaped association was found between BP status and GCIPLT and RNFLT, and that both hypotension and hypertension were associated with thinning of the inner retinal layers. 18 However, most of these studies were cross-sectional in nature with small samples, and only a few longitudinal studies were conducted. To the best of our knowledge, no study has specifically analyzed the association between different BP metrics and longitudinal changes in RNFLT and GCIPLT.…”

Effects of Blood Pressure and Arterial Stiffness on Retinal Neurodegeneration: Cross-Sectional and Longitudinal Evidence From UK Biobank and Chinese Cohorts

“…5,7 Moreover, an inverted U-shaped association was found between BP status and GCIPLT and RNFLT, and that both hypotension and hypertension were associated with thinning of the inner retinal layers. 8 However, most of these studies were cross-sectional in nature with small samples, and only a few longitudinal studies were conducted. 5,7 To date, no study has specifically analyzed the association between different BP metrics and longitudinal changes in RNFLT and GCIPLT.…”