Higher blood pressure was associated with thinning of several retinal layers. Photo: Getty Images. Click image to enlarge. 

Upon investigating the relationship between blood pressure and the thickness of different retinal layers in the macula, researchers recently found that the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL) and photoreceptor outer segment (POS) thickness was inversely associated with higher blood pressure, while inner nuclear layer (INL) thickness was positively associated. The thickness of the other retinal layers did not significantly correlate with blood pressure.

The population-based Beijing Eye Study included 2,237 participants (mean age: 61.8±8.4). Participants did not have retinal or optic nerve disease. All underwent medical and ophthalmological examinations including OCT of the macula. The team applied a multiple-surface segmentation solution to automatically segment the retina into its various layers.

Mean thicknesses of the RNFL, GCL, inner plexiform layer, INL, outer plexiform layer, outer nuclear layer/external limiting membrane, ellipsoid zone, POS and retinal pigment epithelium-Bruch membrane were 31.1μm, 39.7μm, 38.4μm, 34.8μm, 28.1μm, 79.2μm, 22.9μm, 19.2μm and 20.7μm, respectively. In multivariable analysis, higher systolic blood pressure (SBP) and diastolic blood pressure (DBP) were associated with a thinner GCL and a thicker INL, after adjusting for age, sex and axial length. Higher SBP was additionally associated with a thinner POS, and higher DBP with a thinner RNFL. A 10mm Hg elevated SBP/DBP changed the thickness of the RNFL, GCL, INL and POS by 2.0μm, 3.0μm, 1.5μm and 2.0μm, respectively.

“The findings may be helpful for refinement of the morphometric detection of retinal diseases,” the study authors concluded in their paper.

Xie H, Pan Z, Xue CC, et al. Arterial hypertension and retinal layer thickness: the Beijing Eye Study. Br J Ophthalmol. November 25, 2022. [Epub ahead of print].