Correlation between Peripapillary Atrophy and Optic Nerve Head Blood Flow in Eyes with Untreated Normal-Tension Glaucoma

Introduction: To evaluate relationships between the area and extent of peripapillary atrophy (PPA) and optic nerve head (ONH) blood flow and between PPA parameters and structural and functional damage in eyes with untreated normal-tension glaucoma (NTG). Methods: Thirty-six eyes (36 subjects) with newly diagnosed, untreated NTG were included. Correlations between PPA and ONH blood flow were examined. The PPA was examined using confocal scanning laser ophthalmoscopy, ONH was examined using laser speckle flowgraphy, and circumpapillary retinal nerve fiber layer thickness was measured using spectral-domain optical coherence tomography. Retinal function was examined using standard automated perimetry mean deviation (MD). Results: The PPA area was significantly correlated with the refractive spherical equivalent (r = -0.418, P = 0.010), mean blur rate (MBR) inside the ONH (MBRA; r = -0.394, P = 0.016), and MBR of ONH tissue (MBRT; r = -0.328, P = 0.048). Total angular extent around the ONH of PPA was significantly correlated with MD (r = -0.344, P = 0.037), MBRA (r = -0.360, P = 0.029), and MBRT (r = -0.368, P = 0.025). Multiple regression analyses revealed that PPA area significantly contributed to changes in MBRA. Total angular extent of PPA significantly contributed to changes in MBRT. Conclusions: Significant relationships between PPA and ONH blood flow parameters were identified in eyes with untreated NTG.