To investigate the correlation between 24-hour ambulatory blood pressure (BP) monitoring and peripapillary retinal vessel width and visual field (VF) defect progression in normal tension glaucoma (NTG) patients.

All patients were classified by 24-hour ambulatory BP monitoring as non-dipper (nocturnal dip < 10%) and dipper (nocturnal dip ≥ 10%) group. Vessel diameter, mean deviation (MD) value by VF test and VF progression from Glaucoma Progression Analysis (GPA) were compared among non-dipper and dipper groups.

Retinal arterial diameter was wider in the non-dipper group compared to the dipper group ( p = 0.015), while retinal venous diameter had no significant relationship between the two groups ( p = 0.131). The MD value at baseline and 2 years after was worse in the non-dipper group than the dipper group, respectively ( p = 0.006, p = 0.030). But, there was no significant relationship between nocturnal dip and GPA progression ( p = 0.658).

There was a statistically significant correlation between nocturnal dips and retinal arterial diameter and MD values. These results suggest that non-invasive fundus photography can predict hemodynamic features like nocturnal dip.