Rigidity of Retinal Vessel in Untreated Eyes of Normal Tension Primary Open-angle Glaucoma Patients

To analyze pulse wave propagation in the ocular circulation and vessel stiffness in untreated eyes of normal tension primary open-angle glaucoma (NTG) patients.Inferotemporal retinal vessels of 22 NTG eyes and 25 controls were examined with a Retinal Vessel Analyzer. Inferotemporal peripapillary retinal nerve fiber layer thickness was measured by ocular coherence tomography. Phase delay between venous trough and arterial peak was assessed at 3 sites centrifugal from the disc and a choroid-to-retina pulse delay was calculated as an estimation of vessel rigidity.There was choroid-to-retina pulse delay of 0.26±0.08, 0.30±0.11, and 0.33±0.11 seconds, respectively, in NTG eyes at proximal, middle, and distal sites; in control eyes, the corresponding values were 0.28±0.10, 0.35±0.12, and 0.40±0.17 seconds. Average choroid-to-retina pulse delay was shorter in NTG eyes (P=0.028). Retinal nerve fiber layer (inferotemporal) showed an opposite correlation with choroid-to-retina pulse delay in controls (r=-0.48, P=0.019) and in NTG eyes (r=0.47, P=0.032 ).Untreated NTG eyes show stiffer retinal vessels. Vessel rigidity correlates with level of glaucomatous damage.