Pulsatile movement of the optic nerve head and the peripapillary retina in normal subjects and in glaucoma.

PURPOSE To measure the pulsatile movement of neuroretinal tissue at the optic nerve head synchronous with the cardiac cycle. METHODS We used a noninvasive imaging device based on Fourier domain low-coherence interferometry to measure the pulsatile movements of the optic nerve head, peripapillary retina, and cornea with submicron accuracy along a line across the fundus. We also measured the change in the Axial Distance between the peripapillary Retina and the base of the optic disc Cup (ADRC) during the cardiac cycle. Twelve normal subjects and 20 subjects with open-angle glaucoma were tested. RESULTS In normal subjects, the mean fundus pulsation amplitude (defined as the fundus movement minus the simultaneous corneal movement) were 13.0 ± 2.5 μm, 9.0 ± 2.1 μm, and 8.7 ± 2.9 μm at the base of the optic nerve head cup, the nasal peripapillary retina, and the temporal peripapillary retina, respectively, compared with 16.7 ± 6.8 μm, 17.3 ± 10.9 μm, and 12.7 ± 6.2 μm for the corresponding values in the glaucoma group (P = 0.26, P = 0.008, and P = 0.12, respectively). The mean changes in ADRC during the cardiac cycle in normal subjects were 10.7 ± 2.1 μm and 11.6 ± 1.8 μm for the nasal and temporal side of the optic disc, respectively, compared to 14.9 ± 5.6 μm and 14.0 ± 4.9 μm in glaucoma subjects (P = 0.03 and P = 0.10, respectively). CONCLUSIONS There was an approximately 11-μm pulsatile change in the ADRC in normal subjects, and on the nasal side of the disc, this amount was significantly greater in glaucoma patients.