Data from: Quantitative analysis of fundus-image sequences reveals phase of spontaneous venous pulsations

Purpose: Spontaneous venous pulsation correlates negatively with elevated
intracranial pressure and papilledema, and it relates to glaucoma. Yet,
its etiology remains unclear. A key element to elucidate its underlying
mechanism is the time at which collapse occurs with respect to the heart
cycle, but previous reports are contradictory. We assessed this question
in healthy subjects using quantitative measurements of both vein diameters
and artery lateral displacements; the latter being used as the marker of
the ocular systole time. Methods: We recorded 5-second fundus sequences
with a near-infrared scanning laser ophthalmoscope in 12 young healthy
subjects. The image sequences were coregistered, cleaned from
microsaccades, and filtered via a principal component analysis to remove
nonpulsatile dynamic features. Time courses of arterial lateral
displacement and of diameter at sites of spontaneous venous pulsation or
proximal to the disk were retrieved from those image sequences and
compared. Results: Four subjects displayed both arterial and venous
pulsatile waveforms. On those, we observed venous diameter waveforms
differing markedly among the subjects, ranging from a waveform matching
the typical intraocular pressure waveform to a close replica of the
arterial waveform. Conclusions: The heterogeneity in waveforms and
arteriovenous phases suggests that the mechanism governing the venous
outflow resistance differs among healthy subjects. Translational
relevance: Further characterizations are necessary to understand the
heterogeneous mechanisms governing the venous outflow resistance as this
resistance is altered in glaucoma and is instrumental when monitoring
intracranial hypertension based on fundus observations.