A comparison between laser interferometric measurement of fundus pulsation and pneumotonometric measurement of pulsatile ocular blood flow 1. Baseline considerations

Purpose Several methods have been proposed for the investigation of the human choroidal circulation. The aim of the present study was to compare laser interferometric measurements of cardiac synchronous fundus pulsations with pneumotonometric measurements of intraocular pressure pulse and pulsatile ocular blood flow in humans. Methods The association between fundus pulsation amplitude as assessed with laser interferometry and pulse amplitude (PA) and pulsatile ocular blood flow (POBF) as assessed with pneumotonometry was investigated in 28 healthy subjects. Additionally, we investigated the distribution of fundus pulsation amplitude (FPA) in a region of -15 degrees to +15 degrees around the macula (n = 18) and the influence of accommodation paralysis with cyclopentolate on FPA (n = 10). Results There was a high association between FPA and PA (r = 0.86, p < 0.001) and FPA and POBF (r = 0.70, p < 0.001). Fundus pulsations in the macula were significantly smaller than in the optic disc, but significantly larger than those in peripheral regions of the retina. Administration of cyclopentolate did not influence FPA. Conclusions On the basis of the strong correlation between laser interferometric measurements of FPA and pneumotonometric measurements of PA and POBF, we conclude that the FPA is a valid index of pulsatile choroidal perfusion in humans.