[Critical assessment of light reflection rheography. Comparative studies of phlebodynamometry using invasive measurement of venous pressure, photoplethysmography and light reflection rheography].Dtsch Med Wochenschr. 1985 Nov 22; 110(47):1817-20.DM
In chronic venous insufficiency, phlebodynamometry by invasive venous-pressure measurement demonstrates a reduced pressure drop and an accelerated pressure rise, resulting from the action of the ankle-joint-calf muscle "pump". On the other hand, light-reflexion rheography and photoplethysmography can measure only the duration of the refilling period. Simultaneous measurements were made on 47 legs after phlebography (normal: 8; side-arm varicosities: 17; long-saphenous insufficiency: 15; postthrombotic syndrome: 7). Refilling time by photoplethysmography correlated better with that measured invasively than by light-reflexion rheography. Refilling half-time cannot be measured accurately with either noninvasive method. Sclerosing treatment of single side-branch varicosities in ten legs demonstrated that merely measuring refilling time (invasively or noninvasively) was not sufficient, because this value did not indicate any improvement in haemodynamics even after successful treatment.