We present the results obtained after studying two groups of patients with dynamic register techniques, using A-scan, standardised A-scan following Ossoinig's procedure and B-scan. One group comprised 50 patients with retinal detachment and proliferative vitreoretinopathy while the other consisted of 15 patients with choroidal melanoma. In the group of patients with retinal detachment and proliferative vitreoretinopathy 90% of cases demonstrated waves with 100% amplitude on A-scan when the ultrasound beam was directed perpendicularly over the detached retina. Likewise in these same 90% of cases we observed a small split in the wave peak during the after movements. Conversely on B-scan 80% of these patients with retinal detachment and proliferative retinopathy showed retinal mobility. In the group of patients with choroidal melanoma rapid spontaneous movements were detected in the internal echoes on A-scan and standardised A-scan. Moreover in 3 of the 15 cases (those of greatest size) movement could also be detected on B-scan.