A- and B-scan characteristics of shifting fluid level

A shifting fluid level (SFL) was detected by A- and B-scans in 155 eyes. All eyes had a hemorrhage into the vitreous. In 129 of the 155 eyes (83%) the vitreous hemorrhage resulted from proliferative diabetic retinopathy. In 11 (7%) and seven eyes (5%), respectively, the hemorrhage was a complication of closed vitrectomy and scleral buckling procedures. In eight eyes (5%), the hemorrhage resulted from severe penetrating ocular trauma. The SFL was characterized by a high-amplitude echo on A-scan, and straight horizontal or vertical linear echo on horizontal or vertical B-scan, respectively. It showed a typical shift toward the most posterior portion of the globe when the eye was moved in the different positions of gaze. The SFL was overlying the retina in 150 eyes (97%) and was suspected to be subretinal in five eyes (3%). SFL represented a layer of sedimented red blood cells on the surface of the retina or choroid.