title: Volume displacement of scleral buckles.
abstract: Indentation of the eye wall by a scleral buckle displaces volume from the vitreous cavity. We developed a mathematical formula to calculate the volume displacement caused by a scleral buckle and verified the accuracy of this mathematical model by performing scleral buckles in 21 cadaver eyes and three eyes undergoing retinal reattachment surgery. A single 5-mm radial sponge of moderate height displaces about 0.2 mL of fluid and a circumferential 2.5-mm-wide band of moderate height displaces about 0.5 mL of fluid. Larger circumferential tires of 7- to 10-mm width displace 1.1 to 1.8 mL of fluid, depending on the height and configuration of the scleral buckle. A 7- to 10-mm-wide circumferential scleral buckle with a buckle height of 4 mm may displace up to 45% of the volume of the vitreous cavity. This volume displacement should be considered when injecting expansile gases or pharmacologic agents into the vitreous cavity.
mesh_terms: D001826:Body Fluids / Q000378:metabolism*; D005125:Eye Banks; D005544:Forecasting; D006801:Humans; D008954:Models, Biological; D012163:Retinal Detachment / Q000601:surgery; D012591:Scleral Buckling; D014822:Vitreous Body / Q000378:metabolism*