[Fluid-gas exchange in vitreous surgery using the BIOM, VPFS and SDI wide-angle observation systems]

The wide-angle observation systems for vitreous surgery introduced by Spitznas and Reiner (BIOM, VPFS, and SDI) have the following advantages: (1) wide angle of view, (2) large depth of field, (3) stereopsis, (4) good visualization in hazy media (5) upright, true-to-side image, (6) magnification with the microscope zoom, (7) beam splitter for the assistant, (8) good visualization in gas-filled or silicone-filled eyes, (9) free mobility of the eye for peripheral surgery. With these systems, surgery is possible from the posterior pole to the vitreous base and the anterior loop traction, regardless of whether the eye is phakic, pseudophakic, or aphakic. This is not possible with conventional contact lenses for vitreous surgery.