Pars plana vitrectomy (PPV) is a surgical technique originally introduced by Robert Machemer in 1971. The pars plana approach to the vitreous cavity allows access to the posterior segment to treat many vitreoretinal diseases. A successful vitrectomy can restore vision and improve the quality of life in patients suffering from many vitreoretinal diseases. However, the procedure can also be associated with complications. Although the chances are low when performed correctly, these complications can cause severe patient morbidity and blindness. Therefore, it is essential that clinicians have thorough knowledge regarding the topic, understand the procedure, when to use it, how to perform it, and post-operative management. A silicone oil (SO) is any liquid polymerized siloxane with organic side chains. The most important member is polydimethylsiloxane. These polymers are of commercial interest because of their relatively high thermal stability, lubricating, and dielectric properties. Ultrasound biomicroscopy (UBM) was first developed by Pavlin’s group in Canada over 30 years ago. Instead of using the 10 MHz most widely used in ophthalmic diagnostic ultrasound, UBM uses ultrasound frequencies in the 50 to 100 MHz range, allowing examination of living subsurface ocular tissues at very high resolution. UBM has found widespread usage as a method of imaging much ocular pathology, from adnexal, conjunctiva, scleral, corneal, anterior chamber to anterior vitreous and retina. However, its major contribution has been to the understanding of the structure of the anterior segment, particularly in glaucoma.