27G: Development of 27G -- Differences between 27G and 25G /23G -- Disadvantages -- Advantages. Tools for 27G: Devices -- Instruments -- Future Developments / Needs. Techniques for 27G: Endoillumination -- Usage of Vitreous Cutter -- Posterior Hyaloid Detachment -- Membrane Peeling -- Delamination of Diabetic Membranes -- PVR Treatment -- Hemostasis and Marking of Retinal Tears -- Laser Treatment -- Fluid Air Exchange. Surgical Indications: Non Combined Vitrectomy -- Combined Phaco Vitrectomy -- MICVIT (Microincisional Cataract / Vitrectomy) -- Vitrectomy for Floaters -- Macular Pucker -- Macular Hole -- Vitreomacular Traction -- Dropped Nucleous -- Combined 27G PPV + Secondary IOL implantation -- Retinal Detachement -- Diabetic Retinopathy -- Silicone Oil Tamponade -- Silicone Oil Extraction -- Pediatric Vitrectomy -- Vitrectomy for Long Eyes -- Hybrid Procedures.