Studeny P, et al. - Experts ascertained the frequency of formation of various types of bubbles and the potential impact of donor and lamella parameters on this frequency and identified possible risk factors of unsuccessful “big-bubble” creation in preparation of pre-Descemet endothelial keratoplasty and Descemet membrane endothelial keratoplasty with peripheral stromal support. After cataract surgery, endothelial cell density, shorter DPT, and the presence of corneal scars were identified as risk factors threatening successful bubble formation. Higher donor age was the only risk factor for creating type II bubbles.