Descemet's stripping automated endothelial keratoplasty (DSAEK) is a partial-thickness corneal transplant procedure that selectively replaces the diseased endothelial layer with a donor graft, offering faster visual recovery and less refractive change compared to full-thickness transplants. It is primarily used to treat endothelial dysfunction conditions such as Fuchs' dystrophy and pseudophakic bullous keratopathy.