Pseudophakic Bullous Keratopathy
Cataract surgery causes some damage to the back endothelial layer of the cornea. This cell loss is generally less than 10%, leaving enough of endothelial cells to keep the cornea clear.
Occasionally, during complicated cataract surgery, the endothelial layer of the cornea is damaged more than usual, leaving too few cells to keep the cornea clear, and the cornea becomes swollen. This can happen even with the best of cataract surgeons and is one of the known risks of cataract surgery. This condition, called pseudophakic bullous keratopathy, is a frequent cause for corneal transplantation.