The corneal endothelium is incapable of proliferation. When the cellular pump function drops below the minimum capacity to maintain deturgescence of the stroma, corneal edema ensues. For half a century, the only successful treatment of endothelial failure has been full-thickness penetrating keratoplasty. Penetrating keratoplasty has many well-known operative and postoperative challenges. One of the most vexing has been the slow recovery of vision postoperatively, often reaching a suboptimal plateau marked by spectacle acuity below the retinal potential, high amounts of astigmatism, irregular astigmatism (now more accurately known as high-order aberrations), and ongoing difficulties with suture loosening and vascularization, infection, and dehiscence of the incision. While long-term clarity of corneal grafts is typically high, the quality of vision often does not match the appearance at the slitlamp examination. An all-too-frequent observation is that a skilled contact lens fitter is a corneal surgeon's best friend.
Steinert RF. Posterior Lamellar Endothelial KeratoplastyCorneal Transplantation and Refractive Surgery Intersect. Arch Ophthalmol. 2008;126(2):263-264. doi:10.1001/archophthalmol.2007.57