Bowman’s layer transplantation may be safer surgery for patients with advanced keratoconus

For most eyes with advanced keratoconus, penetrating keratoplasty is a bad option. It permanently weakens the cornea, precipitates cataracts, promotes glaucoma, provides an often uneven and unstable refractive surface, presents the constant risk of allograft reaction and graft rejection, and — perhaps worst of all — produces many unhappy patients, particularly if the surgery was elective and not emergently required.Nevertheless, PK so far remains the most common surgical treatment worldwide for patients with advanced keratoconus. And while alternatives to conventional PK have emerged, including deep anterior lamellar keratoplasty and new femtosecond technology for creating and shaping the donor and recipient surfaces, for the most part, these innovations have merely mitigated the impact of some of the above problems without actually solving any of them. Meanwhile, ultraviolet corneal cross-linking and intracorneal ring segments have arrived but, presently, are still limited in their application exclusively to patients with mild to moderate stage disease. What has been sorely lacking is a new treatment option for patients with advanced keratoconus that is effective and, at the same time, free from the considerable difficulties that both PK and DALK frequently entail.