Mushroom Penetrating Keratoplasty: A Narrative Review

Abstract

While full-thickness penetrating keratoplasty (PK) has seen a decline in favor of partial-thickness techniques like endothelial keratoplasty (EK) and anterior lamellar keratoplasty (ALK), PK remains indicated for corneal disease involving the entire corneal thickness. Mushroom keratoplasty (MK) is a noteworthy modification of PK, designed to combine the refractive benefits of a large-diameter anterior lamellar graft with the graft survival advantage of limited replacement of the corneal endothelium. Leveraging the use of a microkeratome, the MK donor graft can be prepared by microkeratome dissection, thereby achieving a central interface compatible with 20/20 Snellen vision. This review explores the various surgical techniques, visual outcomes, graft survival rates, and complication rates associated with MK for various indications.

Keywords: cornea; mushroom keratoplasty; penetrating keratoplasty.

Figure 1

Schematic diagram of penetrating keratoplasty (A), two-piece microkeratome-assisted mushroom keratoplasty (B), and one-piece excimer or femtosecond laser-assisted mushroom keratoplasty (C).

Figure 2

Preoperative clinical picture of a full-thickness herpetic corneal scar with extensive neovascularization. (A) Five years postoperatively, the corneal graft is perfectly clear and well adapted, with Snellen visual acuity of 20/20. (B) Ten years postoperatively, the graft remains clear, with vision maintained throughout the follow-up period (C).