Penetrating Keratoplasty With Minimal Endothelial Replacement: A Novel Technique for High-Risk Large-Diameter Corneal...

The purpose of this study was to analyze the outcome of large-diameter penetrating keratoplasty with minimal endothelial replacement (PKMER).

Two eyes (2 patients) with advanced keratoconus and central full-thickness pathology, namely, scar and failed graft, were studied. Both eyes had relatively healthy endothelium in the periphery. They were operated using the PKMER technique that involved a large-diameter keratoplasty with retained central island of endothelium in the donor corresponding to the visual axis, whereas the peripheral Descemet membrane was removed. In effect, the peripheral endothelium and deep stroma of the recipient were preserved. Patients were followed up using anterior segment optical coherence tomography and specular microscopy postoperatively for a minimum period of 6 months in one eye and 3 years in the other.

In both eyes, the central cornea maintained clarity throughout follow-up. The astigmatism reduced significantly, and the final uncorrected and best-corrected vision improved from hand motions close to the face to 6/12/n8 in one eye and 6/12/n12 in the other. Anterior segment optical coherence tomography in both eyes showed satisfactory apposition of interfaces at 1 month postkeratoplasty, and the same was maintained throughout follow-up. Both eyes withstood phacoemulsification for preexisting cataracts, which was performed in the second sitting after the PKMER. There were no complications noted except a temporary initial detachment of the peripheral interface in some quadrants in the early postoperative period.

PKMER may be considered as an alternative technique to large-diameter full-thickness keratoplasty. It is a relatively easier and cost-effective manual technique, which may be used as an alternative to traditional mushroom keratoplasty in selected cases.