Keratoplasty has been successfully employed to remedy certain corneal defects, but only a moiety of procedures have been devised to meet the indications present in anterior staphyloma. When a protruding but circumscribed corneal ectasia has proved to be more or less obstructive to the vision, and the remaining tissues of the globe have not been seriously involved in the pathologic process, conservative surgery demands that a mobile globe shall be preserved, and, whenever it is possible, that a modicum of useful vision shall be secured.
To meet these indications I devised, in 1895, a simple form of corneal excision, which I have designated as trefoil keratectomy. It is adapted chiefly to those cases in which a limited portion of the cornea is staphylomatous and in which correction of the ectasia can be made by the removal of a three-leaved flap from the lower part of the pendulous cornea (Fig. 1).
ZIEGLER SL. TREFOIL OR STELLATE KERATECTOMY FOR ANTERIOR STAPHYLOMA. JAMA. 1914;LXIII(10):839-842. doi:10.1001/jama.1914.02570100025007