To the Editor.
—Current standard corneal transplantation techniques use circular, round, mechanical trephines either operated by hand or motor driven, under visual control through the operating microscope. The anatomic and functional results of this sight-improving procedure are acceptable.1 The two major problems of the procedure are disturbing astigmatism and immunologic graft rejections. Excessive corneal astigmatism and optical irregularities are caused by incongruent cut surfaces of donor and patient corneas and disparities in corneal thickness.1 Immunologic graft rejection occurs in 10% of avascular corneas and increases in frequency in vascularized corneas and as the diameter of the corneal graft increases.While for optical purposes it is desirable to have the corneal graft as large as possible, immunologic requirements aim for the opposite result.The ultraviolet excimer laser technique enables us to overcome the mechanical limitations of the trephination procedure and to produce noncircular trephinations.2,3 We now introduce a
Lang GK, Naumann GO, Koch JW. A New Elliptical Excision for Corneal Transplantation Using an Excimer Laser. Arch Ophthalmol. 1990;108(7):914-915. doi:10.1001/archopht.1990.01070090016004