• Forty-six patients were examined in a prospective, randomized clinical study to compare the use of the same size trephine on both donor and recipient with the use of a 0.5-mm larger trephine on the donor in aphakic keratoplasty and in keratoplasty combined with lens extraction. The results showed no statistically significant difference in refractive error, either in spherical equivalents or in astigmatism. The larger donor tissue may have some value in reducing high plus-refractive error and in reducing intraocular pressure after surgery.
Randall J. Olson, Thomas P. Mattingly, Stephen R. Waltman, Herbert E. Kaufman. Refractive Variation and Donor Tissue Size in Aphakic KeratoplastyA Prospective Randomized Study. Arch Ophthalmol. 1979;97(8):1480–1481. doi:10.1001/archopht.1979.01020020142011