As part of a prospective randomized clinical trial 179 eyes of 76 females and 103 males were included , that had primary central PK without previous intraocular surgery between 10/1992 and 12/1997 for Fuchs ' dystrophy ( diameter 7.5 mm , n = 73 ) or keratoconus ( 8.0 mm , n = 106 ) .
