“…However, although it has been used for some time and there is profuse literature on its short-and medium-term results [2,3,9,22,23,24], documentation of long-term results is sparse [25], and the data that have been published are all based on average perspectives of 3-10 years following surgery [4,8,13,16,19,20,21,26,27]. While penetrating keratoplasty appears very successful with an overall 1-year survival rate as high as 90% [27], the long-term reality is that the overall success rate progressively diminishes at 5 years and 10 years [27].…”