Purpose: To describe the technique and to evaluate the safety of protected penetrating keratoplasty (PPK).
Methods: A technique for penetrating keratoplasty is described. The postoperative endothelial cell counts of 17 eyes in which this operative technique was used were compared with those in 24 eyes in whom the standard operative technique for penetrating keratoplasty (PK) was used. The post-operative time periods were grouped as follows: 3-6 months, 7-12 months and >12 months. For statistical analysis, the Mann-Whitney U non-parametric test was employed.
Results: There was no case where tissue extrusion occurred during the procedure. The endothelial cell count was similar in both groups for the 3-6 month period (PK = 2,086, DS 566; PPK = 1,858, DS 671; p = 0.2702) and >12 months period (PK = 1,574, DS 745; PPK = 1,419, DS 810; p = 0.2882). There was a significant difference in the 7-12 month period (PK = 2,255, DS 831; PPK = 1,569, DS 623; p = 0.0397).
Conclusions: The described technique of PPK may reduce the risk of per-operative complications. Damage to the endothelium is not increased compared with that seen following the standard PK procedure.