Functional Results and Graft Failure after Repeat Keratoplasty

Abstract

Background and Purpose Keratoplasty is the oldest and most successful transplantation method in man. Despite the immunological privilege of the cornea, the graft fails in up to 10 % of patients, depending on corneal disease, quality of donor tissue and patient compliance, and repeat keratoplasty may then be necessary. The aim of this study was to verify factors which affect the functional result and graft survival after repeat keratoplasty. Patients and Methods In this single centre, consecutive retrospective case series, patients were included who were treated at Department of Ophthalmology, Saarland University Medical Centre with repeat keratoplasty between January 1st 2001 and December 31st 2010. Data were recorded with an Access Database from the medical records and statistically analysed with SPSS 19.0. The surgical reports and the results from the follow-up examinations concentrated on visual acuity, intraocular pressure, endothelial cell density, corneal topography and tomography and corneal graft reactions. Results The results of the study showed that trephination with the excimer laser was significantly superior (p = 0.009) to mechanical trephination with a motor trephine with respect to corrected visual acuity. Corrected visual acuity after 2 years was 0.39 in the laser group, compared to 0.16 in the group with mechanical trephination. A graft diameter under 7.5 mm showed a significant negative impact on postkeratoplasty astigmatism (p = 0.004). After a follow-up period of 120 months, the rate of immunological graft rejection was 20/60 % (p = 0.259) in the patient group with graft diameters ≤ 7.5 mm/> 7.5 mm, respectively. Conclusion The present study shows that repeat keratoplasty using excimer laser gives better functional rehabilitation, if corneal morphology permits this (for example, the vascularisation). However, the trephination method has no significant impact on graft survival. The basic principle for repeat keratoplasties is that the diameter of the graft should be as great as possible but as small as necessary.