Purpose: Endothelial graft rejection and intraocular pressure elevation are the most common causes of graft failure following penetrating keratoplasty (PK). Aim of this study was to evaluate the visual rehabilitation and the development of intraocular pressure during and after graft rejection.
Patients and methods: The study included 20 eyes of 20 patients (age 54.7 +/- 19.8 years) with endothelial graft rejection, that fulfilled the following inclusion criteria 1) graft rejection was diagnosed and treated in our department; 2) at least one year follow-up after graft rejection; 3) avascular corneal pathology. The mean follow-up was 23 +/- 14 months. According to the type of surgical procedure patients were classified in PK only (n = 15, one after cataract extraction), PK combined with extracapsular cataract extraction and intraocular lens (IOL) implantation (n = 1); PK combined with secondary IOL-implantation or IOL-exchange (n = 4). Standardized complete ophthalmological examinations were performed on a regular basis before, during the acute graft rejection und then regularly in a defined examination raster in an out-patient service with cornea specialization.
Results: The time interval between first symptom of 18 acute diffuse and 2 chronic focal graft rejection and start of treatment was 9 +/- 13 days. Best-corrected visual acuity (CVA) was 0.6 +/- 0.2 before graft rejection and decreased significantly at the time of diagnosis (0.2 +/- 0.2; p = 0.001). Six weeks after graft rejection CVA was 0.5 +/- 0.2 and remained almost stable until one year after rejection (0.6 +/- 0.3) in 16 patients with reversible graft rejection. Only 4 patients (20%) showed an irreversible graft failure requiring Re-PK. Intraocular pressure (IOP) was not elevated in 75% of the patients (n = 15) and did not need any antiglaucomatous treatment during and after the rejection phase. In 5 eyes (25%) (3 after PK combined with anterior chamber IOL-explantation and secondary posterior chamber IOL-implantation; 1 with secondary pseudoexfoliation glaucoma and 1 steroidal responder) IOP was elevated during graft rejection (26 +/- 7 mmHg), but was controlled by intensive topical antiglaucomatous treatment.
Conclusion: Typically, the visual rehabilitation after graft rejection was good if the clinical signs were diagnosed just in time and treated adequately. There is no direct correlation between graft rejection and intraocular pressure elevation. However, the development of intraocular pressure elevation seems to be strongly associated with preexisting glaucoma, preexisting anterior synechiae and/or simultaneous anterior chamber lens implant removal. A careful patient management after PK plays an important role to prevent the development of irreversible graft failure due to graft rejection.