Abstract
Purpose :
To analyze the impact of ratio of graft size to recipient corneal size and graft decentration on the frequency of endothelial immune reactions (IR) after penetrating keratoplasty (PKP).
Methods :
We analyzed eleven years of our longitudinal PKP database at the Department of Ophthalmology in Homburg/Saar (2009-2019). This retrospective study included 2160 patients. Two types of IR were observed: acute diffuse or chronic focal endothelial reaction. The patient age ranged from 1 to 95 years. Microsoft Access and SPSS version 25 were used for statistical analysis and the corneal measurements were performed with ImageJ. With this software we measured the area of the graft and the host cornea as well as the distances between the interface and the limbus at four points (12, 3, 6 and 9 o'clock).
Results :
A total of 203 (9.4%) patients presented with an IR (158 (7.1 %) acute diffuse and 50 (2.3 %) chronic focal). The IRs happened on average 14.9 months after PKP for acute diffuse IR and 15.3 months after PKP for chronic focal IR. There were no discernible differences between males and females. There was no significant correlation between donor age and frequency of IR. The smaller the size of the graft, the lower the likelihood of an IR (p< 0.0001). A significant correlation between centration from the graft and an IR was found: the smaller the distance between the graft and the limbus (at 12, 3, 6, and 9 o'clock), the higher the likelihood of an immune reaction (p< 0.01). Moreover, the strongest correlation appeared at the inferior limbus (6 o'clock) (p< 0.0001).
Conclusions :
The monitoring in the second postoperative year after PKP should be intensified to detect an IR early. The bigger the size of the graft in relation to the host and the smaller the distance from the limbus, especially at 6 o'clock, the higher the likelihood of an immune reaction. Therefore, the graft size should be adjusted individually to the size of the host cornea. Further advanced methods (possibly intraoperative) for the limbal centration of the graft will be needed, in order to minimize future risk factors of immune response and to improve the postoperative outcome.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.