Morphologische Kriterien der Transplantatauswahl und Verlaufskontrollen bei perforierender Keratoplastik

Impact of Pre- and Intraoperative Factors on Endothelial Cell Density in the Early and Late Stage after Penetrating Keratoplasty

AIM

This retrospective investigated the impact of donor age, recipient age, donor endothelial cell density, vis-à-tergo, and additional intraoperative lens exchange (triple-procedure) on overall early and late phase postoperative endothelial cell density (ECD) following penetrating keratoplasty (PKP) in various diagnosis groups.

PATIENTS AND METHODS

In 590 cases with diagnosed keratoconus (KC), Fuchs dystrophy (FD) and herpes simplex virus infection (HSV) who underwent PKP or triple surgery, the ECD in cells/mm² was analysed, both preoperatively, with all-sutures-in (early postoperative stage), and after last suture removal. The factors were tested by Mann-Whitney U-test, correlation analysis and linear regression analysis.

OUTCOME

Correlation analysis demonstrated a weak negative correlation between the patient's ECD and donor age (early postoperative stage: r = - 0.25, p < 0.001; after last suture removal: r = - 0.16; p = 0.003). Regression analysis revealed that donor age did not impact postoperative patient ECD. There was a weak negative correlation between postoperative ECD and recipient age (early postoperative stage: r = - 0.31, p < 0.001; after last suture removal: r = - 0.34, p < 0.001). Regression analysis confirmed the negative impact of recipient age on patient ECD (early postoperative stage: β = - 13.2, p = 0.001; after last suture removal: β = - 4.6, p < 0.001). Correlation analysis determined a weak positive correlation between postoperative ECD and donor endothelial cell density (early postoperative stage: r = 0.37, p < 0.001; after last suture removal: r = 0.32, p < 0.001). Regression analysis also determined that donor endothelial cell density had a positive impact on postoperative ECD following last suture removal (β = 0.4, p < 0.001). Vis-à-tergo and additional lens exchange (triple procedure) had no significant effect on postoperative ECD (p > 0.05). This was also confirmed by the results of the regression analysis after last suture removal.

CONCLUSION

Recipient age and donor endothelial cell density have a significant impact on postoperative ECD following PKP. Not all of the statistical tests proved donor age to be a significant influencing factor. Vis-à-tergo and additional lens exchange (triple procedure) had no significant effect on postoperative ECD following PKP.

Endothelial cell density after penetrating keratoplasty using long-time banked donor material after long distance transportation (Denmark-Sweden)

Central corneal cell density was evaluated from photographs obtained by a clinical non-contact specular microscope (Zeiss) in 48 patients at a mean post-operative time of 7 1/2 months after penetrating keratoplasty for a number of different causes, keratoconus being the most frequent indication. Cell density decrease on this occasion was compared to pre-operative data from the Eye Bank in Arhus, Denmark, which supplied corneo-scleral preparations transported by ferry and train to Linköping, Sweden. A mean decrease in cell density of 4.4% was recorded during bank time (11-27 days). A further mean decrease from final preparation to post-operative photography of 36.5% was found. Mean total cell density decrease amounted to 39.4%, which compares well with results found in other studies. Among several factors studied, the only one associated with significantly (P less than 0.02) greater cell density decrease than other factors was long post-mortal time periods (death to bank preparation). Mean final endothelial cell density was 1899 cells/mm2, which should correspond to a good functional reserve of donor endothelium. Neither the long bank time, nor the transportation seemed to be of major importance with respect to donor material quality. Foreign material supply can be a good solution to local corneal shortage.