Abstract
Purpose: :
To determine the influence of donor age on endothelial cell survival following penetrating keratoplasty (PKP), we conducted a controlled trial comparing young donors (18–55 years) to very old donors (80 and above). The latter had a slightly lesser endothelial cell density (ECD) at harvest, a difference which tended to be maintained after 14 days of organ culture (mean 147 cell/mm², 95%CI[–3;297]). Our study design differed from that of the US Cornea Donor Study which measured the percentage of clear grafts 5 years after PKP in recipients with diverse pathologies receiving donor tissue between 10–65 vs 66–75 years old (results expected in 2007). Our principal criterion was ECD estimation 1 year after PK (known surrogate criterion for graft survival)
Methods: :
A tricentric randomised double–blinded study (Regional Hospital Clinical Research Trial 2002–142) evaluated recipients with normal endothelium (keratoconus or lattice dystrophy), aged 36±12 years (range 18–76) receiving grafts, all of 8 mm diameter. The ECD, coefficient of variation (CV, %) and hexagonalityv(%) were measured by specular microscopy (Topcon SP2000) at day 5, Month1, M3, M6, M9 et M12 after PKP. Secondary criteria were best corrected visual acuity (BCVA), graft transparency, oedema, rejection and gerontoxon
Results: :
At 1 year postPKP, ECD in group 1, young donors (n=46), 1692±391 cells/mm² (range 930–2406) differed from group 2, very old donors (n=40), 1490±405 cells/mm² (range 625–2626) (p=0.023) by mean 203 cells/mm², 95%CI [28;377]. Morphometry: CV [27%±4 vs 28%±6 (p=0.429)] and hexagonality [53%±8 vs 56%±9 (p=0.062)] was comparable in both. BCVA (20/40) was 68% (group 1) vs 81% (group 2)(p=0.208)
Conclusions: :
Endothelial cell survival in recipients 1 year postPKP with tissue from very old donors is comparable to that from young donors. The ECD difference between 2 groups (mean 203 cells/mm²) reflects only on initial ECD difference (mean 147 cells/mm²) against favour of corneas from very old donors. In view of the high frequency of very old donors, the need of suitable graft tissue in majority of Europe, and the findings of our study, it does not seem medically justified to impose donor age restrictions.
Acknowledgements: :
P Chavarin, O Garraud, S Herrag, M Zhao, H Hegelhoffer, P Ligot.
Keywords: aging • clinical (human) or epidemiologic studies: outcomes/complications • cornea: storage