We don’t graft as many endothelial cells as we think (Part 1): what early post‐operative endothelial cell counts tell us

Abstract

AbstractPurpose The decrease of endothelial cells density (ECD) after penetrating keratoplasty (PK), is calculated form ECD given by eye banks (ebECD) and post‐operative specular counts. To better understand the difference between both counts, usually considered caused by EC mortality, we have introduced a new concept of viable ECD (vECD) experimentally determined with a triple staining of viable and dead EC. We demonstrated that vECD just before graft was lower than the ebECD by 12+/‐9% (IOVS 2011.52:6018). The aim of this prospective study was to measure post PK ECD as early as possible in order to compare it with vECD and deduce the true post op EC mortalityMethods Standard ebECD were determined 48h before graft with a validated analyzer (Samba cornea) on a minimum of 300 EC. Postoperative central ECD were determined by a non‐contact specular microscope (Topcon SP2000P) with manual determination of contours of the maximum of EC. Thirty‐four PK done by the same surgeon (>1000 PK) were analysed at D5, D15, and M1. Non‐parametric tests for paired data were usedResults All PK were uneventful. ebECD (n=40) was 2585(482) cells/mm² (mean(SD)). Postoperative ECD at D5 (n=22), D15 (n=29), and M1 (n=33) were respectively 1850(386), 1655(285) and 1650 (408) cells/mm² and were lower than ebECD (P<0,05). They corresponded to apparent EC loss of respectively 28%, 36% and 36% compared to ebECDConclusion ECD at D5 is dramatically lower than ebECD but subsequent decrease seems low. Results are consistent with the vECD that we previously noticed and suggest that EC mortality triggered by surgery and perioperative events may only minimally contribute to the decrease of ECD