Measurement limitations and other factors confound determination of endothelial cell loss after endothelial keratoplasty

Endothelial cell loss after endothelial keratoplasty could be due to surgical handling, but in fact may be overestimated for a variety of reasons, said Isabel Dapena, MD, PhD, at the 5th EuCornea Congress. “Since endothelial cell loss in endothelial keratoplasty has generally been attributed to donor tissue manipulation during surgery, when DMEK became a standardized ‘no touch’ technique, we expected it would be associated with a lower endothelial cell loss rate than DSAEK. To our surprise, there was no difference,” said Dr. Dapena, cornea specialist, Melles CorneaClinic, Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands. “Therefore, we considered there must be factors other than tissue handling that may be affecting our measurements.” Outlining the possible contributors, Dr. Dapena noted that there are limitations introduced by the measurement techniques. Cell counting techniques used in eye banks generally lead to overestimation of the preoperative donor endothelial cell density, she said. In addition, the in vivo postoperative measurements are performed by a different observer using different methodology and different instrumentation.