Precision of cell density estimates and endothelial cell loss with age
H. Cheng, P. M. Jacobs, K. McPherson and M. J. Noble
The precision of estimating endothelial cell density of the cornea, using a
noncontact method of specular microscopy, was assessed by asking eight
individuals with known densities in one operated-on and one unoperated-on
eye to have photography on two occasions in the same day. Three photographs
of each eye were assessed by two individuals using masking procedures.
Interobserver differences were negligible and estimates were similar except
for one eye with low density values. The method was applied to a natural
history study in which 103 eyes had cell-density estimates at zero and two
years, and mean cell loss was found to be 2%. A collateral study using only
good photographs that were available at both zero and two years showed a
similar loss of 1.86% and reduced the number of counts showing unexpectedly
high gains and losses.
