Quantitative analysis of wide-field specular microscopy. II. Precision of sampling from the central corneal endothelium.

The precision of the measurement of mean endothelial cell area obtained by sampling with small-field and wide-field specular microscopy from the central 4 mm of human corneal endothelium was studied by comparing endothelial cell parameters from individual specular micrographs in vivo to the results obtained by montaging the micrographs from the entire central 4 mm of the same corneas. The small samples were at least 10% from the true mean cell size of all cells of the central 4 mm in any endothelium other than that with the most homogeneous pattern. A new algorithm for sampling with these two specular microscopes will need to be derived to permit a more precise measure of the mean area of endothelial cells in the central 4 mm of the human corneal endothelium.