Four methods of measuring human corneal endothelial cells from specular photomicrographs
G. O. Waring 3rd, M. A. Krohn, G. E. Ford, R. R. Harris and L. S. Rosenblatt
We measured central corneal endothelial cell density and area from contact
specular photomicrographs of ten normal and ten abnormal corneas, comparing
the precision, cost, and speed of four methods: a rectangle, planimeter,
digitizer, and cell sizer. The rectangle, planimeter, and digitizer gave
results that differed less than 10% from each other; therefore, the three
methods can be used interchangeably for clinical purposes. There are
statistically significant differences among the three techniques that may
be important in basic research. The cell sizer gave a rapid, less precise
estimate of mean cell area and cell density. The planimeter and digitizer
measured individual endothelial cell size, and the latter entered data
directly into a computer that printed both a copy of the endothelial mosaic
and a histogram of cell size frequency, and computed cell density and mean
cell area. We make the following recommendations: Count cells in a
rectangle used for routine clinical measurement. use a cell sizer for rough
estimation, as in an eyebank setting. Use a computerized digitizer to study
individual endothelial cell size.
