Non-contact specular microscopy of human corneal endothelium.

The non-contact specular microscope enables a large area of the corneal endothelium to be examined and photographed without any risk of traumatizing the anterior surface of cornea. This non-contact technique is described in detail. Standard deviation of the relative difference between two independent estimates of central endothelial density from 24 eyes was 3.7%. Standard deviation of the relative difference between counts from left and right eyes from 57 subjects was 4.7%. A significant negative correlation between age and endothelial cell density was found (r = -0.59, P less than 0.001, n = 76). The interindividual variation in cell densities was found to be larger in the old age group, indicating that cell loss during aging varies among different individuals.